TWI620470B - X-ray tube for improving electron focusing - Google Patents

Abstract

The present invention discloses an improved electron-focusing X-ray tube capable of effectively guiding the release of hot electrons from the filament to the target of the X-ray irradiation port and reducing the specific gravity of the filament adsorption impurity. The electron-focusing X-ray tube for improvement according to the present invention is a non-conductive hose that forms a main body and is hollow, and an upper portion of the shielding tube, and an X-ray irradiation port that irradiates the X-ray to the target facing the upper portion, and shields the soft a sealing portion at the lower portion of the tube, extending from the outer side of the sealing portion to the inner side of the hose, and supplying a predetermined plurality of wires of negative high voltage, connected between the wires extending into the inside of the hose, releasing the filament of the hot electrons, and a first focusing tube for wrapping the filaments for accumulating the above-mentioned hot electrons released by the filament; the present invention further comprises a shielding shell of a conductive material covering the outer surface of the hose, and the voltage of the shielding shell is supplied to the wire The negative high voltage is the same voltage. The electron-focusing X-ray tube for improvement proposed by the present invention has the following advantages: 1. A focus tube is additionally provided to the lower portion of the X-ray irradiation port to efficiently move the hot electrons released from the filament to the target. 2. The negative high pressure inside the hose is supplied to the shielding shell, so that the impurities which are separated from the target into liquid state are absorbed by the inner wall of the hose, thereby reducing the probability of adsorption of the filament (-voltage) inside the focusing tube, thereby improving the filament life. 3. The first focusing tube forms a shielding wing, dividing the inner space of the hose into two, improving the probability of the hot electrons released from the filament moving to the X-ray irradiation port.

Description

Improved electronic focusing X-ray tube

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an improved electron-focusing X-ray tube, and more particularly to an object capable of effectively guiding the release of hot electrons from a filament to a target of an X-ray irradiation port, and reducing the specific gravity of the filament adsorbing impurities. Ray tube.

Generally, according to the penetrability of a substance, a radiation having low penetration which is easily absorbed in a thin air layer is called soft X-ray, and a radiation having high penetration such as a roentgen is called hard X-ray.

Soft X-rays have one-tenth the energy of hard X-rays and are equally less affected by actual investigations.

A description of distinguishing the characteristics of soft X-rays and hard X-rays is shown in Table 1 below.

It is well known that soft X-rays produced by soft X-ray generators are accelerating The electrons are generated when they hit the metal target (Be), so the soft X-ray generator is composed of a high voltage generating device that accelerates electrons and a target.

When the voltage applied to the electrode is called a target voltage, the kinetic energy E of the electron at the time of collision is expressed by the following equation.

E=eV=(1/2)mv ²

At this time, e: the amount of charge (-1.602 X 10 ^-19 C)

m: electronic quality (9.109 ^-31 kg)

V: Accelerating voltage

v: the speed of the electron

As we all know, when the kinetic energy of an electron hits a target, most of it is converted into heat, and only about 1% of the energy is emitted by soft X-rays. The equation for the efficiency of soft X-ray generation is as follows: Incidence efficiency = 1.1 X 10 ^-9 ZV

At this time, Z is the atomic number of the target substance.

This soft X-ray irradiation type is formed by neutralizing the ions required for neutralizing the charged body and the photon absorption of gas molecules and atoms around the charged object. This soft X-ray irradiation type is characterized by being capable of generating a high concentration of ions. And electrons, so static electricity can be eliminated in a short time, and the residual voltage can be maintained at almost 0V. It can also eliminate the advantage of static electricity in an inactive liquid state in the atmosphere, and is widely used to eliminate static electricity.

It is well known that a corona discharge type static elimination device needs to be additionally equipped with a blowing device for transmitting ions, and a soft X-ray irradiation type static eliminating device has a windless state. It also eliminates the advantages of static electricity.

Fig. 1 shows an example of an X-ray tube which is produced by the applicant and which is sold in the city and which is connected to a high voltage electric generator in the ion to irradiate soft X-rays.

2 and 3 are a front view and a rear view, respectively, showing the X-ray tube shown in Fig. 1. (There is a filament connected to the kovar wire inside the cylindrical negative electrode that acts as a reference focusing tube, but is not shown in the drawing)

As shown in FIG. 1 , the X-ray tube includes a glass tube 100 and an X-ray radiation unit 200 (including a metal target such as Be and W coated thereon, which is called an X-ray irradiation port) connected to the tail of the glass tube, and a glass tube. 100 is a sealing portion 300 of the glass joined at the top of the other side or a material having a physicochemical property similar thereto (hereinafter referred to as a glass material).

Further, the X-ray tube shown in Fig. 1 further includes a cylindrical cathode 110 (also referred to as a focus tube) that collects hot electrons released from a filament (not shown, attached inside the focus tube), and supplies a high voltage. A conductive wire 120 (kovar wire) of a voltage of about -1 K to -60 KV output from a generator (not shown), a glass clip 130 connected to a conductive wire 120 inserted into the inside of the glass tube 100, and one side The other side of the cathode 110 attached to the cylindrical shape is in close contact with the inner wall of the glass tube, the guide spring 140 supporting the cathode 110, the getter 150 (getter) for maintaining the vacuum state inside the glass tube 100, and the like, the X-ray tube The interior maintains a predetermined vacuum intensity that is controlled according to direct vacuum evacuation.

In order to efficiently move the hot electrons released from the filament to the X-ray radiation port 200, such an X-ray tube generally uses the cylindrical tube 110 of the cylindrical structure shown in Figs.

However, the X-ray tube of the present configuration having such a structure has the following problems:

1. Despite being equipped with a focusing tube, the efficiency of the hot electrons released by the filament to the target is still It is low.

2. Since the hot electron collides with the target, it is detached from the target, becomes an liquefied form of impurities, collides with other hot electrons, and transfers cations. This cation-containing impurity is adsorbed to the filament (-voltage) inside the focusing tube, and is lowered. Filament life.

Prior technical literature

Patent literature

(Patent Document 0001) 1. Patent Application No.: 10-2013-0047924, title of the invention: "X-ray tube hose structure"

The present invention has been made to solve the problems of the prior art, and an object thereof is to provide an electron focusing X for improving the specific gravity of a filament which is capable of efficiently guiding the release of the filament to the X-ray irradiation port and reducing the specific gravity of the filament adsorption impurity. Ray tube.

The electron focusing X-ray tube for improvement according to the present invention comprises: a hollow non-conductive hose forming a main body; an X-ray irradiation port covering the upper portion of the hose, wherein the target opposed thereto emits hot electrons to illuminate X-ray; a sealing portion that shields the lower portion of the hose; a plurality of wires extending from the outside of the sealing portion to the inside of the hose and supplying a predetermined negative high pressure; connected between the wires extending to the inside of the hose and releasing hot electrons a filament; a first focusing tube for wrapping the filament of hot electrons released by the filament; and a shielding shell of a conductive material covering the outer surface of the hose. The voltage of the shielded enclosure is the same as the negative voltage supplied to the wire. A voltage.

An electron-focusing X-ray tube for improvement according to the present invention, further comprising an inner side of the hose opposite to the first focusing tube and disposed at a lower portion of the X-ray irradiation port for releasing the target from the first focusing tube to the X-ray irradiation port Hot electrons, the second focusing tube that is again gathered.

According to the improved electron-focusing X-ray tube of the present invention, the first focusing tube has a hollow cylindrical shape for the purpose of incorporating the filament, and the outer periphery of the first focusing tube is spaced apart from the inner wall of the hose by a predetermined distance.

According to the improved electron-focusing X-ray tube of the present invention, the first focusing tube is connected to the inner wall of the hose in a radial extension for the shielding wing formed by the periphery of the first focusing tube in which the filament is hollow, and the hose is The inner space is covered by the wing portion so that the upper space of the shielding wing is the first space and the lower space is the second space.

According to the improvement of the present invention, the electron-focusing X-ray tube has a filament which is opposite to the filament and which is elongated in a vertical horizontal direction.

With the improvement of the electronically focused X-ray tube proposed in accordance with the present invention, there are several advantages.

1. Provide another focusing tube at the lower portion of the X-ray irradiation port to efficiently move the hot electrons released from the filament to the target.

2. The collision between the hot electrons and the target is reduced, so that the detachment from the target becomes a probability that the liquefied impurities are adsorbed to the filament (-voltage) inside the focusing tube, thereby improving the life of the filament, thereby prolonging the service life of the X-ray tube.

100‧‧‧Hose

110‧‧‧Cylindrical cathode

120‧‧‧Electrical wire

130‧‧‧ clip

140‧‧‧guide spring

150‧‧‧ getter

200‧‧‧X-ray exposure

300‧‧‧ Sealing Department

400‧‧‧wire

500‧‧‧filament

600‧‧‧First focus tube

700‧‧‧shaded enclosure

800‧‧‧second focus tube

1 to 3 are schematic views showing an example of an X-ray tube hitherto.

4 to 6 are schematic views of the first to third embodiments of the improved electron-focusing X-ray tube proposed by the present invention, respectively.

The invention will now be described in detail with reference to the drawings.

For reference, in the technical terms used in the present invention, the X-ray irradiation port is a general term for the general constituent elements of the hose and the upper metal target, the stainless steel flange, and the metal flange which are sequentially combined with each other.

Further, the X-ray tube described in the present invention basically consists of a glass-shaped sealing portion of a flat circular structure and a plurality of wires penetrating through the edge of the glass material sealing portion, and a filament which is connected between the wires to release hot electrons. The X-ray tube further includes a hollow cylindrical hose integrated with the glass material sealing portion for the cylindrical focusing tube that collects the hot electrons released from the filament and the getter that joins the outside of the focusing tube. It is well known in the industry to research and develop X-ray tubes that the structure has been confirmed before the description.

Meanwhile, the metal material used for the filament of the present invention may contain an alloy of W, W, and Re (铼), an alloy of W and ThO ₂ (cerium oxide), and the like. This is due to the thermal electron release efficiency and the durability of the filament.

Further, the material of the glass-made sealing portion and the cylindrical hose used in the present invention may include bismuth citrate, SiO ₂ (quartz glass), UV glass or the like.

The X-ray tubes described above are generally used, and additional explanations are omitted. Embodiments of the invention are described below.

Figure 4 is a first embodiment of an improved electronically focused X-ray tube in accordance with the present invention. A schematic of an embodiment.

As shown, the electron-focusing X-ray tube for improvement according to the first embodiment of the present invention comprises: a hollow non-conductive hose 100 forming a main body; and an X-ray irradiation port 200 covering the upper portion of the hose, wherein the opposite The target therein emits hot electrons to emit X-rays; and the sealing portion 300 of the lower portion of the hose is shielded.

The electronic focus X-ray tube for improvement according to the first embodiment of the present invention further includes: a plurality of wires 400 extending from the outer side of the sealing portion 300 to the inner side of the hose 100 and supplying a predetermined negative high voltage, connected to extend to the soft Between the above-mentioned wires 400 inside the tube 100, a filament 50 of thermoelectrons is released, and a conductive shielding cylindrical shield case 700 encasing the hose.

For reference, the shielded outer casing 700 has at least a length that encloses the seal 300 and the first focus tube 600.

According to the first embodiment of the present invention, the first focusing tube 600 has a hollow cylindrical shape for the purpose of incorporating the filament, and the outer periphery of the first focusing tube 600 is spaced apart from the inner wall of the hose by a predetermined distance.

The steps according to the first embodiment of the present invention are as follows.

The hot electrons emitted from the filament are directed toward the X-ray irradiation port to collide with the X-ray irradiation port target.

At this time, since the hot electron collides with the target, the detachment from the target and the liquefied form are generated in the inside of the hose. Such impurities carry cations after colliding with other hot electrons released by the filament or the like. A portion of the impurity carrying the cation will be adsorbed on the filament carrying the negative pressure. In the case of the present invention, a cylindrical shielded outer casing having a conductive material on the outside of the wrapped hose also carries a negative high voltage state (the same voltage as the wire). Therefore, a part of the cation impurities will be absorbed by the inner wall of the hose which is attached to the shielding case.

Then, the amount of impurities adsorbed on the filament can be reduced as compared with a conventional X-ray tube which has not been shielded from the outer casing so far. The result is improved filament service life.

Figure 5 is a schematic illustration of a second embodiment of an improved electronically focused X-ray tube in accordance with the present invention.

As shown, the second embodiment of the improved electron-focusing X-ray tube according to the present invention is the same as the first embodiment, and basically includes a hollow non-conductive hose 100 forming a main body; The X-ray irradiation port 200 in which the target opposed thereto emits hot electrons to emit X-rays; and the sealing portion 300 of the lower portion of the hose is shielded.

An electron-focusing X-ray tube for improvement according to a second embodiment of the present invention includes: an outer side of the sealing portion 300 extending to the inner side of the hose 100, and supplying a plurality of wires 400 of a predetermined negative high voltage, connected to the hose 100 Between the inner wires 400, the filaments 500 for releasing the hot electrons, the first focusing tube 600 for wrapping the filaments for collecting the hot electrons discharged from the filaments 500, and the inner side of the hose 100 opposite to the first focusing tube 600 are provided at the above X In the lower portion of the radiation irradiation port 200, in order to release the hot electrons emitted from the first focus tube 600 to the X-ray irradiation port 200 toward the target, the cylindrical second focusing tube 800 which is gathered again, and the conductive material circle of the wrapped hose The cylindrical shielding case 700. For reference, the above-described shielding case 700 has at least the length of the package sealing portion 300 and the first focusing tube 600.

According to the second embodiment of the present invention, the first focusing tube 600 has a hollow cylindrical shape for the purpose of incorporating the filament, and the outer periphery of the first focusing tube 600 is spaced apart from the inner wall of the hose by a predetermined distance.

For reference, according to the second embodiment of the present invention, since the second focus tube is provided, the length of the hose is longer than that of the first embodiment.

The steps according to the second embodiment of the present invention are as follows.

The hot electrons emitted by the filament located inside the first focusing tube pass through the first focusing tube, and then pass through the second focusing tube opposite to the first focusing tube and spaced apart from the first focusing tube, and the X-ray located in the upper portion of the second focusing tube Target collision at the irradiation port.

At this time, since the hot electrons collide with the target, the impurities which are detached from the target and become liquefied are formed inside the hose. Such impurities carry cations after colliding with other hot electrons released by the filament or the like. A portion of the impurity carrying the cation will be adsorbed on the filament carrying the negative pressure. In the case of the present invention, a cylindrical shielded outer casing having a conductive material on the outside of the wrapped hose also carries a negative high voltage state (the same voltage as the wire). Therefore, a part of the cation impurities will be absorbed by the inner wall of the hose which is attached to the shielding case.

Subsequently, the amount of impurities adsorbed on the filament can be reduced as compared to a conventional X-ray tube without a shielded outer casing. The result is improved filament service life.

Meanwhile, according to the case of the second embodiment of the present invention, by providing the second focus tube, the hot electrons passing through the first focus tube, and the second focus tube are effectively transmitted to the X-ray irradiation port, the X-ray tube is further improved. X-ray exposure ability.

Figure 6 is a schematic illustration of a third embodiment of an improved electronically focused X-ray tube in accordance with the present invention.

As shown, the third embodiment of the improved electron-focusing X-ray tube according to the present invention is the same as the first embodiment and the second embodiment, and basically includes a hollow non-conductive hose 100 which is formed into a main body. An X-ray irradiation port 200 that shields the upper portion of the hose, wherein the target opposed thereto emits hot electrons to emit X-rays; and the sealing portion 300 of the lower portion of the hose is shielded.

An improved electronically focused X-ray tube according to a third embodiment of the present invention includes a plurality of wires 400 extending from the outside of the sealing portion 300 to the inside of the hose 100 and supplying a predetermined negative high voltage, connected to the hose 100 Between the inner wire 400, releasing the thermoelectric a filament 500, a first focusing tube 600 for wrapping the filaments of the hot electrons released by the filament 500, opposite to the first focusing tube 600 on the inner side of the hose 100, and disposed at the lower portion of the X-ray irradiation port 200, in order to The focusing tube 600 releases the hot electrons that are incident on the X-ray irradiation port 200 toward the target, the cylindrical second focusing tube 800 that is again gathered, and the conductive material cylindrical shielding case 700 that wraps the hose. For reference, the above-described shielding case 700 has at least the length of the package sealing portion 300 and the first focusing tube 600.

The shape of the filament according to the third embodiment of the present invention is different from that of the first embodiment and the second embodiment in that it is a horizontal direction extending left and right in order to improve the straightness of the hot electrons. This structure can also be applied to the first embodiment and the second embodiment.

According to a third embodiment of the present invention, the first focusing tube is different from the first embodiment and the second embodiment described in the present invention, and a shielding wing portion is formed for the periphery of the first focusing tube in which the filament is hollow. It is extended in a radial shape and is attached to the inner wall of the hose.

Moreover, according to the first focus tube shielding wing portion, the lower portion of the second focusing tube of the hose is partitioned between the shielding wing portions of the first focusing tube and the shielding portion below the first focusing tube to the sealing portion. The space is divided into the second space. In this way, the thermal electrons generated in the No. 1 space are moved to the No. 2 space, and the efficiency of moving the hot electrons in the No. 1 space to the X-ray irradiation port is improved.

The steps according to the third embodiment of the present invention are as follows.

The hot electrons emitted by the filament located inside the first focusing tube pass through the first focusing tube, and then pass through the second focusing tube opposite to the first focusing tube and spaced apart from the first focusing tube, and the X-ray located in the upper portion of the second focusing tube Target collision at the irradiation port.

At this time, since the hot electrons collide with the target, the impurities which are detached from the target and become liquefied are formed inside the hose. Such impurities carry cations after colliding with other hot electrons released by the filament or the like. Part of the impurity carrying the cation will be adsorbed on the negative high voltage On the filament. In the case of the present invention, the cylindrical shielding casing having a conductive material on the outside of the wrapping hose also carries a negative high pressure state, so that a part of the cationic impurities is absorbed by the inner wall of the hose which is attached to the shielding casing.

Then, the amount of impurities adsorbed on the filament can be reduced as compared with a conventional X-ray tube which has not been shielded from the outer casing so far. The result is improved filament service life.

Meanwhile, according to the case of the third embodiment of the present invention, similar to the second embodiment, by providing the second focus tube, the hot electrons passing through the first focus tube, and the second focus tube are effectively transmitted to the X-ray irradiation. The mouth is more effective in improving the X-ray irradiation ability of the X-ray tube.

Moreover, according to the third embodiment of the present invention, the shielding wing portion formed on the outer surface of the first focusing tube is extended in a radial form, and is attached to the inner wall of the hose, and the hose is covered by the shielding wing portion of the first focusing tube. The upper space of the shielding duct of the first focusing tube (the first space) and the lower space of the shielding wing (the second space), this spatial separation blocks the movement of the hot electrons released into the first space by the filament to the second space, improving The probability of the hot electrons in the first space moving to the X-illumination port.

Moreover, according to the case of the third embodiment of the present invention, the filament 500 is formed in the horizontal direction.

The horizontal direction here means the horizontal direction at right angles to the length of the hose or the focus tube.

Generally, the filament is in the shape of a circular arc, and the hot electrons are released in the form of radiation. However, in the present invention, the filament is formed in a horizontal direction for the purpose of improving the probability of direct collision of hot electrons with the target.

Improved focus electronically focused X-rays according to the present invention Tube, including the following advantages:

1. A focusing tube is additionally provided to the lower portion of the X-ray irradiation port to efficiently move the hot electrons released from the filament to the target.

2. The negative high pressure inside the hose is supplied to the shielding shell, so that the impurities which are separated from the target into liquid state are absorbed by the inner wall of the hose, thereby reducing the probability of adsorption of the filament (-voltage) inside the focusing tube, thereby improving the filament life.

3. The first focusing tube forms a shielding wing, dividing the inner space of the hose into two, improving the probability of the hot electrons released from the filament moving to the X-ray irradiation port.

Claims (5)

An improved electron focusing X-ray tube comprising: a hollow non-conductive hose forming a body; an X-ray irradiation port shielding an upper portion of the hose, wherein a target opposed thereto emits hot electrons to emit X-ray; a sealing portion shielding the lower portion of the hose; extending from the outside of the sealing portion to the inside of the hose, and supplying a predetermined number of negative high-voltage wires; connected to the wire extending to the inside of the hose a filament that releases the hot electron; and a first focusing tube that wraps the filament for collecting the hot electrons released by the filament; the improved electronic focusing X-ray tube further comprises a conductive material covering the outer surface of the hose The shielding case; wherein the shielding case carries a voltage equal to a negative high voltage supplied to the wire. The electronic focus X-ray tube for improvement according to claim 1, further comprising an inner side of the hose opposite to the first focusing tube, disposed at a lower portion of the X-ray irradiation port, in order to The tube is released to the X-ray irradiation port to the target of the hot electrons, and the second focusing tube is again gathered. The electronic focusing X-ray tube for improvement according to claim 1 or 2, wherein the first focusing tube has a hollow cylindrical shape for the purpose of incorporating the filament, and the periphery of the first focusing tube and the soft The inner walls of the tubes are separated by a predetermined distance. The electronic focusing X-ray tube for improvement according to claim 1 or 2, wherein the first focusing tube is hollow, and the filament is embedded; the periphery of the first focusing tube forms a shielding wing, and the soft The inner space of the tube is the first space and the second space by the shielding wing portion, wherein the upper space of the shielding wing is the first space, and the lower space of the shielding wing is the second space. The electronic focus X-ray tube for improvement according to claim 4, wherein the filament opposite to the filament is elongated in a vertical horizontal direction.