KR101150157B1 - X-ray tube and X-ray generator - Google Patents

Abstract

The present invention relates to an X-ray tube and an X-ray generator, and more particularly, to an electron generator that emits electrons using a field emission device (FE), and an anode protrudingly elongated in a tubular shape and around the anode. Forming a magnetic field to focus the electrons generated in the electron generating unit to collide with the target (Target) to form an X-ray tube for generating X-rays and to form an X-ray tube accommodating case for accommodating the X-ray tube in a high-voltage generator The present invention relates to an X-ray generator for easily inserting and detaching the X-ray tube by forming an electrode accommodating part such that an electrode is connected to the X-ray tube accommodating case.

X-ray tube, anode (anode), field emission, CNT, metal nano powder.

Description

X-ray tube and X-ray generator

The present invention relates to an X-ray tube and an X-ray generator, and more particularly, to an electron generator that emits electrons using a field emission device (FE), and an anode protrudingly elongated in a tubular shape and around the anode. Forming a magnetic field to focus the electrons generated in the electron generating unit to collide with the target (Target) to form an X-ray tube for generating X-rays and to form an X-ray tube accommodating case for accommodating the X-ray tube in a high-voltage generator The present invention relates to an X-ray generator for easily inserting and detaching the X-ray tube by forming an electrode accommodating part to connect an electrode to the X-ray tube accommodating case.

In general, an X-ray generator is a device that includes an electron gun and a target in a high-pressure vacuum-reduced container, generates X-rays by injecting electrons generated from the electron gun into a target, and emits the generated X-rays through a window. In general, the operating principle of the X-ray source is that when the filament of the cathode is heated by electric current, hot electrons are generated, and when the voltage is applied to the anode to accelerate the electrons, the movement speed of the electrons is increased, which impacts the target located at the anode, resulting in shorter wavelengths and greater penetration. Generates X-rays with

In addition, a metal cup and a focusing lens are used to collect electrons colliding with the target at a small focal point for the purpose of obtaining a clear transmission image, and the cup has an electrostatic lens function to move the emitted electrons directly to the anode. The filament is a source that emits electrons from the cathode. Filaments generally use tungsten wire with good electrical properties. Due to the electrical properties of tungsten, current flows through the filament and is heated to a temperature where electrons can be generated. At this time, when the voltage applied to the filament is changed, the filament current changes and electrons are emitted. That is, the number of emission of electrons changes as the current flowing through the tube changes.

1 is a cross-sectional view showing a conventional X-ray tube.

As shown in FIG. 1, the electron source 11 emits electrons disposed on a predetermined tube axis in the tube 10, and emits from the electron source 11 as a target T disposed on the tube axis. Electrons are focused as a target (T) for generating X-rays according to incident electrons and one or more electrodes (12a, 12b) disposed between the electron source (11) and the target (T). It accelerates and collides with the target T to obtain X-rays, and the X-rays are drawn out of the tube through the X-ray window 13. In order to shorten the distance between the target T and the window 13 for the purpose of increasing the magnification of the transmitted image, the axis of the cathode 14 and the axis of the anode 15 are disposed at 90 degrees, and the anode and the cathode are insulated from each other. Insulated).

However, such a conventional X-ray tube is easy to form and control the potential for electron focusing because the cathode 14 has a low voltage, while the anode 15 and the target T become high voltage, so that the X-ray tube is cooled in order to insulate and cool at the same time. There is a disadvantage to be accommodated in the insulating oil.

In addition, the conventional X-ray tube is an anode reflecting tube, the X-ray generating efficiency is low, the power consumption is large, and the heat generated in the anode is relatively high, there is a difficulty in cooling.

In addition, the means for maintaining the insulation of the anode and the electron generating portion of the conventional X-ray tube is a cylindrical insulator having a straight cross section, in order to maintain a high insulation voltage has a disadvantage that the length of the insulator is increased to increase the size of the X-ray tube.

2 is a cross-sectional view showing a conventional X-ray generator.

As shown in FIG. 2, the X-ray generator 20 using the X-ray tube 10 includes an insulating block 22 in which the high-voltage power supply unit 21 is embedded, and is fixed to the insulating block 22, and has an insulating property therein. A metal tube part 24 filled with the liquid material 23 is provided, and the X-ray tube 10 is accommodated in the tube part 24.

However, such a conventional X-ray generating apparatus separates an X-ray tube from a container containing a liquid insulating material in order to replace the X-ray tube when the life of the X-ray tube ends or a defect occurs, and then replenishes the liquid insulating agent after replacement. , There is a problem that a lot of time and cost to replace because the skilled worker has to go through several steps until the sealing through the defoaming process of the insulation to work with a predetermined dedicated equipment.

An object of the present invention devised to solve the above problems is to provide an X-ray tube and an X-ray generator that can be easily removed and exchanged without oil insulation because of the small size and easy high voltage insulation.

In addition, the present invention provides an X-ray tube and an X-ray generating apparatus having a long-life target, and in order to provide electrons collide with a small electron focus point on the target to provide a clear transmission image, the magnification of the target by acting as a window The present invention provides an X-ray tube and an X-ray generator for obtaining a large magnified image.

In addition, the present invention is easy to manufacture by forming a ceramic tube with a combination of two tubes, by using a resistance on the combined electrode of the two tubes to uniform the non-uniform electric field to prevent high-voltage discharge, anode and electron generation An object of the present invention is to provide an X-ray tube and an X-ray generator that make an electric field uniform even at a high pressure by distance from a part.

According to the present invention, the anode of the X-ray tube is formed in a tubular shape, and the distance between the target and the insulator supporting the metal electrode is far, and the emitted electrons are reflected and returned to accumulate on the insulator, thereby suppressing the charge up phenomenon caused by the magnetic field around the anode. The present invention provides an X-ray tube and an X-ray generator that form a magnetic coil that generates an electron to prevent electrons from being dispersed while reaching the target, and focus the electrons.

X-ray tube according to the present invention in order to achieve the above object, in the X-ray tube, the inverted U-shaped cross-section formed in the inverted U-shaped, but the length of the inverted U to extend the length of the inverse direction to both ends of the inverted U-shaped tube and A ceramic tube inserted into the cylindrical tube and coupled to each other, the cylindrical tube being coupled to the upper portion of the coupling part; An electron generator for emitting electrons into the ceramic tube; An anode coupled coaxially with the open end of the ceramic tube at a predetermined distance away from the electron generating unit coaxially, and protruding outwardly in a tube shape; A magnetic coil provided to form a magnetic field to focus electrons around the anode; And a target generated by converting electrons into X-rays at one end of the anode.

In the present invention, the ceramic tube is characterized in that to apply an electric potential between the anode and the electron generating portion by forming an electrode in the coupling portion where the inverted U-shaped tube and the cylindrical tube are coupled to each other.

In the present invention, the ceramic tube is characterized in that the bonding portion is formed by brazing at a temperature in the range of 650 to 850 degrees by applying a metal layer to the portion where the inverted U-shaped tube and the cylindrical tube is formed.

In the present invention, the electron generating unit is an emitter formed by sintering a metal nano powder and carbon nanotubes (CNT) on a metal plate to emit electrons in the ceramic tube; And a cylindrical grid and focusing electrode formed by applying an electric field having a potential to the carbon nanotubes (CNT) to control the emission amount of electrons and converging the emitted electrons using a field emission device (FE). It is characterized by.

In the present invention, the magnetic coil, the focusing coil and the deflection coil is further provided.

In the present invention, the target is characterized in that the transmission (Transmission) configuration.

In the present invention, the metal nano powder is characterized by consisting of 40 to 70% by weight of nickel (Ni) nano powder and 30 to 60% by weight of silver (Ag) nano powder.

In the present invention, the emitter is characterized in that the metal nano-powder and carbon nanotubes are formed into a paste and then applied and heated to a temperature range of 600 to 800 degrees.

In order to achieve the above object, the X-ray generator according to the present invention has an inverted U-shaped cross section, but an inverted U-shaped tube and a cylindrical tube formed with a coupling part by extending a predetermined length further outward at both ends of the inverted U. X-ray tube that is inserted into the inverted U-shaped tube and coupled to each other, but having an X-ray tube having a ceramic tube shape coupled to the upper portion of the cylindrical tube and a high voltage transformer and a high voltage generator having a high voltage back voltage circuit. Forming an accommodating case, the X-ray tube receiving case is characterized in that the electrode receiving portion which can be attached and detached and electrically connected.

X-ray tube generating apparatus according to the present invention is that the X-ray tube is coupled to the case, but can be attached and detached, it is easy to replace and replace the X-ray tube when a defect occurs in the X-ray tube is easy to replace, other parts can be used as it is cost It is effective for saving.

In the X-ray tube according to the present invention, the anode is formed in a long tube shape, and the distance between the insulator supporting the target and the metal electrode is far, and the emitted electrons are reflected and returned to be accumulated on the insulator, thereby suppressing charge up phenomenon. By forming a magnetic coil to generate a magnetic field to prevent electrons from being dispersed while reaching the target, there is an effect to focus the electrons.

In addition, the present invention by forming a deflection coil together with the magnetic coil to focus and price the electrons at any position of the target by moving to the other side when the target is damaged by electron exposure to focus the price of the target It has the effect of extending the life.

In addition, the present invention is easy to manufacture by forming a ceramic tube with a combination of two tubes, there is an effect of preventing the discharge of a high voltage by uniformizing an uneven electric field by using a resistance on the combined electrode of the two tubes, The distance between the anode and the electron generating unit (cathode) is far away, so that the electric field is uniform even at high pressure.

In addition, the present invention has the effect of eliminating the resistance non-uniformity between the carbon nanotubes and carbon nanotubes by mixing and sintering the metal nano powder and carbon nanotubes.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention in more detail as follows.

3 is a cross-sectional view illustrating an X-ray tube according to the present invention, FIG. 4 is an enlarged cross-sectional view of the X-ray tube of FIG. 3, FIG. 5 is an enlarged cross-sectional view of an electron generating unit of the X-ray tube of FIG. 3, and FIG. 6 is The figure which shows the tube of the X-ray tube which concerns on this invention.

As shown in FIGS. 3 to 6, the X-ray tube 140 according to the present invention includes a ceramic tube 144, an electron generating unit 147, an anode (anode, 143), a magnetic coil 142, and a target. (Target, 145).

Here, the ceramic tube 144 is formed in an inverted U-shaped cross section, but the inverted U-shaped tube (144a) and the cylindrical tube is coupled to each other by forming a coupling portion by extending a predetermined length further outward at both ends of the inverted U-shaped. However, it is preferable to couple the lower portion of the cylindrical tube (144b) to the upper portion of the coupling portion. In addition, it is preferable that the inverted U-shaped tube 144a and the cylindrical tube 144b forming the coupling portion are made of ceramic as the main material.

The ceramic tube 144 described above is formed in the form (a) and (b), as shown in Figure 6, wherein (a) is an inverted U-shaped tube, (b) is a cylindrical tube .

The inverted U-shaped tube 144a of (a) is led upward from the lower portion of the cylindrical tube 144b of (b) to connect the coupling portion of the lower portion of the inverted U-shaped tube 144a and the lower portion of the cylindrical tube 144b. Fasten together.

At this time, the inverted U-shaped tube 144a and the cylindrical tube 144b by applying a metal layer to the portion bonded to the brazing at a temperature in the range of 650 to 850 degrees, it is preferable that the ceramic tube 144 is reverse U An electrode 146 is formed at a coupling portion where the female tube 144a and the cylindrical tube 144b are coupled to each other.

In this case, the metal layer is composed of molybdenum (Mo) and manganese (Mn).

By forming the ceramic tube 144 in the same manner as described above, the manufacturing is simple, the electrode introduction portion for forming a potential to uniformly distribute the non-uniform electric field by using the contact surface of the coupling portion of the two tubes as one electrode 146 Make it available. By doing so, the size is small and high voltage insulation is easy without oil insulation.

In addition, the surface distance of the insulator between the anode 143 and the electron generating unit 147 may be farther away to withstand high voltages.

Here, the electron generator 147 is formed by sintering the metal nano powder 148 and the carbon nanotubes (CNT, 149) on a metal plate to emit electrons in the ceramic tube 144, 147a And a cylindrical grid and focusing electrode 147b formed by applying an electric field having a potential to the carbon nanotubes 149 to control the emission amount of electrons and converging the emitted electrons by using a field emission device (FE). Configure.

In this case, the metal nanopowder 148 is composed of 40 to 70% by weight of nickel (Ni) nanopowder and 30 to 60% by weight of silver (Ag) nanopowder, and the metal nanopowder is mixed with carbon nanotube paste After forming and applying to heat to a temperature range of 600 to 800 degrees.

At this time, the silver (Ag) nanopowder is melted and permeated into the nickel (Ni) nanopowder and sintered together with the carbon nanotubes 149 to form an emitter.

Accordingly, the emitter 147a of the electron generating unit according to FIG. 5 adds the carbon nanotubes 149 of the nano-sized metal that can be melted at a low temperature at which the carbon nanotubes 149 are not degraded. And resistance nonuniformity between the carbon nanotubes 149 and the improved adhesion between the metal electrodes 141a and 141b and the carbon nanotubes 149.

In this case, the electron generating unit 147 connects one of the metal electrodes 141a and the emitter 147a, and connects another metal electrode 141b and the grid and focusing electrode 147b. At this time, the number of the metal electrodes (141a, 141b) is not limited to two or more metal electrodes (141a, 141b).

In this case, the anode 143 is formed of copper at a position spaced apart by a predetermined distance in the direction in which the electrons generated from the electron generating unit 147 proceeds, but is formed in a tube shape. In this case, the anode 143 is formed in a tube shape so that the reflectance of electrons generated in the electron generating unit is lowered. In addition, the anode 143 is made of copper and has a high thermal conductivity capable of conducting high temperature heat from a target.

Here, the magnetic coil 142 is configured together with the focusing coil 142b and the deflection coil 142a, and the magnetic coil 142 is provided around the anode 143 while the electrons reach the target. It forms a magnetic field that prevents dispersion and focuses electrons.

In addition, by forming a deflection coil to adjust the direction of the electron beam, by focusing the electrons at any position of the target and price, it is possible to move the focus point arbitrarily to extend the life of the target.

The target 145 is provided at one end of the anode 143 to convert electrons generated by the electron generator 147 into X-rays. At this time, the target 145 is formed by coating or adhering the target material on a beryllium plate through which X-rays are well transmitted, and is formed in close contact with the anode end in order to transfer heat generated to the outside in a short time.

In this case, since the target material has a plateau number, a melting temperature is high, and a material having a low vapor pressure, tungsten, gold, platinum, or the like is preferably used.

In addition, the target is preferably configured by a transmission method.

7 is a cross-sectional view showing an X-ray generator according to the present invention, Figure 8 is a cross-sectional view showing an X-ray tube accommodating case according to the present invention, Figure 9 shows an X-ray tube inserted into the X-ray tube accommodating case according to the present invention It is a cross section.

As shown in FIGS. 7 to 9, the X-ray generator 100 according to the present invention includes a bellows 110, a high voltage transformer 120, and a high voltage back voltage circuit in the X-ray generator metal outer cylinder 150. 130 and the X-ray tube accommodating case 151.

Here, the bellows 110 is expanded when the temperature of the insulating oil introduced into the X-ray generator metal outer cylinder 150 increases, and when the temperature of the insulating oil decreases, the bellows 110 shrinks and is repeatedly cracked to form a weld surface. Prevents leaks.

At this time, the insulating oil is oil having a low viscosity, it is preferable that the insulation breakdown voltage is large, the cooling action is good, and even if used for a long time does not oxidize and deteriorate.

 In addition, it is obvious that the insulating oil can be insulated with an insulating material that is solidified, such as epoxy resin or insulating silicon, and in this case, it is obvious that the bellows 110 does not have to be provided.

Here, the high voltage transformer 120 converts a low AC voltage into a high AC voltage by using an electromagnetic induction action.

Here, the high voltage back voltage circuit 130 includes a cocroft Walton circuit for converting an AC voltage generated from a high voltage transformer into a higher DC voltage and is a high voltage circuit capable of generating grid power.

Here, as shown in FIG. 7, the X-ray tube accommodating case 151 is formed in a structure capable of accommodating a ceramic tube, but may accommodate electrodes 141a and 141b provided in the X-ray tube ( 151a).
At this time, the X-ray tube is formed in an inverted U-shaped cross-section, but the inverted U-shaped tube and the cylindrical tube is formed in the inverted U-shaped tube to form a coupling portion by extending a certain length in the outward direction at both ends of the inverted U-shaped, It has a ceramic tube shape that combines a cylindrical tube lower part on the upper part of the coupling part.

Here, in coupling the X-ray generator metal outer cylinder 150 and the X-ray tube receiving case 151, the X-ray tube receiving portion sealing flange 152 is welded to the upper surface of the X-ray generator metal outer cylinder 150 and the X After inserting the O-ring into the O-ring groove provided along the line and the concentric circle of the upper part of the accommodating part sealing flange 152, the X-ray tube accommodating case 151 is inserted into the line generator metal outer cylinder 150, and the X-ray tube accommodating part is crimped. By assembling the flange 153 with a screw, an X-ray high pressure generator that can be sealed without leakage of the insulating oil or the like can be configured.

As described above, by combining the X-ray tube generating autonomous metal outer cylinder 150 and the X-ray tube housing case 151, when the X-ray tube is plugged into the housing case 151, the electrodes 141a and 141b naturally come into contact with the electrode receiving portion 151a. And are in close contact with each other, so that the X-ray tube accommodating case 151 and the X-ray tube 140 are not spaced apart by using the X-ray tube support lid 154.

10 is a diagram showing data simulated using an X-ray tube according to the present invention.

As shown in FIG. 10, as a result of the simulation using the present invention, electrons are focused on the target by the magnetic coil and collide with the target even if electrons are generated and spread out at any point. At this time, the smaller the cross-sectional diameter of the intersection point, the smaller the size of the focus point that can be focused on the magnetic coil.

While the present invention has been particularly shown and described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of course, this is possible. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the equivalents as well as the claims described below.

1 is a cross-sectional view showing a conventional X-ray tube.

2 is a cross-sectional view showing a conventional X-ray generator.

3 is a cross-sectional view showing an X-ray tube according to the present invention.

4 is an enlarged cross-sectional view of the X-ray tube of FIG.

5 is an enlarged cross-sectional view of an electron generating unit of the X-ray tube of FIG. 3;

6 shows a tube of an X-ray tube according to the invention.

7 is a cross-sectional view showing an X-ray generating apparatus according to the present invention.

8 is a cross-sectional view showing an X-ray tube accommodating case according to the present invention.

Figure 9 is a cross-sectional view showing an X-ray tube inserted into the X-ray tube receiving case according to the present invention.

10 is a view showing data simulated using an X-ray tube according to the present invention.

<Description of the symbols for the main parts of the drawings>

100: X-ray generator 110: Bellows (Bellows)

120: high voltage transformer 130: high voltage back voltage circuit

140: X-ray tube 141a, 141b, 146: electrode

142: magnetic coil 142a: deflection coil

142b: focusing coil 143: anode (anode)

144: ceramic tube 144a: inverted U-shaped tube

144b: round tube 145: target

147: electron generating unit 147a: emitter

147b: grid and focusing electrode 148: metal nanopowder

149: carbon nanotube (CNT) 150: X-ray generator metal outer cylinder

151: X-ray tube accommodating case 151a: electrode accommodating part

152: X-ray tube accommodating sealing flange 153: X-ray tube accommodating crimp flange

154: X-ray tube support lid

Claims (9)

In the X-ray tube, Cross-section is formed in an inverted U-shaped, but the both ends of the inverted U-shaped inversely extending the length of the inverse U-shaped tube and a cylindrical tube to form a coupling portion to each other, but the ceramic coupling the lower portion of the cylindrical tube on the coupling portion A tube; An electron generator for emitting electrons into the ceramic tube; An anode coupled coaxially with the open end of the ceramic tube at a predetermined distance away from the electron generating unit coaxially, and protruding outwardly in a tube shape; A magnetic coil provided to form a magnetic field to focus electrons around the anode; And And a target generated by converting electrons into X-rays at one end of the anode. The method of claim 1, The ceramic tube is an X-ray tube, characterized in that for forming an electrode in the coupling portion where the inverted U-shaped tube and the cylindrical tube are coupled to each other to apply a potential between the anode and the electron generating portion. The method of claim 1, The ceramic tube is X-ray tube, characterized in that for bonding by brazing at a temperature in the range of 650 degrees to 850 degrees by coating a metal layer on the portion where the inverted U-shaped tube and the cylindrical tube is formed. The method of claim 1, The electron generating unit is an emitter formed by sintering a metal nano powder and carbon nanotubes (CNT) on a metal plate to emit electrons in the ceramic tube; And And a cylindrical grid and focusing electrode formed by applying an electric field having a potential to the carbon nanotubes (CNT) to control the emission amount of electrons and converging the emitted electrons using a field emission device (FE). X-ray tube characterized by. The method of claim 1, And the magnetic coil, the focusing coil and the deflection coil. The method of claim 1, The target is an X-ray tube, characterized in that configured in the transmission (Transmission) method. In the X-ray generator, Cross-section is formed in an inverted U-shaped, but the both ends of the inverted U-shaped inversely extending the length of the inverse U-shaped tube and a cylindrical tube to form a coupling portion to each other, but the ceramic coupling the lower portion of the cylindrical tube on the coupling portion An X-ray tube having a tube, Forming an X-ray tube accommodating case for accommodating the X-ray tube on one side of the high voltage generator having a high voltage transformer and a high voltage back voltage circuit,  An X-ray generator, characterized in that for forming an electrode receiving portion that can be detached and electrically connected to the X-ray tube receiving case. The method of claim 4, wherein The metal nano powder is composed of 40 to 70% by weight of nickel (Ni) nano powder and 30 to 60% by weight of silver (Ag) nanoparticles, characterized in that composed of. The method of claim 4, wherein The emitter is an X-ray tube, characterized in that the metal nano-powder and carbon nanotubes are mixed to form a paste and then applied and heated to a temperature range of 600 degrees to 800 degrees.

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