CN222546286U - X-ray tube, X-ray source and irradiation device - Google Patents

Abstract

The utility model provides an X-ray tube, an X-ray source and an irradiation device, wherein the X-ray tube comprises a tube body, a heat dissipation structure and a focus control electrode pair, a cathode structure extending along a set surface and an anode target arranged at intervals with the cathode are arranged in a vacuum cavity formed by the tube body, the heat dissipation structure comprises a liquid cooling pipeline, the liquid cooling pipeline is arranged on one side of the anode target far away from the cathode structure, the heat dissipation structure is welded on the tube body, the welded part of the tube body and the heat dissipation structure is of a metal structure, and the focus control electrode pair is arranged between the cathode structure and the anode target and is used for controlling the movement path of electrons emitted from the cathode structure through voltage applied between the focus control electrode pair, so that the focus range formed by focusing of electrons emitted from the cathode structure on the anode target is controlled not to exceed the effective heat dissipation range on the anode target. The utility model can prepare the X-ray tube with stronger heat radiation capability so as to realize high-power and long-time continuous operation.

Description

X-ray tube, X-ray source and irradiation device

Technical Field

The utility model relates to the technical field of irradiation, in particular to an X-ray tube, an X-ray source and an irradiation device.

Background

The irradiation technology is a treatment means for realizing sterilization, preservation, material modification and other effects by utilizing the interaction of high-energy rays and substances. The high-energy rays commonly used in industry include gamma rays generated during the decay of radioactive isotopes, high-energy electron beams generated by electron accelerators, X-rays generated by X-ray tubes, and the like. Compared with other high-energy rays, the X-ray tube is easier to protect.

The traditional fixed anode X-ray tube is mainly applied to intermittent working such as imaging or low-dose irradiation scenes such as blood irradiation and the like due to the requirement of imaging on focus and the limitation of anode heat radiation capability, and is difficult to meet the irradiation requirement of continuous working of a radiation source such as sterilization, modification and the like at a high dose rate. The two ideas of improving the heat radiation structure and increasing the focal area of electrons on the anode are to improve the heat radiation capacity of the anode, thereby realizing the continuous high-power operation of the X-ray source.

The existing X-ray tube is usually made of ceramic or glass and the like, and an axial concentric pipeline is reserved in a metal anode head communicated with the back of an anode target to form a heat dissipation structure, so that external cooling liquid can flow in from a central pipeline and then flow out from a peripheral pipeline when the X-ray tube is used. However, because the difference between the thermal expansion coefficients of the metal and the ceramic or glass is large, in order to ensure the air tightness of the sealing interface between the metal and the ceramic or glass after the anode temperature is raised, the size of the sealing interface of the X-ray tube is often small, so that the complexity of the heat dissipation structure is limited, and the heat dissipation capability of the anode is improved by using a complicated pipeline design with large flow.

Further, although the current tube using the rotary anode can increase the actual focal area formed by emitted electrons, thereby reducing the local heat radiation pressure, the target material rotates fast, remarkably increases the manufacturing cost, and is not suitable for irradiation application without requirement on the focal size.

Therefore, there is a need to produce an X-ray tube with a high heat dissipation capacity to achieve high power and continuous operation for a long time.

Disclosure of utility model

In view of this, embodiments of the present utility model provide an X-ray tube, an X-ray source, and an irradiation apparatus capable of improving the heat radiation capability of an anode by improving a heat radiation structure and increasing an electron focal area to realize continuous high-power operation of a device.

One aspect of the present utility model provides an X-ray tube comprising:

A tube body for forming a closed vacuum cavity, a cathode structure extending along a set surface and anode targets spaced from the cathode are arranged in a cavity formed by the tube body of the ray tube;

the heat radiation structure comprises a liquid cooling pipeline, the heat radiation structure is in direct or indirect contact with the anode target and is arranged on one side of the anode target far away from the cathode structure, the heat radiation structure is welded on the tube body of the ray tube, and the part of the tube body welded with the heat radiation structure is of a metal structure;

And a focus control electrode pair disposed between the cathode structure and the anode target for controlling a movement path of electrons emitted from the cathode structure by a voltage applied between the focus control electrode pair, thereby controlling a focus range formed by focusing the electrons emitted from the cathode structure on the anode target to be not more than an effective heat dissipation range on the anode target.

In some embodiments of the utility model, the heat dissipating structure further comprises a heat dissipating substrate for coating the liquid cooling conduit and for directly contacting the anode target for dissipating heat from the anode target.

In some embodiments of the utility model, a temperature sensor is provided either internally or externally to the heat dissipating substrate.

In some embodiments of the utility model, the cathode structure comprises one electron emitter or a plurality of electron emitters connected in parallel, each electron emitter being in the form of a wire, rod or sheet, wherein the wire-shaped electron emitters are linear or helical.

In some embodiments of the utility model, the cathode structure further comprises an elastic stretching structure connected between one end of the electron emitter and the extraction electrode of the electron emitter for stabilizing the electron emitter position by stretching.

In some embodiments of the present utility model, the anode target is planar or curved, and the arrangement dimension of the electron emitters in each direction of the set face is smaller than the dimension of the anode target in the corresponding direction.

In some embodiments of the utility model, the X-ray tube further comprises a grid disposed between the cathode structure and the anode target, and/or

And the electron shielding structure is arranged on one side of the cathode structure, which is away from the anode target.

In some embodiments of the utility model, the liquid cooling conduit is arranged in a single tube detour or a multiple tube shunt arrangement to form a cooling surface for engaging the anode target.

Another aspect of the utility model provides an X-ray source comprising:

an X-ray tube as in any one of the above embodiments, and

The tube comprises an additional tube body, wherein the additional tube body is connected to one end of an extraction electrode of a cathode structure of the tube body of the tube, an insulator close to one side of the tube body of the tube is arranged in the additional tube body, and a negative high-voltage plug is arranged on one side far away from the tube body of the tube.

Another aspect of the present utility model provides an X-ray irradiation apparatus including:

The X-ray source of the above embodiment, a support structure for fixing the X-ray source, an irradiation stage located in an irradiation area of the X-ray source, and a shielding case.

The X-ray tube, the X-ray source and the irradiation device can fix the heat radiation structure and the X-ray tube body in an all-metal welding mode, reduce the possibility of air leakage of the X-ray tube caused by temperature change at the interface of the heat radiation structure and the tube body, further improve the heat radiation capability of the X-ray tube from the angle of improving the heat radiation structure, and effectively reduce the surface temperature of a target from the angle of increasing the area of an electronic focus by matching the effective heat radiation range formed by the electronic focus range and the liquid cooling pipeline through the focus control electrode pair. Based on the improvement angle, the X-ray tube with strong heat dissipation capacity can be prepared, so that the X-ray tube can continuously work with high power.

Additional advantages, objects, and features of the utility model will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the utility model. The objectives and other advantages of the utility model may be realized and attained by the structure particularly pointed out in the written description and drawings.

It will be appreciated by those skilled in the art that the objects and advantages that can be achieved with the present utility model are not limited to the above-described specific ones, and that the above and other objects that can be achieved with the present utility model will be more clearly understood from the following detailed description.

Drawings

The accompanying drawings, which are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this specification, illustrate and together with the description serve to explain the utility model. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the utility model. Corresponding parts in the drawings may be exaggerated, i.e. made larger relative to other parts in an exemplary device actually manufactured according to the present utility model, for convenience in showing and describing some parts of the present utility model. In the drawings:

Fig. 1 is a schematic structural diagram of an X-ray tube according to an embodiment of the present utility model.

Fig. 2 is a schematic diagram of a liquid cooling pipeline according to an embodiment of the utility model.

Fig. 3 is a schematic structural diagram of a pair of focus control electrodes according to an embodiment of the utility model.

Fig. 4 is a schematic view of a cathode structure according to an embodiment of the utility model.

Fig. 5 is a schematic view of a cathode structure according to another embodiment of the utility model.

FIG. 6 is a graph showing simulated electron probability density using a specific electron emission structure in accordance with one embodiment of the present utility model.

Fig. 7 is a graph showing simulated temperature profiles of an X-ray tube in a thermal equilibrium state in accordance with an embodiment of the present utility model.

Fig. 8 is a schematic view of an X-ray irradiation apparatus according to an embodiment of the present utility model.

Reference numerals illustrate:

Tube body 110, x-ray window 113, heat dissipating structure 130, liquid cooling tube 131, heat dissipating substrate 133, cathode structure 150, electron emitter 151, extraction electrode 153, anode target 170, focus control electrode pair 190, metal structure 111, grid 120, electron shielding structure 140, additional tube 210, negative high voltage plug 250, insulator 230

Detailed Description

The present utility model will be described in further detail with reference to the following embodiments and the accompanying drawings, in order to make the objects, technical solutions and advantages of the present utility model more apparent. The exemplary embodiments of the present utility model and the descriptions thereof are used herein to explain the present utility model, but are not intended to limit the utility model.

It should be noted here that, in order to avoid obscuring the present utility model due to unnecessary details, only structures and/or processing steps closely related to the solution according to the present utility model are shown in the drawings, while other details not greatly related to the present utility model are omitted.

It should be emphasized that the term "comprises/comprising" when used herein is taken to specify the presence of stated features, elements, steps or components, but does not preclude the presence or addition of one or more other features, elements, steps or components.

It is also noted herein that the term "coupled" may refer to not only a direct connection, but also an indirect connection in which an intermediate is present, unless otherwise specified.

Hereinafter, embodiments of the present utility model will be described with reference to the accompanying drawings. In the drawings, the same reference numerals represent the same or similar components, or the same or similar steps.

The method is limited by a principle and a preparation process, the limit heat radiation capability of the X-ray tube in the prior art is low, irradiation requirements of continuous work with high dosage rate in the fields of sterilization, fresh keeping, material improvement and the like are difficult to meet, the improvement of a heat radiation structure in the prior art is limited, and the heat radiation efficiency of the anode is difficult to effectively improve while the cost is controlled. Based on the above, the application adopts an all-metal welding mode to fix the heat radiation structure and the X-ray tube body so as to improve the heat radiation capability of the anode target material by adopting a pipeline design with large flow and complexity, and controls the focal area formed by electron flow at the anode through the focal control electrode pair so as to enable the electrons to be uniformly emitted to the anode target material. The application improves the heat radiation structure and increases the two dimensions of the electronic focus area, effectively improves the heat radiation capability of the X-ray tube, and realizes the continuous high-power operation of the X-ray source.

The X-ray tube of the present utility model is a vacuum diode operating at high voltage and comprises at least a cathode, an anode, a vacuum cavity and other structures. During operation, electrons emitted from the cathode bombard the anode under the acceleration of an electric field, most of energy of the high-energy electrons is reserved in the anode in the form of heat energy, and a small part of energy is emitted in the form of X-rays. Fig. 1 is a schematic view of an X-ray tube according to an embodiment of the present utility model. As shown in fig. 1, the X-ray tube according to the present utility model includes:

A tube body 110, wherein the tube body 110 is used for forming a closed vacuum cavity, and a cathode structure 150 extending along a set surface and an anode target 170 (or an anode target structure 170) arranged at intervals from the cathode are arranged in the cavity formed by the tube body 110;

A heat-dissipating structure 130 including a liquid-cooled tube 131, the heat-dissipating structure 130 being in direct or indirect contact with the anode target 170 and being disposed on a side of the anode target 170 remote from the cathode structure 150, and the heat-dissipating structure 130 being welded to the tube body 110, a portion of the tube body 110 welded to the heat-dissipating structure 130 being a metal structure 111 (for example, the heat-dissipating structure at the welded portion may also be made of a metal material);

A pair of focus control electrodes 190 (including a first focus control electrode 191 and a second focus control electrode 193) disposed between the cathode structure 150 and the anode target 170 for controlling a movement path of electrons emitted from the cathode structure 150 within the X-ray tube by a voltage applied between the pair of focus control electrodes 190, thereby controlling an electron beam emitted from the cathode structure 150 to be focused on the anode target 170 and an focal range formed by the electrons emitted from the cathode structure 150 to be focused on the anode target 170 to be not more than an effective heat dissipation range on the anode target 170.

Since the X-ray tube needs to be applied with a high voltage during application, the tube body 110 is usually required to be subjected to an uncharged process, such as grounding the tube body 110, in order to ensure the use safety. Further, an X-ray window 113 for transmitting X-rays generated by the anode target structure 170 is provided on the tube body 110. The welded part of the tube body and the heat dissipation structure 130 is a metal structure 111, which can be prepared by adopting a metal material which is the same as that of the heat dissipation structure at the welding position, or a metal material which has better welding compatibility with the material of the heat dissipation structure at the welding position is adopted to prepare the metal structure 111, the X-ray window 113 can be prepared by adopting a metal (such as aluminum, beryllium, titanium and the like) with higher radiation transmittance, an alloy material or glass and the like so as to reduce the absorption of the tube body to X-rays, and other parts of the tube body 110 except for the part of the tube body comprising the metal structure 111 and the X-ray window 113 can be prepared without adopting metal materials (such as ceramics, glass, aluminum, beryllium, titanium and alloys prepared by aluminum, beryllium, titanium and the like) as preparation materials due to smaller heating values. The junctions of different materials on the tube body 110 may be connected by vacuum brazing or the like, so that the tube body 110 forms a closed vacuum cavity.

To ensure that the X-ray tube can meet the high power heat dissipation requirements, the heat dissipation power and thermal resistance of the heat dissipation structure 130 need to be considered. In general, increasing the coolant flow rate and the heat exchange area of the heat sink structure 130 increases the heat sink power of the heat sink structure 130, and in the case where the product of the coolant flow rate and the heat exchange area is fixed, increasing the heat exchange area (in which case the coolant flow rate needs to be decreased) decreases the convective heat transfer thermal resistance, thereby decreasing the surface temperature of the anode target 170. Accordingly, the heat dissipation capability of the heat dissipation structure 130 may be enhanced by increasing the heat exchange area between the heat dissipation structure 130 and the anode target 170. The size of the effective heat dissipation range on the anode target 170 can be used to represent the size of the heat exchange area between the heat dissipation structure 130 and the anode target 170, the size of the effective heat dissipation range is determined by the arrangement boundary of the liquid cooling pipelines 131 in the heat dissipation structure 130, and the area formed by projecting the arrangement boundary of the liquid cooling pipelines 131 in each direction on the anode target 170 is the effective heat dissipation range.

In some embodiments of the utility model, liquid-cooled conduit 131 may employ a single-tube serpentine arrangement (as in (a) of fig. 2) or a multi-tube split arrangement (as in (b) and (c) of fig. 2) to form a cooling surface that conforms to anode target 170, thereby increasing the area of liquid-cooled conduit 131. For example, the ratio of the effective heat exchange area of the liquid cooling conduit 131 to the cross-sectional area of the liquid cooling conduit 131 (which may refer to the cross-sectional area of the liquid cooling conduit inlet) may be provided to be greater than 20. As shown in fig. 2, the liquid cooling pipeline 131 adopts a bending form to improve the complexity of the liquid cooling pipeline 131, effectively increase the heat exchange area and improve the heat dissipation capability of the anode target structure 170. The liquid cooling pipelines in (a) of fig. 2 are arranged in series, cooling liquid can flow along a single pipeline from one end to flow out, the (b) of fig. 2 adopts a parallel pipeline structure, the cooling liquid can flow along different pipelines from one end to flow in, and the (c) of fig. 2 adopts a serial-parallel pipeline structure, namely, the pipelines are divided into multiple paths at a certain section of the serial pipeline. The serial structure is easy to keep the cross section basically consistent, so the local resistance and erosion are smaller, the parallel structure is suitable for being matched with an external cooling system with large flow, the effective heat dissipation area is easy to be increased through the design of multi-channel fins and the like, the parallel structure is suitable for the situation that the flow is smaller and the anode target area is smaller, and the serial-parallel structure is arranged between the two.

In addition, the heat exchange area of the cooling liquid may be increased by changing the shape of the liquid-cooled tube, and for example, the liquid-cooled tube may include a tube type such as a round tube, a square tube, a star tube, or a fin tube.

The liquid cooling pipe 131 includes at least one inlet and one outlet for ensuring a normal flow of the cooling liquid.

In some embodiments of the present utility model, heat dissipation structure 130 further comprises a heat dissipation substrate 133 for coating liquid cooling conduit 131 and for directly contacting anode target 170 for dissipating heat from anode target 170.

If the heat-dissipating structure 130 includes only the liquid-cooled tube 131, the liquid-cooled tube 131 is welded to the metal structure 111 and the liquid-cooled tube 131 is in contact with the anode target 170 for heat dissipation, and if the heat-dissipating structure 130 includes the liquid-cooled tube 131 and the heat-dissipating substrate 133, the heat-dissipating substrate 133 is welded to the metal structure 111 (or the case where the liquid-cooled tube 131 is welded to the metal structure 111) and the anode target structure 170 is in contact with the heat-dissipating substrate 133 for heat dissipation (in this case, the liquid-cooled tube 131 is in indirect contact with the anode target 170).

By way of example, the heat dissipating substrate 133 may be made of a metal material having good heat conductivity, for example, the heat dissipating substrate may be made of at least one of tantalum, iron, copper, and aluminum. In order to improve the air tightness of the radiation source, a metal material with a difference of no more than 10% in thermal expansion coefficient between metals may be selected to prepare the portion of the heat dissipation structure 130 welded to the metal structure 111 and the metal structure 111, respectively. Namely, the heat radiation structure 130 is fixed through the metal structure 111 in an all-metal sealing mode to form the closed tube type ray source, so that the possibility of air leakage after the welding interface is heated is reduced, and the service life of the X-ray tube is prolonged.

Further, when the heat exchange area of the heat dissipation substrate 133 is increased, the liquid cooling pipeline can be directly prepared on the heat dissipation substrate 133 by drilling, die casting, slot milling or the like, or the liquid cooling pipeline 131 can be arranged inside the hollow heat dissipation substrate 133 by embedding or compound welding or the like. In addition, the liquid cooling pipe 131 can be fixed inside the heat dissipation base 133, so that it is not easy to move.

In some embodiments of the present utility model, a temperature sensor is disposed inside or outside the heat dissipating substrate 133, and the temperature of the surface of the anode target structure 170 facing the side of the heat dissipating structure 130 or the surface (inner surface or outer surface of the tube) of the liquid-cooled tube 131 can be measured by the temperature sensor. For example, a temperature sensor may be disposed within the heat dissipating substrate 133 proximate to the anode target structure 170.

The cathode structure 150 and the anode target 170 are located inside the tube body 110, but the cathode structure 150 and the anode target 170 cannot be too close to the tube body 110 in order to avoid discharge. Also, as shown in fig. 1, the cathode structure 150 and the anode target 170 may be suspended and disposed parallel to each other.

The above-mentioned arrangement of the cathode structure 150 and the anode target 170 is merely an example, and the electrons emitted from the cathode structure 150 can be located within the effective heat dissipation range on the anode target 170.

In view of the relative positions of cathode structure 150, anode target 170, and heat sink structure 130 in an X-ray tube, and to increase heat sink efficiency, the present application employs a reflective target as anode target 170. Anode target 170 is disposed opposite X-ray window 113 for generating X-rays and emitting through X-ray window 113.

As an example, to increase the heat dissipation capacity of anode target 170, the effective heat dissipation range on anode target 170 is not less than the focal range formed on anode target 170 by the electron beam exiting cathode structure 150. As shown in fig. 3, the anode target structure 170 may take a planar structure or a curved structure that bows toward the cathode structure 150.

As an example, the overall height of the heat sink structure 130 may be greater than 1cm and the thickness of the anode target structure 170 may be greater than 1mm.

In some embodiments of the utility model, the shortest distance between anode target 170 and the side tube comprising metal structure 111 is greater than 1cm, and the minimum distance of the boundary of metal structure 111 from the center of the tube of liquid-cooled tube 131 at the weld is 3cm.

The anode target 170 may be in direct contact with the heat sink structure 130 to reduce thermal resistance, or an intermediate layer of solder or solder may be added between the heat sink structure 130 and the anode target structure 170 to indirectly contact the heat sink structure 130 with the anode target 170, thereby reducing the welding stress caused by mismatch in thermal expansion coefficients of the target material and the heat sink structure material. Wherein the intermediate layer or solder may be a metal or alloy of an alloy phase with the material of the anode target 170 and the material of the heat sink base 133 (or liquid cooled tube 131), such as titanium, rhenium, molybdenum, copper, gold, silver, or the like. Anode target 170 can be made of one or more of tungsten, molybdenum, chromium, rhodium, niobium, tantalum, rhenium, and the like.

The cathode structure 150 may be energized to emit electrons and maintain a distance from the grounded tube body 110 to avoid discharge. Further, when the focus control electrode pair is unchanged from the cathode structure, the farther the distance between the cathode structure 150 and the anode target 170, the smaller the spatial angle of the cathode structure relative to the target surface, and the smaller the proportion of X-ray attenuation due to the shielding of the cathode structure.

In terms of cathode structure improvement, a transmission type X-ray source adopting a linear cathode is disclosed in U.S. Pat. No. 7346147B2, so that the heat dissipation pressure of a single point on an anode is reduced, and the Chinese patent application CN 115954250A introduces a through cooling pipeline at the back of the anode on the basis of adopting a linear cathode structure, so that the continuous use power is improved. In the application, the utilization rate of the cathode structure can be improved by arranging parallel cathodes.

In some embodiments of the present utility model, as shown in fig. 4, the cathode structure 150 may include one electron emitter 151, or the cathode structure 150 may include a plurality of electron emitters 151 connected in parallel. The electron emitter 151 is in the form of a wire, rod, or sheet, and the wire-shaped electron emitter is in the form of a wire or spiral.

The shape of the electron emitter 151 described above is only an example, and the present utility model is not limited thereto.

As an example, the electron emitter 151 in the present application may be a heat emitting filament made of one or more materials selected from tungsten, molybdenum, iridium, osmium, carbon, yttria, barium oxide, alumina, scandium oxide, calcium oxide, lanthanum hexaboride, and samarium hexaboride. In addition, although the collimation requirements for the electron emission are low in the X-ray tube of the present application, the cathode structure 150 may be a cold cathode.

In some embodiments of the present utility model, in the case where the electron emitter 151 is a heat-emitting filament, since the filament is elongated due to temperature rise during operation, the focus range formed is easily shifted, and the electron emitter 151 can be kept in a stable position in the X-ray tube by means of an elastic stretching structure (e.g., a stretching spring, etc.). That is, the cathode structure 150 may further include an elastic stretching structure connected between one end of the electron emitter 151 and the extraction electrode 153 of the electron emitter 151 for stabilizing the electron emitter position by stretching. For example, if the cathode structure 150 is a parallel connection of electron emitters, the elastic stretching structure may be provided as shown in fig. 5.

In some embodiments of the present utility model, the arrangement dimension of the electron emitters 151 in each direction of the set face is smaller than the dimension of the anode target 170 in the corresponding direction.

To fully utilize the heat dissipation capacity of the cooling fluid within the heat dissipation structure 130, electrons should be more uniformly driven onto the anode target 170. The present application adjusts the focal range of electrons on anode target 170 by providing a pair of focus control electrodes 190 between cathode structure 150 and anode target 170. The pair of focus control electrodes 190 may comprise several structures as shown in fig. 3, symmetrically disposed along the cathode structure 150. The potential of the focus control electrode to which a negative voltage is applied is not higher than the cathode potential (e.g., the potential of the focus control electrode pair 190 may be-100V with respect to the cathode structure 150, and the lower the potential across the focus control electrode pair 190, the smaller the electron exit angle, the smaller the focal range over which electrons are focused on the anode target 170), and the potential of the focus control electrode to which a positive voltage is applied is higher than the cathode potential.

As an example, with the electron emission structure shown in (a) of fig. 6, assuming that a single electron emitter 151 (a cathode structure shown in (a) of fig. 4) in a straight line is spaced 5cm from a planar anode target 170, a tube voltage is 80kV, and a focus control electrode is 500V lower than the electron emitter 151 potential, a probability density distribution of electrons is shown in (b) of fig. 6 if electron bombardment positions are simulated by using the monte carlo method. As can be seen from fig. 6, based on the above-mentioned parameters related to the tube, the shape and position of the focus control electrode pair 190 can be combined to achieve the effect of more uniformly striking the anode target on the premise of ensuring that electrons are all within the anode range.

In some embodiments of the utility model, the X-ray tube further includes a grid 120, the grid 120 may be disposed between the cathode structure 150 and the anode target 170, and/or

An electron shielding structure 140 is disposed on a side of the cathode structure 150 facing away from the anode target 170.

More specifically, disposing the grid 120 between the cathode structure 150 and the anode target 170 can achieve the effect of controlling the electron focal range, and disposing the grid 120 at a position closer to the cathode structure 150 can not only control the electron focal range, but also limit the ability of the cathode structure 150 to emit electrons in other directions, so as to ensure that as much electrons generated by the cathode structure 150 strike the anode target 170 as possible. The grid 120 can be used to control the magnitude of the electron current emitted by the cathode structure 150 and prevent the cathode structure 150 from being damaged by direct sparking between the cathode structure 150 and the anode target 170, and the electron shielding structure 140 can intercept electrons emitted by the cathode structure 150 in a direction away from the anode target 170 and prevent the electrons from directly bombarding the grounded tube body at the same potential as the anode.

As an example, the respective parameters may be set such that the inventive X-ray tube continuously operates normally at high power. Assume that the flow rate of the cooling liquid is 18L/min, a heat dissipation substrate is prepared from brass (and a liquid cooling pipeline is directly prepared on the heat dissipation substrate by drilling and the like), the diameter of the liquid cooling pipeline is 15mm, the thickness of a tungsten target is 5mm, the heated area of the surface of the tungsten target is 2cm multiplied by 10cm, the cooling liquid in the liquid cooling pipeline is water, and the inlet temperature is 20 ℃. Based on the parameters, the COMSOL software is adopted to simulate the temperature condition of the X-ray tube during working, and the phase change influence caused by overhigh water temperature is not considered in the simulation process.

The maximum temperature reached by the tungsten target when the X-ray source was operated at different powers was simulated in COMSOL software according to the present application, and the results are shown in Table 1. Further, the application carries out thermal equilibrium state simulation through COMSOL software, and the tungsten target and the heat dissipation matrix prepared from brass can reach thermal equilibrium within 1min under the power of 5kW (namely the power of electron beam current of a ray source), and the temperature distribution is shown in figure 7. Under the state of thermal equilibrium, the highest temperature of the heat dissipation matrix is lower than 200 ℃, the surface temperature of the tungsten target close to one side of the cathode structure is lower than 250 ℃, and the constant-speed creep strain rate of the heat dissipation matrix is lower than 10 ^-10/s, so that the risk that the tungsten target falls off from the heat dissipation matrix in long-term use can be effectively avoided.

TABLE 1 simulated maximum temperatures (temperature units: K) for each structure at different powers

The X-ray tube provided by the utility model has the following advantages:

1. the liquid cooling pipeline structure with more complex structure can be adopted, and the heat exchange area of the heat dissipation structure and the anode target structure is increased by arranging the heat dissipation substrate, so that the heat dissipation capacity of the X-ray tube is stronger, the X-ray tube is suitable for continuous work with higher power, and the total processing speed of the single-ray source is improved.

2. The heat radiation structure and the tube body of the X-ray tube are welded in an all-metal mode, so that the possibility of air leakage after the interface is heated is reduced, and the service life of the X-ray tube is prolonged.

3. The electron emergent angle is changed by regulating and controlling the electric potential on the focus control electrode pair, the focus range of electrons on the anode target structure is matched with the effective heat dissipation range formed by the liquid cooling pipeline, and the local heat dissipation pressure of the target is effectively reduced.

In some embodiments of the present utility model, as shown in fig. 1, another aspect of the present utility model provides an X-ray source including the X-ray tube according to any one of the above embodiments, an additional tube 210 connected to one end of the tube body 110 having the extraction electrode of the cathode structure 150, and a negative high voltage plug 250 disposed inside the additional tube 210 at a side far from the tube body and an insulator 230 disposed at a side near the tube body, wherein the negative high voltage plug 250 is used to be applied with a voltage to drive the cathode structure 150 to emit electrons, and the insulator 230 is used to suspend the cathode structure 150 and the focus control electrode pair 190. In addition, the additional tube 210 is filled with insulating oil, which can be used to ensure insulation of the additional tube 210.

More specifically, when the X-ray tube is in use, the tube body 110 and the anode target 170 are grounded, and an external negative high voltage power supply supplies power to the cathode structure 150 through the negative high voltage plug 250, so that the cathode structure 150 emits electrons that bombard the anode target 170 to generate X-rays. In this process, the coolant flows in and out of the liquid cooling pipe 131 in the heat radiation structure 130 through the external pump unit, takes away heat on the anode target 170, and cools the flowing coolant through the external device.

In a specific embodiment of the utility model, setting the respective parameters results in an X-ray source that continuously operates normally at a power of approximately 5 kW. For example, the main parameters of the X-ray tube in the utility model can be that the electron beam power of the ray source is approximately 5kW, the tube voltage is 160kV, the tube current is 30mA, the cathode-anode distance is 5cm, the electron emission angle formed by the focus control electrode pair and the cathode structure is 160 degrees, the cooling water flow is 18L/min, the preparation material of the heat dissipation matrix is brass, the diameter of the liquid cooling pipeline is 14mm, and the thickness of the tungsten target is 3mm. And after long-time continuous operation, the temperature of the anode target structure near the heat dissipation substrate is lower than 300 ℃.

Another aspect of the present utility model proposes an X-ray irradiation apparatus comprising:

The X-ray source according to the above embodiment, the support structure for supporting and fixing the X-ray source, the irradiation stage (for placing the irradiated object) located in the irradiation area of the X-ray source, and the shielding case for preventing the X-rays from leaking.

More specifically, as shown in fig. 8, the tube body of the X-ray tube adopts a cylindrical shape, the support structure fixes the relative position of the source and the irradiation stage, and the shielding case is used for preventing the X-rays from leaking to the outside of the irradiation apparatus. Moreover, because the X-ray dose rate is related to the electron exit angle besides the focal distance, the irradiation stage can adopt an arc irradiation stage, and the consistency of the X-ray dose rate at each position is ensured. The structure of the coolant pipe, the negative high-voltage power supply, and the like placed outside the shield case is not shown in fig. 8.

The irradiation device is suitable for irradiation articles including fresh solid, prefabricated vegetable, chinese herbal medicine, bottled wine, etc. and small volume article comprising tea, spice, coffee bean, etc. in arc container or small package. In order to improve the utilization rate of X-rays, the device is suitable for processing more irradiation samples at one time, but not a small amount of samples.

The utility model is not limited to the shape of the tube body, and may be circular or square in cross-section, for example. The relative positions of the X-ray source, the support structure and the irradiation stage in the X-ray irradiation device are not limited.

It should be understood that the utility model is not limited to the particular arrangements and instrumentality described above and shown in the drawings. For the sake of brevity, a detailed description of known methods is omitted here. In the above embodiments, several specific steps are described and shown as examples. The method processes of the present utility model are not limited to the specific steps described and shown, but various changes, modifications and additions, or the order between steps may be made by those skilled in the art after appreciating the spirit of the present utility model.

In this disclosure, features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments and/or in combination with or instead of the features of the other embodiments.

The above description is only of the preferred embodiments of the present utility model and is not intended to limit the present utility model, and various modifications and variations can be made to the embodiments of the present utility model by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.

Claims (10)

1. An X-ray tube, comprising:

The cathode structure is arranged in the cavity formed by the ray tube body, and the cathode structure extends along the set surface and the anode targets are arranged at intervals with the cathode;

The heat radiation structure comprises a liquid cooling pipeline, the heat radiation structure is in direct or indirect contact with the anode target and is arranged on one side of the anode target far away from the cathode structure, the heat radiation structure is welded on the ray tube body, and the part of the ray tube body welded with the heat radiation structure is of a metal structure;

A focus control electrode pair arranged between the cathode structure and the anode target for controlling the movement path of electrons emitted from the cathode structure by a voltage applied between the focus control electrode pair, thereby controlling the focus range formed by focusing the electrons emitted from the cathode structure on the anode target not to exceed the effective heat dissipation range on the anode target.

2. The X-ray tube of claim 1, wherein the heat dissipating structure further comprises a heat dissipating substrate for encasing the liquid cooled tube and in direct contact with the anode target for dissipating heat from the anode target.

3. The X-ray tube according to claim 2, wherein the heat dissipating substrate is internally or externally provided with a temperature sensor.

4. The X-ray tube according to claim 1, wherein the cathode structure comprises one electron emitter or a plurality of electron emitters connected in parallel, each electron emitter being wire-like, rod-like or sheet-like, wherein the wire-like electron emitters are of a linear or spiral type.

5. The X-ray tube of claim 4, wherein the cathode structure further comprises an elastic stretching structure connected between one end of the electron emitter and the extraction electrode of the electron emitter for stabilizing the electron emitter position by stretching.

6. The X-ray tube according to claim 4, wherein the anode target is a flat surface or a curved surface, and the arrangement dimension of the electron emitters in each direction of the set surface is smaller than the dimension of the anode target in the corresponding direction.

7. The X-ray tube of claim 1, further comprising a grid disposed between the cathode structure and the anode target, and/or

And the electron shielding structure is arranged on one side of the cathode structure, which is away from the anode target.

8. The X-ray tube of claim 1, wherein the liquid cooling conduit forms a cooling surface in contact with the anode target in a single tube serpentine arrangement or a multi-tube split arrangement.

9. An X-ray source, the X-ray source comprising:

an X-ray tube as claimed in any one of claims 1 to 8, and

The tube comprises an additional tube body, wherein the additional tube body is connected to one end of an extraction electrode with a cathode structure of the tube body of the tube, and an insulator close to one side of the tube body of the tube and a negative high-voltage plug positioned at one side far away from the tube body of the tube are arranged in the additional tube body.

10. An irradiation apparatus, comprising:

The X-ray source of claim 9, a support structure for holding the X-ray source, an irradiation stage positioned within an irradiation region of the X-ray source, and a shielding enclosure.