JP2004031067A - X-ray equipment - Google Patents

Abstract

In an X-ray apparatus that generates X-rays, high efficiency, miniaturization, and low cost can be achieved with a simple configuration, and a more precise X-ray measurement apparatus can be realized. Damage to the subject due to X-ray irradiation can be suppressed.
A cold cathode source is used for a cathode 2 of an X-ray tube, and a Cu target is used for an anode 3, for example. Then, a DC high voltage is applied between the cathode 2 and the anode 3 by the high-voltage power supply 1 to generate X-rays. At this time, the X-ray detector 6 detects X-rays generated from the X-ray tube, and controls the FET 4 via the controller 5 based on the detection result, thereby stabilizing the current flowing through the X-ray tube.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention particularly relates to an X-ray apparatus using a cold cathode source for an X-ray tube.
[0002]
[Prior art]
As an apparatus for generating X-rays, an apparatus using thermoelectrons has been widely used. For example, as shown in Patent Publication Nos. 271093 and 271094, a target film that receives thermal electrons and emits X-rays is provided in a substrate formed of an X-ray-transparent material. And utilizes an electron emission phenomenon by a hot cathode. An X-ray apparatus using a cold cathode source is also known.
[0003]
X-rays are generated when electrons from the cathode collide with the anode under high voltage in a vacuum glass tube. The point where the tube voltage between the cathode and anode determines the X-ray transparency When the tube voltage is low, X-rays have a long wavelength with a low transmission power, and when the tube voltage is high, X-rays have a short wavelength with a high transmission power.
[0004]
Recently, an X-ray generator using a nanostructure has been put to practical use. This device, CNT those obtained by making the (carbon nanotube) and Spindt (Spindt) type cold cathode source using nanostructures, called cold emission (Cold emission), the cause electron emission 10 ^- Requires a high vacuum of ⁶ torr or less.
[0005]
The X-ray generator using the CNT described above uses a cold cathode electron emission source composed of CNT as a cathode as shown in, for example, Japanese Patent Application Laid-Open Publication No. 2001-250496. Thus, various problems caused by using the hot cathode can be solved.
[0006]
[Problems to be solved by the invention]
By the way, the conventional X-ray generator utilizing thermionic electrons from the cathode as described above has the following problems.
[0007]
(1) Since a metal cathode such as W (tungsten) is heated from 2000 ° C. to 3000 ° C. to generate electrons, energy efficiency for generating electrons is low (generally about 0.1%).
[0008]
(2) A large current power supply is required to generate heat, which increases the cost and increases the size of the equipment (increased size of the apparatus).
[0009]
(3) A cooling mechanism such as water cooling is required to prevent the parts other than the cathode from melting.
[0010]
(4) Since the heat of the cathode portion is high, the cathode reacts with the remaining oxygen and H ₂ O to deteriorate or disappear.
[0011]
Further, in order to solve the above-mentioned problem, when a cold cathode source is manufactured and used as an X-ray generator, a high vacuum is required, and when a high voltage is applied to the cathode and anode portions, molecules and the like are applied to the portions. There is a problem that the emission of electrons becomes unstable due to the adsorption, and the generated X-ray fluctuates greatly.
[0012]
The present invention has been made in view of the above-described problems, and can achieve high efficiency, miniaturization, and cost reduction with a simple configuration, and realize a more precise X-ray measurement device. It is an object of the present invention to provide an X-ray apparatus that can perform X-ray irradiation and can also suppress damage to a subject due to X-ray irradiation.
[0013]
[Means for Solving the Problems]
The X-ray apparatus according to the present invention is configured as follows.
[0014]
(1) An X-ray tube and a high-voltage power supply for supplying a high voltage to the X-ray tube, and control means for controlling a discharge current flowing through the X-ray tube are provided.
[0015]
(2) In the above (1), the control means comprises a detector for detecting X-rays generated from the X-ray tube, and a control element for varying the current of the X-ray tube according to the detection result. did.
[0016]
(3) In the above (1), the control means comprises a pulse generator for generating a predetermined pulse and a control element for pulsating the X-ray tube by the pulse.
[0017]
(4) In any of the above (1) to (3), the control element is a transistor connected in series with the X-ray tube.
[0018]
(5) In any one of the above (1) to (3), the control element is an Orston switch connected in series with the X-ray tube.
[0019]
(6) In the above (5), the light irradiation source for operating the Oston switch is a light emitting diode.
[0020]
(7) In the above (5), the light irradiation source for operating the Orston switch is a laser diode.
[0021]
(8) In the above (1), the control means includes a light irradiation source for irradiating the cathode with light, and a control element for controlling the light irradiation source.
[0022]
(9) In the above (8), the control element controls the light irradiation of the light irradiation source according to the detection result of the detector that detects the X-ray generated from the X-ray tube.
[0023]
(10) In the above (8), the control element controls the light irradiation source by a predetermined pulse from the pulse generator to cause the X-ray tube to perform a pulse operation.
[0024]
(11) In any one of the above (8) to (10), the light irradiation source is constituted by a light emitting diode.
[0025]
(12) In any one of the above (8) to (10), the light irradiation source is constituted by a laser diode.
[0026]
(13) An X-ray tube and a high-voltage power supply for supplying a high voltage to the X-ray tube, wherein the high-voltage power supply has a control function for varying the current of the X-ray tube.
[0027]
(14) An X-ray tube and a high-voltage power supply for supplying a high voltage to the X-ray tube, wherein the high-voltage power supply has a control function of pulsating the X-ray tube.
[0028]
(15) In any one of the above (1) to (14), the X-ray tube has a bipolar structure.
[0029]
(16) In any one of the above (1) to (14), the X-ray tube has a three-pole structure.
[0030]
(17) In any one of the above (1) to (16), the anode of the X-ray tube was coated with an insulator except for the tip to make microfocus X-ray.
[0031]
(18) In any one of the above (1) to (17), the anode of the X-ray tube has a periodic and aperiodic fine structure pattern of micrometer or less.
[0032]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0033]
FIG. 1 is a configuration diagram of a first embodiment of the present invention, and schematically shows a schematic configuration of an X-ray generator using a cold cathode source.
[0034]
In FIG. 1, reference numeral 1 denotes a DC high-voltage power supply for applying a high voltage between a cathode 2 of a cold cathode source constituting an X-ray tube and an anode 3 using a metal target. Reference numeral 4 denotes a high withstand voltage FET (transistor) as a control element connected in series to the X-ray tube. A controller 5 is connected to the gate, and an X-ray detector 6 for detecting X-rays generated from the X-ray tube. The control means for varying the current flowing through the X-ray tube in accordance with the detection result of, and controlling the discharge current flowing through the X-ray tube together with the X-ray detector 6.
[0035]
In this embodiment, a metal anode 3 and a cathode 2 are arranged on a glass tube so as to face each other. Various metals can be used as the anode 3, and the energy of characteristic X-rays generated by changing this target also changes. In addition to the characteristic X-rays, bremsstrahlung X-rays are generated according to the acceleration voltage.
[0036]
As the cathode 2, it is possible to use a silicon nanostructure, CNT, GNF (graphite nanofiber), and a Spindt electrode in which a metal or semiconductor is sharpened so that electric field concentration is easily caused. When considering generation of pulsed X-rays, CNT and GNF, which can provide a large emission current density, are preferable.
[0037]
The above-mentioned GNF can be uniformly formed on a relatively large substrate, as shown in, for example, Japanese Patent Laid-Open Publication No. 2001-279441. Also, a field emission cathode represented by a Spindt-type electrode having a stable emission current characteristic can be easily obtained.
[0038]
Further, by using a material having a negative electric affinity, for example, AIN, BN, diamond semiconductor, or the like, electrons are emitted from a low voltage, and a high current density can be obtained with high efficiency. Can be generated.
[0039]
The distance between the cathode 2 and the anode 3 depends on the threshold voltage of field emission (field emission) and the energy of characteristic X-rays (depending on the target) to be generated. For example, when a combination of Cu and a CNT target is used, Since a characteristic X-ray is not generated unless a voltage of 10 kV or more is applied between Cu and CNT, an interval of approximately 3 mm is required since the threshold voltage of CNT is approximately 4 V / μm.
[0040]
Therefore, the anode 3 and the cathode 2 are arranged in a vacuum at the above intervals. At this time, when a glass tube is used as a vacuum container, since the transmittance of X-rays in a low energy (2 keV-20 keV) region is poor, the glass is perforated or the like, and the holes are made of beryllium, graphite, polyimide, or the like. It is necessary to block with a thin film such as aluminum, titanium or boron to prevent vacuum leakage.
[0041]
At this time, for example, when the cheapest polyimide film is used, the absorption coefficient α becomes 6.68 cm ⁻¹ with CuKa and the energy of 8.04 keV. It is possible to use a polyimide film having a thickness of the order.
[0042]
Then, the glass tube as described above is sealed at 10 ^-1 to 10 ^-8 torr using a vacuum pump to complete the X-ray generator. If it is desired to focus the generated X-rays on micro focus, the anode electrode is sharpened, and the other end is coated with an insulating material such as Teflon (R) or enamel as shown in FIG. Electric field concentration occurs, and electrons extracted from the cold cathode collide with the uncoated tip portion, so that X-rays are efficiently generated from a minute portion at the tip, and can be converted into microfocus X-rays. .
[0043]
At this time, the relationship between the stopping power of electrons and the accelerating voltage is as follows. In the case of a Cu electrode, the stopping power of 50 keV electrons is 5 × 10 ⁻³ (g / cm ² ), and the density of Cu is 8.94 (g / cm ² ). cm ³ ), the reach of 50 keV electrons is about 5.6 μm from these figures. When it is desired to maintain the degree of vacuum of the X-ray generator, it is preferable to enclose a getter material made of a metal such as Ti in a glass tube to make a vacuum.
[0044]
By inserting a transistor (FET 4 in this embodiment) on the ground side of the X-ray generation unit of the X-ray generation device thus manufactured and externally modulating the current flowing between the cathode 2 and the ground, as shown in FIG. In addition to stabilizing the X-ray intensity, the X-ray can be modulated at a high speed as shown in FIG. At this time, it is necessary to select a high breakdown voltage transistor that can precisely control the amount of current flowing. For example, when the amount of flowing current is microamperes (μA), controllability of about 10 to 100 nA is required.
[0045]
2A and 2B are waveform diagrams showing the operation of the present embodiment. FIG. 2A shows the time change of the X-ray intensity when the FET 4 is not provided, and FIG. 2B shows the time change of the X-ray intensity when the FET 4 is externally attached. Is shown.
[0046]
Next, an apparatus for stabilizing X-rays shown in FIG. 1 will be described. The X-ray source manufactured by the above method is stabilized by forming a feedback loop. That is, the X-ray intensity currently being generated by the X-ray detector 6 for detecting the X-ray intensity is monitored in real time. Since the X-ray intensity generated at this time fluctuates greatly as shown in FIG. 2A, the amount of current flowing through the FET 4 is received by the output of the detector 6 so as to stabilize the fluctuation. Control.
[0047]
For example, when a transistor having a positive polarity is used, when the X-ray output decreases, the gate voltage is increased and feedback is applied so that more current flows between the anode and the cathode. At this time, if the time constant of the feedback circuit is not properly adjusted, the fluctuation may be rather large (known as an oscillation phenomenon). By forming a feedback circuit in this way and stabilizing, it is possible to obtain a stabilized output as shown in FIG.
[0048]
FIG. 3 is a diagram showing the configuration of the second embodiment of the present invention, and the same reference numerals as those in FIG. 1 denote the same components. In this embodiment, a pulse X-ray generator is constructed. In place of the X-ray monitor and feedback circuit in the X-ray stabilizer of the above embodiment, a pulse generator capable of applying a desired electric pulse to a transistor is used. The container 7 is used. As a result, the current flowing between the anode and the cathode can be controlled in a pulse manner, and as a result, as shown in FIG. 4A, a pulse X-ray that follows the pulse generator 7 can be generated. FIGS. 4A and 4B are waveform diagrams showing the operation of the present embodiment.
[0049]
FIG. 4 shows a result of about kHz as the X-ray modulation frequency. This is because the time resolution of a general X-ray detector is at this level, and the response speed of the X-ray generation system can be faster, and modulation over MHz can be performed. It is.
[0050]
In the above example, an X-ray tube having a two-electrode structure having only an anode and a cathode has been described. However, the above-described effect is similarly obtained for an X-ray tube having a three-electrode structure having a grid (anode, cathode, grid). Obtainable.
[0051]
In addition, by using a semiconductor cathode, the above-described transistor can be integrated with a cold cathode source and can be manufactured, so that a more compact and lower cost can be achieved.
[0052]
FIG. 9 is a configuration diagram showing a third embodiment of the present invention. In the present embodiment, an Auston switch (Auston Switch) 11 is inserted in place of the transistor used in the first embodiment, and the current flowing between the cathode and the ground is externally modulated. It is possible to stabilize the X-ray intensity in the same manner as described above.
[0053]
Here, the Orston switch 11 is a kind of an optical switch, and a metal electrode that has been disconnected (a gap of the disconnected portion is generally 1-10 micron) is provided on a substantially insulating semiconductor, and a light having an energy gap equal to or larger than the energy gap is provided at the disconnected portion. Is irradiated by using a semiconductor light emitting element (LED) or a semiconductor laser to generate carriers, and thereby change from a disconnected state to a conductive state (for example, Optics, 1997, Vol. 26, No. 2, 86p). ,reference).
[0054]
FIG. 10 is a diagram showing the configuration of the fourth embodiment of the present invention, and the same reference numerals as in FIG. 9 indicate the same components. In this embodiment, a pulse X-ray generator is configured. Instead of the X-ray monitor and the feedback circuit in the X-ray stabilizing device of the above-described embodiment, a desired electric pulse can be applied to the Ooston switch. A pulse generator 7 is used. As a result, the current flowing between the anode and the cathode is controlled in a pulsed manner, and as a result, a pulse X-ray following the pulse generator 7 is generated, similar to the results shown in FIGS. 4A and 4B. be able to.
[0055]
FIG. 5 is a diagram showing the configuration of the fifth embodiment of the present invention. In this embodiment, the emission current generated by irradiating the LED (light emitting diode) light or the LD (laser diode) light to the cold cathode source is controlled, and the generated X-ray intensity is stabilized. . In the figure, 8 is a light irradiation source, and 9 is a controller for controlling the light irradiation source.
[0056]
In order to control the X-ray generation system by irradiating light, it is necessary to irradiate light above the band gap to generate and control electrons. Therefore, a P-type or intrinsic semiconductor without electrons emits electrons by irradiating light with little leakage current. This is a suitable material to cause the occurrence. Here, an electrode in which a P-type GaAs semiconductor is sharpened to the above-mentioned Spindt type as a cold cathode source will be described.
[0057]
An electric field that generates characteristic X-rays is applied between the cathode 2 and the anode 3. However, since a P-type semiconductor is used, electron emission is less likely to occur than in an N-type semiconductor. At this time, a large amount of electrons can be generated in the P-type semiconductor by irradiating the cathode 2 with light having energy equal to or larger than the band gap of the GaAs semiconductor, for example, from the back surface as shown in FIG. Since the GaAs semiconductor has a high mobility (6000 cm ² / Vs), the thickness of the cathode 2 does not depend much on the cold cathode emission phenomenon. 2 is selected (exp (−αd) = 0.1 to 0.01, where α is the absorption coefficient for the irradiation light wavelength and d is the thickness of the cathode 2).
[0058]
As described above, electron emission can be caused by light irradiation, and emission current can be controlled by controlling irradiation light intensity. Therefore, similarly to the above-described embodiment, it is possible to stabilize the intensity of the generated X-rays by forming a feedback loop between the X-ray monitor, the controller 9, the light irradiation source 8, and the cathode 2. Become.
[0059]
FIG. 6 is a diagram showing the configuration of the sixth embodiment of the present invention. In the present embodiment, in order to configure a pulse X-ray generator by irradiating light, a desired electric pulse can be applied to the controller 9 instead of the X-ray monitor and feedback circuit in the above-described X-ray stabilizer. A pulse generator 7 is used. As a result, a pulse-like current can be generated between the anode and the cathode by light irradiation, and a pulse X-ray that follows the pulse generator 7 as shown in FIG. 4A can be generated.
[0060]
At this time, in order to generate a shorter pulse, the high-speed photodiode technology can be directly applied to the cathode 2. That is, the electron transport phenomenon caused by light absorption can be used, and high-speed modulation of about 300 GHz can be performed by applying the technology of the single traveling carrier photodiode.
[0061]
The above-mentioned single traveling carrier photodiode has an operation mechanism using only electrons as active carriers. The carrier mobility is suppressed by the high electron mobility, and the electric field modulation effect is reduced, so the band is secured. In addition, high-current and low-voltage operation is possible.
[0062]
In addition, by using the semiconductor cathode, the above-described light emitting unit and the cold cathode source can be integrally manufactured, and further reduction in size and cost can be achieved. In the above example, the case of a GaAs cathode has been described, but the material is not limited to this, and this technology is generally applied to I-VII, II-VI, III-V, IV group semiconductors, metal materials, and carbon-based materials. Is applicable.
[0063]
In the above, the description has been given of the X-ray tube having the two-electrode structure having only the anode and the cathode. However, the same effect can be obtained for the X-ray tube having the three-electrode structure having the grid.
[0064]
FIGS. 7 and 8 are diagrams showing the configuration of the seventh and eighth embodiments of the present invention.
[0065]
In the figure, reference numeral 10 denotes a high-voltage power supply for applying a high voltage between the cathode 2 and the anode 3 and has a control function for controlling the X-ray tube. The high-voltage power supply 10 shown in FIG. The high-voltage power supply 10 shown in FIG. 8 has a control function of pulsating the X-ray tube by a predetermined pulse from the pulse generator 7. .
[0066]
The present invention can stabilize the X-ray intensity if the high-voltage power supply itself can be controlled without using the transistor technology and the light irradiation technology as in the above-described embodiment. It is possible to perform high-speed modulation of a line, generate a pulse X-ray, and the like. At that time, in order to modulate a high-voltage power supply of 1 KV or more, it becomes a very expensive device as compared with a price using a transistor, an LED, or the like.
[0067]
Regardless of the above-described embodiment, unless special measures are taken for the anode, the power of the X-rays (external quantum efficiency) generated with respect to the input power is generally about 0.1%. However, by producing a microscopic microstructure that suppresses the generation of infrared rays and, as a result, heat as shown in FIG. , It is possible to improve the generation power (external quantum efficiency) of X-rays generated by about one to two orders of magnitude.
[0068]
The cavity quantum electrodynamics described herein relates to a method of modulating a blackbody radiation spectrum at the same temperature. That is, a normal blackbody radiation spectrum is a spectrum that is shown when an object having a three-dimensional spread is heated to a certain temperature, but by reducing the size of the object, the state density that the system can take, It is possible to modulate the resonance frequency and, as a result, to greatly modulate the blackbody radiation spectrum at the same temperature in a lower dimension than in a three-dimensional case. By applying this principle, it becomes possible to manufacture an X-ray source in which generation of heat is suppressed.
[0069]
For example, in incandescent lamps, a method has been devised in which a periodic pattern in the nanometer region is processed on the filament surface to suppress infrared radiation, and only visible light is extracted to the outside.
[0070]
As described above, each embodiment of the present invention has been described. According to the above-described embodiment, it is possible to achieve high efficiency, miniaturization, and low cost with a simple configuration, and more accurate X-ray measurement. The apparatus can be realized, and damage to the subject due to X-ray irradiation can be suppressed.
[0071]
That is, the following operation and effect can be obtained.
[0072]
(1) Compared to an X-ray generator using thermoelectrons, the use of a cold cathode source can achieve higher efficiency, smaller size, and lower cost.
[0073]
(2) When X-rays are pulse-generated by a conventional X-ray generator using a hot cathode, the pulse width is on the order of ms because of the shutter system, but the cold cathode source is combined with the present invention. This makes it possible to shorten the pulse width by about three to six digits. At the same time, it becomes possible to generate ultrashort pulse X-rays with a low-cost device.
[0074]
(3) The conventional X-ray generator using a cold cathode source has a problem in stabilization. However, the present invention can be used to stabilize the X-ray output with a simple device, so that more accurate X-ray output can be achieved. A simple measuring device.
[0075]
(4) Pulse generation was difficult in a conventional X-ray generator using a cold cathode source, but by using the present invention, pulse X-rays and modulated X-rays can be generated with a simple device. Therefore, an unprecedented detection technique using X-rays can be realized. For example, various applications such as X-ray phase detection technology (more accurate detection by combination with a lock-in amplifier), dynamic X-ray structure analysis, X-ray diffraction, time-resolved X-ray spectroscopy, time-resolved X-ray fluorescence spectroscopy, etc. It is possible to think. In addition, since the pulse width can be freely controlled, it becomes possible to control the X-ray irradiation amount so as not to damage the subject.
[0076]
(5) Since a quantum mechanical structure that controls the process of converting heat energy is formed on the anode, X-rays can be generated with higher efficiency than before.
[0077]
Note that the present invention is not limited to the above-described embodiments, and for example, may be configured by variously combining the embodiments. Further, the present invention provides, for example, an X-ray apparatus, an X-ray projection imaging apparatus, an XPS apparatus, an XRD apparatus, a time-resolved X-ray spectrometer, an X-ray nondestructive inspection apparatus, an X-ray lithography light source, an X-ray sterilizer, an X-ray spectrometer, The present invention can be applied to various devices that require X-rays, such as a small SOR device and an X-ray resin curing device.
[0078]
【The invention's effect】
As described above, according to the present invention, with a simple configuration, high efficiency, miniaturization, and cost reduction can be achieved, and a more precise X-ray measurement device can be realized. There is an effect that damage to the subject due to the radiation can be suppressed.
[0079]
That is, according to the present invention, the following effects can be obtained.
[0080]
(1) Compared to an X-ray generator using thermoelectrons, the use of a cold cathode source can achieve higher efficiency, smaller size, and lower cost.
[0081]
(2) When X-rays are pulse-generated by a conventional X-ray generator using a hot cathode, the pulse width is on the order of ms because of the shutter system, but the cold cathode source and this patent are combined. This makes it possible to shorten the pulse width by about three to six digits. At the same time, it becomes possible to generate ultrashort pulse X-rays with a low-cost device.
[0082]
(3) The conventional X-ray generator using a cold cathode source has a problem in stabilization, but the present invention can stabilize the X-ray output with a simple device. Can be provided.
[0083]
(4) It is difficult to generate a pulse with a conventional X-ray generator using a cold cathode source. However, according to the present invention, a simple device can generate pulse X-rays and modulated X-rays. An unprecedented detection technique used can be made possible. For example, various applications such as X-ray phase detection technology (more accurate detection by combination with a lock-in amplifier), dynamic X-ray structure analysis, X-ray diffraction, time-resolved X-ray spectroscopy, time-resolved X-ray fluorescence spectroscopy, etc. It is possible to think. Further, since the pulse width can be freely controlled, it becomes possible to control the X-ray irradiation amount so as not to damage the subject.
[0084]
(5) Since a quantum mechanical structure that controls the process of converting to heat energy is formed on the anode, X-rays can be generated with higher efficiency than before.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a first embodiment of the present invention; FIG. 2 is a waveform diagram showing the operation of the first embodiment; FIG. 3 is a configuration diagram of a second embodiment of the present invention; FIG. 5 is a waveform diagram showing the operation of the second embodiment. FIG. 5 is a configuration diagram of a fifth embodiment of the present invention. FIG. 6 is a configuration diagram of a sixth embodiment of the present invention. FIG. 8 is a block diagram of an eighth embodiment of the present invention. FIG. 9 is a block diagram of a third embodiment of the present invention. FIG. 10 is a block diagram of a fourth embodiment of the present invention. FIG. 11 is an explanatory view showing an example of the shape of an anode electrode in an embodiment. FIG. 12 is a view showing a microscopic fine structure of an anode.
1 High voltage power supply 2 Cathode 3 Anode 4 FET
5 Controller 6 X-ray detector 7 Pulse generator 8 Light irradiation source 9 Controller 10 High voltage power supply 11 Orston switch

Claims (18)

An X-ray apparatus comprising: an X-ray tube; a high-voltage power supply for supplying a high voltage to the X-ray tube; and control means for controlling a discharge current flowing through the X-ray tube. 2. An X-ray detector according to claim 1, wherein said control means comprises a detector for detecting X-rays generated from the X-ray tube, and a control element for varying the current of said X-ray tube according to the detection result. Line equipment. 2. The X-ray apparatus according to claim 1, wherein the control means comprises a pulse generator for generating a predetermined pulse, and a control element for pulsating the X-ray tube by the pulse. 4. The X-ray apparatus according to claim 1, wherein the control element is a transistor connected in series with the X-ray tube. The X-ray apparatus according to any one of claims 1 to 3, wherein the control element is an Oston switch connected in series with the X-ray tube. The X-ray apparatus according to claim 5, wherein the light irradiation source for operating the Orston switch is a light emitting diode. The X-ray apparatus according to claim 5, wherein the light irradiation source for operating the Orston switch is a laser diode. 2. The X-ray apparatus according to claim 1, wherein the control means comprises a light irradiation source for irradiating the cathode with light, and a control element for controlling the light irradiation source. The X-ray apparatus according to claim 8, wherein the control element controls light irradiation of the light irradiation source according to a detection result of a detector that detects X-rays generated from the X-ray tube. 9. The X-ray apparatus according to claim 8, wherein the control element controls the light irradiation source by a predetermined pulse from the pulse generator to cause the X-ray tube to perform a pulse operation. 11. The X-ray apparatus according to claim 8, wherein the light irradiation source comprises a light emitting diode. The X-ray apparatus according to any one of claims 8 to 10, wherein the light irradiation source comprises a laser diode. An X-ray apparatus comprising: an X-ray tube; and a high-voltage power supply for supplying a high voltage to the X-ray tube, wherein the high-voltage power supply has a control function for varying a current of the X-ray tube. . An X-ray apparatus comprising: an X-ray tube; and a high-voltage power supply that supplies a high voltage to the X-ray tube, wherein the high-voltage power supply has a control function of performing a pulse operation of the X-ray tube. The X-ray apparatus according to any one of claims 1 to 14, wherein the X-ray tube has a bipolar structure. 15. The X-ray apparatus according to claim 1, wherein the X-ray tube has a three-pole structure. The X-ray apparatus according to any one of claims 1 to 16, wherein an anode of the X-ray tube is coated with an insulator except for a tip portion to obtain microfocus X-rays. The X-ray apparatus according to any one of claims 1 to 17, wherein the anode of the X-ray tube has a periodic and aperiodic microstructure pattern of micrometer or less.

Images