CN115954250A - An X-ray tube for irradiation and its irradiation device - Google Patents

Abstract

The invention discloses an X-ray tube for irradiation and an irradiation device thereof. The X-ray tube for irradiation according to the present invention includes: the filament-type solar cell comprises a strip-shaped vacuum cavity, wherein a thermionic emission filament and an anode are arranged in the vacuum cavity; the thermal electron emission filament and the anode are oppositely arranged along the length direction of the vacuum cavity and are separated by vacuum; the thermal electron emission filament is fixed between the two metal electrodes penetrating through the vacuum cavity; the anode comprises a reflective metal target and a cooling pipeline fixed with the reflective metal target; the cooling pipeline penetrates through the vacuum cavity and is used for cooling the reflective metal target. The invention can output high-power X-rays. The irradiation device comprises a shielding shell with at least one inlet, wherein the shielding shell is used for preventing X-rays from leaking, and a shielding door is arranged at the inlet; one or more of the X-ray tubes for irradiation are distributed inside the shielding shell.

Description

An X-ray tube for irradiation and its irradiation device

technical field

The invention belongs to the field of ray irradiation, in particular to an X-ray tube for irradiation and an irradiation device thereof.

Background technique

X-ray irradiation has been used in many fields such as food processing, breeding, material modification, sterilization and disinfection of medical equipment, blood irradiation, etc., and has produced good economic benefits.

X-rays can be generated by an X-ray tube, which contains an electron-emitting cathode and anode in a closed vacuum chamber. The electrons emitted by the cathode are accelerated by high voltage and bombarded to the anode, and X-rays are emitted through bremsstrahlung or atomic energy level transitions. . Traditional X-ray tubes are mainly used to meet the needs of X-ray imaging in industrial or medical fields. To achieve high imaging resolution, the electrons emitted by the cathode must be focused and bombarded on a point as small as possible on the surface of the anode. Small focal spot size, so conventional X-ray tubes can be seen as point X-ray sources with smaller radiation space angles. On the one hand, the high-energy electron beam bombards a small point on the anode, causing the point to be subjected to high temperature locally. In order to prevent it from melting, the power of the X-ray tube is greatly limited. On the other hand, the small radiation space angle makes the spatial uniformity of X-ray radiation intensity poor; at the same time, the utilization rate of ray energy is low, and only about one percent of the energy of X-rays is effectively used. All of these make the traditional X-ray tube can only provide a small radiation power, which is difficult to meet the needs of radiation applications.

In order to overcome the above technical problems of traditional X-ray tubes, X-ray tubes specially used for irradiation have been invented in recent years. In order to achieve a large radiation space angle and improve the spatial uniformity of the radiation intensity, the American Rad Source Technology Company invented a linear transmission X-ray tube, which adopts a linear filament arranged along the axial direction of the cylindrical ray tube and along the inside of the cylindrical ray tube. The technical solution of the transmission-type target set on the wall realizes a linear X-ray tube with a 360-degree irradiation angle and good uniformity of axial irradiation intensity (US Patent: US 7346147 B2, US 2016/0189907 A1). Although there have been many improved X-ray tubes for irradiation at home and abroad, they still all adopt the technical scheme of transmission target and the target is arranged on the inner wall of the vacuum cavity of the X-ray tube (US Patent: US 9818569 B2; China Patents: 202022817990.1, 202221581224.2, 202110729700.4, 201210302279.X). However, in order to prevent X-rays from being absorbed by the target, the transmission target requires the metal target to be thin enough (generally a few microns thick), which increases the processing difficulty and cost, and weakens the target's ability to resist electron bombardment. Limits the power of the X-ray tube. In addition, the scheme that the target is arranged on the inner wall of the vacuum chamber of the X-ray tube increases the technical difficulty of cooling the X-ray tube. The current technical solutions either use air-cooling technology with poor cooling effect, or use a water-cooled layer around the X-ray tube or a water-cooled tube, which will significantly increase the proportion of X-rays absorbed and reduce the output of X-rays power.

Since the previous X-ray tubes for irradiation could not provide high-power X-ray output, previous X-ray irradiation devices have always been limited by low irradiation power. In addition, how to achieve uniform distribution of radiation intensity in three dimensions in the irradiated space is also a technical problem faced by X-ray irradiation devices before.

Contents of the invention

The purpose of the present invention is to invent an X-ray tube for irradiation that can output high-power X-rays for the above limitations of the previous X-ray tube and irradiation device, and further invent a high-irradiation X-ray tube on this basis. Irradiation device with power and three-dimensional uniform distribution of radiation intensity.

Technical scheme of the present invention is:

An X-ray tube for irradiation, characterized in that it comprises:

A sealed elongated vacuum cavity, a thermionic emission filament and an anode arranged inside the vacuum cavity;

The thermionic emission filament and the anode are arranged opposite to each other along the length direction of the vacuum cavity and separated by a vacuum;

The thermionic emission filament is fixed between two metal electrodes running through the vacuum chamber;

The anode includes a linear or strip reflective metal target, and a metal cooling pipe fixed to the metal target, and the cooling pipe runs through the vacuum chamber through two through holes on the vacuum chamber , the purpose of cooling the metal target is realized through the cooling liquid in the cooling pipeline.

Further, the X-ray tube for irradiation also includes a cooling device consisting of a cooling liquid, a power pump, a radiator, and a conduit. The conduit of the cooling device is connected to the cooling pipeline of the anode, and the cooling liquid Driven by the pump, the conduit and the cooling pipe circulate and flow between the radiator and the anode, so as to conduct heat away from the anode.

Further, the X-ray tube for irradiation also includes a power drive device, the power drive device applies a voltage to the thermionic emission filament through the two metal electrodes to make it emit electrons, and the thermal electron emission filament and A high voltage is applied between the anodes to generate X-rays, where the anode is grounded and the thermionic emission filament is applied with a negative high voltage.

Further, the vacuum cavity of the X-ray tube for irradiation is made of glass, and the metal electrode and the cooling pipeline are made of Kovar alloy.

Further, the thermal emission filament of the X-ray tube for irradiation is linear or helical, and is made of one or more of the following materials: tungsten, molybdenum, iridium, osmium, carbon, yttrium oxide, barium oxide , alumina, scandium oxide, calcium oxide, lanthanum hexaboride, samarium hexaboride.

Further, the metal target of the X-ray tube for irradiation is made of one or more of the following materials: tungsten, molybdenum, gold, silver, copper, chromium, rhodium, aluminum, niobium, tantalum, rhenium, iron, cobalt, nickel.

Further, the X-ray tube for irradiation also includes one or more filament support devices, the filament support devices are located inside the vacuum chamber and between the two metal electrodes to support thermal electrons emit filament.

An X-ray irradiation device is characterized in that it comprises:

A shielding shell with at least one entrance, the shielding shell is used to prevent X-rays from leaking out of the shell, the entrance is provided with a shielding door;

One or more X-ray tubes for irradiation as described above, the X-ray tubes for irradiation are distributed inside the shielding shell;

a cooling device as described above, providing cooling function for all said X-ray tubes for irradiation;

An above-mentioned power drive device, which provides power drive for all the X-ray tubes for irradiation;

One or more supports located inside the shielded enclosure for holding the object to be irradiated.

Further, the X-ray irradiation device includes a plurality of X-ray tubes for irradiation, and the plurality of X-ray tubes for irradiation are divided into two rows and arranged in parallel to each other, so as to obtain uniform irradiation intensity in three-dimensional space.

Further, the power pump and radiator of the cooling device of the X-ray irradiation device are located outside the shielding shell.

Further, the power drive device of the X-ray irradiation device is located outside the shielding shell.

Further, the X-ray irradiation device includes a sensor located inside the shielding shell to monitor the radiation dose rate or the accumulated radiation dose.

Further, the X-ray irradiation device includes a refrigeration device for controlling the temperature inside the shielding enclosure, and the outdoor unit and the indoor unit of the refrigeration device are respectively located outside and inside the shielding enclosure.

Further, the X-ray irradiation device includes a control system, and the control system intelligently controls the switching and coordination of the cooling device, the power drive device and the refrigeration device, so as to maintain a specific temperature inside the shielding shell, and the irradiated The purpose of irradiating an object to obtain a specific radiation dose.

Further, the X-ray irradiation device can be used for, but not limited to, the irradiation of the following objects: fruits, vegetables, meat, aquatic products, cooked food, cakes, starchy staple food, coarse grain staple food, seasoning, edible oil, grain , feed, snacks, Chinese medicinal materials, western medicine, health care products, tea, coffee, beverages, alcohol, dairy products, tobacco, medical appliances, medical waste, seeds.

Compared with the prior art, the beneficial effects of the present invention are:

1. The present invention adopts electron emission filaments and linear or strip-shaped reflective targets arranged along the length direction of the elongated vacuum cavity, which increases the thickness of the target and the area of the electron bombarded target, and reduces the impact of the target. The extremely melted pressure improves the working current and voltage of the X-ray tube and the X-ray power generated; at the same time, it realizes a 180-degree radiation angle and uniformly distributed radiation intensity along the length direction. Large angle and high power linear or strip X-ray output make the X-ray tube of the present invention have excellent irradiation effect in the field of X-ray irradiation.

2. The present invention also arranges a cooling pipeline fixed to the reflective target along the length direction of the X-ray tube, which can realize efficient cooling of the target through the cooling liquid, so that the X-ray tube can work at high power, thereby further ensuring the realization of High power X-ray output.

3. The X-ray tube of the present invention has a uniform radiation intensity in the longitudinal direction, and the plan that two rows of X-ray tubes are arranged in parallel makes it also have a relatively uniform radiation intensity in a plane perpendicular to the X-ray length direction, so this The inventive irradiation device has relatively uniform irradiation intensity in three directions in space.

Description of drawings

Fig. 1 is a schematic longitudinal cross-sectional view of an X-ray tube for irradiation of the present invention.

Fig. 2 is a schematic cross-sectional view of an X-ray tube for irradiation of the present invention.

Fig. 3 is a schematic longitudinal cross-sectional view of an X-ray tube for irradiation with a cooling device and a power drive device according to the present invention.

Fig. 4 is a schematic diagram of an irradiation device based on an X-ray tube for irradiation of the present invention.

Fig. 5 shows that the dotted line is the radiation intensity distribution of a single X-ray tube along the transverse direction of the irradiation device of the present invention, and the solid line is the overall irradiation intensity distribution along the transverse direction of the irradiation device of the present invention.

In Fig. 6, the dotted line is the radiation intensity distribution of a single X-ray tube along the longitudinal direction of the irradiation device, and the solid line is the overall radiation intensity distribution along the longitudinal direction of the irradiation device.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings, and the examples given are only used to explain the present invention, and are not intended to limit the scope of the present invention.

Example 1:

Referring to Fig. 1 and Fig. 2, Fig. 1 and Fig. 2 are schematic longitudinal and transverse cross-sectional views of an X-ray tube for irradiation provided in Embodiment 1 of the present application, respectively.

An X-ray tube for irradiation, comprising:

A sealed elongated cylindrical vacuum chamber 1, a thermionic emission filament 2 and an anode arranged inside the vacuum chamber 1;

The thermionic emission filament 2 and the anode are arranged opposite to each other along the length direction of the vacuum chamber 1 and separated by a vacuum;

The thermionic emission filament 2 is fixed between two metal electrodes (the first metal electrode 51 and the second metal electrode 52) that run through the vacuum chamber;

The anode includes a strip-shaped reflective metal target 3, and a metal cooling pipeline 4 fixed to the metal target 3, and has good mechanical contact and thermal contact between the metal target 3 and the cooling pipeline 4, and the cooling The pipeline 4 runs through the vacuum chamber 1 through two through holes (i.e., the first through hole 41 and the second through hole 42) on the vacuum chamber 1, and the metal target is cooled by the cooling liquid in the cooling pipeline 4. purpose of pole 3;

A filament support device 6, the filament support device 6 is located inside the vacuum chamber and between the two metal electrodes, for supporting the thermionic emission filament.

The vacuum cavity 1 of the X-ray tube used for irradiation in this embodiment is made of glass, and the metal electrodes (the first metal electrode 51 and the second metal electrode 52 ) and the metal cooling pipe 4 are made of Kovar alloy.

The thermal emission filament 2 of the X-ray tube for irradiation in this embodiment is linear or helical, and is made of one or more of the following materials: tungsten, molybdenum, iridium, osmium, carbon, yttrium oxide, barium oxide, Aluminum oxide, scandium oxide, calcium oxide, lanthanum hexaboride, samarium hexaboride.

The metal target 3 of the X-ray tube used for irradiation in this embodiment is made of one or more of the following materials: tungsten, molybdenum, gold, silver, copper, chromium, rhodium, aluminum, niobium, tantalum, rhenium, iron, cobalt ,nickel.

Example 2:

See FIG. 3 , which is a schematic longitudinal cross-sectional view of an X-ray tube for irradiation provided in Embodiment 2 of the present application.

In addition to all the parts of the X-ray tube described in Embodiment 1, the X-ray tube for irradiation in this embodiment also includes a cooling device consisting of a power pump 7, a radiator 8, a cooling liquid 9, and a conduit 10. The conduit 10 of the cooling device is connected to the cooling pipeline 4 of the anode through two connectors (the first connector 111 and the second connector 112), and the cooling liquid 9 is driven by the power pump 7 to pass through the conduit 10 and the cooling The pipeline 4 circulates between the radiator 8 and the anode (including the metal target 3 and the cooling pipeline 4 ), so as to conduct heat away from the metal target 3 .

The X-ray tube for irradiation in this embodiment also includes a power drive device made up of a power source 121 and a power source 122. The power drive device passes the power source 121 through the two metal electrodes (the first metal electrode 51 and the second metal electrode 51). The electrode 52) applies a voltage to the thermionic emission filament 2 to make it emit electrons, and applies a high voltage between the thermionic emission filament 2 and the metal target 3 through the power supply 122 to generate X-rays, wherein the anode is grounded through the cooling pipeline 4, and the thermal A negative high voltage is applied to the electron emission filament 2 .

The X-ray tube of this embodiment works in the following way: the thermionic emission filament 2 is applied a voltage to emit electrons through the power supply 121 through the two metal electrodes (the first metal electrode 51 and the second metal electrode 52), and the power supply 122 applies a high voltage between the thermionic emission filament 2 and the target 3, electrons are accelerated by the high voltage and bombard the ribbon target, and then emit X-rays through bremsstrahlung or atomic level transition. Because this embodiment adopts the reflective metal target 3, the thickness of the target can be thicker than 1mm, and it is made of high-melting-point metals such as tungsten and molybdenum. At the same time, the electron beam bombards the entire strip target surface, which makes the target difficult to Melting, so the X-ray tube can work at relatively large electron beam current and accelerating voltage, and generate relatively high-power X-rays. In addition, X-rays are uniformly radiated from the strip-shaped target, and the radiation angle can reach 180 degrees, so a strip-shaped X-ray source with uniform distribution along the length direction and a large radiation angle can be obtained (see Figure 2). On the other hand, the heat generated by the target 3 can be quickly conducted away through the cooling pipe 4 and dissipated through the radiator 8, which further ensures that the X-ray tube of this embodiment can work at a relatively high power.

The cooling liquid in this embodiment can be water and other substances suitable for cooling liquid.

Example 3:

Referring to FIG. 4 , FIG. 4 is a schematic diagram of an irradiation device based on the X-ray tube for irradiation in Example 2 provided in Example 3 of the present application.

An X-ray irradiation device, comprising:

A shielding shell 14 with an entrance, the shielding shell is used to prevent X-rays from leaking out of the shell, and a shielding door 141 is provided at the entrance;

6 X-ray tubes 15 for irradiation described in Embodiment 2, the 6 X-ray tubes are divided into two rows and distributed in parallel on the upper and lower sides of the shielding shell 14;

A bracket 16 located in the middle of the shielding shell for placing the irradiated object 17;

A sensor 18 installed on the bracket 16 for monitoring the radiation dose rate or the cumulative radiation dose;

A cooling device 19 provides cooling function for the above six X-ray tubes 15 at the same time, and the power pump and radiator of the cooling device 19 are located outside the shielding shell 14;

A power drive device 20 provides power drive for all the above six irradiation X-ray tubes at the same time, and the power drive device 20 is located outside the shielding shell 14;

A refrigerating device 21 for controlling the temperature inside the shielding enclosure, the outdoor unit 211 and the indoor unit 212 of the refrigerating device are respectively located outside and inside the shielding enclosure.

A control system 22, the control system intelligently controls the switching and coordination of the cooling device 19, the power drive device 20 and the cooling device 21, so as to maintain a specific temperature inside the shielding shell 14 and obtain a specific radiation for the irradiated object 17. According to the purpose of dosage.

The above control system 22 and the cooling device power pump 7 , the power drive device 20 , and the refrigeration device 21 are connected with necessary electric wires for control.

The irradiated object 17 can be but not limited to the following substances: fruits, vegetables, meat, aquatic products, cooked food, cakes, starchy staple food, coarse grain staple food, seasoning, edible oil, grain, feed, snacks, Chinese medicinal materials, Western medicine, health products, tea, coffee, beverages, alcohol, dairy products, tobacco, medical devices, medical waste, seeds.

The irradiation device works in the following manner: (1) under the condition that all X-ray tubes 15 are closed, the irradiated object 17 enters the shielding shell 14 through the shielding door 141 and is placed on the support 16; (2) Close the screen door, and set the temperature inside the shielding case 14 and the radiation dose of the irradiated object 17 as required, and start the control system 22 to control the opening and coordination of the cooling device 19, the power drive device 20 and the refrigeration device 21 , after reaching the irradiation temperature and dose, the control system 22 automatically shuts down the cooling device 19, the power drive device 20 and the refrigeration device 21; (3) Take out the irradiated object through the screen door 141.

In this embodiment, in the lateral direction of the irradiation device, the X-ray tubes are arranged in parallel at intervals, so that uniform irradiation intensity can be obtained in the lateral direction (as shown in FIG. 5 ). In the longitudinal direction of the irradiation device, a layout in which two rows of X-ray tubes are arranged in parallel and facing each other is adopted, which makes the irradiation intensity uniform in the longitudinal direction (as shown in Figure 6). In addition, the X-ray tube for irradiation of the present invention also has a uniform radiation intensity distribution along the length direction of the X-ray tube (ie, the direction perpendicular to the plane of the irradiation device in FIG. 4 ). Therefore, the irradiation device of this embodiment obtains uniform radiation intensity in three spatial directions, which well solves the technical problem of uneven spatial distribution of irradiation intensity in previous irradiation devices. In addition, the X-ray tube for irradiation of the present invention can provide relatively high-power X-ray irradiation. These make the irradiation device of this embodiment have better irradiation performance than the previous irradiation device.

Although specific embodiments of the present invention are disclosed for the purpose of illustration, the purpose is to help understand the content of the present invention and implement it accordingly. Those skilled in the art can understand that: without departing from the spirit and scope of the present invention and the appended claims Inside, various substitutions, changes and modifications are possible. Therefore, the present invention should not be limited to the content disclosed in the preferred embodiment, and the protection scope of the present invention is subject to the scope defined in the claims.

Claims (10)

1. An X-ray tube for irradiation, comprising:

the filament-type solar cell comprises a strip-shaped vacuum cavity, wherein a thermionic emission filament and an anode are arranged in the vacuum cavity; the thermionic emission filament and the anode are oppositely arranged along the length direction of the vacuum cavity and are separated by vacuum;

the thermal electron emission filament is fixed between the two metal electrodes penetrating through the vacuum cavity;

the anode comprises a reflective metal target and a cooling pipeline fixed with the reflective metal target; the cooling pipeline penetrates through the vacuum cavity and is used for cooling the reflective metal target.

2. The X-ray tube for irradiation of claim 1, wherein the reflective metal target is a linear or ribbon reflective metal target.

3. The X-ray tube for irradiation of claim 1, further comprising a cooling device comprising a cooling fluid, a power pump, a heat sink, and a conduit, wherein the conduit is connected to the cooling tube, and wherein the cooling fluid is driven by the power pump to circulate between the heat sink and the anode through the conduit and the cooling tube.

4. The X-ray tube for irradiation of claim 1, 2 or 3, further comprising a power driving means for applying a voltage to the thermionic emission filament via the two metal electrodes to cause it to emit electrons, and applying a high voltage between the thermionic emission filament and the anode to generate X-rays, wherein the anode is grounded, and the thermionic emission filament is negatively pressurized.

5. The X-ray tube for irradiation according to claim 1, 2 or 3, wherein the vacuum chamber is made of glass, and the metal electrode and the cooling duct are made of kovar alloy; and a filament supporting device is arranged in the vacuum cavity and is positioned between the two metal electrodes to support the thermionic emission filament.

6. The X-ray tube for irradiation of claim 1, 2 or 3, wherein the heat emitting filament is linear or spiral and is made of one or more of the following materials: tungsten, molybdenum, iridium, osmium, carbon, yttrium oxide, barium oxide, aluminum oxide, scandium oxide, calcium oxide, lanthanum hexaboride, and samarium hexaboride; the reflective metal target is made of one or more of the following materials: tungsten, molybdenum, gold, silver, copper, chromium, rhodium, aluminum, niobium, tantalum, rhenium, iron, cobalt, nickel.

7. An irradiation device, comprising

A shielding shell with at least one inlet, wherein the shielding shell is used for preventing X-rays from leaking, and a shielding door is arranged at the inlet;

one or more X-ray tubes for irradiation as defined in claim 1 distributed inside the shielded enclosure;

a cooling device for connecting with the cooling pipeline of the X-ray tube for irradiation;

a power supply driving device for providing power supply drive for all the X-ray tubes for irradiation;

one or more supports located inside the shielding shell for placing the irradiated object.

8. The irradiation device according to claim 7, wherein the shielding case contains a plurality of said X-ray tubes for irradiation inside, and the plurality of said X-ray tubes for irradiation are divided into two rows arranged in parallel and oppositely to obtain irradiation intensity with uniform distribution in three-dimensional space.

9. The irradiation device of claim 7, wherein the cooling device comprises a cooling fluid, a power pump, a heat sink, a conduit, the power pump, heat sink being located outside the shielded enclosure; the guide pipe is connected with the cooling pipeline, and the cooling liquid circularly flows between the radiator and the anode through the guide pipe and the cooling pipeline under the driving of the power pump; the power supply driving device is positioned outside the shielding shell; and a sensor for monitoring the irradiation dose rate or accumulating the irradiation dose is arranged in the shielding shell.

10. The irradiation device of claim 7, further comprising a refrigeration device for controlling the internal temperature of said shielded enclosure; the outdoor unit and the indoor unit of the refrigerating device are respectively positioned outside and inside the shielding shell.

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