JP2001015299A - Multiple passing type accelerator, accelerating cavity, and electron beam.x-ray irradiation treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an accelerating cavity small and inexpensive and to facilitate the adjustment of an accelerating particle orbit by installing a deflecting magnet pair having different magnet field intensities and the same magnetic field polarities, oppositely arranged on the opposite sides of the accelerating cavity between a resonator shell and an accelerating electrode and using the accelerating particle orbit as an orbit attended with precession, and an accelerating gap where the whole linear part of the accelerating particle orbit is passed. SOLUTION: Electron beams from an electron gun 4, when they are accelerated in an accelerating gap 3 within an accelerating cavity 1a, are deflected 180 deg. right and left with a right deflecting magnet 6 and a left deflecting magnet 6 having stronger magnetic field intensity than the right deflecting magnet 6, and uniform magnetic field distribution. An electron beam orbit 17 is sufficiently separated from an electron incident orbit 5 and attended with precession, and ratio of the length of the accelerating cavity 1a to the number of orbits is small. Since the right of the deflection magnet 6 is larger than left, taking out beams are easily taken out without installing specific structure, and by adjusting right and left opposing distances, the whole length of one round of the accelerating particle orbit 17 is increased to decrease phase shift.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-pass type accelerator capable of generating an accelerated particle beam having a high energy by passing accelerating particles in an accelerating cavity multiple times.
The present invention relates to an acceleration cavity and an electron beam / X-ray irradiation apparatus using the same.

[0002]

2. Description of the Related Art FIG.
No. 9 and Proceedings of the Fi
rst Symposium on Accelara
tor and Related Technology
y for Application 1998, To
Kyo is a conventional multi-pass accelerator,
(A) is a side sectional view, (b) is a sectional view taken along line XX of (a), and (c) is a sectional view taken along line YY of (b). In the figure, 101 is a resonator outer shell which is a housing of a resonator in which an acceleration electrode 102 and the like are installed, 102 is an acceleration electrode to which a high-frequency voltage is applied, 103 is an acceleration gap for accelerating particles passing therethrough, 104 Is an electron gun for generating electrons as incident particles, 105 is an electron orbit, and 106 is 18
The 0-degree deflection magnet 107 is an accelerated electron trajectory that has finished accelerating. Reference numeral 108 denotes an acceleration cavity including the resonator shell 101 and the acceleration electrode 102. 109 is the accelerating electrode 102
And holes through which the accelerating particles are formed in the outer shell 101 of the resonator.

Next, the operation will be described. Electron gun 104
The electrons generated by the electron beam are incident on the accelerating cavity 108 and pass through hole 1
09 through the acceleration gap 103. The traveling direction of the accelerated electrons is changed by 180 degrees by a 180-degree deflecting magnet 106 installed outside the acceleration cavity 108, and is again incident on the acceleration cavity 108 to be accelerated.
Enter 03. The radius of curvature of the 180-degree deflecting magnet 106 and the facing radius of the 180-degree deflecting magnet 106 are set so that the time from passing through the acceleration gap 103 to reentering the acceleration gap 103 is half the period of the high-frequency electric field used for acceleration or an odd multiple thereof. Between the 180-degree deflecting magnets 106 (hereinafter, referred to as a linear portion)
Are set in the distance, so that the electrons
Each time it passes, it is accelerated to high energy. A deflecting device is provided on both sides or the outer peripheral portion of the accelerating cavity 108 as described above, and an accelerator in which the folded electron trajectory also passes through the accelerating cavity 108 is disclosed in Japanese Patent Application Laid-Open No. H10-260,197.
In JP-A-503609, it is called a multi-pass accelerator.

In the above accelerator, the 180-degree deflecting magnet 1
Numeral 06 indicates that the polarities of the magnetic fields are opposite on both sides of the accelerating cavity 108, whereby the electron orbit is bent in the opposite direction. At this time, the electron trajectory is shifted by the deflection radius of the electron trajectory in the deflection magnet 106 by 180 degrees.
08, and a 180 ° deflection magnet 106
Is shifted in a certain direction each time the light passes through.

Since the acceleration cavity 108 is operated in the TE mode, the magnetic flux is directed in the left-right direction in FIG. 18A, and all the magnetic flux returns through the space at the left and right end portions. It is designed to be. Under such conditions, the voltage between the accelerating electrodes 102 becomes substantially constant in the longitudinal direction of the accelerating electrodes 102. However, actually, there is a slight magnetic flux returning across the acceleration gap 103,
A deflection force is given to the accelerating particle beam.

In the above accelerator, the electron gun 104
Even if the electron beam of C is incident, the phase width of the electron beam that can be accelerated is limited, so that the electron beam that has been accelerated is not DC continuous but a pulse. However, since the pulse is continuous (every 360 degrees with respect to the high frequency), a high-power electron beam is obtained on average.

[0007]

Since the conventional multi-pass accelerator is constructed as described above, the trajectory of the accelerating particles is constantly shifted in a certain direction while being accelerated, so that the accelerating particles are accelerated to a high energy. Had a problem that the accelerating cavity became large.

Further, there is a problem that the cost is increased due to the necessity of a large number of deflection magnets, and the adjustment of the trajectory of the accelerating particles is not easy due to the large number of deflection magnets.

In addition, since the amount of deflection of the accelerated particle beam deflected by the magnetic flux returning across the acceleration gap cannot be accurately predicted, the accelerated particles collide with an acceleration electrode or the like, and the passage efficiency of the accelerated particles in the passage hole is reduced. There was a problem that was bad.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the acceleration is achieved by collecting the orbits of the accelerating particles passing through the acceleration gap in a narrow range as the precession orbits of the accelerating particles. It is an object of the present invention to obtain a multi-pass accelerator capable of reducing the size of a cavity.

Further, the present invention deflects the accelerating particles by a pair of deflecting magnet pairs and passes the accelerating particles through the accelerating cavity in a multiplex manner, thereby facilitating the adjustment of the accelerating particle trajectory at low cost. The aim is to obtain an accelerator.

Further, the present invention provides a multi-pass accelerator capable of accelerating accelerated particles to high energy by using the above-described multi-pass accelerator as one constituent unit and connecting a plurality of the units. With the goal.

It is a further object of the present invention to provide an accelerating cavity with improved passage efficiency of accelerating particles in a passage hole.

It is a further object of the present invention to provide an electron beam / X-ray irradiation apparatus using the above-mentioned accelerating cavity or multi-pass accelerator.

[0015]

A multipass accelerator according to the present invention is different from an accelerating cavity comprising a resonator outer shell and an accelerating electrode provided in the resonator outer shell in a magnetic field intensity of each of them. A pair of deflecting magnets arranged opposite to both sides of the accelerating cavity so that the accelerating particle trajectory is set to a value, and each magnetic field polarity is equal, and the accelerating particle trajectory is a trajectory with precession, And an acceleration gap through which all the straight portions pass and accelerate the accelerating particles along the accelerating particle trajectory.

In the multi-pass accelerator according to the present invention, an acceleration cavity including a resonator outer shell and an acceleration electrode provided in the resonator outer shell, each magnetic field strength is set to a different value, and The accelerating particles taken out of the first pair of deflecting magnets are placed next to each other on both sides of the accelerating cavity so that the magnetic field polarities are equal and the accelerating particle trajectory is a trajectory with precession. Comprising a plurality of pairs of deflection magnets provided so as to be incident on the pair of deflection magnets, and an acceleration gap through which all the linear portions of the trajectories of the accelerated particles pass to accelerate the accelerated particles along the trajectories of the accelerated particles. It is.

A multi-pass accelerator according to the present invention is an injector for accelerating a cavity composed of a resonator outer shell and an acceleration electrode provided in the resonator outer shell, and for projecting particles to be accelerated into the acceleration cavity. And, so that the orbit of the incident particle and the orbit of the deflected accelerated particle are sufficiently separated, the respective magnetic field strengths are set to different values, and the respective magnetic field polarities are equal,
A pair of deflecting magnets arranged opposite to both sides of the accelerating cavity and all the linear portions of the accelerating particle trajectory pass so that the accelerating particle trajectory is a trajectory accompanied by precession, and And an acceleration gap for accelerating the accelerating particles along.

A multi-pass accelerator according to the present invention is an injector for accelerating a cavity including a resonator outer shell and an accelerating electrode provided in the resonator outer shell, and for projecting particles to be accelerated into the acceleration cavity. And, so that the orbit of the incident particle and the orbit of the deflected accelerated particle are sufficiently separated, the respective magnetic field strengths are set to different values, and the respective magnetic field polarities are equal,
The accelerating particle trajectory is arranged opposite to both sides of the accelerating cavity so as to be a trajectory with precession, so that the accelerating particles taken out from the first deflecting magnet pair are incident on the next deflecting magnet pair. And an acceleration gap through which all of the linear portions of the accelerating particle trajectory pass and accelerate the accelerating particles along the accelerating particle trajectory.

The multi-pass type accelerator according to the present invention is characterized in that an injection device for inputting particles to be accelerated is arranged in an acceleration cavity.

In the multi-pass accelerator according to the present invention, the beam of the accelerated particles taken out from the acceleration cavity is scanned by periodically changing the electric or magnetic field applied to the particles to be incident on the acceleration cavity by the injector. It is characterized by the following.

The multi-pass type accelerator according to the present invention is characterized in that the magnetic field intensity increases from the first pair of deflection magnets to the next pair of deflection magnets.

In the accelerating cavity according to the present invention, the accelerating electrode has a through hole through which the accelerating particles pass. It is characterized by being a long hole in which at least a portion through which the accelerated particles pass at the initial stage of incidence is sufficiently wider in the horizontal or vertical direction than the region through which the accelerated particles pass.

The acceleration cavity according to the present invention is characterized in that one passage hole of the opposing acceleration electrode is made wider in the horizontal or vertical direction than the other passage hole.

The acceleration cavity according to the present invention is characterized in that the passage hole of the acceleration electrode on the opposite side is made wider in the horizontal or vertical direction than the passage hole of the acceleration electrode on the side where the acceleration particles are incident.

The acceleration cavity according to the present invention is characterized in that the cross section of the cavity of the resonator is rectangular.

A multi-pass accelerator according to the present invention is a multi-pass accelerator in which the trajectory of an accelerating particle is deflected a plurality of times and passes through the inside of the accelerating cavity. It is assumed that.

[0027] A multi-pass accelerator according to the present invention is provided with the acceleration cavity according to claim 8.

A multi-pass accelerator according to the present invention is provided with the acceleration cavity according to the ninth aspect.

A multi-pass accelerator according to the present invention is provided with the acceleration cavity according to the tenth aspect.

The multi-pass type accelerator according to the present invention is characterized in that the deflecting magnet is made of a permanent magnet.

The multi-pass accelerator according to the present invention is characterized in that a magnetic field gradient is provided in the deflecting magnet so that the magnetic field strength becomes weaker as it goes inward from the entrance and exit of the accelerating particles.

The multi-pass type accelerator according to the present invention is characterized in that a magnetic field gradient is provided in the deflecting magnet so that the magnetic field strength becomes stronger as it goes from the incident position of the accelerating particles to the longitudinal direction of the deflecting magnet. .

The multi-pass type accelerator according to the present invention includes a plurality of cylindrical electrodes provided corresponding to each of the accelerating particle orbits so that the accelerating particle orbit of the linear portion passes.

The multi-pass accelerator according to the present invention is characterized in that a focusing device is arranged in a cylindrical electrode.

The multi-pass accelerator according to the present invention is characterized in that focusing devices having different polarities are arranged in opposed cylindrical electrodes.

The multi-pass accelerator according to the present invention is described in claim 1, claim 3, claim 5, or claim 12.
The multi-pass accelerator described in any one of the above items 1 is connected so that accelerated particles taken out from the first multi-pass accelerator are incident on the next multi-pass accelerator and are sequentially accelerated. It is characterized by the following.

The multi-pass accelerator according to the present invention is characterized in that the magnetic field strength of the pair of deflecting magnets increases from the first multi-pass accelerator to the next multi-pass accelerator.

The multi-pass type accelerator according to the present invention is characterized in that the cross section of the outer shell of the resonator is square.

The multi-pass type accelerator according to the present invention is characterized in that the deflecting magnet is formed of an electromagnet, and takes out accelerated particles by changing the deflection angle of the deflecting magnet.

An electron beam / X-ray irradiation processing apparatus according to the present invention is provided with the accelerating cavity according to claim 8.

An electron beam / X-ray irradiation processing apparatus according to the present invention is provided with the multi-pass accelerator according to the first aspect.

[0042]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a view showing a multi-pass accelerator according to Embodiment 1 of the present invention, in which FIG.
(B) is a sectional view taken along line AA of (a). FIG. 2 is a configuration diagram showing an example of an electron beam incident device in the multi-pass accelerator according to Embodiment 1 of the present invention. In the drawing, reference numeral 1 denotes a resonator outer shell which is a housing of a resonator in which an accelerating electrode 2 is installed, and 2 denotes an accelerating electrode to which a high-frequency voltage is applied. Has a hollow structure so that
In this hollow space, the entire inside of the accelerating electrode 2 may be hollow, or a space may be opened only in a portion where the electron orbit passes. Reference numeral 2a denotes an end of the accelerating electrode 2, which protrudes in order to flatten the acceleration voltage distribution between the accelerating gaps 3. This is a structure conventionally used.

Numeral 3 denotes an opposing interval of the acceleration voltage 2, which is an acceleration gap for accelerating particles passing therethrough. Reference numeral 4 denotes an electron gun for generating electrons as accelerating particles, and reference numeral 5 denotes an incident trajectory of the electrons generated by the electron gun 4 (trajectory of the incident particles).
It is. Reference numeral 6 denotes a 180-degree deflection magnet, which is an electromagnet constituted by an electromagnetic coil 10 described later in the illustrated example. Further, by arranging two 180-degree deflecting magnets 6 opposite each other via the acceleration cavity 1a, a pair of 180-degree deflecting magnet ( (Deflecting magnet pair). This one
In the illustrated example, the 80-degree deflection magnet pair is 180
The 180 degree deflection magnet 6 on the left side of the degree deflection magnet 6 is set to have a higher magnetic field strength. The magnetic field distribution is uniform in each of the 180-degree deflecting magnets 6 and the magnetic field polarities are the same, so that the trajectories of the electrons as the accelerating particles are deflected in the same direction. Reference numeral 7 denotes an extraction beam (accelerated particles) of electrons whose acceleration has been completed, and reference numeral 8 denotes an incident device for injecting an electron beam of electrons generated from the electron gun 4 into the acceleration cavity 1a. The incident device 8 is called an electrostatic inflector or an electrostatic septum in a normal accelerator.

Reference numeral 9 denotes an active clamp for obtaining a converging force of the electron beam in the y-axis direction and the z-axis direction (in some cases, the 180-degree deflecting magnet 6 cannot converge the electron beam in the y-axis direction), such as a microtron. Traditionally used for
As shown in the figure, a unit formed integrally or a plurality of units arranged along each electron trajectory may be used. 10 is 1
The electromagnetic coil of the 80-degree deflecting magnet 6 is a correction magnet, and the correction magnet 11 is for finely adjusting the electron trajectory. In a normal accelerator, the deviation of the trajectory of the accelerated particle due to an error in setting the electromagnet is corrected. Used to Reference numeral 12 denotes a block tuner, and 13 denotes a tuner driving mechanism of the block tuner 12. The block tuner 12 and its tuner driving mechanism 13 are for adjusting the resonance frequency. The above-described resonator outer shell 1 and acceleration electrode 2 may be cooled by providing a cooling channel. The coupler for supplying high-frequency power is not shown.

Although not shown in FIG.
A buncher is provided in front of, and a DC beam of electrons from the electron gun 4 is changed into a trajectory like a matrix of dumplings in accordance with the cycle of the operating frequency of the acceleration cavity 1a. By adjusting to the acceleration phase in this way, most of the electron beams generated by the electron gun 4 can be accelerated to the end. Although not shown, a slit or the like is provided in a low energy portion where the accelerating particle beam does not pass through the acceleration gap 3 so that the energy cannot be used until the end or the energy is too different even if the acceleration is performed. A high-acceleration particle beam is extinguished at a stage where the energy of the acceleration particle is low. Thereby, it is possible to reduce the activation of the device (particles having greatly different energy collide with the vacuum container of the device and disappear, but the part where the particles collide is activated), and the high-frequency power can be reduced. . The installation position of the slit may be, for example, an exit from the deflection magnet 6 of the first deflected acceleration particle trajectory, or an exit of the second deflection of the acceleration particle trajectory from the deflection magnet 6.

Reference numeral 1a denotes an acceleration cavity, which comprises a cylindrical resonator outer shell 1 and two accelerating electrodes 2 mounted inside the resonator outer shell 1 at opposing positions. When high-frequency power of, for example, about 100 MHz is supplied into the acceleration cavity 1a, a high-frequency electric field is excited. This 100MH
In the case of a high frequency of z, the diameter of the resonator shell 1 is about 1 m
About. Further, the electromagnetic field mode in the acceleration cavity 1a is the TE mode as described in the related art, whereby a strong electric field is generated in the acceleration gap 3.

Reference numerals 14, 15, and 16 denote components of the above-described incident device 8, which are a cathode, an anode, and a high-voltage power supply, respectively. The electron orbit is deflected by an electrostatic field generated between the cathode 14 and the anode 15. Reference numeral 17 denotes an orbit of the electron closest to the cathode 14 (accelerated particle), which is 180
It is deflected twice by the angle deflecting magnet 6 and is incident on the acceleration cavity 1a.

The accelerator is arranged in a vacuum vessel, and all places where electrons pass, such as in the deflecting magnet 6 by a vacuum pump (not shown), are kept in a vacuum state.

Next, the operation will be described. The electron beam emitted from the electron gun 4 is deflected by the incident device 8 and is incident on the acceleration cavity 1a. The incident electrons pass through the acceleration electrode 2 and are accelerated in the acceleration gap 3. After this, FIG.
(A) It is deflected by 180 degrees by the right-side 180 degree deflecting magnet 6 and is again incident on the accelerating cavity 1a and accelerating gap 3
Is accelerated again. The orbit 17 of this electron is shown in FIG.
The electron trajectory is deflected by 180 degrees by the 180-degree deflecting magnet 6 on the left side (x-axis direction side) in FIG.

At this time, if both deflecting magnets 6 of the 180 ° deflecting magnet pair have the same magnetic field strength, the energy of the electrons is increased every time the acceleration is accelerated. The deflection radius in the deflection magnet 6 increases, and the orbital trajectory 17 of the electron shifts downward from the case of FIG. 1A, and intersects the electron trajectory 5 or collides with the cathode 14 of the incident device 8. Resulting in. For this reason, the magnetic field strength of the left deflecting magnet 6 is set to be different from that of the right deflecting magnet 6, and in the case of the drawing, the magnetic field strength of the left (x-axis direction) is set to the right (-x axis direction). Is set so that the electron incident orbit 5 and the electron orbit 17 are sufficiently separated.

When the magnetic field strengths of the left and right deflecting magnets 6 are set as described above, as shown in FIG. 1A, the electron trajectory moves while the race track type trajectory goes up or down. Take a trajectory accompanied by a precession in which the rotation axis shifts upward, and all the electron trajectories pass through the acceleration gap 3. Thereafter, when the electrons reach a desired energy, they are extracted as an extraction beam 7 and used for various purposes. Since the orbit of the accelerating particle takes a trajectory accompanied by precession, the ratio of the length of the accelerating cavity 1a to the number of orbits passing through the accelerating gap 3 is reduced as compared with the conventional multi-pass accelerator. And the size of the device can be reduced.

At this time, since the deflection radius of the electron trajectory also increases in each deflecting magnet 6 with an increase in the energy of the electrons, all the electron trajectories passing between the deflecting magnets 6 (hereinafter referred to as linear portions) are used. In order to pass through the acceleration gap 3, the size of the left and right deflecting magnets 6 must be able to allow the above-described deflection radius. In the example shown in the figure, the magnetic field strength of the right deflecting magnet 6 is smaller than that of the left deflecting magnet 6, so that the deflection radius is large. In accordance with this, the space through which the accelerating particles pass in the right deflecting magnet 6 becomes large. The size of the deflection magnet 6 is made larger than that of the left side. Thus, when the electrons reach the desired energy, the accelerated electrons can be easily extracted (extraction beam 7) as shown in FIG. 1A without providing a special extraction structure.

Next, conditions for efficiently accelerating particles will be described. In order to accelerate an accelerating particle such as an electron every time it passes through the accelerating gap 3, an accelerating phase that satisfies a synchronization condition in which the phase of the high-frequency power applied to the accelerating electrode 2 changes by 180 ° every time the accelerating particle passes. Acceleration gap 3 having the following formula:

If the particle velocity of the accelerating particles is v, the light velocity is c, the ratio is β (= v / c), and the wavelength of the high frequency is λ, the distance at which the phase of the high frequency changes by 180 degrees is βλ /
Given by 2. Thus, the accelerator according to the present invention is configured so that the sum of twice the distance from the acceleration gap 3 to the deflecting magnet 6 and the length of the semicircular orbit of the accelerating particles in the deflecting magnet 6 becomes approximately βλ / 2 or an odd multiple thereof. Are determined.

The deflection radius of the electron trajectory in the deflecting magnet 6 changes as the energy of the electron changes, but the speed of the electron immediately approaches the speed of light and does not change much, so that the above-mentioned synchronization condition is satisfied in all energy regions. It is impossible. However, assuming that the acceleration voltage in the acceleration gap 3 is V0 cos θ, the electrons are always accelerated when θ is between −90 degrees and +90 degrees, so that acceleration to a certain energy is possible. The above condition of βλ / 2 is determined by optimizing the interval (linear portion) between the two deflection magnets 6 so that the energy of the extraction beam 7 is maximized.

As an example of the above-described beam simulation, an electron beam is emitted from the electron gun 4 to an energy of 50%.
Assuming that the voltage of the acceleration gap 3 is 540 kV at keV, by passing through the acceleration gap 3 ten times, 5 MeV
An electron beam having the energy is obtained. X-rays are generated by applying an electron beam to a target in food irradiation, etc., and the energy of the electron beam is specified to be 5 MeV or less when the X-ray is used for irradiation, and 10 MeV or less when the electron beam is directly irradiated. The above-mentioned electron beam energy is applicable to the former.

In order to accelerate the particles efficiently, it is necessary to reduce the shift of the acceleration phase accompanying the increase in the energy of the accelerated particles. Since the deviation of the acceleration phase is caused by a change in the deflection radius of the accelerating particles in the deflection magnet 6, by increasing the interval between the two deflection magnets 6,
The influence of the displacement can be reduced. That is, if the deflection orbit length is smaller than the entire length of the orbit of the accelerating particle orbit,
The phase shift due to the change in the deflection orbit length can also be reduced. This means that the lower the frequency of the high frequency excited in the acceleration cavity 1a (that is, the longer the wavelength), the more efficiently the particles can be accelerated. On the other hand, in the accelerator of the first embodiment, since there are only two deflection magnets 6, the opposing interval can be easily adjusted, so that the entire length of one circumference of the orbit of the accelerated particle can be increased.

In addition to the above, if the deflection radius is reduced by increasing the magnetic field strength of both deflecting magnets 6, the distance between the linear portions can be increased by the same amount in the case of the same frequency. Can be reduced. But,
In this case, if the deflection radius is too small, in a low energy region, the beam is deflected by 180 degrees in the leakage magnetic field of the deflection magnet 6, and good deflection cannot be performed. further,
In addition to the above, the higher the voltage of the acceleration gap 3 is, the easier the acceleration can be. However, since the power consumption of the acceleration cavity 1a is proportional to the square of the voltage, it is not suitable for a device in which the operation cost is important.

On the other hand, in the accelerator of the present invention, the accelerating particle trajectory takes a trajectory accompanied by precession, and all of the accelerating particle trajectories pass through the acceleration gap. In this case, the number of passing orbits of the accelerating particle passing through the acceleration gap 3 can be increased with a low voltage, and the particles can be accelerated efficiently.

In the above description, the acceleration gap 3 is located at the center between the two deflecting magnets 6. However, depending on the above parameters, the acceleration gap 3 can be shifted to the left or right in FIG. As this method, the acceleration cavity 1a may be shifted, or the position of the acceleration gap 3 in the acceleration cavity 1a may be shifted by changing the length of each acceleration electrode 2.

In the first embodiment, the particles are made incident using the incident device 8, but the incident device 8 can be omitted in the case described later. First, the deflection of the accelerated particle beam by the incident device 8 will be described. FIG. 3 is a diagram showing the difference in the trajectory after passing through the acceleration gap when the incident particle undergoes acceleration and when it does not. In FIG. 3, when the incident particle is not accelerated, its trajectory goes straight in the accelerating electrode, but when accelerated, it is deflected to approach an accelerated particle trajectory with precession indicated by a broken line. The degree of deflection of the particle trajectory due to such acceleration is considered as follows. A point O (gap center) in the acceleration gap 3 equidistant from the two acceleration electrodes 2 in FIG. 3 is set as an origin, and a trajectory of an incident particle which is not accelerated is represented by a straight line passing through the origin O. It is assumed for simplicity that the trajectory of the incident particle receiving the trajectory is a straight line refracted with respect to the origin O, and the inclination of the two straight lines is considered as the degree of deflection of the particle trajectory. That is, it is assumed that the more the straight line of the particle trajectory is refracted by acceleration and the inclination thereof is reduced, the more strongly the particle trajectory is deflected.

The decrease in the slope is achieved by setting the ratio between the particle velocity v and the light velocity c to β = v / c and the relativistic factor to γ = 1 + T / E0 (T
Is the kinetic energy of the particle, and E0 is the static energy), and is inversely proportional to βγ. Due to this, depending on the energy difference between the incident particle and the accelerated particle, the accelerated particle will not be able to completely enter the accelerated particle trajectory with precession, making it impossible to accelerate efficiently There are cases. Therefore, by efficiently deflecting the incident particles to the above-described accelerated particle trajectory by the incident device 8, efficient particle acceleration can be performed.

However, for example, the energy of the accelerated particle that has passed through the acceleration gap 3 once compared to the energy of the incident particle such that the energy of the incident particle is approximately 50 keV and the energy of the accelerated particle that has passed once through the acceleration gap 3 is approximately 500 keV. When the energy becomes large, the inclination of the accelerated particle orbit in FIG. 3 after passing through the acceleration gap 3 is approximately 1 from the above-mentioned ratio β of the particle velocity to the light velocity and the relativistic factor γ.
/3.8, which is close to zero and the particle trajectory follows the accelerated particle trajectory accompanied with the precession. Therefore, depending on the energy difference between the incident particle and the accelerated particle that has passed through the acceleration gap 3 once, the incident device can be omitted. In this case, the device configuration can be simplified and the cost can be reduced.

In the first embodiment, electrons are used as accelerating particles, but protons or ions may be accelerated. In particular, in the case of protons or ions, the energy is proportional to the square of the particle velocity in the energy range of 5 MeV or 10 MeV because the mass is larger than that of electrons. Accordingly, the above-described shift in the acceleration phase is reduced, and it can be expected that effective acceleration is achieved.

As described above, according to the first embodiment, the acceleration cavity 1a including the resonator outer shell 1 and the acceleration electrode 2 provided in the resonator outer shell 1, and the acceleration cavity 1a Each of the magnetic field strengths is set to a different value so that the incident device 8 for inputting the particles to be accelerated to the target and the orbit 5 of the incident particles and the deflected orbiting accelerated particle orbit 17 are sufficiently separated from each other.
And a pair of 180-degree deflecting magnets disposed opposite to each other on both sides of the accelerating cavity 1a so that the accelerating particle trajectory is a trajectory accompanied by precession with equal magnetic field polarities, and a linear portion of the accelerating particle trajectory. And the acceleration gap 3 for accelerating the accelerating particles along the accelerating particle trajectory, the accelerating particles are accelerated along the precession trajectory. Can be collected in a small area,
The length of the acceleration cavity 1a can be reduced. As a result, the effect of reducing the size of the entire accelerator can be obtained. In addition, since the power loss of the acceleration cavity 1a is proportional to the length of the acceleration cavity 1a, not only the cost of the device can be reduced by downsizing the accelerator, but also the operation cost thereof can be reduced.

Further, since there are only two 180-degree deflecting magnets 6, the cost of the apparatus can be reduced, and the start-up adjustment of the accelerated particle beam is easy.

Furthermore, since the 180-degree deflecting magnet 6 has an internal space that can tolerate a deflection radius that increases with an increase in energy, the 180-degree deflecting magnet 6 can collide with the inner wall even if the orbit of the accelerated particle beam slightly shifts. The orbiting of the accelerating particles can be performed without any change. In addition, since the acceleration condition is asynchronous and the range of the allowable acceleration phase is wide, the accelerated particle beam can be easily extracted. This ease of acceleration is a great advantage for mass production equipment. In some cases, the correction magnet 11 shown in FIG. 1 can be omitted.

Further, since all the accelerated particle orbits gathered in a narrow length range in the accelerated particle orbit accompanied by precession pass through the acceleration gap, a larger number of orbits can be passed through the acceleration gap 3 as compared with the prior art. Thus, an effect that particles can be accelerated more efficiently than before can be obtained.

Embodiment 2 In the first embodiment, the incident device 8 is arranged outside the acceleration cavity 1a. In the second embodiment, the incident device 8 is arranged inside the acceleration cavity 1a.

FIG. 4 is a partial cross-sectional view showing the structure of the periphery of the incident device of the multi-pass accelerator according to the second embodiment of the present invention. In the figure, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals, and redundant description will be omitted. FIG.
As shown in (1), the injection device 8 of the multi-pass accelerator according to the second embodiment is arranged in the acceleration electrode 2, and the electrons generated by the electron gun 4 enter the acceleration cavity 1a.

As described above, according to the second embodiment, since the incident device 8 is disposed in the acceleration cavity 1a, the space between the acceleration cavity 1a and the 180-degree deflecting magnet 6 is increased. Can be. In other words, since the position adjustment of the facing gap of the 180-degree deflecting magnet pair can be performed in a wide range, there is an effect that the adjustment range for a shift in the acceleration phase and the like can be widened.

Embodiment 3 In the first and second embodiments, the deflecting electric field or the deflecting magnetic field applied to the particles to be incident on the accelerating cavity by the injector is fixed. It is made to change in a way.

By changing the intensity of the deflection electric field or the deflection magnetic field applied to the particles to be made incident on the acceleration cavity by the incident device, for example, sinusoidally, the particle trajectory emitted from the incident device also changes. . Here, a case is considered in which the multi-pass accelerator according to the third embodiment is used as an irradiation device for sterilizing / sterilizing an irradiation target. If the irradiation object has a size of, for example, several tens cm or more, the accelerated particle beam taken out from the irradiation device is scanned so that the beam hits the entire irradiation object. In order to scan the accelerating particle beam in this manner, a scanning electromagnet that periodically changes the magnetic field intensity applied to the accelerating particles is used. On the other hand, in the third embodiment, the deflection electric field or the deflection magnetic field applied to the particles to be incident on the acceleration cavity in the incident device is periodically changed. This allows
In the same manner as described above, the accelerated particle beam to be irradiated can be scanned in the size range of the irradiation object.

As described above, according to the third embodiment, the injection device periodically changes the electric or magnetic field applied to the particles to be incident on the accelerating cavity, so that the accelerating particles extracted from the accelerating cavity are changed. Since the beam is scanned, the function of the scanning electromagnet is replaced by the incident device, so that the scanning electromagnet can be eliminated. Thereby, the apparatus cost can be reduced.

Embodiment 4 In the above embodiment, 180
The magnetic field intensity is set uniformly in one of the 180 degree deflection magnets of the pair of degree deflection magnets. However, the 180 degree deflection magnet of the multi-pass accelerator according to the fourth embodiment increases the focusing power of the accelerated particle beam. Is provided with a magnetic field gradient.

FIG. 5 is a cross-sectional view showing a 180-degree deflecting magnet of a multi-pass accelerator according to Embodiment 4 of the present invention. In the figure, 6a, 6b and 6c are 180 degree deflection magnets, 18a and 18b are magnetic poles of the deflection magnet 6, and 18 is a magnetic pole gap which is a gap between the magnetic poles 18a and 18b. The smaller the magnetic pole gap 18, the stronger the magnetic field generated there. Note that the same components as those shown in FIG. 1 are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 5A shows the deflection magnet 6 used in the above embodiment, which is an electromagnet constituted by an electromagnetic coil 10. The magnetic poles 18a and 18b of the deflection magnet 6 are parallel to each other along the x-axis direction, and the magnetic field strength in the x-axis direction is uniform. On the other hand, the deflection magnet 6 shown in FIG.
a is a deflection magnet made of a permanent magnet having a uniform magnetic field strength in the x-axis direction as described above. By forming the deflection magnet with a permanent magnet instead of an electromagnet as described above, a power supply required for the electromagnet is not required, and the operating cost can be reduced.

The deflecting magnet 6b shown in FIG. 5C has a structure in which the magnetic pole gap 18 has a structure in which the distance between the entrance and exit of the accelerating particles is narrowed, and the distance becomes wider as the distance goes inward. The magnetic field gradient is provided so that the magnetic field strength decreases along the direction. As a result, the accelerating particle beam obtains a focusing force in the y-axis direction and the z-axis direction in the drawing, and the beam can be efficiently accelerated. In addition, the active clamp 9 shown in the first embodiment can be omitted, but a stronger focusing force can be obtained by using the active clamp 9 together. Further, by forming a bending magnet having a structure provided with the above-described magnetic field gradient with a permanent magnet as shown in FIG.
In addition to the above effects, the operating cost can be reduced by eliminating the need for a power supply required for the electromagnet. In order to give a magnetic field gradient to the deflecting magnet 6c formed by the permanent magnet, the magnetic pole gap 1
It is good also as a structure which can make 8 variable.

As described above, according to the fourth embodiment, since the 180-degree deflecting magnets 6 are made of permanent magnets, no power supply is required and the effect of reducing operating costs can be obtained.

Further, since the magnetic field gradient is provided so that the magnetic field strength becomes weaker as going from the inlet / outlet side of the accelerating particle toward the inside, the focusing power of the accelerating particle beam is obtained, and the beam can be efficiently accelerated. The effect that can be obtained is obtained.

The deflection magnet according to the fourth embodiment can be applied to all the embodiments of the present invention.

Embodiment 5 In the above embodiment, a cylindrical resonator shell having a circular cross section is used. However, the resonator shell of the accelerating cavity of the multi-pass accelerator according to the fifth embodiment has a cross section. It is a rectangle.

FIG. 6 is a cross-sectional view showing a resonator shell of an acceleration cavity of a multipass accelerator according to Embodiment 5 of the present invention. The resonance frequency of the accelerating cavity 1a is largely determined by the inductance proportional to the cross-sectional area of the resonator shell 1b and the capacitance C between the accelerating electrode 2. Accordingly, if it is desired to increase the space between the deflecting magnet 6 and the acceleration cavity 1a in order to widen the adjustment range with respect to the deviation of the acceleration phase, etc., if the cross section is a quadrangle, the cross section is long in the z-axis direction in the figure. For example, even if the length in the x-axis direction is reduced, the resonance frequency does not change.

As described above, according to the fifth embodiment, the cross-sectional shape of the resonator shell 1 is rectangular, so that the same effects as those of the above-described embodiment can be obtained. When the space between the deflecting magnet 6 and the accelerating cavity 1a is desired to be widened in order to widen the range of adjustment, the design of the resonator shell is easy.

The resonator shell according to the fifth embodiment can be applied to all the embodiments of the present invention.

Embodiment 6 FIG. In the above-described embodiment, the protruding end 2a is provided on the acceleration electrode 2, but in the sixth embodiment, the end 2a is omitted.

FIG. 7 is a longitudinal sectional view showing an acceleration cavity of a multi-pass accelerator according to Embodiment 6 of the present invention. As shown in the figure, the accelerating electrode 2b of the multi-pass accelerator according to the sixth embodiment does not have a protruding end 2a and has a simple and easy-to-manufacture structure. As described above, the end portion 2a is provided to flatten the acceleration voltage distribution between the acceleration gaps 3. However, in a device having a short acceleration cavity 1a, a structure without the end portion 2a as described above is sufficient. And the same effect as in the above embodiment can be obtained.

Embodiment 7 In the first embodiment, the extraction beam 7 is finally deflected by 180 degrees and extracted by the right deflection magnet 6 as shown in FIG. 1A. However, in the seventh embodiment, the deflection angle is changed to accelerate the beam. This is to extract a particle beam.

FIG. 8 is a longitudinal sectional view showing a configuration of a multi-pass accelerator according to Embodiment 7 of the present invention. FIG.
The same components as those described above are denoted by the same reference numerals, and redundant description will be omitted. In the figure, an acceleration particle beam is extracted in the y-axis direction with the deflection angle of the deflection magnet 6 through which the acceleration particle trajectory finally passes is about 90 degrees. This deflection angle is arbitrarily set according to the size of the deflection magnet 6.

When the energy of the accelerating particles increases, the interval between the accelerating particle orbits increases, and the number of accelerating particle orbits passing through the accelerating electrode 2 per unit length in the longitudinal direction decreases. For this reason, the efficiency of acceleration deteriorates. Further, since the acceleration phase approaches 90 degrees, the increase in energy is reduced.
Therefore, the mechanism for extracting the accelerated particle beam in the seventh embodiment slightly reduces the energy of the extracted beam 7. However, since the accelerating particle beam can be extracted from any deflection electrode 6, the entire apparatus can be downsized.

As described above, according to the seventh embodiment, the deflecting magnet is used as the electromagnet and the deflection angle is made variable so that the accelerated particle beam is taken out without passing through the acceleration gap 3. Therefore, there is no need to provide a special beam extraction mechanism, and an effect of reducing the size of the entire apparatus can be obtained.

The accelerating particle beam extracting mechanism according to the seventh embodiment can be applied to all the embodiments of the present invention.

Embodiment 8 FIG. In the above embodiment, 180
The magnetic field strength in the longitudinal direction of the 180-degree deflecting magnet from the incident position of the accelerating particles of the 180-degree deflecting magnet pair was uniform, but in the eighth embodiment, the intensity of the magnetic field was 180 degrees from the incident position of the accelerating particles of the 180-degree deflecting magnet pair. The magnetic field gradient is provided so that the magnetic field intensity becomes stronger as it goes in the longitudinal direction of the deflection magnet.

FIG. 9 is a longitudinal sectional view showing a configuration of a multi-pass accelerator according to an eighth embodiment of the present invention. In the drawing, the deflection magnet 6 on the left side is the same as that used in the first embodiment, and the deflection magnet 19 on the right side is provided with a magnetic field gradient so that the magnetic field strength increases in the y-axis direction.

As the energy of the accelerating particle increases, the deflection radius of the orbit of the accelerating particle increases. However, as the magnetic field strength increases in the y-axis direction as described above, the increase in the deflection radius can be suppressed. Further, when the accelerating particles undergo the initial deflection of about 90 degrees with this magnetic field gradient, a focusing force of the accelerating particle beam (focusing force in the y-axis direction) is obtained in the z-axis direction, and thereafter, the deflection force of about 90 degrees During the irradiation, a diverging force of the accelerating particle beam (a focusing force in the y-axis direction) is obtained in the z-axis direction. In such focusing and diverging, the spread of the accelerated particle beam is suppressed as a whole, and the beam is focused. Therefore, the focusing force in the z-axis direction is obtained by the magnetic field gradient.

FIGS. 10A and 10B are diagrams showing an example of the deflecting magnet according to the eighth embodiment, wherein FIG. 10A is a plan view as viewed from the x-axis direction in FIG. 9, and FIG. It is sectional drawing along the line. Thus, in order to obtain the magnetic field gradient of the deflection magnet shown above, in the illustrated example, the magnetic pole gap 18 is set to y
The structure becomes narrower as it goes in the axial direction. Also,
In this example, the deflection magnet is an electromagnet, but may be a permanent magnet, and the magnetic pole gap 18 may be variable in the y-axis direction.

In the deflecting magnet 19 according to the eighth embodiment, the trajectory of the accelerating particle whose deflection radius is increased due to the increase in the energy of the accelerating particle receives a strong magnetic field.
Since the deflection is performed at a deflection angle of 0 degree or more, fine adjustment of the trajectory of the accelerating particle by the correction magnet 11 is necessary.

In the above description, the same deflection magnet as that of the first embodiment is used as the left deflection magnet in the figure. However, the same effect can be obtained by giving the deflection magnet the magnetic field gradient as described above.

As described above, according to the eighth embodiment, the 180-degree deflecting magnet is shifted 180 degrees from the incident position of the accelerating particles.
The magnetic field gradient is set so that the magnetic field strength becomes stronger as it goes in the longitudinal direction of the deflecting magnet, so it is possible to suppress the increase in the deflection radius of the accelerating particle trajectory due to the increase in the energy of the accelerating particle, and furthermore, the Focusing power can be obtained. As a result, it is possible to prevent an increase in the size of the apparatus due to an increase in the deflection radius and a decrease in the acceleration efficiency due to a shift in the acceleration phase, so that an effect is obtained that the apparatus can be downsized and the acceleration efficiency can be increased.

The deflecting magnet of the eighth embodiment can be applied to all the embodiments of the present invention.

Embodiment 9 FIG. In the above embodiment, the gap (acceleration gap 3) between the two accelerating electrodes 2 is substantially constant in the longitudinal direction of the accelerating electrode 2 (however, in this embodiment, the gap is accelerated to obtain an arbitrary acceleration voltage distribution). Electrode 2
However, in the ninth embodiment, a cylindrical electrode through which the acceleration particle trajectory of the linear portion passes is provided on each opposing surface in the gap between the accelerating electrodes 2.

FIG. 11 is a longitudinal sectional view showing a configuration of a multi-pass accelerator according to Embodiment 9 of the present invention. In the figure, reference numeral 20 denotes a cylindrical electrode that passes through the accelerating particle trajectory of the linear portion, and is made of a conductive material such as copper, aluminum, or stainless steel plated with copper.
Further, the two electrode bases 21 are respectively provided on opposing surfaces to form a pair of cylindrical electrodes. Reference numeral 21 denotes an electrode base, which is an acceleration electrode in which the gap between the two acceleration electrodes is widened and the cylindrical electrode 20 is provided on the opposing surface thereof. ing. Note that the same components as those in FIG. 1 are denoted by the same reference numerals, and redundant description will be omitted.

If the acceleration electrode 2 is substantially constant in the longitudinal direction as in the above embodiment, a strong electric field is generated even in a region where the orbit of the accelerating particles does not pass. For this reason, many wall currents flow in the acceleration cavity 1a, and the power loss increases. As shown in the figure, when the cylindrical electrode 20 is provided, a strong electric field is generated only in a region where the orbit of the accelerating particle passes. When two orbits of the accelerating particles are close to each other, the pair of cylindrical electrodes 20 may pass through two orbits.

It is also conceivable to adopt a structure in which the electrode base 21 is eliminated and only the cylindrical electrode 20 is disposed so that an electric field is generated only in a region where the accelerating particle orbit passes.
Without the electrode base 21, the acceleration voltage distribution cannot be provided in the longitudinal direction of the electrode base 21 (y-axis direction in FIG. 11), and the acceleration voltage distribution becomes a distribution close to a half sine wave. Not suitable.

In the illustrated example, the protruding end 2a is formed on the electrode base 21. However, as in the sixth embodiment, if the acceleration cavity 1a is made short, it can be made unnecessary. Although the correction magnet 11 is not shown, it may be provided if it is necessary to finely adjust the position of the accelerating particle trajectory.

As described above, according to the ninth embodiment, since a plurality of cylindrical electrodes 20 through which the linear acceleration particle orbit passes are provided in the gap between the acceleration electrodes 2 (electrode bases 21), the acceleration particle orbit is provided. A strong accelerating electric field can be generated only in a region where the trajectory passes, and an outflow of the wall current into the accelerating cavity due to the electric field generated in a region where the orbit of the accelerating particles does not pass can be prevented. As a result, an effect that the power loss of the entire apparatus can be reduced is obtained.

Embodiment 10 FIG. The multi-pass accelerator according to the tenth embodiment is a combination of the configurations of the seventh and ninth embodiments.

FIG. 12 is a longitudinal sectional view showing a configuration of a multi-pass accelerator according to Embodiment 10 of the present invention. In the figure, a strong accelerating electric field is generated only in a region where an accelerating particle orbit passes by a cylindrical electrode 20, and an accelerating particle beam having arbitrary energy can be taken out by setting a deflection angle of 180 degrees or less by a deflection magnet. With such a configuration, the same effects as those of the above-described seventh and ninth embodiments can be obtained.

Embodiment 11 FIG. In the ninth embodiment,
The cylindrical electrode through which the accelerating particle trajectory passes is provided in the gap between the accelerating electrodes on each of the opposing surfaces.
Reference numeral 1 denotes a device provided with a focusing device in a cylindrical electrode in order to further focus the beam of accelerated particles.

FIG. 13 is a longitudinal sectional view showing a configuration of a multi-pass accelerator according to Embodiment 11 of the present invention. Also,
14A and 14B are diagrams showing an example of a cylindrical electrode incorporating a focusing device according to the eleventh embodiment, wherein FIG. 14A is a cross-sectional view of the focusing device-equipped cylindrical electrode, and FIG. 14B is a line CC of FIG. FIG. In the figure, reference numeral 22 denotes a quadrupole magnet built-in cylindrical electrode incorporating a quadrupole magnet 23 as a focusing device;
Is a quadrupole magnet for focusing the accelerating particle beam, 24 is a beam aperture which is a space where the accelerating particle beam in the quadrupole magnet built-in cylindrical electrode 22 receives a focusing force, and 24a is a cylindrical electrode 22
And the center axis of the beam aperture 24 and the center of the quadrupole magnetic field of the quadrupole magnet 23. Note that the same components as those in FIG. 1 are denoted by the same reference numerals, and redundant description will be omitted.

As shown in FIG. 14A, the quadrupole magnet 23 has a magnetic pole pair in which two identical magnetic poles are opposed to each other, and a magnetic pole pair of a different magnetic pole is arranged orthogonal to the magnetic pole pair. It has a structure. Further, as shown in FIG. 13, the quadrupole magnet built-in cylindrical electrode 22, which is a cylindrical electrode on which the quadrupole magnet 23 is arranged, is positioned so as to face the opposing surface of the electrode base 21 similarly to the ninth embodiment. I have.

Here, one of the quadrupole magnet built-in cylindrical electrodes 22
In the above, if the magnetic pole pair of the quadrupole magnet 23 gives a converging force in the horizontal direction to the accelerated particle beam, since the magnetic pole pair having the opposite magnetic pole is arranged in the vertical direction, the divergent Power is given. For this reason, the quadrupole magnet 23 inside the quadrupole magnet built-in cylindrical electrode 22 facing the above quadrupole magnet built-in cylindrical electrode 22 is a combination that gives a focusing force in the vertical direction of the accelerating particle beam as a combination having the opposite polarity.

When the positions of adjacent accelerated particle orbits are very close, two accelerated particle orbits may be passed through the beam aperture 24 in the quadrupole magnet built-in cylindrical electrode 22.
In this case, the trajectories of the accelerating particles do not pass through the central axis 24a (that is, the center of the quadrupole magnetic field) of the beam aperture 24 shown in FIG. However, since the opposing quadrupole magnet 23 of the quadrupole magnet built-in cylindrical electrode 22 is a combination of the opposite magnetism, each orbit is deflected in the opposite direction to the above. As a result, the beam deflection by the quadrupole magnet 23 is performed. Becomes smaller. Thereafter, the position of the accelerating particle trajectory may be finely adjusted by the correction magnet 11 or the like.

However, conversely to the above, the combination of the magnetic pole pairs in each quadrupole magnet 23 in the quadrupole magnet built-in cylindrical electrode 22 disposed opposite to each other by the active clamp or the focusing action of the accelerating particle beam by the 180-degree deflecting magnet. May be the same.

As described above, according to the eleventh embodiment, a quadrupole magnet is provided as a focusing device in the cylindrical electrode in order to further focus the accelerated particle beam. Only the accelerating electric field is strongly applied, and a strong focusing force is given to the accelerating particle beam by the quadrupole magnet, so that the effect of accelerating the accelerating particles efficiently can be obtained. In addition, since the magnetism of the focusing device in the opposed cylindrical electrode is reversed, when the positions of adjacent accelerating particle trajectories are very close, even if these two accelerating particle trajectories pass through the focusing device, the converging focusing device faces each other. The effect of focusing the beam by the device is obtained.

In the above embodiment, a permanent magnet is used as the quadrupole magnet 23, but the same effect can be obtained by using an electromagnet or an electrostatic quadrupole lens.

Embodiment 12 FIG. First, the first embodiment
Before explaining 2, the divergence and focusing action of the accelerated particle beam in the acceleration gap will be described. FIG. 15 is a diagram showing a general electric field distribution in the acceleration gap. In the figure,
When the beam of the incident particles exits from the acceleration electrode 2 on the left side in FIG. Thereafter, it is accelerated in the acceleration gap 3 and acts in a direction diverging from the electric field Er when it is incident again on the right acceleration electrode 2 in FIG. Whether the convergence / divergence action becomes a convergence force or a divergence force as a whole is approximately determined by the acceleration phase when the particles pass through the gap center of the acceleration gap 3. But,
When the particle velocity and the particle energy change significantly within the acceleration gap 3 as in the present invention, the focusing power of the accelerated particle beam when the energy of the accelerated particle is low becomes dominant, and as the particle is accelerated, the particle beam becomes excessive. The focusing action results in a diverging force. As a result, if the passage of the accelerating particles provided in the accelerating electrode 2 is circular, the electric field distribution shown in FIG. 15 becomes axially symmetric and receives excessive focusing action in both the horizontal and vertical directions.

Therefore, in the twelfth embodiment, the through-hole of the accelerating particles provided in the accelerating electrode 2 is an elongated hole which is widened in the horizontal or vertical direction so that all the orbits of the accelerating particles can enter, or at least the incident hole. The portion through which the initial accelerating particles pass is formed into a long hole shape which is sufficiently widened in the horizontal or vertical direction from the region where the accelerating particles pass, so that excessive focusing action in the horizontal or vertical direction is prevented.

FIG. 16 is a view showing an accelerating electrode of an accelerating cavity according to the twelfth embodiment of the present invention. FIG. 16 (a) shows a circular through hole through which sufficiently accelerated accelerating particles pass, and shows the acceleration at the initial stage of incidence. FIG. 3B is a perspective view illustrating a passage hole through which particles pass, which is a long hole in the longitudinal direction of the acceleration electrode. FIG. 4B is a perspective view illustrating a passage hole of the acceleration particles that is long in the longitudinal direction (horizontal direction, y-axis direction) of the acceleration electrode. FIG. 14C is a perspective view showing one of the two long holes, and FIG. 15C shows a cross section of the acceleration electrode according to the twelfth embodiment and an electric field distribution in the acceleration gap. Further, in order to simplify the description of the shape of the passage hole, the end face of each acceleration electrode 2 is shown as being transparent. In the figure, reference numerals 2B and 2C denote through holes which are elongated holes sufficiently wider in the horizontal direction (y-axis direction) than the region through which the accelerating particles pass, 2D denotes a side surface of the horizontal inner wall of the through holes 2B and 2C, and 2E denotes a side surface. It shows a circular passage hole through which the sufficiently accelerated accelerating particles pass.

When accelerating particles pass through the passage holes 2B and 2C, considering the passage area as a reference, the passage holes 2B and 2C
The horizontal inner wall side surface 2D of 2C is sufficiently far away. Accordingly, the electric field component in the horizontal direction (y-axis direction) does not exist or is extremely small in the passing region of the accelerating particles, and the effect of the electric field component in the horizontal direction (y-axis direction) can be ignored. For this reason, the accelerating particle beam can be easily focused in the horizontal direction (y-axis direction) by utilizing the above-described action of the magnetic field, or the focusing element may not be necessary. In addition, acceleration gap 3
Of the acceleration electrode 2 facing the surface (that is, the shape of the opening of the passage hole)
16A or 16B, and the same effect as described above can be obtained even if the inside of the acceleration electrode 2 is formed as one space.

However, the convergence and divergence action by an appropriate electric field is provided by an external focusing element (such as a cylindrical electrode 22 with a built-in quadrupole magnet).
Can be focused by itself without providing the laser beam, so that it may be effective in a region where the accelerated particles have high energy. Therefore, FIG.
(B) an example in which the passage hole 2C is one elongated hole that is long in the longitudinal direction (horizontal direction, y-axis direction) of the acceleration electrode 2 as shown in FIG.
As shown in FIG. 16 (a), the through-hole 2E through which the accelerated particles having sufficiently high acceleration and high energy pass is circular.
In both cases, the accelerated particles (having low energy) at the initial stage of the injection are formed as long passage holes 2B long in the longitudinal direction of the acceleration electrode 2. On the other hand, if there is a magnetic flux crossing the acceleration gap 3, the orbit of the accelerating particle is deflected.
If one long hole is provided as in (b), even if the orbit of the accelerated particle changes due to the deflection by the magnetic flux, the accelerated particle does not collide with the acceleration electrode 2 or the like and is lost.

Further, as shown in FIG. 16 (c), the long hole of the opposing acceleration electrode 2 has a vertical dimension (z-axis direction).
Are different, the electric field Er applied to the accelerating particles
Divergence can be reduced. This is because the elongated hole of one of the accelerating electrodes 2 is expanded in the vertical direction (z-axis direction), so that the electric field Er is generated on the inner wall side of the elongated hole (± z-axis direction).
This is because the vertical component of the electric field Er weakens.

As shown in FIG. 16 (c), the above-mentioned effect is obtained by moving the long hole of the acceleration electrode 2 on the opposite side from the long hole of the acceleration electrode 2 on the side where the acceleration particles are incident in the vertical direction (z-axis direction). When it is widened, the effect of reducing the diverging force due to the electric field Er applied to the accelerating particles due to the balance between the focusing and diverging forces is increased.

As described above, according to the twelfth embodiment, the passing hole of the accelerating particles provided in the accelerating electrode 2 is an elongated hole that is widened in the horizontal or vertical direction so that all the orbits of the accelerating particles can be entered. Or, at least the portion through which the accelerated particles pass at the initial stage of incidence has a long hole shape that is sufficiently widened in the horizontal or vertical direction from the passing region of the accelerated particles, so that the effect of the electric field component in the horizontal or vertical direction is ignored. It is possible,
Focusing of the accelerated particle beam in the horizontal or vertical direction can be facilitated. Further, in the case of one elongated hole shape as shown in FIG. 16B, even if the trajectory of the accelerating particle is deflected by the magnetic flux crossing the accelerating gap 3, the passing efficiency is improved without the accelerating particle colliding with the accelerating electrode or the like. Can be improved.

The accelerating cavity of the twelfth embodiment can be applied to all the embodiments of the present invention. The accelerating cavity according to the twelfth embodiment may be applied to any of the multi-pass accelerators disclosed so far, in addition to the configuration of the multi-pass accelerator according to the present invention (for example, a description will be given of a conventional technique). The present invention can also be applied to a configuration having a large number of deflecting magnets, such as a multi-pass accelerator described above, even if the accelerating particles of the present invention are used even if the accelerating particles are deflected by the magnetic flux traversing the acceleration gap. This is because a decrease in passage efficiency can be suppressed).

Embodiment 13 FIG. In the thirteenth embodiment, the multi-pass type accelerator described in the above-described embodiment is used as one constituent unit to form a connection type accelerator in which a plurality of the connection units are connected, and the accelerated particles accelerated by the first accelerator are connected to the next order. The accelerator is accelerated to a high energy by entering the accelerator and accelerating again.

FIG. 17 is a longitudinal sectional view showing a multi-pass accelerator according to Embodiment 13 of the present invention. As shown
The multi-pass accelerator of the tenth embodiment is used as a first acceleration stage for first accelerating electrons. The electron trajectory emitted from the first acceleration stage is deflected by the deflecting magnet 26 and enters the second acceleration stage. The multi-pass accelerator according to the ninth embodiment is used as the second acceleration stage, but the electron beam whose diameter is enlarged while the electron beam is incident on the second acceleration stage by the deflecting magnet 26 is focused. For this purpose, the quadrupole magnet built-in cylindrical electrode 22 is provided at the initial stage of electron beam incidence in the second acceleration stage.

The effects obtained by connecting the two multi-pass accelerators as described above are as follows. 1) The magnetic field strength of the 180-degree deflecting magnet 6 in the accelerator as the second acceleration stage is made larger than that in the accelerator in the first acceleration stage. This suppresses an increase in the deflection radius of the accelerated particle trajectory in the second acceleration stage, and reduces the deflection trajectory length relative to the entire length of the accelerated particle trajectory between the respective deflection magnets 6 of the 180-degree deflecting magnet pair. Therefore, it is possible to prevent the acceleration phase from being shifted. Further, it is possible to suppress an increase in the size of the accelerator device due to an increase in the deflection radius. 2) The deviation of the acceleration phase increases as the energy ratio between the incident energy and the output energy increases, but the particles accelerated to some extent in the first acceleration stage enter the second acceleration stage and are accelerated. The energy ratio between the energy of the particles exiting the stage and the energy of the particles exiting the first acceleration stage does not become relatively large. For example, even if the particles are accelerated to 5 MeV in the first acceleration stage and the energy of the particles exiting the second acceleration stage is accelerated to 10 MeV,
Since the energy ratio is as small as 2, the shift of the acceleration phase can be suppressed, so that efficient acceleration can be performed.

In addition to the above, the deviation of the acceleration phase can be further suppressed by finely adjusting the distance between the deflecting magnet 6 of the accelerator in the first and second acceleration stages and the acceleration cavity 1a.

Further, the deflecting magnet 26 for connecting the first acceleration stage and the second acceleration stage is formed by an electromagnet, and the power of the deflecting magnet 26 is turned off as necessary to set the deflection angle to 0 degree, thereby obtaining the first angle. The electron beam 25 with low energy accelerated only by the acceleration stage can be extracted to the left side (−x-axis direction) in the drawing. Further, when the 180-degree deflecting magnet 6 is formed by an electromagnet and provided with a passage hole for an accelerated particle beam, this 1
By turning off the power of the 80-degree deflecting magnet 6, the deflection angle is set to 0 degree, and the low-energy electron beam 25 can be passed through the passage hole and taken out to the right (x-axis direction) in the figure. By changing the deflection angles of the deflection magnets 6 and 26 and considering the installation position, the energy of the accelerated particle beam can be quickly switched, and the beam can be extracted in any direction. .

As described above, according to the thirteenth embodiment, a connected multi-pass type accelerator in which two multi-pass type accelerators are connected to each other to sequentially accelerate the accelerated particles is provided. It can accelerate to high energy. Further, since the energy ratio of each accelerator becomes relatively small, an effect that acceleration can be performed efficiently can be obtained.

Further, by increasing the magnetic field strength of the 180-degree deflecting magnet in the second accelerator to be larger than that of the first accelerator, it is possible to suppress an increase in the deflection radius of the orbit of the accelerating particle, thereby reducing the size of the apparatus. Can be Further, since the shift of the acceleration phase can be suppressed, an effect that efficient acceleration can be performed is obtained.

Further, since the acceleration particle beam is extracted from each accelerator by changing the deflection angle of the deflection magnet, the effect that the energy of the acceleration particle beam can be quickly switched is obtained.

Although the thirteenth embodiment uses both the quadrupole magnet built-in cylindrical electrode 22 and the cylindrical electrode 20, the present invention is not limited to this. In addition, the same effect can be obtained by omitting the cylindrical electrode and the like and using only the acceleration electrode 2. Furthermore, all of the multi-pass type accelerators and accelerating cavities according to the first to twelfth embodiments can be applied.

Further, in the above-described thirteenth embodiment, an example is shown in which two multi-pass type accelerators are connected, but the number is not limited to this, and the larger the number, the more accelerated particles can be accelerated to higher energy.

Embodiment 14 FIG. Embodiment 1 of the present invention
Reference numeral 4 indicates another example of a linked multi-pass accelerator. FIG.
FIG. 8 is a longitudinal sectional view showing a configuration of a multi-pass accelerator according to Embodiment 14 of the present invention. As shown in the figure, the first acceleration stage uses the accelerator of the tenth embodiment in which the quadrupole magnet built-in cylindrical electrode 22 is installed, and the electron beam 25 is emitted with the deflection angle of the deflection magnet 6 being about 90 degrees. Let it. The emitted electron beam 25 is deflected by one deflecting magnet 26 and is incident on the second acceleration stage. The accelerator of the second acceleration stage is orthogonal to that of the first acceleration stage (in the figure, along the x-axis). (Parallel). Extraction of the accelerated electron beam is performed by changing the deflection angle of the deflection magnets 6 and 26 as in the thirteenth embodiment. In this accelerator, the electron beam 25 having a low energy is taken out to the right side (x-axis direction) in the figure with the deflection angle of the deflection magnet 26 being about 90 degrees, and
Further, the beam is extracted upward (y-axis direction) in the figure by setting the deflection angle of the deflection magnet 6 in the second acceleration stage to 0 degree. The extraction beam 7 accelerated to high energy is extracted to the left (−x-axis direction) in the drawing by setting the deflection angle of the deflection magnet 6 of the second acceleration stage to about 90 degrees, or the deflection angle of the deflection magnet 6 is set to 180 degrees. The electron beam that has passed through the acceleration gap 3 to the end is taken out as a take-out beam 7 by the deflecting magnet 26 to the left (−x-axis direction) in the figure. By changing the deflection angles of the deflection magnets 6 and 26 in this manner, it is possible to easily switch the energy of the accelerated particle beam, and to extract the beam in an arbitrary direction depending on the installation location of the deflection magnets 6 and 26. it can.

FIG. 19 is a longitudinal sectional view showing another configuration of the multi-pass accelerator according to the fourteenth embodiment of the present invention. As shown, the first acceleration stage uses the accelerator of the eleventh embodiment, and the second acceleration stage uses the same one as shown in FIG. These accelerators differ from the linked accelerator shown in FIG. 17 in that two accelerators are connected in parallel (both accelerations are parallel to the x-axis in the figure). Explaining the main operation, the electron beam 25 emitted from the accelerator in the first acceleration stage enters the accelerator in the second acceleration stage without being deflected because the two accelerators are in parallel. The reason why the deflection magnet 26 is provided during this time is to extract the electron beam 25 having low energy to the right side (x-axis direction) in the drawing. Alternatively, the beam 25 may be extracted upward (in the y-axis direction) through the deflection magnet 6 of the second acceleration stage. Further, in the second acceleration stage, the deflection angle of the deflection magnet 6 is set to 90 degrees or 180 degrees, and the beams 7 are taken out, respectively, to the left (-x-axis direction) and the lower side (-y-axis direction) in the figure.
To take out. By changing the deflection angles of the deflection magnets 6 and 26 in this manner, it is possible to easily switch the energy of the accelerated particle beam, and to extract the beam in an arbitrary direction depending on the installation location of the deflection magnets 6 and 26. it can.

In the fourteenth embodiment, both the quadrupole magnet built-in cylindrical electrode 22 and the cylindrical electrode 20 are used. However, the present invention is not limited to this. In addition, the same effect can be obtained by omitting the cylindrical electrode and the like and using only the acceleration electrode 2. Further, all of the multi-pass accelerators and accelerating cavities according to the first to thirteenth embodiments can be applied.

In the fourteenth embodiment, an example is shown in which two multi-pass type accelerators are connected, but the number is not limited to this, and the larger the number, the more accelerated particles can be accelerated to higher energy.

Embodiment 15 FIG. In the multi-pass accelerator according to the fifteenth embodiment, a plurality of deflection magnet pairs are arranged in one accelerating cavity in order to accelerate particles to high energy.

FIG. 20 is a longitudinal sectional view showing a configuration of a multi-pass accelerator according to a fifteenth embodiment of the present invention. In the drawing, reference numeral 1a 'denotes an accelerating cavity in which two pairs of deflection magnets are arranged, and 2A denotes an accelerating electrode provided in a resonator shell 1A constituting the accelerating cavity 1a'. Since the accelerating electrode 2A has the cylindrical electrodes 20 and 22 disposed on the opposing surfaces thereof, the accelerating electrode 2A is also referred to as an electrode base as described above.

Next, the outline will be described. Acceleration cavity 1
In the first acceleration stage located below a ′, the accelerated particle beam is incident on the second acceleration stage located above without using the deflecting magnet 26 as described in the twelfth and thirteenth embodiments. In this second acceleration stage, an accelerated particle beam whose energy has been increased to some extent by the first acceleration stage is incident, and the deflection radius of the accelerated particle trajectory is larger than that in the first acceleration stage. Therefore, by increasing the magnetic field strength of the deflecting magnet 6 in the second acceleration stage to that in the first acceleration stage, the increase in the deflection radius is suppressed. In the first acceleration stage, the magnetic field strength of the deflecting magnet 6 in the deflecting magnet pair is such that the deflecting magnet 6 on the left side (−x axis direction)
In the second acceleration stage, on the contrary, the magnetic field strength of the right-side (x-axis direction) deflection magnet 6 is set to be larger than the left side (-x-axis direction). You. This is because, when the magnetic field strength of the deflection magnet pair of the second acceleration stage is set to be larger on the left side (−x-axis direction) than on the right side (x-axis direction), as in the first acceleration stage, Since the deflection radius of the accelerated particle trajectory in the deflecting magnet 6 (in the x-axis direction) is suppressed to a small value, the incident accelerated particle trajectory and the circulated accelerated particle trajectory approach each other, and the accelerated particle beam circulated in the second acceleration stage becomes the first accelerated particle beam. It may collide with the deflection magnet 6 of the acceleration stage. For this reason, as described above, the first acceleration stage and the second acceleration stage reversely set the combination of the magnetic field strengths of the pair of deflection magnets.

As described above, the accelerating particle beam is sequentially accelerated by the upper and lower acceleration stages, so that the particles can be accelerated to a higher energy than in the case of the multi-pass accelerator alone. Further, since the energy ratio of each acceleration stage becomes relatively small as described in the twelfth embodiment, particles can be efficiently accelerated.

By setting the deflection angle of the deflection magnet 6 to 0 degree, the low energy beam 25 is taken out from both the left and right sides in the figure, and the high energy beam 7 is deflected by about 90 degrees.
The angle is taken out upward (in the y-axis direction) in the figure or rightward in the figure (in the x-axis direction) with a deflection angle of 180 degrees. By providing a beam passage hole at an arbitrary position of the deflecting magnet 6 and changing the deflection angle in this way, the energy of the accelerated particle beam can be quickly switched, and the beam can be extracted in an arbitrary direction. .

As described above, according to the fifteenth embodiment, since a plurality of deflection magnet pairs are arranged in one accelerating cavity, the accelerating particles can be accelerated to high energy. Further, since the energy ratio of each acceleration stage becomes relatively small, an effect that particles can be efficiently accelerated is obtained.

Further, by increasing the magnetic field strength of the deflecting magnet of the second acceleration stage to that of the first acceleration stage, an increase in the deflection radius of the trajectory of the accelerating particle can be suppressed, thereby reducing the size of the apparatus. be able to. Further, since the shift of the acceleration phase can be suppressed, an effect that efficient acceleration can be performed is obtained.

Furthermore, since the acceleration particle beam is extracted from each accelerator by changing the deflection angle of the deflection magnet, the effect that the energy of the acceleration particle beam can be quickly switched is obtained.

In the fifteenth embodiment, both the quadrupole magnet built-in cylindrical electrode 22 and the cylindrical electrode 20 are used. However, the present invention is not limited to this. In addition, the same effect can be obtained by omitting the cylindrical electrode and the like and using only the acceleration electrode 2. Furthermore, all of the multi-pass type accelerators and accelerating cavities according to the first to fourteenth embodiments can be applied.

In the fifteenth embodiment, an example is shown in which two pairs of deflection magnets are used. However, the number of pairs of deflection magnets is not limited to this, and the larger the number, the more accelerated particles can be accelerated to higher energy. Can be.

Embodiment 16 FIG. In the above embodiment, the multi-pass accelerator and the accelerating cavity of the present invention have been described.
In the sixteenth embodiment, an electron beam / X-ray irradiation processing apparatus using a multi-pass accelerator or an acceleration cavity according to the above embodiment will be described.

FIG. 21 is a perspective view showing an electron beam / X-ray irradiation apparatus according to Embodiment 16 of the present invention. In the drawing, reference numeral 30 denotes a multi-pass type accelerator according to the present invention having an acceleration cavity 1a and a deflection magnet 6, 31 a scanning device for deflecting an accelerated electron beam, 32 a vacuum chamber, 33 a target for X-ray generation, Numeral 34 denotes an irradiation object, and numeral 35 denotes a belt conveyor.

Next, the operation will be described. Irradiated object 34
Is placed in a case having a size of about 1 mx 1 mx 1 m, and is fed by a belt conveyor 35. When the case in which the irradiation target 34 is located comes to the front of the electron beam / X-ray irradiation processing apparatus, the irradiation target 34 is irradiated with an electron beam or an X-ray according to the purpose. Here, the operation of irradiating the irradiation object 34 with the accelerated electron beam will be specifically described. Since the electron beam accelerated by the multi-pass accelerator 30 is initially smaller than the irradiation target 34,
It is necessary to spread the accelerated electron beam to the size of the irradiation object 34. For this reason, for example, the apparent electron beam diameter is enlarged by vertically scanning the extracted electron beam with a scanning device 31 having a deflection magnet capable of AC excitation. The repetition frequency of this beam scanning is about 100 Hz. Further, by making the conveying speed of the belt conveyor 35 sufficiently lower than the scanning speed of the accelerated electron beam, a uniform irradiation dose can be given to the entire irradiation object 34. The irradiation may be performed by directly applying an electron beam or by irradiating an X-ray converted by the electron beam. The conversion from electron beams to X-rays uses the principle that X-rays are generated by bremsstrahlung when an electron beam is applied to a target 33 made of heavy metal.

Further, in the above description, the scanning device 31 is used to scan the extracted electron beam. However, the incident device described in the third embodiment may be used to perform beam scanning by this incident device. .

By irradiating an electron beam or an X-ray as described above, it is possible to kill germs attached to the surface of the irradiation object 34. Examples of the irradiation target 34 include medical instruments and medical clothing, and life-derived articles such as potatoes and cut flowers. The higher the dose of electron beam or X-ray irradiation, the greater the above-mentioned sterilization / sterilization effect, and
A large amount of processing can be performed in a short time. However, life-derived articles such as potatoes and cut flowers may be destroyed when exposed to a large amount of irradiation, and may change from their original properties. For this reason, an upper limit is set for the irradiation amount. However, an electron beam having a high intensity of several tens of kW or more is required to exhibit the above-described sterilization / sterilization effect.
Therefore, it is required that the accelerator used has a high beam passing efficiency of the accelerated particles. For example, if 10% of the accelerated particle beam is lost during acceleration, a beam loss on the order of kW results. If this loss is caused by the collision of the accelerating particles with the accelerating electrode 2, the accelerating particles are concentrated and collide with the loss location of the accelerating electrode 2, and the heat generated by the collision may melt the accelerating electrode 2. There is. In addition, since it is necessary to extract extra electron beams from the electron gun 4 in anticipation of loss during acceleration, the life of the electron gun 4 itself may be shortened.

On the other hand, the above problem is solved by using the multi-pass type accelerator and the accelerating cavity according to the present invention shown in the above-mentioned embodiment having high beam passing efficiency of the accelerating particles, and a very effective electron A line or X-ray irradiation process can be performed.

In the electron beam / X-ray irradiation apparatus according to the sixteenth embodiment, all the multi-pass accelerators and accelerating cavities shown in the first to fifteenth embodiments can be used. it can.

As described above, according to the sixteenth embodiment, since the electron beam / X-ray irradiation processing apparatus includes the multi-pass type accelerator and the accelerating cavity according to the above-described embodiment, the beam passing efficiency of the accelerated particles is improved. Due to the above advantages, there is no possibility that the accelerating electrode 2 and the like are damaged even when a high-intensity electron beam or X-ray is irradiated, so that an apparatus with improved safety can be provided. Further, the shortening of the life of the electron gun 4 is suppressed, and the power consumption can be reduced, which is advantageous in terms of cost.

[0158]

As described above, according to the multi-pass type accelerator of the present invention, the accelerating cavity including the resonator outer shell and the accelerating electrode provided in the resonator outer shell, and the respective magnetic field strengths Are set to different values, and the respective magnetic field polarities are equal,
A pair of deflecting magnets arranged opposite to both sides of the accelerating cavity and all the linear portions of the accelerating particle trajectory pass so that the accelerating particle trajectory is a trajectory accompanied by precession, and With an acceleration gap to accelerate the accelerating particles along
Since the accelerating particles are accelerated along the precession trajectory, the trajectory passing through the acceleration gap can be collected in a narrow range, and the length of the accelerating cavity can be reduced. Thereby, there is an effect that the size of the entire accelerator can be reduced. In addition, since the power loss of the accelerating cavity is proportional to the length of the accelerating cavity, the downsizing of the accelerator not only reduces the cost of the device but also reduces the operating cost.

Further, since there are only two deflecting magnets, there is an effect that the cost of the apparatus can be reduced and the start-up adjustment of the accelerated particle beam can be easily performed.

Further, since all the accelerated particle orbits gathered in a narrow length range in the accelerated particle orbit accompanied by precession pass through the acceleration gap, a larger number of orbits can be passed through the acceleration gap as compared with the conventional case. Thus, there is an effect that particles can be accelerated more efficiently as compared with the related art.

According to the multi-pass accelerator of the present invention, the acceleration cavities including the resonator outer shell and the acceleration electrodes provided in the resonator outer shell are set to different values for the respective magnetic field strengths, In addition, the magnetic particles have the same magnetic field polarity, and are arranged opposite to each other on both sides of the accelerating cavity so that the accelerating particle trajectory is a trajectory with precession. A plurality of deflecting magnet pairs provided so as to be incident on the pair of deflecting magnets, and an acceleration gap through which all of the linear portions of the accelerating particle trajectory pass to accelerate the accelerating particles along the accelerating particle trajectory. Therefore, in addition to the above effects, the accelerating particles can be accelerated to high energy. Further, since the energy ratio of the particles accelerated in the acceleration stage having each of the deflection magnet pairs becomes relatively small, there is an effect that the particles can be efficiently accelerated.

According to the multi-pass type accelerator of the present invention, the acceleration cavity including the resonator outer shell and the acceleration electrode provided in the resonator outer shell, and the incident light for causing particles to be accelerated to enter the acceleration cavity. The magnetic field strengths are set to different values and the magnetic field polarities are equal so that the orbit of the incident particle and the orbit of the deflected accelerated particle are sufficiently separated from each other. A pair of deflecting magnets arranged on both sides of the accelerating cavity so as to have a trajectory with differential motion;
Since the acceleration gap for accelerating the accelerating particles along the accelerating particle trajectory is provided by passing all the linear portions of the accelerating particle trajectory, the above paragraphs “0158”, “0159”, and “016” are provided.
In addition to the effect of "0", there is an effect that the incident device deflects the incident particle to an accelerated particle trajectory so that the particle can be efficiently accelerated.

According to the multi-pass accelerator of the present invention, the acceleration cavity including the resonator outer shell and the acceleration electrode provided in the resonator outer shell, and the incident light for causing particles to be accelerated to enter the acceleration cavity. The magnetic field strengths are set to different values and the magnetic field polarities are equal so that the orbit of the incident particle and the orbit of the deflected accelerated particle are sufficiently separated from each other. A plurality of trajectories arranged so as to be opposed to both sides of the accelerating cavity so as to have a trajectory accompanied by differential motion, and provided so that accelerated particles taken out from the first deflecting magnet pair enter the next deflecting magnet pair. And the acceleration gap through which all the linear portions of the accelerating particle trajectory pass to accelerate the accelerating particles along the accelerating particle trajectory. Instrument to move incident particle into accelerated particle trajectory In an effect that can perform acceleration efficient particles by deflecting.

According to the multi-pass type accelerator of the present invention, the space between the accelerating cavity and the deflecting magnet can be widened because the incidence device is arranged in the accelerating cavity, and the opposing gap between the deflecting magnet pair is provided. Can be adjusted in a wide range, so that there is an effect that an adjustment range for a shift of the acceleration phase or the like can be widened.

According to the multi-pass accelerator of the present invention, the beam of the accelerating particles taken out of the accelerating cavity is scanned by periodically changing the electric or magnetic field applied to the particles to be incident on the accelerating cavity by the injector. Therefore, since the function of the scanning electromagnet is replaced by the incident device, the scanning electromagnet can be omitted. Thereby, there is an effect that the apparatus cost can be reduced.

According to the multi-pass accelerator of the present invention, the magnetic field intensity is increased from the first pair of deflecting magnets to the second pair of deflecting magnets. Accordingly, the size of the device can be reduced. Furthermore, since the shift of the acceleration phase can be suppressed, there is an effect that efficient acceleration can be performed.

According to the accelerating cavity of the present invention, the accelerating electrode has a through hole through which the accelerating particles pass, and the through hole is a long hole which is widened in the horizontal or vertical direction so that all of the orbit of the accelerating particles can enter. Or, or at least a portion through which the accelerated particles in the initial stage of the incident pass is a long hole that is sufficiently wider in the horizontal or vertical direction than the passing region of the accelerated particles, so that the action by the horizontal or vertical electric field components is reduced. This has the effect of being negligible and facilitating the focusing of the accelerated particle beam in the horizontal or vertical direction. Further, even if the accelerating particles are deflected by the magnetic flux crossing the accelerating gap, they do not collide with the accelerating electrode, and the beam passing efficiency of the accelerating particles can be improved.

According to the accelerating cavity of the present invention, one passage hole of the opposing acceleration electrode is made wider in the horizontal or vertical direction than the other passage hole, so that the diverging force due to the electric field applied to the accelerating particles is reduced. There is.

According to the acceleration cavity of the present invention, the passage hole of the acceleration electrode on the opposite side is made wider in the horizontal or vertical direction than the passage hole of the acceleration electrode on the side where the acceleration particles are incident. The effect can be further enhanced.

According to the accelerating cavity of the present invention, the cross section of the cavity of the resonator is rectangular, so that the range between the deflecting magnet and the cavity of the cavity is widened in order to widen the adjustment range for the acceleration phase shift. It is easy to design when you want to make the space of the space large.

According to the multi-pass accelerator of the present invention, since the acceleration cavity of claim 8 is provided, the above paragraph "0167"
By using an acceleration cavity having the same effect as described above, it is possible to provide a multi-pass accelerator having a high efficiency of passing accelerated particles.

According to the multi-pass accelerator of the present invention, since the acceleration cavity of claim 9 is provided, the above paragraph "0168"
By using an acceleration cavity having the same effect as described above, it is possible to provide a multi-pass accelerator having a high efficiency of passing accelerated particles.

According to the multi-pass accelerator of the present invention, since the acceleration cavity of claim 10 is provided, the aforementioned paragraph "016"
The multi-pass type accelerator having high efficiency of passing the accelerating particles can be provided by the accelerating cavity having the same effect as 9).

According to the multi-pass accelerator of the present invention, since the deflecting magnet is made of a permanent magnet, there is no need for a power source, and there is an effect that the operating cost can be reduced.

According to the multi-pass type accelerator of the present invention, since the magnetic field gradient is provided in the deflecting magnet so that the magnetic field strength becomes weaker as it goes inward from the entrance and exit of the accelerating particle, the focusing power of the accelerating particle beam can be obtained. This has the effect that particles can be accelerated efficiently.

According to the multi-pass type accelerator of the present invention, the magnetic field gradient is provided in the deflecting magnet so that the magnetic field strength becomes stronger as it goes from the incident position of the accelerating particles to the longitudinal direction of the deflecting magnet. Accordingly, it is possible to suppress an increase in the deflection radius of the accelerated particle trajectory, and to obtain a focusing force of the accelerated particle beam. As a result, it is possible to prevent an increase in the size of the apparatus due to an increase in the deflection radius and a decrease in the acceleration efficiency due to a shift in the acceleration phase, so that the apparatus can be downsized and the acceleration efficiency can be increased.

According to the multi-pass accelerator of the present invention, since the plurality of cylindrical electrodes provided corresponding to the respective accelerating particle orbits are provided so that the accelerating particle orbits of the linear portion pass therethrough, the accelerating particle orbit can pass. A strong accelerating electric field can be generated only in the region where the acceleration particle trajectory does not pass, and it is possible to prevent the wall current from flowing into the accelerating cavity by the electric field generated in the region where the accelerating particle orbit does not pass. Thereby, there is an effect that the power loss of the entire apparatus can be reduced.

According to the multi-pass accelerator of the present invention, since the focusing device is disposed in the cylindrical electrode, the accelerating electric field is applied only to the region where the accelerating particle orbit passes by the cylindrical electrode. Since a strong focusing force is given to the beam, there is an effect that the accelerating particles can be efficiently accelerated.

According to the multi-pass type accelerator of the present invention, since the focusing devices having different polarities are arranged in the opposed cylindrical electrodes, the two accelerating particle orbits whose adjacent orbits of the accelerating particle orbits are very close are the focusing device. Even if you pass inside,
There is an effect that the beam can be focused by the facing focusing device.

According to the multi-pass accelerator of the present invention, a plurality of multi-pass accelerators according to any one of the first, third, fifth and twelfth to twenty-first aspects are connected. Since the accelerated particles taken out from the first multi-pass accelerator are incident on the subsequent multi-pass accelerators and are sequentially accelerated, the accelerated particles can be accelerated to high energy. Further, since the energy ratio of each accelerator becomes relatively small, an effect that acceleration can be performed efficiently can be obtained.

According to the multi-pass accelerator of the present invention, the magnetic field strength of the pair of deflecting magnets is made to increase as going from the first multi-pass accelerator to the next multi-pass accelerator. An increase in the radius can be suppressed, and thus the device can be downsized. Furthermore, since the shift of the acceleration phase can be suppressed, there is an effect that efficient acceleration can be performed.

According to the multi-pass accelerator of the present invention, the cross section of the outer shell of the resonator is rectangular, so that the same effect as described above can be obtained and the adjustment range for the acceleration phase shift and the like can be widened. Therefore, it is easy to design when the space between the deflecting magnet and the resonator shell needs to be widened.

According to the multi-pass accelerator of the present invention, the deflecting magnet is constituted by an electromagnet, and the deflection angle of the deflecting magnet is changed to take out the accelerating particles. Therefore, the accelerating particle beam is taken out from any deflecting magnet. Therefore, there is no need to provide a special beam extraction mechanism, and the entire apparatus can be downsized. Further, there is an effect that the energy of the accelerating particles can be quickly switched.

According to the electron beam / X-ray irradiation processing apparatus of the present invention, the electron beam / X-ray irradiation processing apparatus having a high efficiency of passing an accelerated particle beam is provided since the acceleration cavity according to claim 8 is provided. Can be.

According to the electron beam / X-ray irradiation processing apparatus of the present invention, since the multi-pass accelerator according to claim 1 is provided,
An electron beam / X-ray irradiating apparatus which has the same effects as in the above paragraph "0183" and has improved safety by eliminating the possibility of damaging the accelerating electrode and the like even when irradiating with a high-intensity electron beam or X-ray. There is an effect that can be provided.

In addition, the life of the electron gun can be suppressed from being shortened, and the power consumption can be reduced, which is advantageous in terms of cost.

[Brief description of the drawings]

FIG. 1 is a view showing a multi-pass accelerator according to Embodiment 1 of the present invention, in which (a) is a longitudinal sectional view, and (b) is a sectional view taken along line AA of (a).

FIG. 2 is a configuration diagram illustrating an example of an electron beam incident device in the multi-pass accelerator according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a difference between orbits after passing through an acceleration gap when an incident particle receives acceleration and when it does not receive acceleration.

FIG. 4 is a partial cross-sectional view showing a configuration around an injection device of a multi-pass accelerator according to Embodiment 2 of the present invention.

FIG. 5 is a cross-sectional view showing a 180-degree deflecting magnet of a multi-pass accelerator according to Embodiment 4 of the present invention.

FIG. 6 is a cross-sectional view showing a resonator shell of a multi-pass accelerator according to Embodiment 5 of the present invention.

FIG. 7 is a longitudinal sectional view showing an acceleration cavity of a multi-pass accelerator according to Embodiment 6 of the present invention.

FIG. 8 is a longitudinal sectional view showing a configuration of a multi-pass accelerator according to a seventh embodiment of the present invention.

FIG. 9 is a longitudinal sectional view showing a configuration of a multi-pass accelerator according to an eighth embodiment of the present invention.

10A and 10B are diagrams illustrating an example of a deflection magnet according to the eighth embodiment, where FIG. 10A is a plan view as viewed from the x-axis direction in FIG. 8, and FIG. 10B is a view taken along line BB in FIG. It is sectional drawing along.

FIG. 11 is a longitudinal sectional view showing a configuration of a multi-pass accelerator according to Embodiment 9 of the present invention.

FIG. 12 is a longitudinal sectional view showing a configuration of a multi-pass accelerator according to Embodiment 10 of the present invention.

FIG. 13 is a longitudinal sectional view showing a multi-pass accelerator according to an eleventh embodiment of the present invention.

FIGS. 14A and 14B are diagrams showing an example of a cylindrical electrode incorporating a focusing device according to the eleventh embodiment, wherein FIG. 14A is a cross-sectional view of the focusing device-equipped cylindrical electrode, and FIG. It is sectional drawing along the line.

FIG. 15 is an explanatory diagram showing a general electric field distribution in an acceleration gap.

FIG. 16 shows an acceleration electrode of an acceleration cavity according to Embodiment 12 of the present invention.

FIG. 17 is a longitudinal sectional view showing a multi-pass accelerator according to a thirteenth embodiment of the present invention.

FIG. 18 is a longitudinal sectional view showing a configuration of a multi-pass accelerator according to Embodiment 14 of the present invention.

FIG. 19 is a longitudinal sectional view showing another configuration of the multi-pass accelerator according to Embodiment 14 of the present invention.

FIG. 20 is a longitudinal sectional view showing a configuration of a multi-pass accelerator according to Embodiment 15 of the present invention.

FIG. 21 shows an electron beam according to a sixteenth embodiment of the present invention.
It is a perspective view which shows an X-ray irradiation processing apparatus.

FIG. 22 is a view showing a conventional multi-pass accelerator;
(A) is a side sectional view, (b) is a sectional view taken along line XX of (a), and (c) is a sectional view taken along line YY of (b).

[Explanation of symbols]

1,1A resonator shell, 1a, 1A acceleration cavity, 2,2
A Accelerating electrode, 2B, 2C passing hole, 3 accelerating gap, 5 electron orbit (orbit of incident particle), 8 injection device, 17 orbit of electron beam (acceleration particle orbit), 2
0 cylindrical electrode, 21 electrode base (acceleration electrode), 22
Cylindrical electrode with built-in quadrupole magnet (cylindrical electrode), 23 quadrupole magnet (focusing equipment).

Claims (27)

[Claims] An accelerating cavity comprising a resonator outer shell and an accelerating electrode provided in the resonator outer shell, each magnetic field intensity being set to a different value, and each magnetic field polarity being equal; A pair of deflecting magnets arranged opposite to both sides of the accelerating cavity so that the accelerating particle orbit is a trajectory accompanied with precession, and all of the linear portions of the accelerating particle orbit pass through the accelerating particle orbit. A multi-pass accelerator comprising an acceleration gap for accelerating accelerating particles along an orbit. 2. An accelerating cavity comprising a resonator outer shell and an accelerating electrode provided in the resonator outer shell, each magnetic field strength being set to a different value, and each magnetic field polarity being equal, In order to make the accelerating particle trajectory a trajectory with precession, it is arranged opposite to both sides of the accelerating cavity,
A plurality of deflection magnet pairs provided so that accelerating particles from the first deflection magnet pair are incident on the next deflection magnet pair, and all of the linear portions of the accelerating particle trajectory pass, and And an acceleration gap for accelerating the accelerating particles along the multi-pass accelerator. 3. An accelerating cavity comprising a resonator outer shell and an accelerating electrode provided in the resonator outer shell; an injection device for inputting particles to be accelerated into the accelerating cavity; Each magnetic field strength is set to a different value so that the orbit of the deflected and accelerated particle is sufficiently separated, and each magnetic field polarity is equal, and the orbit of the accelerated particle is a trajectory with precession. As described above, a pair of deflection magnets disposed opposite to both sides of the accelerating cavity, and an accelerating gap through which all of the linear portions of the accelerating particle orbit pass to accelerate accelerating particles along the accelerating particle orbit. The multi-pass accelerator according to claim 1, wherein the accelerator is provided. 4. An accelerating cavity comprising a resonator outer shell and an accelerating electrode provided in the resonator outer shell; an incident device for impinging particles to be accelerated on the accelerating cavity; Each magnetic field strength is set to a different value so that the orbit of the deflected and accelerated particle is sufficiently separated, and each magnetic field polarity is equal, and the orbit of the accelerated particle is a trajectory with precession. A plurality of pairs of deflecting magnets disposed so as to face each other on both sides of the accelerating cavity and provided so that accelerating particles from the first deflecting magnet pair are incident on the next deflecting magnet pair; 3. The multi-pass accelerator according to claim 2, further comprising an acceleration gap through which all of the linear portions of the orbit pass and accelerate the accelerating particles along the accelerating particle orbit. 5. The multi-pass accelerator according to claim 3, wherein an injection device for inputting particles to be accelerated is disposed in the acceleration cavity. 6. The incident device scans a beam of accelerated particles taken out from the acceleration cavity by periodically changing an electric field or a magnetic field applied to particles to be incident on the acceleration cavity. The multi-pass accelerator according to any one of items 3 to 5. 7. The multi-pass accelerator according to claim 2, wherein the magnetic field intensity increases as going from the first pair of deflection magnets to the second pair of deflection magnets. 8. An accelerating cavity comprising a resonator outer shell and an accelerating electrode provided in the resonator outer shell, wherein the accelerating electrode has a through hole through which the accelerating particles pass. It is an elongated hole that is widened in the horizontal or vertical direction so that all of the trajectories of the accelerating particles enter, or at least a portion where the accelerating particles at the initial stage of the incident pass is more horizontal or vertical than the passing region of the accelerating particles. An accelerating cavity characterized by an elongated hole. 9. The accelerating cavity according to claim 8, wherein one of the passage holes of the opposing acceleration electrode is made wider in the horizontal or vertical direction than the other passage hole. 10. The accelerating cavity according to claim 9, wherein the through hole of the accelerating electrode on the opposite side is made wider in the horizontal or vertical direction than the through hole of the accelerating electrode on the side where the accelerating particles are incident. 11. The accelerating cavity according to claim 8, wherein the cross section of the outer shell of the resonator is rectangular. 12. A multi-pass accelerator for deflecting an accelerating particle trajectory a plurality of times to make multiple passes through an acceleration cavity, comprising the acceleration cavity according to claim 8. 13. The acceleration cavity according to claim 8, wherein the acceleration cavity is provided.
2. The multi-pass accelerator according to item 1. 14. The apparatus according to claim 1, further comprising an acceleration cavity according to claim 9.
2. The multi-pass accelerator according to item 1. 15. A multi-pass accelerator according to any one of claims 1 to 7, comprising the acceleration cavity according to claim 10. 16. The multi-pass accelerator according to claim 1, wherein the deflecting magnet is made of a permanent magnet. 17. The deflecting magnet is provided with a magnetic field gradient such that the magnetic field strength becomes weaker as it goes inward from the entrance and exit of the accelerating particles. Item 17. A multi-pass accelerator according to any one of Items 16. 18. The deflecting magnet according to claim 1, wherein a magnetic field gradient is provided so that a magnetic field intensity becomes stronger as it goes from the incident position of the accelerating particles to the longitudinal direction of the deflecting magnet. 18. The multi-pass accelerator according to claim 12, wherein: 19. The apparatus according to claim 1, further comprising a plurality of cylindrical electrodes provided corresponding to each of the accelerating particle orbits so that the accelerating particle orbits of the linear portion pass therethrough. The multi-pass accelerator according to any one of claims 1 to 18. 20. The multi-pass accelerator according to claim 19, wherein a focusing device is disposed inside the cylindrical electrode. 21. A focusing device having different polarities respectively disposed in opposed cylindrical electrodes.
The multi-pass accelerator described. 22. Accelerated particles obtained by taking out the multi-pass accelerator according to any one of claims 1, 3, 5, and 12 to 21 from the first multi-pass accelerator. Are connected so as to be incident on the next-order multi-pass accelerator and accelerated sequentially. 23. The multi-pass accelerator according to claim 22, wherein the magnetic field strength of the pair of deflecting magnets increases as going from the first multi-pass accelerator to the next multi-pass accelerator. 24. The resonator shell according to claim 1, wherein the cross section of the outer shell is square.
The multi-pass accelerator according to any one of claims 2 to 23. 25. The deflecting magnet comprises an electromagnet, and takes out accelerated particles by changing the deflecting angle of the deflecting magnet.
The multi-pass accelerator according to any one of the above. 26. An electron beam / X-ray comprising: a multi-pass accelerator for deflecting the accelerating particle orbit multiple times and passing the accelerating particle beam through the accelerating cavity multiple times; and an irradiation field expanding means for expanding the irradiation field of the accelerating particle beam. An electron beam / X-ray irradiation apparatus, comprising: the acceleration cavity according to claim 8. 27. An electron beam / X-ray comprising a multi-pass accelerator for deflecting an accelerating particle trajectory a plurality of times and passing through an accelerating cavity multiple times, and an irradiation field expanding means for expanding an irradiation field of the accelerating particle beam. An electron beam / X-ray irradiation apparatus, comprising the multi-pass accelerator according to claim 1.