JP2008084656A - X-ray irradiation type ionizer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray irradiation type ionizer utilizing X-ray. <P>SOLUTION: In the X-ray irradiation type ionizer 1 equipped with a gas supply exhaust port capable of supplying and exhausting an outside gas and an irradiation window 3 capable of transmitting the X-ray in an airtight cabinet 4 in which the interior can be retained to have a low pressure airtight state, this X-ray irradiation type ionizer 1 is equipped with an insulator 5 arranged and installed inside the airtight cabinet 4 nearly in parallel to the irradiation window 3 and a filamentary electrode 6 which is arranged and installed between the insulator 5 and the irradiation window 3 so as to oppose to the insulator 5, applies voltage to the insulator 5 and electrifies its surface. According to necessity, it is equipped with a protecting member 7 for preventing scattering of the X-ray and protecting the irradiation window 3 which protrudes to the outside along the peripheral part of the irradiation window 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an X-ray irradiation ionizer using X-rays.

  In the manufacturing process of electronic devices such as liquid crystal panels and plasma display panels, it is performed under a coon room. When static electricity is generated in these manufacturing processes, the insulator constituting the electronic device is electrically destroyed. This leads to problems such as so-called dielectric breakdown, loss of insulation and so-called dielectric breakdown, and problems that attract and attract fine particles floating in the air to semiconductor circuits constituting electronic devices, causing short circuits. This is a major cause of decreasing the yield of electronic devices and the like. In addition, problems caused by contamination of impurities due to static electricity also occur during the powder packing operation and in the process of transporting the optical film in the optical film production line used for the liquid crystal display.

  In order to prevent these problems caused by static electricity, a static eliminator is required to neutralize static electricity, but as the static eliminator used for these, a high voltage was applied to the tip of fibers or wires. Corona discharge ionizers that use corona discharge that occurs during the process are used. In addition, in the conventional X-ray ionizer 100 as shown in FIG. 6, a cylindrical flow path shield part 103 having an inflow port 101 on one side and an irradiation port 102 on the other side, and a flow path shield part 103, an X-ray irradiation device 104 that irradiates X-rays, and a blower unit 106 that is disposed on the inlet 101 side of the flow path shield unit 103 and blows air into the flow path shield unit 103 in the direction of the arrow 105, The irradiation region limit line 107 closest to the irradiation port 102 side of the X-ray and the opening surface of the irradiation port 102 of the flow path shield part 103 are substantially parallel, and the other X-rays approach the inlet 101 side. Is radiated toward the inner wall of the flow path shield part 103 to form an X-ray irradiation region 108, and ions generated in the X-ray irradiation region 108 are radiated from the irradiation port 102 to the object to be neutralized 109. (For example, Patent Document 1). And the conventional X-ray generator used for them employ | adopts many thermionic acceleration type | mold X-ray tubes which generate | occur | produce X-rays by colliding a thermoelectron with a metal target.

Japanese Patent Laid-Open No. 2005-243325

  However, in the corona discharge ionizer described above, when corona discharge occurs, ozone harmful to the human body and electromagnetic noise affecting the human body and electronic equipment are generated, and the electrode part deteriorates and wears due to repeated use, There is a possibility that they may become dust, and problems such as unstable static elimination performance occur. Furthermore, in the corona discharge type ionizer, the generated ions need to be sent by wind, and therefore cannot be used in a field that is adversely affected by turbulence of air current such as powder packing, and its application is limited. Moreover, the ionizer using the X-ray shown in FIG. 6 is also provided with a blower, and its use is limited in the same manner as the corona discharge ionizer described above. A thermoelectron source such as a cathode or a filament constituting a thermoelectron accelerated X-ray tube that generates conventional X-rays is a gas that is heated and evaporated under a high vacuum or remains in a vacuum-sealed envelope. When the ions collide, the amount of thermionic radiation deteriorates with time, but the envelope is sealed in a vacuum, so the cathode and filament cannot be removed and replaced. Usually, when the lifetime is reached in about one year, the thermionic acceleration type X-ray tube itself must be replaced each time, leading to cost increase and complicated management. Furthermore, the conventional X-ray generator has a possibility of exposing the X-ray generated by the user, and has a problem in safety.

  The present invention has been made for the purpose of solving the various problems as described above, and does not expose the user to X-rays. Further, the ionizer can be miniaturized and maintenance can be facilitated. Furthermore, an X-ray irradiation type ionizer that can efficiently neutralize the object to be neutralized is provided.

  In order to achieve the above object, the X-ray irradiation ionizer according to claim 1 is capable of transmitting X-rays through a gas supply / exhaust port through which an external gas can be supplied to and discharged from an airtight housing that can be maintained in a low-pressure airtight state. In an X-ray irradiation ionizer comprising an irradiation window, an insulator disposed substantially parallel to the irradiation window inside the hermetic housing, and the insulator is disposed between the insulator and the irradiation window And a filament electrode that charges the surface of the insulator by applying a voltage to the insulator to ionize the gas outside the irradiation window.

  The X-ray irradiation ionizer according to claim 2 is characterized in that the irradiation window is made of aluminum.

  According to a third aspect of the present invention, the X-ray irradiation ionizer includes a protective member for preventing scattering of X-rays and protecting the irradiation window at a peripheral portion of the irradiation window.

  The X-ray irradiation ionizer according to claim 4 is characterized in that the protective member is a frame body that protrudes outward along the peripheral edge of the irradiation window.

  The X-ray irradiation type ionizer according to claim 1, wherein an insulator disposed substantially parallel to the irradiation window inside the hermetic housing, and the insulator is disposed between the insulator and the irradiation window. And a filament electrode for applying a voltage to the insulator to charge the surface thereof. Accordingly, there is an advantage that the X-ray irradiation area is widened and the surrounding gas can be efficiently ionized. Further, by charging the insulator and generating X-rays, it is possible to generate high-intensity X-rays at a low applied voltage without using a high vacuum.

  In the X-ray irradiation ionizer according to claim 2, since the irradiation window is made of aluminum, X-rays having a photon energy of about 1560 eV or more are cut by the absorption edge of the aluminum, and X-rays having a photon energy of less than about 1560 eV are Irradiated from the irradiation window. Thereby, X-rays irradiated from the irradiation window are absorbed in the air after traveling several centimeters in a direction away from the irradiation window, that is, ionize gas molecules in the air efficiently in a short period of time. Therefore, the object can be discharged efficiently, and there is no risk that the user will be exposed to X-rays.

  According to a third aspect of the present invention, the X-ray irradiation ionizer includes a protective member for preventing the X-ray from scattering at the periphery of the irradiation window and protecting the irradiation window. As a result, the user can use it safely without exposing X-rays, and the irradiation window can be protected from physical impact.

  In the X-ray irradiation type ionizer according to claim 4, since the protective member is a frame body that protrudes outward along the peripheral edge of the irradiation window, the user can be surely and safely exposed without exposing the X-ray. It can be used and the irradiation window can be protected from physical impact.

  BEST MODE FOR CARRYING OUT THE INVENTION The best embodiment of the X-ray irradiation ionizer 1 of the present invention will be described with reference to the drawings. The X-ray irradiation ionizer 1 of the present invention has an airtight housing 4 capable of maintaining a gas supply / exhaust port 2 through which external gas can be supplied and discharged and an irradiation window 3 through which X-rays can pass through in a low-pressure airtight state. In the X-ray irradiation ionizer 1 provided in FIG. 1, an insulator 5 disposed substantially parallel to the irradiation window 3 in the hermetic housing 4, and the insulator 5 between the insulator 5 and the irradiation window 3. And a filament electrode 6 which is arranged so as to face the insulator 5 and charges the surface by applying a voltage to the insulator 5, and, if necessary, along the peripheral edge of the irradiation window 3. A protective member 7 for preventing X-ray scattering and protecting the irradiation window 3 is provided.

  The airtight housing 4 includes a gas supply / exhaust port 2 through which external gas can be supplied and discharged, and an irradiation window 3 through which X-rays can be transmitted, and the inside thereof is held in a low-pressure airtight state. The hermetic casing 4 is preferably made of a member having a low X-ray transmittance, such as lead, gold, copper, or brass, or a member containing them, although it can shield X-rays. Other members may be used, and the thickness of the airtight casing 4 can also be designed according to the member to be used. Further, the airtight housing 4 is a housing that keeps the inside of the airtight state without gas entering and exiting from other than the gas supply / exhaust port 2, and the airtight container made of, for example, glass provided with the gas supply / exhaust port 2 is described above. It may be configured to cover with a member having a low X-ray transmittance. Further, in the embodiment of the present invention, the shape of the airtight casing 4 is a substantially rectangular parallelepiped, but is not limited to this shape, and the shape can accommodate the above-described members inside, and the inside of the airtight casing 4 is low-pressure airtight. As long as it can withstand the pressure when it is held in a state, it may be spherical or other shapes.

The gas supply / exhaust port 2 can supply and discharge external gas. In the embodiment of the present application, as shown in FIG. 1, the gas supply / exhaust port 2 is provided at one end of the airtight casing 4 in the longitudinal direction. When the pressure inside the airtight housing 4 is reduced, the pressure is adjusted as appropriate by using a pressure reducing pump 8 connected to the gas supply / exhaust port 2 and having a pressure adjusting function. And it is preferable that the pressure of the airtight housing 4 is, for example, 2.0 × 10 ^{−2 to} 5.0 × 10 ⁻² Torr because X-ray generation efficiency is high and X-rays are stably generated. It may be higher or lower than those pressures.

  Moreover, when using the pressure reduction pump 8 which does not have a pressure control function, the gas supply / exhaust port 2 has the discharge port which discharges | emits the gas inside the airtight housing | casing 4 outside, and the gas outside the airtight housing | casing 4 inside. Each may be divided into inlets (not shown). And when decompressing the inside of the airtight housing 4, the gas inside the airtight housing 4 is exhausted to the outside using the decompression pump 8 connected to the discharge port. When the pressure decreases below the target pressure, the pressure inside the hermetic casing 4 is adjusted by supplying the gas outside the hermetic casing 4 from the inlet as necessary. Moreover, the number and attachment position of these gas supply / exhaust ports 2 are not limited to an Example of this application, and can be selected suitably.

  The irradiation window 3 is for transmitting the generated X-rays and irradiating the X-rays in the air. These materials are not particularly limited as long as they transmit X-rays, but a metal film containing magnesium or silicon, or a resin film such as polyimide can be used as appropriate. However, in consideration of moldability, material cost, X-ray transmittance, etc., it is preferable to use aluminum.

  Here, in the embodiment of the present application, the irradiation window 3 is made of aluminum having a thickness of about 10 μm and showing an X-ray transmittance as shown in FIG. When the generated X-rays pass through the aluminum irradiation window 3 having a thickness of about 10 μm, the X-rays having a photon energy of about 1560 eV or more are absorbed by the absorption edge of the aluminum as shown in FIG. As a result, X-rays having high photon energy that adversely affect the human body can be cut by the irradiation window 3, and X-rays having a photon energy of less than about 1560 eV can be extracted. Further, as shown in FIG. 4, since the generated X-rays are transmitted through aluminum having a thickness of about 10 μm, the X-ray transmittance in the vicinity of photon energy of about 1560 eV is about 0.35. X-ray intensity sufficient to ionize gases such as can be obtained. The aluminum having a thickness of about 10 μm used for the irradiation window 3 may be used, for example, by attaching an aluminum foil having a thickness of about 10 μm to a substrate such as glass. The thickness may be about 10 μm. Furthermore, when the airtight housing 4 is configured to cover a gastight container made of, for example, glass having the gas supply / exhaust port 2 as described above with a member having a low X-ray transmittance, The irradiation window 3 may be provided in the inside, and these irradiation windows 3 are the mounting method and its position as long as the generated X-ray is a position where the X-ray is irradiated through the irradiation window 3. Is not limited to the embodiments of the present application. If the aluminum irradiation window 3 is used as in the present embodiment, it is not necessary to use beryllium which is harmful to the human body, which is conventionally used, and it is safe for the user.

  And since the irradiation window 3 becomes detachable (not shown), consumable members, such as the internal filament electrode 6 and the insulator 5, can be replaced easily. As a result, in the conventional vacuum-sealed thermoelectron accelerated X-ray tube, the above-described consumable members cannot be replaced alone, and the thermoelectron accelerated X-ray tube itself must be replaced. Can be solved. Furthermore, there is a possibility that the irradiation window 3 itself deteriorates due to the generated X-rays or is damaged by a physical impact, but in this case, the irradiation window 3 can be easily replaced. In addition, the above-described replacement of each member may be performed, for example, by providing an opening (not shown) on the side surface of the airtight casing 4 or other places (not shown).

The insulator 5 is disposed substantially in parallel with the irradiation window 3 inside the hermetic casing 4. For example, an inorganic insulator crystal such as lithium niobate (LiNbO ₃ ) or an organic insulating material such as polytetrafluoroethylene is used. Can be used. In addition, insulators such as Nacl, glass (SiO ₂ ), NiF ₂ can be used, but are not limited to these materials. And when it applies a voltage to these insulators, it forms in the thickness which does not produce a dielectric breakdown.

  The filament electrode 6 is disposed between the insulator 5 and the irradiation window 3 so as to face the insulator 5, and a voltage is applied to the insulator 5 to charge the surface thereof. Further, in this embodiment, as shown in FIG. 3, in order to widen the X-ray irradiation region, the airtight housing 4 that is electrically connected to an external voltage power source (not shown) through the conductor 9. The end electrodes 10 provided at both ends are electrically connected using a substantially linear filament electrode 6. In this case, the insulator 5 is disposed so as to face the above-described substantially linear filament electrode 6, and the insulator 5 having a substantially rectangular shape is used. The material used for the end electrode 10 and the filament electrode 6 is a commonly used conductive material such as tungsten, gold, or platinum that is difficult to chemically react such as oxidation, and the filament electrode 6. The shape and arrangement are not limited to a substantially linear shape as used in the embodiments of the present application, and may be circular or curved. At that time, the shape of the insulator 5 is also changed corresponding to the filament electrode 6.

When X-rays are generated, for example, a voltage of 1.0 to 2.0 kV is applied to the filament electrode 6, and the pressure inside the hermetic casing 4 is set to, for example, 2.0 × 10 ^{−2 to} 5. By reducing the pressure to 0 × 10 ⁻² Torr, polarization occurs in the insulator 5 and the surface of the insulator 5 is charged. The electrons generated from the filament electrode 6 repeatedly collide with the residual gas in the hermetic enclosure 4 to generate X-rays. Thus, by utilizing the charging phenomenon of the insulator, it is possible to efficiently generate X-rays with a low applied voltage and without a high vacuum.

  The protective member 7 prevents X-rays from scattering so that the operator does not expose the X-rays emitted from the irradiation window 3. In the embodiment of the present application, the protection member 7 is provided so as to protrude outward along the peripheral edge of the irradiation window 3 as shown in FIGS. In addition, as the protective member 7, a member that can shield X-rays is used similarly to the above-described airtight housing 4.

Here, after the generated X-rays are transmitted through the aluminum irradiation window 3 having a thickness of about 10 μm, they are X-rays having a photon energy of less than about 1560 eV, and the most photon energy among the X-rays irradiated from the irradiation window 3. It can be seen that the X-rays with a high photon energy are about 1560 eV. Considering these factors, the transmittance of X-rays having a photon energy of about 1560 eV after passing through the air layer by about 5 cm is about 1.0 × 10 ⁻³ from FIG. 5, most of which is absorbed by the air layer. At the same time, it can be seen that most of the X-rays whose photon energy is lower than the vicinity of about 1560 eV are absorbed by the air layer. That is, the air is efficiently ionized and there is no risk that the user will be exposed to X-rays.

  Therefore, when aluminum having a thickness of about 10 μm is used as the irradiation window 3 as in the embodiment of the present invention, the X-rays irradiated from the irradiation window 3 are air layers at a location 5 cm or more away from the irradiation window 3. Most of it is absorbed. Therefore, it is not necessary to provide the protective member 7 at a location 5 cm or more away from the irradiation window 3, and it is not necessary to provide an excessively large protective member 7 when the protective member 7 is attached. As a result, by providing the protective member 7 on the periphery of the irradiation window 3 in consideration of the X-ray transmittance of the irradiation window 3 and the X-ray transmittance of the surrounding gas, the entire apparatus is made small and light. And high safety can be obtained. Furthermore, by providing the protective member 7, the irradiation window 3 can be protected from a physical impact from the outside.

  Moreover, the shape of the protection member 7 should just be a shape which can protect the irradiation window 3, and a user does not expose X-ray | X_line, These are X-ray transmissive of the irradiation window 3 like an Example of this application. The shape is not limited as long as it is designed in consideration of the rate and the X-ray transmittance of the surrounding gas. Moreover, the graph of FIG.4 and FIG.5 is one of the Examples of this application, The X-ray transmittance of the irradiation window 3 and the X-ray transmittance of surrounding gas are not limited to these, It uses It changes depending on the material of the irradiation window 3, the surrounding gas, the permeation distance, and the like, and the protection member 7 can be appropriately designed according to them.

An operation of the X-ray irradiation ionizer according to the embodiment of the present application when discharging the object to be discharged 11 will be described. As shown in FIG. 1, an approximately rectangular insulator 5 is connected to a substantially linear filament electrode 6 disposed between the insulator 5 and the irradiation window 3 so as to face the insulator 5. A voltage of 1.0 to 2.0 kV is applied using a voltage power source (not shown). Then, the pressure reducing pump 8 connected to the gas supply / exhaust port 2 and having a pressure adjusting function is operated to reduce the pressure inside the airtight casing 4 to 2.0 × 10 ^{−2 to} 5.0 × 10 ⁻² Torr. By doing so, X-rays are generated inside the airtight housing 4.

  The generated X-rays are irradiated into the air through the irradiation window 3. By passing through the aluminum irradiation window 3 having a thickness of about 10 μm, the photon energy is reduced by the absorption edge of aluminum as shown in FIG. High-energy X-rays of 1560 eV or higher are cut, and X-rays having a photon energy of less than about 1560 eV are emitted from the irradiation window 3. Then, as described above, the X-rays irradiated from the irradiation window 3 are irradiated to the gas molecules 12 in the surrounding air, so that the gas molecules 12 are ionized and the generated ions are charged. By neutralizing the charge on the surface of the object 11 to be discharged, the charged object 11 can be discharged. That is, as in the present embodiment, for example, the surface of the object 11 to be positively charged can be neutralized by canceling the positive charge with the ionized gas molecules 12.

  In addition, since the ionized gas molecules 12 reach the object to be neutralized 11 by natural convection and diffusion of air, in the present embodiment, the object to be neutralized 11 is neutralized even at a location 5 cm or more away from the irradiation window 3. In addition, under work that is not affected by air convection, the gas molecules 12 that are forcibly ionized by sending wind with a fan or the like may be sent toward the object to be neutralized 11.

  As described above, according to the embodiment of the present invention, by using an X-ray irradiation type ionizer that utilizes charging of an insulator, the X-ray irradiation type ionizer is driven at a low applied voltage and without a high vacuum. be able to. Therefore, it is possible to work in a narrow installation space without requiring a large-scale device. In addition, since it has a wide X-ray irradiation region, it can efficiently ionize the gas, and since the protective member 7 as described above is provided at that time, it is safe without exposing the user to X-rays. It is. Further, it is possible to further reduce the size by using a dry battery as the voltage power source.

  The present invention can be used not only as a static eliminator but also as a sterilization / sterilization apparatus by irradiating surrounding gas with X-rays and ionizing the gas.

Upper sectional view of the embodiment of the present application AA sectional view in FIG. BB sectional view in FIG. Graph of X-ray transmittance of irradiation window used in this application example X-ray transmittance graph of air layer in the embodiment of the present application Diagram showing conventional technology

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 X-ray irradiation type ionizer 2 Gas supply / exhaust port 3 Irradiation window 4 Airtight housing 5 Insulator 6 Filament electrode 7 Protective member 8 Depressurization pump 9 Conductor 10 End electrode 11 Electric discharge object 12 Gas molecule

Claims (4)

In an X-ray irradiation ionizer comprising a gas supply / exhaust port through which an external gas can be supplied / discharged and an irradiation window through which X-rays can pass through an airtight housing that can be maintained in a low-pressure airtight state.
An insulator disposed substantially parallel to the irradiation window inside the hermetic housing;
A filament electrode disposed between the insulator and the irradiation window so as to face the insulator and applying a voltage to the insulator to charge its surface;
An X-ray irradiation ionizer characterized by ionizing the gas outside the irradiation window.   2. The X-ray irradiation ionizer according to claim 1, wherein the irradiation window is made of aluminum.   The X-ray irradiation ionizer according to claim 2, further comprising a protective member for preventing the scattering of X-rays and protecting the irradiation window at a peripheral portion of the irradiation window.   The X-ray irradiation ionizer according to claim 3, wherein the protective member is a frame body that protrudes outward along the peripheral edge of the irradiation window.

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