JP2014120418A - Radiation generation device and radiographic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation generation device in which creeping discharge around the outer periphery of a radiation generation tube is suppressed and reliability of voltage resistance is improved by suppressing the flow of an insulative liquid between the radiation generation tube and an outer cylindrical tube and reducing creeping charge around the outer periphery of the radiation generation tube.SOLUTION: In a radiation generation device which comprises: a radiation generation tube 2 including a cathode 8, an anode 9 and an insulation tube 10; an outer cylindrical tube 5 in the outer periphery of the radiation generation tube; and an accommodation container 3 filled with an insulative liquid 4, one opening of the outer cylindrical tube 5 is positioned at a side opposite to the anode with the cathode as a criterion, and the other opening of the outer cylindrical tube is positioned at a side opposite to the cathode. Between an electrode fixed to the outer cylindrical tube 5 at the side opposite to the anode with the cathode as a criterion and regulated to a potential higher than the cathode and an electrode fixed to the outer cylindrical tube 5 at the side opposite to the cathode and regulated to a potential lower than the anode, at least one electrode is included.

Description

  The present invention relates to a radiation generator and a radiation imaging apparatus.

  Conventionally, radiation generators generally have a configuration in which a radiation generator tube is housed in a storage container filled with an insulating liquid. The insulating liquid is used to improve the pressure resistance (high voltage) characteristics inside the storage container of the radiation generator. Furthermore, as in Patent Document 1, in order to improve the pressure resistance between the radiation generating tube and the storage container or other components in the storage container, an insulating sleeve made of a dielectric material is provided on the outer periphery of the radiation generating tube. (Hereinafter referred to as an outer tube) may be provided. Moreover, in patent document 1, in order to cool a radiation generating tube, it has the structure which provided the gap | interval between a radiation generating tube and an outer cylinder tube, and ensured the flow path of the insulating liquid.

JP 2007-080568 A

  When a high voltage is applied to the radiation generating tube, the insulating liquid in the storage container convects due to the EHD (Electrohydrodynamics) effect. In the case of a structure in which a gap is provided between the radiation generating tube and the outer cylindrical tube and a flow path for the insulating liquid is secured as in Patent Document 1, the gap between the radiation generating tube and the outer cylindrical tube is insulated. The conductive liquid flows, and the peripheral creepage surface of the radiation generating tube is charged by friction between the insulating liquid and the radiation generating tube. In particular, depending on the use conditions such as movie shooting, a high voltage may be applied continuously to the radiation generating tube, charging on the outer periphery of the radiation generating tube is accumulated, and on the outer periphery of the radiation generating tube in the insulating liquid. In this case, creeping discharge may occur.

  The present invention suppresses the creeping discharge on the outer periphery of the radiation generating tube by suppressing the flow of the insulating liquid between the radiation generating tube and the outer cylindrical tube, and reduces the charging on the outer periphery of the radiation generating tube. An object of the present invention is to provide a high-quality radiation generator.

The radiation generating apparatus of the present invention includes a radiation generating tube including a cathode, an anode facing the cathode, an insulating tube sandwiched between the cathode and the anode, and a space along the outer periphery of the radiation generating tube. And surrounding the radiation generating tube, a cylindrical outer cylindrical tube made of a dielectric, a storage container for storing at least the radiation generating tube and the outer cylindrical tube, and inside the storage container, In a radiation generating apparatus comprising: a radiation generating tube and an insulating liquid stored so as to be in contact with the outer tube.
One opening of the outer tube is located on the opposite side of the anode with respect to the cathode in the tube axis direction, and the other opening of the outer tube is the cathode with respect to the anode in the tube axis direction. Located on the opposite side of
An electrode fixed to the outer tube on the side opposite to the anode with respect to the cathode and defined at a higher potential than the cathode; and an electrode on the outer tube on the side opposite to the cathode with respect to the anode It is characterized by having at least one of the fixed electrode and the electrode defined at a lower potential than the anode.

  The radiation imaging apparatus of the present invention integrates the radiation generation apparatus, a radiation detector that detects radiation emitted from the radiation generation apparatus and transmitted through a subject, and the radiation generation apparatus and the radiation detector. And a device control unit for controlling the device.

  According to the present invention, it is possible to provide a highly reliable radiation generating apparatus and radiation imaging apparatus having high pressure resistance characteristics.

It is sectional drawing of the radiation generator in this invention. It is sectional drawing of the radiation generator shown as a comparative example of this invention. It is a conceptual diagram of the radiography apparatus of this invention.

  Hereinafter, exemplary embodiments of the radiation generating apparatus of the present invention will be described in detail with reference to the drawings. However, the materials, dimensions, shapes, relative arrangements, and the like of the constituent members described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified.

  FIG. 1A is a cross-sectional view schematically showing the inside of the radiation generator of the present invention. 1B and 1C are cross-sectional views taken along the line A-A ′ of FIG.

  1A to 1C, 1 is a radiation generator, 2 is a radiation generator tube, 3 is a storage container, 4 is an insulating liquid, 5 is an outer tube, 6 is a first electrode, and 7 is a first electrode. The second electrode.

  In the radiation generating apparatus 1, at least the radiation generating tube 2 is stored in a storage container 3 filled with an insulating liquid 4.

  The radiation generating tube 2 is a transmission type radiation generating tube whose detailed configuration will be described later, and is mainly a vacuum container formed by a cathode 8, an anode 9, and an insulating tube (tubular member) 10 sandwiched between them. It is. During the operation of the radiation generating apparatus 1, a high voltage is applied between the cathode 8 and the anode 9 of the radiation generating tube 2.

  The storage container 3 is preferably at a ground potential from the viewpoint of operational stability and safety of the radiation generator 1. As the material of the storage container 3, metals such as iron, stainless steel, lead, brass, and copper can be used from the viewpoint of radiation shielding properties, strength, and surface potential regulating performance.

  The cathode 8 of the radiation generating tube 2 is defined as Vc (V), and the anode 9 is defined as Va (V). Va> Vc, and a voltage of Va−Vc (V) is applied between the cathode 8 and the anode 9. Further, when the storage container 3 is set to the ground potential, the cathode 8 of the radiation generating tube 2 is Vc <0 (negative potential) and the anode 9 is Va> 0 (positive potential) from the viewpoint of pressure resistance stability inside the radiation generator. It is preferable to regulate the potential.

  The insulating liquid 4 fills the periphery of the radiation generating tube 2 and the outer cylindrical tube 5 and is used from the viewpoint of pressure resistance characteristics of the radiation generating device 1 and stability during operation. That is, the insulating liquid 4 is used for ensuring insulation between the cathode 8 and the anode 9 of the radiation generating tube 2 and improving heat dissipation during operation of the radiation generating tube 2. Therefore, the insulating liquid 4 is preferably one having high electrical insulation, high cooling capacity, and less deterioration due to heat. For example, electrical insulating oil such as silicone oil, transformer oil, fluorine oil, hydrofluoroether, etc. Fluorine-based insulating liquid or the like can be used.

  The outer tube 5 is made of a dielectric material, is separated along the outer periphery of the radiation generating tube 2, and has a cylindrical shape surrounding the radiation generating tube 2, and the radiation generating tube 2 and the storage container 3 or It is used to improve the pressure resistance with other components (not shown) in the storage container 3. Accordingly, the outer tube 5 is preferably an oil-resistant resin, and is preferably a polyetherimide resin or an acrylic resin. In order to cool the radiation generating tube 2, it is preferable to provide a gap through which the insulating liquid 4 can flow between the radiation generating tube 2 and the outer tube 5.

  Here, when the radiation generating apparatus 1 is operated, the potential applied to the cathode 8 and the anode 9 of the radiation generating tube 2 is set between the cathode 8 and the anode 9, between the cathode 8 and the storage container 3, and between the anode 9 and A potential difference (= voltage) occurs between the storage containers 3. This voltage causes the insulating liquid 4 to convect due to the EHD effect. In particular, due to the voltage between the cathode 8 and the anode 9, flows 11 and 12 of the insulating liquid 4 are generated along the outer circumferential surface of the radiation generating tube 2.

  First, the state of the flow 11 when the 1st electrode 6 and the 2nd electrode 7 are not provided is shown using FIG. The present inventors have confirmed that the flow 11 between the radiation generating tube 2 and the outer cylindrical tube 5 is not one-way, but fluctuates in time and place. The direction of the arrow of the flow 11 does not indicate a steady flow direction, but is merely shown for explanation. When the first electrode 6 and the second electrode 7 are not provided, the flow 11 cools the radiation generating tube 2, while rubbing the insulating liquid 4 and the tubular member 10 to charge the creeping surface of the tubular member 10. cause. Depending on how the radiation generator 1 is used, the charge on the creeping surface of the tubular member 10 may accumulate, leading to unwanted discharge. In particular, when a high voltage is continuously applied for moving image shooting or the like, the possibility of occurrence of discharge increases.

  In the present invention, as shown in FIG. 1, a first electrode 6 and a second electrode 7 are provided to generate a flow 12 opposite to the flow 11, and a flow 11 between the radiation generating tube 2 and the outer tube 5. The flow rate is slow. Also in FIG. 1, the directions of the arrows of the flows 11 and 12 do not indicate a steady flow direction, but are merely illustrated for comparison with FIG. In order to generate the backward flow 12, the first electrode 6 is disposed on the opposite side of the anode 9 with respect to the cathode 8 in the tube axis direction, and is defined at a higher potential than the cathode 8. The second electrode 7 is disposed in the tube axis direction, is disposed on the opposite side of the cathode 8 with respect to the anode 9, and is defined at a lower potential than the anode 9. Furthermore, in order to ensure the breakdown voltage between the first electrode 6 and the cathode 8 and between the second electrode 7 and the anode 9, the first electrode 6 and the second electrode 7 are arranged on the outer peripheral portion of the outer tube 5. It is good to provide in. In order to realize such an arrangement, the opening on the cathode 8 side of the outer tube 5 is located on the side opposite to the anode 9 with respect to the cathode 8 in the tube axis direction, and the anode 9 side of the outer tube 5 Must be located on the side opposite to the cathode 8 with respect to the anode 9 in the tube axis direction. In addition, the reference | standard mentioned above is a boundary with the tubular member 10, ie, a junction part, in detail.

  Here, when a potential Vcg higher than the potential Vc of the cathode 8 is applied to the first electrode 6, the anode 9 having a higher potential than the cathode 8 and the first electrode 6 are opposed to each other across the cathode 8. It is arranged and tries to generate a reverse flow with the cathode 8 as a boundary. Similarly, when a potential Vag lower than the potential Va of the anode 9 is applied to the second electrode 7, the cathode 8 and the second electrode having a potential lower than that of the anode 9 are arranged so as to face each other with the anode 9 interposed therebetween. Then, a reverse flow is attempted to occur at the anode 9 as a boundary. In this way, the flow 12 reverse to the flow 11 is generated at both openings of the outer tube 5, and as a result, the flow velocity of the flow 11 can be reduced. As a result, friction between the insulating liquid 4 and the tubular member 10 is reduced, charging along the tubular member 10 is suppressed, and pressure resistance is improved. Even if the first electrode 6 and the second electrode 7 are provided, the flow 11 does not disappear, and it is possible to improve the pressure resistance performance while providing cooling capability.

  The backward flow 12 is preferably generated around the entire opening of the outer tube 5, and the first electrode 6 and the second electrode 7 are formed of a conductive annular member as shown in FIG. Alternatively, as shown in FIG. 1C, the conductive members are preferably discretely arranged in an annular shape. The conductive member illustrated in FIG. 1C may be electrically connected to the adjacent conductive member through the wiring 13.

  Further, in order to eliminate the steady bias of the flows 11 and 12, it is preferable that the radiation generating tube 2 and the outer tube 5 are arranged at a certain distance along the outer peripheral direction. In particular, when a radiation generating tube 2 having a circular cross section as shown in FIGS. 1B and 1C is used, the radiation generating tube 2, the outer tube 5, the first electrode 6 or the second electrode. 7 are preferably arranged concentrically.

  When the storage container 3 is regulated to the ground potential, if both the first electrode 6 and the second electrode 7 are regulated to the ground potential, there is no need to provide a separate power source, and the radiation generator 1 can be reduced in size and weight. Good for.

  Here, the transmission-type radiation generating tube 2 shown in FIG. 1 and described in detail later has a structure in which radiation 20 is emitted toward the anode 9 when viewed from the cathode 8, and the target 15 generates radiation on the anode 9. Located on the outer surface of the tube 2. Although the target 15 generates heat by irradiation with the electron beam 17, since heat is conducted to the anode 9, it is possible to cool the target 15, which is a heat generating part, by cooling the anode 9. Since the convection of the insulating liquid 4 also occurs between the anode 9 and the storage container 3, in the case of the transmission type, regardless of the presence or absence of the first electrode 6 and the second electrode 7, 9 can be cooled. That is, the target 15 whose temperature rises most can be effectively cooled. Therefore, in the transmission type radiation generating tube 2, the cooling capacity required for the flow 11 is reduced. Therefore, it can be said that the transmission type radiation generating tube is a preferable form for applying the present invention.

  Although the present invention has been described in the case where both the first electrode 6 and the second electrode 7 are provided as electrodes, the effect of the present invention can be obtained even when any one of the electrodes is provided. .

  Finally, the basic structure of a transmission type radiation generating tube to which the present invention is suitably applied will be described. A transmission type target is opposed to an electron emission source and emits radiation by irradiation of electrons emitted from the electron emission source. The target layer is generated and a base material made of a material that supports the target layer and transmits the radiation. The transmission target is connected to the anode member, and the anode member and the transmission target constitute an anode. The radiation generating tube provided with such a transmission type target is referred to as a transmission type radiation generating tube in the present specification. Next, it demonstrates in detail based on FIG.

  The radiation generating tube 2 includes a cathode 8, an electron emission source 14 connected to the cathode 8, an anode 9, a target 15 connected to the anode 9, and a tubular member 10. The cathode 8 and the anode 9 are respectively connected to two openings provided in the tubular member 10 at positions separated from each other. The electron emission source 14 is disposed in the internal space of the radiation generating tube 2 and has an electron emission portion 16. The internal space of the radiation generating tube 2 is depressurized (evacuated) to such an extent that electrons emitted from the electron emission unit 16 can be irradiated onto the target 15 as an electron beam 17. The degree of vacuum in the internal space of the radiation generating tube 2 can be appropriately selected in consideration of the type of electron emission source 14 to be used, driving conditions, and the like. For example, the degree of vacuum is set to 1E-4 to 1E-8 Pa. It is possible. When a cold cathode type electron emission source such as Spindt type or MIM is used, a vacuum degree of 1E-6 Pa or less is more preferable from the viewpoint of stability of electron emission characteristics. In order to maintain the degree of vacuum, a getter (not shown) can be installed in the internal space of the radiation generating tube 2 or an auxiliary space (not shown) communicating with the internal space.

  The electron emission source 14 may be any electron emission source that can control the amount of emitted electrons from the outside of the radiation generating tube 2, and a hot cathode type electron emission source is appropriately applied in addition to the aforementioned cold cathode type electron emission source. It is possible. A hot cathode electron emission source of an impregnated cathode can be preferably used in that a large current electron beam 17 can be stably taken out.

  The electron emission source 14 is connected to a drive circuit 19 installed outside the radiation generating tube 2 so that the amount of electron emission and the on / off timing of electron emission can be controlled via a current introduction terminal 18 provided on the cathode 8. Electrically connected.

  The electron emission unit 16 includes driving electrodes necessary for electron emission according to the type of electron source (not shown). In the case of adding an electron optical function such as electron beam convergence and astigmatism correction, several auxiliary electrodes (not shown) are further provided. The electrode group composed of the driving electrode and the auxiliary electrode can be connected to the driving circuit 19 outside the radiation generating tube 2 from the cathode 8 side via the current introduction terminal 18.

  The target 15 is disposed inside the radiation generating tube 2 so that it can be irradiated with electrons emitted from the electron emission unit 16. From the viewpoint of the symmetry of the electric field between the cathode 8 and the anode 9, it is preferable that the target 15 is disposed to face the electron emission portion 16.

  A positive potential of 10 kV to 200 kV is applied to the target 15 with respect to the electron emission portion 16, and electrons emitted from the electron emission portion 16 have an incident energy of 10 keV to 200 keV as an electron beam 17. 15 and the target 15 generates radiation. The target 15 includes a target material containing a heavy element that generates radiation 20 by electron collision. The target 15 can be in a self-supporting form made of only the target material. The self-supporting form includes a form in which a diaphragm-like metal thin film is connected to the anode 9. Moreover, the target 15 is made into a dispersion | distribution form which contained the target material in the state which disperse | distributed in the material which permeate | transmits radiation, or the metal thin film containing a target material was laminated | stacked on the board | substrate which consists of a material which permeate | transmits radiation. It is also possible to use a stacked type. The substrate that transmits radiation is preferably a substrate made of a low atomic number material such as beryllium or diamond. The metal thin film is preferably formed on the substrate with a thickness of several μm from the viewpoint of suppressing radiation attenuation and suppressing defocus due to thermal deformation of the target 15. The metal thin film is preferably made of a heavy metal material having an atomic number of 26 or more from the viewpoint of the conversion efficiency of radiation dose / incident electron quantity. Specifically, tungsten, molybdenum, chromium, copper, cobalt, iron, rhodium, rhenium, or the like, or an alloy material thereof can be used. In the case of forming a metal thin film on a substrate, it is not limited to a specific manufacturing method as long as adhesion to the substrate is ensured, and various film forming methods such as sputtering, CVD, and vapor deposition can be used.

  The potential of the target 15 is regulated by the anode 9. In addition, the anode 9 can be separately provided with a shield (not shown) that can define the irradiation range of the radiation 20. In this case, the potential of the target 15 can be regulated via the shield.

  The cathode 8 and the anode 9 are regulated in potential by a voltage source (not shown). The cathode 8 and the anode 9 have a function of defining an electrostatic field inside the radiation generating tube 2. Therefore, it is desirable that the cathode 8 and the anode 9 make the electric field distribution in the vicinity of the electron emission source 14 and the target 15 as close to a parallel electric field as possible. Therefore, each of the cathode 8 and the anode 9 preferably regulates a potential within a predetermined area, and more preferably matches the opening cross-sectional area of the tubular member 10.

  The material of the cathode 8 and the anode 9 can be determined by conductivity, air tightness, strength, and linear expansion coefficient matching with the tubular member 10, and Kovar, tungsten, or the like can be applied.

  The storage container 3 is provided with a radiation transmitting window 21 corresponding to the radiation 20.

  The tubular member 10 is dielectric and includes at least two openings that connect the cathode 8 and the anode 9 respectively. Further, the tubular member 10 is not limited to a circular tubular cross section, and the outer peripheral shape and inner peripheral shape of the cross section may be polygonal. The material of the tubular member 10 is selected from the viewpoints of electrical insulation, air tightness, low outgassing properties, heat resistance, and linear expansion coefficient matching with the cathode 8 and the anode 9, but insulation such as boron nitride and alumina. Insulating inorganic glass such as conductive ceramic and borosilicate glass is applicable.

  The cathode 8 or the anode 9 and the tubular member 10 are joined with a joining material (not shown). As the bonding material, a hard brazing (a brazing alloy) such as silver brazing, copper brazing or the like, which has electrical conductivity and has good heat resistance and good bonding between different kinds of metal-insulator materials, can be preferably applied.

<Example 1>
This example is an example of the configuration exemplified in the above embodiment, and will be described in detail below with reference to FIGS. 1A is a cross-sectional view of the radiation generating apparatus 1 of the present embodiment, and FIG. 1B is a cross-sectional view corresponding to the position AA ′ in FIG. 1A.

  The radiation generating tube 2 is a transmission type, and is sealed with a cathode 8 and an anode 9 so as to close two openings of the tubular member 10. Connected to the cathode 8 is an electron emission source 14 having an electron emission portion 16 based on the cathode potential. The anode 9 is provided with a target 15 that emits radiation when the electron beam 17 emitted from the electron emission portion 16 collides. Kovar was used for the cathode 8 and anode 9, and alumina was used for the tubular member 10, and they were joined by brazing. The cathode 8 and the anode 9 were circular (disk shape) with a thickness of 3 mm, and the tubular member 10 was cylindrical. An impregnated cathode was used as the electron emission source 14, and a target 15 was formed by depositing tungsten on a diamond substrate. The radiation generating tube 2 has an outer diameter of Φ50 mm, a length in the tube axis direction of 66 mm, and the distance between the cathode 8 and the anode 9 on the outer periphery is 60 mm.

  The outer tube 5 was an acrylic cylindrical tube. The inner diameter is 56 Φmm, the outer diameter is Φ66 mm, and the length in the tube axis direction is 86 mm.

  The radiation generating tube 2 and the outer tube 5 are fixed so that the center is concentric in the circumferential direction and the center of the tubular member 10 and the center of the outer tube 5 are aligned in the tube axis direction. . The radiation generating tube 2 and the outer cylindrical tube 5 were fixed to each other by arranging resin spacers (not shown) in the circumferential direction every 120 degrees. Similarly, in the tube axis direction, the radiation generating tube 2 was fixed at two locations in the tube axis direction using resin spacers (not shown). The outer tube 5 protrudes 13 mm outward from the joint between the cathode 8 and the tubular member 10 and the joint between the anode 9 and the tubular member 10 outward in the tube axis direction.

  The first electrode 6 and the second electrode 7 were brass annular electrodes having an inner diameter of 66 mm, an outer diameter of 68 mm, and a width of 3 mm, and were fixed with screws (not shown). The locations in the tube axis direction are each 1 mm from the open end of the outer tube 5. Moreover, it connected with the storage container 3 by wiring not shown. As a result, the first electrode 6 is positioned 9 mm away from the junction of the cathode 8 and the tubular member 10 and is shifted to the opposite side of the anode 9, and the second electrode 7 is the junction of the anode 9 and the tubular member 10. 9 mm from the cathode 8 and shifted to the opposite side to the cathode 8.

  The radiation generating tube 2 integrated with the outer tube 5 by mutual fixation as described above is housed in the storage container 3 together with the drive circuit 19, and the drive circuit 19 and the radiation generating tube 2 are electrically connected by a wiring (not shown). Connected. Furthermore, high-pressure insulating oil A (manufactured by JX Nippon Mining & Energy Co., Ltd.) was filled into the storage container 3 as an insulating liquid 4 from an injection port (not shown) to produce the radiation generator 1. The storage container 3 is made of brass, and a radiation transmitting window 21 is provided in accordance with the radiation 20 from the radiation generating tube 2.

  In this radiation generating apparatus 1, the time until discharge is performed with the storage container 3, the first electrode 6 and the second electrode 7 grounded, the cathode 8 set to -57.5 kV, and the anode 9 set to +57.5 kV. The withstand voltage reliability was confirmed by measuring. A tube voltage could be continuously applied to the cathode 8 and the anode 9 with a voltage of 115 kV for 100 hours, and fluctuations in the tube current were not observed.

  Further, when the cathode 8 is set to −50 kV, the anode 9 is set to 50 kV, Va is set to 100 kV, and the electron emission source 14 is continuously driven at a pulse width of 9 ms and a frequency of 15 Hz for 30 minutes, an abnormal temperature rise is not recognized and stable. Confirmed radiation emission.

<Example 2>
The radiation generating apparatus 1 was produced in the same manner as in Example 1 except that only the anode-side electrode 7 was mounted as an electrode, not on the cathode side, and the test was performed in the same manner. Also in this embodiment, it was possible to maintain the withstand voltage for 100 hours, and almost no fluctuations in the tube current were observed, and it was confirmed that good reliability was exhibited.

<Comparative Example 1>
As a comparative example, the radiation generating apparatus shown in FIG. 2 was manufactured without providing the first electrode 6 and the second electrode 7 with respect to the radiation generating apparatus 1 manufactured in Example 1. FIG. 2 is a cross-sectional view of the radiation generator 1 of this comparative example, and the same members as those in FIG.

  In this radiation generating apparatus 1, the withstand voltage reliability was confirmed by measuring the time until the storage container 3 was grounded, the cathode 8 was set to -57.5 kV, and the anode 9 was set to +57.5 kV to discharge. As a result of the withstand voltage reliability, it was possible to continuously apply 115 kV as the tube voltage Va for 100 hours as in the case of Example 1, but the fluctuation of the tube current was recognized. In this comparative example, it is considered that minute discharges are generated a plurality of times between the outer tube 5 and the radiation generating tube 2, and the reliability does not reach that in the first and second embodiments. Met.

<Example 3>
The present embodiment is a radiation imaging apparatus using a radiation generator. As shown in FIG. 3, the radiation imaging apparatus of the present embodiment includes a radiation generation apparatus 1, a radiation detector 31, a signal processing unit 32, an apparatus control unit 33, and a display unit 34. The radiation detector 31 is connected to the device control unit 33 via the signal processing unit 32, and the device control unit 33 is connected to the display unit 34 and the voltage control unit 35. As the radiation generator 1, the radiation generator of Example 1 was used. Processing in the radiation generating apparatus 1 is comprehensively controlled by the apparatus control unit 33. For example, the device control unit 33 controls radiation imaging by the radiation generator 1 and the radiation detector 31. The radiation 20 emitted from the radiation generator 1 is detected by the radiation detector 31 through the subject 36, and a radiation transmission image of the subject is taken. The captured radiation transmission image is displayed on the display unit 34. In addition, for example, the apparatus control unit 33 controls the driving of the radiation generation apparatus 1 and controls a voltage signal applied to the radiation generation tube via the voltage control unit 35, whereby the radiation generation apparatus 1 and the radiation detector 31 are controlled. Integrate and control.

  The radiographic apparatus of the present example had a good performance capable of obtaining a stable radiographic image.

  1: Radiation generator, 2: Radiation tube, 3: Storage container, 4: Insulating liquid, 5: Outer tube, 6: First electrode, 7: Second electrode, 8: Cathode, 9: Anode 10: Insulating tube (tubular member), 11: flow, 12: reverse flow, 13: wiring, 14: electron emission source, 15: target, 16: electron emission unit, 17: electron beam, 31: radiation detector 32: signal processing unit, 33: device control unit, 34: display unit, 35: voltage control unit, 36: subject

Claims (11)

A radiation generating tube comprising a cathode, an anode facing the cathode, and an insulating tube sandwiched between the cathode and the anode, and spaced apart along the outer periphery of the radiation generating tube to surround the radiation generating tube. A cylindrical outer cylindrical tube made of a dielectric material, a storage container for storing at least the radiation generating tube and the outer cylindrical tube, and the radiation generating tube and the outer cylindrical tube inside the storage container A radiation generator comprising: an insulating liquid stored in contact with
One opening of the outer tube is located on the opposite side of the anode with respect to the cathode in the tube axis direction, and the other opening of the outer tube is the cathode with respect to the anode in the tube axis direction. Located on the opposite side of
An electrode fixed to the outer tube on the side opposite to the anode with respect to the cathode and defined at a higher potential than the cathode; and an electrode on the outer tube on the side opposite to the cathode with respect to the anode A radiation generating apparatus comprising: at least one of fixed electrodes and a potential lower than that of the anode.   A first electrode fixed to the outer tube on the side opposite to the anode with respect to the cathode and defined at a higher potential than the cathode; and the outer side on the side opposite to the cathode with respect to the anode. The radiation generating apparatus according to claim 1, further comprising a second electrode fixed to a cylindrical tube and defined at a lower potential than the anode.   The radiation generating apparatus according to claim 2, wherein the first electrode and the second electrode are formed on an outer peripheral portion of the outer tube.   The radiation generator according to claim 2, wherein the first electrode and the second electrode are made of a conductive annular member.   The radiation generating apparatus according to claim 3, wherein the first electrode and the second electrode have conductive members discretely arranged in an annular shape.   6. The radiation generating apparatus according to claim 1, wherein an outer periphery of the radiation generating tube and an outer periphery of the outer cylindrical tube are arranged concentrically.   The radiation generating apparatus according to claim 1, wherein the first electrode and the second electrode are defined to have the same potential.   The anode is defined as a positive potential with respect to a ground potential, the cathode is defined as a negative potential with respect to the ground potential, and the first electrode and the second electrode are defined as a ground potential. Item 8. The radiation generator according to any one of Items 7 to 9.   The radiation generating apparatus according to claim 1, wherein the insulating liquid is any one of silicone oil, transformer oil, and fluorine oil.   The radiation generating apparatus according to claim 1, wherein the radiation generating tube is a transmissive radiation generating tube including a transmissive target connected to the anode member.   A radiation generator according to any one of claims 1 to 10, a radiation detector that detects radiation emitted from the radiation generator and transmitted through a subject, the radiation generator, and the radiation detector. A radiation imaging apparatus comprising: an apparatus control unit that performs integrated control.

Images