JP2009212010A - Soft x-ray generator, and static eliminator using it - Google Patents

Abstract

A soft X-ray having a large output can be generated in a large area in a stable state with a small electric field, and the irradiation direction of the generated X-ray is controlled to efficiently concentrate on a non-irradiated object. Provided is a soft X-ray generator that can be irradiated and is inexpensive and has high performance.
In a sealable cylindrical vacuum housing, an anode having a curved surface made of an X-ray emitting substance is provided along the longitudinal direction of the inner wall surface of the housing, and the needle-like bodies are closely packed on the surface of the substrate. A soft X-ray generator comprising: a cold cathode made of an electrode material formed in parallel and spaced apart from the anode and emitting X-rays generated from the anode toward the cold cathode.
[Selection] Figure 2

Description

  The present invention relates to a soft X-ray generator in which a cold cathode and an anode are arranged opposite each other in a sealable vacuum housing, and a static eliminator using the soft X-ray generator.

  As an apparatus for generating X-rays, an apparatus that uses a hot cathode such as a tungsten filament and emits X-rays from a target (anode) by thermoelectrons emitted from the hot cathode has been widely used. However, an X-ray generator using a hot cathode requires a high-power heating source, and the cathode is very hot, so a design for countermeasures against the surrounding heat is required. There were problems such as becoming.

In order to solve such problems, various X-ray generators using cold cathodes made of materials such as carbon nanotubes instead of hot cathodes have been proposed (see, for example, Patent Documents 1 and 2). ), It is difficult to stably output a necessary dose of X-rays.
JP 2007-66694 A JP 2005-26227 A

On the other hand, various uses of an X-ray generator have been proposed for removing static electricity from a charged object using soft X-rays having a wavelength of 1 to several hundreds of kilometres (for example, patents). References 3 and 4). These static eliminators, for example, in an LSI or liquid crystal manufacturing process, ionize the air around a charged object by irradiating a charged silicon wafer or glass substrate for liquid crystal with low-energy soft X-rays, and charge the charged object. Neutralize.
Japanese Patent No. 2749202 JP 2007-305565 A

Small soft X-ray tubes used for static elimination are miniaturized by narrowing the distance between the anode that generates X-rays and the cathode that generates electrons, and the distance between the cathode and anode is relatively small. Used at low voltage.
In a conventional apparatus, a hot cathode having a relatively small diameter such as a tungsten filament is used, and the thermoelectrons generated from the cathode are accelerated by the anode voltage, with a thickness of several μm on the surface of an X-ray transmitting material (window) such as beryllium. By colliding with the deposited anode made of an X-ray generating material such as tungsten, the generated X-rays are transmitted through the transmission window and radiated to the outside.

When performing static elimination with X-rays, if the X-ray source can be brought close to the target charged object and the X-ray irradiation area can be increased, the X-ray intensity distribution can be made uniform. Operation at low voltage is possible.
However, in the conventional X-ray tube, the X-ray emission angle emitted from the point light source is about 90 to 150 degrees. Therefore, since only a small area can be removed when approaching the object, the X-ray tube is usually disposed at a position about 1 m away from the object. For this reason, a decrease in the X-ray intensity due to the distance and an X-ray intensity distribution within the irradiation area occur, and uniform static elimination cannot be performed in a short time. When the device is downsized, when it is used in a natural cooling system, it is usually a small output of about 0.1 to 0.2 mA at a voltage of 9 to 10 kV, and it is difficult to make a large output device. .

Therefore, as shown in FIG. 10, in the conventional X-ray static eliminator, the X-ray source is arranged at a position considerably away from the charged object to increase the irradiation area, or a plurality of X-ray sources are installed. It was necessary to do. Since the X-ray output is small, the static elimination performance decreases in inverse proportion to the cube of the distance between the X-ray source and the charged object, and the X-ray intensity distribution is generated in the irradiation region. It was also extremely disadvantageous.
In addition, in the conventional X-ray neutralization apparatus, it has been impossible to efficiently neutralize the charged object by intensively irradiating the charged object with X-rays generated from the radiation source.

Therefore, the present invention solves these problems of the prior art, can generate soft X-rays with a large electric field in a stable state with a small electric field, and can control the irradiation direction of the generated X-rays. An object of the present invention is to provide an inexpensive and high-performance soft X-ray generator capable of efficiently concentrating and irradiating a non-irradiated object.
Another object of the present invention is to provide a static eliminator that can be reduced in size and has excellent static eliminator performance, in which the soft X-ray generator is arranged close to a charged object.

As a result of intensive studies, the present inventors have provided an anode having a curved surface made of an X-ray emitting substance along the longitudinal direction of the inner wall surface of the cylindrical vacuum housing, and the needle-like bodies are concentrated on the substrate surface. It was discovered that the cold cathode made of the formed electrode material is arranged in parallel with the anode at an interval, and X-rays generated from the anode are emitted to the cold cathode side to solve the above problem. Completed the invention.
That is, the present invention employs the following configurations 1 to 15.
1. An anode having a curved surface composed of an X-ray emitting material is provided in the sealable cylindrical vacuum housing along the longitudinal direction of the inner wall surface of the housing, and needles are formed densely on the surface of the substrate. A soft X-ray generator, comprising: a cold cathode made of an electrode material arranged in parallel with a distance from the anode, and radiating X-rays generated from the anode toward the cold cathode.
2. 2. The soft X-ray generator according to 1, wherein a mesh-shaped or lattice-shaped bent extraction electrode is disposed between the cold cathode and the anode substantially in parallel with the anode.
3. 3. The soft X-ray generator according to 1 or 2, wherein a window made of an X-ray transparent material is provided on the cold cathode side of the housing.
4). The soft X-ray generator according to any one of 1 to 3, wherein the anode is an X-ray reflective layer.
5. The soft X-ray generator according to any one of claims 1 to 4, wherein the electrode material constituting the cold cathode is one in which needle-like bodies are formed radially in the circumferential direction of the conductive fiber.
6). The soft X-ray generation device according to any one of 1 to 5, wherein the needle-like body is provided with a conductive film at a tip portion.
7). Any one of 1 to 6, wherein the needle-like body has a carbon film surrounding the periphery of the needle-like body in a wall shape, and a needle-like body made of carbon is formed in the central portion. The soft X-ray generator described in 1.
8). The soft X-ray generator according to any one of 1 to 7, wherein the anode is configured by a plate-like body.
9. The soft X-ray generator according to any one of 1 to 7, wherein the anode is constituted by a plurality of rod-like bodies or tubular bodies.
10. 10. The soft X-ray generator according to 9, wherein a voltage applied to each rod-like body or tubular body constituting the anode can be controlled independently of other rod-like bodies or tubular bodies.
11. Any one of 1 to 10, wherein the cold cathode is arranged at or near the focal point of the curved surface of the anode so that X-rays emitted from the soft X-ray generator are emitted in parallel. A soft X-ray generator according to claim 1.
12 The soft X-ray generator according to any one of 1 to 11, wherein a voltage applied between the electrodes is 0.5 to 10 keV.
13. A static eliminator comprising: the soft X-ray generator according to any one of 13.1 to 12; and a support unit that supports a charged object disposed in proximity to the soft X-ray generator.
14 14. The static eliminator according to 13, wherein the soft X-ray generator is disposed over the entire length in the width direction of the charged object.
15. 15. The static eliminator according to 13 or 14, wherein the soft X-ray generator is disposed on both sides of the charged object with the charged object interposed therebetween.

According to the present invention, soft X-rays with a large output can be generated in a stable state with a small electric field, and the irradiation direction of the generated X-rays is controlled to efficiently concentrate on non-irradiated objects. It is possible to obtain a soft X-ray generator that is inexpensive and has high performance.
Further, in the static eliminator using the soft X-ray generator, the X-ray source can be arranged at a position close to the charged object, so that the apparatus can be reduced in size and cost. Furthermore, the generated X-rays can be efficiently concentrated and irradiated over the entire width direction of the charged object, and the necessary X-ray dose can be irradiated even if the distance from the charged object is changed by controlling the anode electrode. Therefore, it is possible to greatly improve the static elimination performance.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
1-3 is a figure which shows one example of the X-ray generator of this invention. 1 is a conceptual diagram showing the overall configuration of the apparatus, FIG. 2A is a schematic diagram (perspective view) showing the configuration of the apparatus, FIG. 2B is a schematic longitudinal sectional view of the apparatus, and FIG. It is an expansion schematic diagram of the electrode material which comprises a cathode.
This X-ray generator 1 densely gathers needles radially in the circumferential direction of conductive fibers in a sealable cylindrical vacuum housing 2 provided with a window 3 made of an X-ray transmitting material such as beryllium. The cold cathode 4 composed of the electrode material 101 formed in this manner is disposed in the center of the housing, and the anode 5 is disposed in parallel with the cold cathode 4 with a space therebetween.

The anode 5 is a target electrode made of a metal material such as tungsten or copper, and has a curved surface similar to the cylindrical vacuum housing 2 by bending a single plate-like body. It arrange | positions along an inner wall surface along a longitudinal direction. Button-type stems 12 and 13 are welded to both ends of the housing 2 to seal the housing 2. One stem 12 is provided with anode terminals 14 and 14 connected to the anode 5, and the other stem 13 is connected to the cathode terminals 15 and 15 connected to the cold cathode 4 and the inside of the housing 2. An exhaust pipe 16 is provided (see FIG. 2B). The exhaust pipe 16 is sealed by welding after evacuating the inside of the housing. The cold cathode 4 and the anode 5 are connected to a high-voltage power source 8 that applies a voltage between the electrodes by a conducting wire 7 via terminals 14 and 15 respectively.
The apparatus 1 is operated in a high vacuum state (the vacuum degree of the housing is about 1 × 10 ⁻² to 1 × 10 ⁻⁷ Pa, particularly about 1 × 10 ⁻³ to 1 × 10 ⁻⁵ Pa). The housing 2 and the stems 12 and 13 and the exhaust pipe 16 are made of a sealable pressure-resistant material such as metal or glass. However, when these members are made of the same material, hydrogen is used. It is preferable because each member can be easily joined by welding using a gas flame or the like. Moreover, the shape of the housing 2 can be an arbitrary shape such as a cylindrical body having an elliptical or quadrilateral cross section.

When this apparatus 1 is evacuated to about 1 × 10 ⁻³ to 1 × 10 ⁻⁵ Pa and a voltage is applied between the cold cathode 4 and the anode 5 by the power supply 8, the needle 1 of the cold cathode 4 is applied to the tip of the needle-like body. A strong electric field is generated, and electrons (dotted arrows in FIG. 1) are emitted toward the anode 5 by field emission. This field emission can be controlled by the power supply 8. Then, the X-rays generated from the anode 5 due to the collision of the electrons are emitted toward the outside of the housing 2 from the window 3 made of an X-ray transmitting material such as beryllium as shown by the solid arrow in FIG. (Reflection type X-ray generator).

  In the X-ray generator of the present invention, the irradiation direction of X-rays emitted from the window 3 made of an X-ray transmitting material is adjusted by adjusting the curvature of the curved surface of the anode 5 and the distance from the cold cathode 4 to the anode 5. Can be controlled to be parallel or focused. The conventional X-ray generator is a point light source type, the X-ray radiation angle is about 90 degrees, and it is necessary to install the X-ray generator at a distance from the non-irradiated object. Therefore, it is difficult to concentrate and irradiate X-rays efficiently. Moreover, since the output of X-rays was small, it was not possible to irradiate a sufficient amount of X-rays. On the other hand, in the X-ray generator of the present invention, a large amount of X-rays can be efficiently concentrated and irradiated on a non-irradiated object. For example, when used in a static eliminator or the like, The irradiation efficiency of the rays can be greatly improved.

FIG. 3 is an enlarged schematic view showing an electrode material constituting the cold cathode 4 of the X-ray generator.
This electrode material 101 is obtained by growing needle-like bodies 103 radially in the circumferential direction of conductive fibers 102 such as carbon fibers. In the electrode material 101, the number density at the distal end portion 104 of the needle-like body 103 is significantly reduced as compared with the number density at the root portion 105. Therefore, in the X-ray generator of the present invention in which the electrode material 101 is used as the cold cathode 4 and the anode 5 facing the cold cathode 4 is provided, the electric field concentrated on the tip 104 of the needle-like body 103 is greatly increased. The anode voltage can extract a necessary amount of electrons, and X-rays can be efficiently generated from the anode 5 by the electrons.

It is known to use a material having a needle-like body on the surface of a substrate as an electrode material for a cold cathode (see, for example, Patent Documents 5 and 6), and the X-ray generator of the present invention can be obtained by these known methods. The electrode material having a needle-like body can be used for the cold cathode.
JP 2007-70140 A JP 2001-35424 A

Preferred electrode materials constituting the cold cathode 4 include carbon fibers, conductive fibers such as copper, gold, silver, platinum, and aluminum, etc., or wires made of stainless steel, NiO ₂ alloy, etc. An electrode material formed by closely gathering needle-like bodies radially in the circumferential direction of the “conductive fiber”).
As such a needle-like body, it has a needle-like carbon film formed by the plasma CVD method described in Patent Document 5, particularly a carbon film that surrounds the periphery of the base in a wall shape, and the center part is made of carbon. Examples thereof include a needle-like body (hereinafter, may be abbreviated as “carbon nano-X: CNX”) in which a configured needle-like body is formed. (The SEM image of CNX is shown in FIG. 4.)
Moreover, you may use the acicular body of metal oxides including zinc oxide formed by the open air CVD method described in Patent Document 6.

The length of the needle-like body formed on the surface of the conductive fiber is preferably about 5 to 30 μm, the electric field coefficient β value in field emission is about 1000 to 5000, and the density is preferably about 10 ⁴ to 10 ⁸ pieces / mm ^2. .
The electrode material in which the needle-like body is grown in the circumferential direction of the conductive fiber exhibits a large radiation current characteristic with a small electric field, and therefore is suitably used as a material constituting the cold cathode of the X-ray generator. The electric field concentration coefficient can be further improved by providing a conductive coating (topcoat) selected from a metal oxide film or an amorphous carbon-based film, if desired, at the tip of the needle-like body. Preferable materials constituting the top coat include magnesium oxide, yttrium oxide, amorphous hydrogenated carbon nitride, diamond, carbon nanotube, and the like.
By using such an electrode material, the X-ray generator of the present invention can generate X-rays efficiently even when the voltage applied between the electrodes is as low as 0.5 keV to 10 keV, particularly 1 keV to 4 keV. Is possible. As the base material for forming the needle-like body, a long and narrow plate-like body may be used instead of the conductive fiber.

FIG. 5 is a schematic view (perspective view) showing another example of the X-ray generator of the present invention.
In this device 11, the anode 5 'is configured by arranging a large number of rod-like bodies 9 having a circular cross section in the longitudinal direction and joining them so that the cross section of the anode 5' has a curved surface. In addition, each rod-shaped body constituting the anode 5 ′ is sequentially applied to each pair of rod-shaped bodies by making a pair of conductors 7 one by one from both outsides and connecting to the variable DC high voltage power source 8 ′. The voltage can be controlled independently from other rod-shaped bodies. Each rod-like body constituting the anode 5 ′ is fixed by welding to a field-through terminal of a button type stem provided on both sides of the housing 2. The other structure of this apparatus 11 is the same as that of the X-ray generator 1 of FIGS. In the X-ray generator 11, the electric field on the cold cathode surface can be precisely controlled by the voltage applied to each rod-like anode 9. Since the amount of electrons emitted from the cold cathode and the acceleration speed can be changed, for example, when used for the X-ray source of the static eliminator, the irradiation distance, the shape of the target substance, non-uniform charging, etc. Regardless of whether or not, it is possible to perform static elimination efficiently.
In this example, the anode 5 ′ of the X-ray generator is configured by joining a large number of rod-shaped bodies 9 having a circular cross section in the longitudinal direction, but by joining a hollow tubular body instead of the rod-shaped body. The anode 5 ′ may be configured.

FIG. 6 is a conceptual diagram showing another example of the X-ray generator of the present invention.
This apparatus 21 includes a mesh-like or lattice-like extraction electrode (gate electrode) 6 made of a metal material such as stainless steel between the cold cathode 4 and the anode 5 in the X-ray generator 1 of FIG. In addition, the cold cathode 4 and the extraction electrode 6 are connected to a high voltage power source 10 for applying a voltage between the electrodes by a conducting wire 7. Other configurations of the device 21 are the same as those of the device 1 of FIG. In this device 21, the electrons emitted from the whisker tip of the cold cathode 4 can draw out the necessary amount of electrons at a very low voltage independently of the anode voltage by the extraction electrode 6. The X-ray energy can be controlled by colliding with the target (anode) by the anode voltage. The shape and dimensions of the extraction electrode 6 are arbitrary, but it is preferable that the extraction electrode 6 is bent in the same manner as the shape of the anode 5 and matches the dimensions of the anode.
In the wiring shown in FIG. 6, the extraction electrode 6 may be grounded, and the positive power supply 8 may be connected between the anode 5 and the extraction electrode 6, and the negative power supply 10 may be connected between the cathode 4 and the extraction electrode 6.

7 and 8 are schematic views showing still another example of the X-ray generator of the present invention, and FIG. 7 is a transverse sectional view of the apparatus. FIG. 8 is a terminal connection diagram of electrodes constituting the apparatus.
In this apparatus 201, in the apparatus 21 of FIG. 5, the anode 5 ′ is configured by arranging rod-shaped bodies a to j and a ′ to j ′ having a circular cross section on the circumference of one side of the ellipse. The cold cathode 4 is arranged at the intersection of the long axis and the short axis. Further, the vacuum housing 2 having a circular arc cross section is provided with a window 3 made of an X-ray transmitting material such as beryllium.
In this example, by adopting the above configuration, the voltage applied independently for each pair of electrodes can be controlled to make the X-ray dose uniform, and the X-rays radiate from the window 3 substantially in parallel. It is made to be done. Other configurations of the apparatus 201 are the same as those of the apparatus 21 in FIG.

FIG. 9 is a schematic view showing an example in which the X-ray generator of the present invention is applied to a static eliminator used in an LSI, liquid crystal manufacturing process, etc. FIG. 9A is a plan view showing the main part of the device. , And (B) are also front views.
The static eliminator 31 includes a support means 33 including a belt conveyor that supports and conveys a charged object 32 such as a liquid crystal substrate, and the X-ray generator 1 of the present invention disposed in the vicinity of the support means 33. is there. The X-ray generator 1 has a length that extends over the entire length in the width direction of the belt conveyor that supports the charged object 32, and is configured so that the generated X-rays can be uniformly irradiated to the entire charged object 32. . The belt conveyor 33 is supported by a plurality of rolls 34 and conveys the substrate 32 in the arrow direction. In order to prevent leakage of X-rays, these members constituting the main part of the static elimination device 31 are preferably covered with a shielding cover (not shown) made of a thin metal plate such as aluminum. Moreover, it can replace with the belt conveyor 33 and can also use other conveyance means, such as a chain conveyor.

FIG. 10 is a schematic view showing a static eliminator using a conventional X-ray generator.
In the static eliminator 41, the X-ray generator 1 'close to one or a plurality of point ray sources is used as the X-ray source. Therefore, in order to irradiate the entire charged object 32 with X-rays, the X-ray generator 1 It is necessary to install 'at least 60 cm away from the charged object 32.
Further, as shown by the dotted line in FIG. 10, since the X-ray is emitted from the radiation source so as to diffuse widely, the X-ray cannot be intensively applied to the charged object. Since the charge removal performance of the charge removal device decreases in inverse proportion to the cube of the distance between the X-ray source and the charged object, the charge removal performance of the charge removal device 41 cannot be said to be sufficient.

  On the other hand, in the static eliminator 31 of FIG. 9, for example, by using the X-ray generator 1 of the present invention shown in FIG. 1, the X-ray generation efficiency is remarkably improved, and the generated X-rays are reduced. As shown by the dotted line in FIG. 9, it is possible to concentrate on the charged object 32 and irradiate the entire charged object 32 uniformly, so that the static elimination performance is extremely excellent. Further, since the X-ray generator 1 can be disposed close to the charged object 32, the apparatus can be downsized and the price can be significantly reduced.

FIG. 11 is a schematic diagram (front view) showing another example of the static eliminator of the present invention.
The static eliminator 51 uses a chain conveyor 53 in which the ends of a number of elongated rigid rods are connected by a chain in place of the belt conveyor 33 in the static eliminator 31 of FIG. Two X-ray generators 1 and 1 are arranged on both sides of a chain conveyor 53 that supports the charged object 32 so as to sandwich the charged object 32 therebetween. The other configuration of the device 51 is the same as that of the static elimination device 31 of FIG.
In this apparatus 51, as shown by the dotted line in FIG. 11, X-rays can be irradiated from both the front and back sides of the charged object 32, so that the charge removal efficiency of the charged object 32 can be further improved.

EXAMPLES Next, the present invention will be further described with reference to examples, but the following specific examples are not intended to limit the present invention.
(Production Example 1: Production of cold cathode constituent material (emitter))
A wire made of SUS304 having a diameter of 1 mm and a length of 68 mm serving as a substrate was set on the anode electrode in the film formation chamber of the plasma CVD apparatus, and the film formation chamber was evacuated. Methane and H ₂ were allowed to flow through the film forming chamber at a mixing ratio of 1/12 of methane (CH ₄ ) / H ₂ gas, and the chamber pressure was controlled to be 80 Torr. Next, 5 kW of electric power was applied between the anode electrode and the cathode electrode to generate a mixed plasma of methane / H ₂ . In the plasma, a carbon precursor in which methane was efficiently decomposed was deposited on the surface of a SUS304 wire heated to about 1000 ° C., and a nanocarbon thin film (CNX) was formed in a film formation time of 30 minutes. After stopping the power application, the inside of the apparatus is cooled, and after the inside of the film forming chamber is purged with N ₂ , the SUS wire on which CNX is formed is taken out. A base material made of SUS304 wire on which CNX is formed is hereinafter referred to as an emitter.
When the electrical characteristics (current-voltage characteristics) of the emitter were measured at a vacuum of 1 × 10 ⁻⁴ Pa, a current of 10 A / cm ² was obtained when an electric field of 2.5 V / μm was applied on the emitter surface. . Moreover, the result of having observed the emitter with the scanning electron microscope (SEM) is shown to (A) and (B) (partial enlarged view) of FIG. As can be seen from these figures, the emitter has a pyramidal lower portion and a spindle-shaped long thick needle formed at the top portion, and the density thereof is 1 × 10 ⁷ / cm ² . The total length is several tens of μm.

Example 1
In the X-ray generator 1 shown in FIGS. 1 to 3, the CNX emitter cathode 4 having a diameter of 1 mm and a length of 68 mm obtained in Production Example 1 above, an inner diameter of 13 mm and a thickness of 0.5 mm obtained by bending a plate-like body. A tungsten anode 5 having a length of 70 mm is placed in a glass vacuum housing 2 in which an X-ray extraction window 3 made of beryllium is welded in advance, the emitter cathode 4 being the center, and the anode 5 being coaxial with the housing 2 in a cylindrical shape. It arrange | positioned so that it might become (only a semicircle part).
The emitter cathode 4 and the anode 5 were welded to the glass stems 12 and 13 on both sides of the housing. The X-ray generator 1 was manufactured by inserting the both-side stems 12 and 13 into the vacuum housing 2 and welding them using a heating means such as a hydrogen flame. The assembled device 1 is connected to an ultra-high vacuum evacuation device (not shown) through an exhaust pipe 16, and the device 1 is heated to about 300 ° C. and about 1 × 10 ⁻⁵ Pa with a degree of vacuum of about 1 After evacuation at night, after cooling, the exhaust pipe 16 was sealed and cut with a hydrogen flame. In order to maintain the degree of vacuum, it is preferable to put a getter.

The cathode terminal 15 and the anode terminal 14 of the obtained X-ray generator 1 were connected to a DC power supply 8 and a positive voltage was applied to 0 to 5 kv with the anode terminal serving as a positive electrode and the cathode terminal 15 serving as a negative electrode. . The amount of X-ray generation relative to the voltage at that time was measured with a 5000 type survey meter (manufactured by Toyo Medic). The distance between the X-ray generator 1 and the survey meter is 50 mm. The generation amount of X-rays started at 1 μSu / h or more when a voltage of 2 kv was applied, and became 10 μSu / h or more at 2.5 kv. Since the survey meter used in this example cannot measure 10 μSu / h or more, the measurement was terminated.
As described above, it was confirmed that high output soft X-rays were generated at a very low voltage.

(Example 2)
Using the CNX emitter cathode having a diameter of 1 mm and a length of 68 mm obtained in Production Example 1 and 20 tungsten rods having a diameter of 1 mm and a length of 80 mm, the X-ray generator 201 of FIGS. 7 and 8 was produced. As shown in FIG. 7, the emitter cathode 4 is placed at the intersection (center) of the major axis and the minor axis of the ellipse, and the anode 5 ′ is formed symmetrically from the intersection of the circumference and the minor axis on the semicircle of the ellipse. Ten rod-like bodies a, b, c..., J, a ′, b ′, c ′.
Each anode rod-like body was welded and fixed to the feed-through terminals of the button type glass stems on both sides of the housing 2, and the emitter cathode 4 was similarly fixed. Next, after inserting the window 3 made of beryllium into a vacuum housing 2 made of glass (Be / Uval / Uval glass) previously welded, the housing 2 and the left and right stems were welded, and the X-ray generator 201 was assembled. . Next, while heating the apparatus at a baking temperature of 300 ° C., it is evacuated overnight at a vacuum of 1 × 10 ⁻⁵ Pa or less, and after cooling, the exhaust pipe is dissolved and sealed with a hydrogen flame or the like to complete the X-ray generator. I let you. The anode side electrodes (10, because of left-right symmetry) of the assembled X-ray generator were connected together and connected to the positive pole of the DC power source, and the negative electrode 4 was connected to the negative pole.

A DC voltage was applied to the obtained X-ray generator while increasing the pressure to 0 to 4 kv, and the X-ray generation amount at that time was measured with a 5000 type surveyer (manufactured by Toyo Medic).
As a result, X-rays of 1 μSu / h were generated at 2.2 kv, and a very large output of 10 μSu / h was obtained at 3.0 kv. Further, in the terminal connection diagram of FIG. 8, it is possible to independently control the voltage applied to each counter electrode (a, a ′, etc.) by connecting to the power source, and X-rays are generated at the outer periphery. It was possible to prevent the amount from decreasing. By this method, the generation of uniform X-rays of 10 μSu / h or more with an X-ray width of 20 mm was confirmed.

  In each of the above examples, an example in which the cold cathode of the X-ray generator is configured with a CNX emitter has been described. Needless to say, an electrode material or the like on which a metal oxide needle-like body is formed can be used.

It is a figure which shows one example of the X-ray generator of this invention. It is a schematic diagram which shows the structure of the apparatus of FIG. It is an expansion schematic diagram of the electrode material which comprises the cold cathode of the apparatus of FIG. In the SEM image of the electrode material constituting the cold cathode obtained in Production Example 1, (B) is a partially enlarged image of (A). It is a figure which shows the other example of the X-ray generator of this invention. It is a figure which shows the other example of the X-ray generator of this invention. It is a figure which shows the other example of the X-ray generator of this invention. FIG. 8 is a terminal connection diagram of electrodes constituting the apparatus of FIG. 7. It is a figure which shows one example of the static elimination apparatus using the X-ray generator of this invention. It is a figure which shows one example of the static elimination apparatus using the conventional X-ray generator. It is a figure which shows the other example of the static elimination apparatus using the X-ray generator of this invention.

Explanation of symbols

1,11,21,201 X-ray generator 2 Vacuum housing 3 Window 4 Cold cathode 5 Anode 6 Extraction electrode 7 Conductors 8, 8 ', 10 Power supply
12, 13 Stem 14, 15 Terminal 16 Exhaust pipes 31, 41, 51, Static eliminator 32 Charged object 33 Belt conveyor 34 Roll 53 Chain conveyor 101 Electrode material 102 Conductive fiber 103 Needle 104 Front end 105 Root

Claims (15)

  An anode having a curved surface composed of an X-ray emitting material is provided in the sealable cylindrical vacuum housing along the longitudinal direction of the inner wall surface of the housing, and needles are formed densely on the surface of the substrate. A soft X-ray generator, comprising: a cold cathode made of an electrode material arranged in parallel with a distance from the anode, and radiating X-rays generated from the anode toward the cold cathode.   The soft X-ray generator according to claim 1, wherein a mesh-shaped or lattice-shaped bent extraction electrode is disposed substantially parallel to the anode between the cold cathode and the anode.   The soft X-ray generator according to claim 1 or 2, wherein a window made of an X-ray transparent material is provided on the cold cathode side of the housing.   The soft X-ray generator according to any one of claims 1 to 3, wherein the anode is an X-ray reflective layer.   The soft X-ray generator according to any one of claims 1 to 4, wherein the electrode material constituting the cold cathode is a needle-like body formed radially in the circumferential direction of the conductive fiber. .   The soft X-ray generator according to any one of claims 1 to 5, wherein the needle-like body is provided with a conductive film at a tip portion.   7. The acicular body according to claim 1, wherein the acicular body has a carbon film that surrounds the periphery of the acicular body in a wall shape, and a acicular body made of carbon is formed in the center of the acicular body. The soft X-ray generator in any one.   The soft X-ray generator according to claim 1, wherein the anode is configured by a plate-like body.   The soft X-ray generator according to any one of claims 1 to 7, wherein the anode is constituted by a plurality of rod-like bodies or tubular bodies.   The soft X-ray generator according to claim 9, wherein the voltage applied to each rod-like body or tubular body constituting the anode can be controlled independently of other rod-like bodies or tubular bodies. .   11. The cold cathode is disposed at or near the focal point of the curved surface of the anode so that X-rays emitted from the soft X-ray generator are emitted in parallel. The soft X-ray generator in any one of.   The soft X-ray generator according to any one of claims 1 to 11, wherein a voltage applied between the electrodes is 0.5 to 10 keV.   13. A static eliminator comprising: the soft X-ray generator according to claim 1; and support means for supporting a charged object disposed in proximity to the soft X-ray generator.   The static eliminator according to claim 13, wherein the soft X-ray generator is arranged over the entire length of the charged object in the width direction.   15. The static eliminator according to claim 13 or 14, wherein the soft X-ray generator is disposed on both sides of the charged object with the charged object interposed therebetween.

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