阅读说明：本技术 一种用于小型中子发生器的双层石英玻璃管型高压单元 (Double-layer quartz glass tube type high-voltage unit for small neutron generator ) 是由 陈红涛 赵芳 张凯 阮锡超 侯龙 刘世龙 龚新宝 刘邢宇 张坤 于 2020-05-26 设计创作，主要内容包括：本发明属于中子发生器技术领域,具体涉及一种用于小型中子发生器的双层石英玻璃管型高压单元,包括设置在直管型的冷却液导流管(2)的两端的高压输入模块(1)和靶电极(3),靶电极(3)外部为光滑的外壳体,内部设有靶片(24),冷却液导流管(2)内部设有能够通过冷却液的循环流道,用于为靶片(24)制冷；高压输入模块(1)通过贯穿在冷却液导流管(2)内部的高压连接杆(20)向靶电极(3)提供高压电。高压输入模块(1)简单小巧,可避免高压输入时发生高压打火,能承载130kV高电压；冷却液导流管(2)的电击穿电压达到35kV/mm；靶电极(3)中所有不规则结构和尖端都在靶电极(3)内部,保证了电场分布的均匀性,可有效抑制二次电子。(The invention belongs to the technical field of neutron generators, and particularly relates to a double-layer quartz glass tube type high-voltage unit for a small-sized neutron generator, which comprises a high-voltage input module (1) and a target electrode (3) which are arranged at two ends of a straight-tube type cooling liquid guide tube (2), wherein the outside of the target electrode (3) is a smooth outer shell, a target sheet (24) is arranged inside the target electrode, and a circulating flow passage capable of passing through cooling liquid is arranged inside the cooling liquid guide tube (2) and used for refrigerating the target sheet (24); the high-voltage input module (1) provides high voltage electricity to the target electrode (3) through a high-voltage connecting rod (20) penetrating through the cooling liquid guide pipe (2). The high-voltage input module (1) is simple and small, can avoid high-voltage ignition during high-voltage input, and can bear 130kV high voltage; the electric breakdown voltage of the cooling liquid guide pipe (2) reaches 35 kV/mm; all irregular structures and tips in the target electrode (3) are arranged in the target electrode (3), so that the uniformity of electric field distribution is ensured, and secondary electrons can be effectively inhibited.)

1. A double-layer quartz glass tube type high-voltage unit for a small neutron generator is characterized in that: the device comprises a high-voltage input module (1) and a target electrode (3) which are arranged at two ends of a straight-tube type cooling liquid guide pipe (2), wherein the outside of the target electrode (3) is a smooth outer shell, a target sheet (24) is arranged inside the target electrode, and a circulating flow passage capable of passing through cooling liquid is arranged inside the cooling liquid guide pipe (2) and used for refrigerating the target sheet (24); the high-voltage input module (1) provides high-voltage electricity to the target electrode (3) through a high-voltage connecting rod (20) penetrating through the cooling liquid guide pipe (2).

2. The double-quartz glass tube type high voltage unit for a small neutron generator of claim 1, wherein: the target electrode (3) comprises a cylindrical outer shell which is composed of a target base (18) and an electrode (19) and has a smooth appearance, and a target sheet (24) which is arranged on the target base (18) and is positioned in the outer shell, wherein a cooling liquid channel (29) is arranged on the target base (18), and a beam current channel (30) is arranged on the electrode (19);

the target base (18) is made of copper materials and is cylindrical, one end of the target base is provided with the cooling liquid channel (29), the other end of the target base is provided with an inclined plane (31) with a target sheet opening (32), and a target base inner cavity (33) is formed between the inclined plane (31) and the cooling liquid channel (29); one end of the cooling liquid channel (29) positioned on the outer shell is an arc-shaped opening, and the surface of the cooling liquid channel is smooth and has no sharp edges; the electrode (19) is a stainless steel cylinder, one end of the electrode is the beam channel (30) and is an arc-shaped opening, the surface of the electrode is smooth, no sharp corner exists, the other end of the electrode is an opening with internal threads, and the electrode is connected with the target base (18) through threads;

the angle of the inclined plane (31) is 45 degrees, the target sheet (24) is arranged on the target sheet opening (32) in a sealing mode, and the target sheet (24) is connected with the inclined plane (31) in an insulating and sealing mode; the edge of one side of the target sheet opening (32) facing the beam current channel (30) is provided with a groove, and the target sheet (24) is arranged in the groove; a second sealing ring (25) is arranged between the target sheet (24) and the groove, the target sheet (24) is pressed on the second sealing ring (25) through a pressing ring (23), and the insulating sealing connection between the target sheet (24) and the inclined plane (31) is realized;

the tail end of the high-pressure connecting rod (20) extends into the target base inner cavity (33) through the cooling liquid channel (29), and the tail end of the high-pressure connecting rod (20) is L-shaped and is connected to the side wall of the target base (18); the high-pressure connecting rod (20) is made of stainless steel; the top end of the high-voltage connecting rod (20) is provided with a high-voltage connector (17) for connecting high-voltage electricity; the high-voltage connector (17) is made of copper;

further comprising a resistor (26) connected between the pressure ring (23) and the target base (18);

still including setting up a pair of permanent magnet (27) in electrode (19), permanent magnet (27) are the rectangle thin slice, set up through iron sheet support (28) in electrode (19), are located inclined plane (31) with position between beam current passageway (30), the N utmost point and the S utmost point of permanent magnet (27) set up relatively.

3. The double-quartz glass tube type high voltage unit for a small neutron generator of claim 2, wherein: the second sealing ring (25) is made of polytetrafluoroethylene, and the thickness of the second sealing ring is larger than the depth of the groove; the inclined plane (31) is provided with a plurality of threaded holes, the compression ring (23) is connected with the inclined plane (31) through screws (22) and the threaded holes, and bakelite insulating sleeves (21) are sleeved on the peripheries of the screws (22);

the target sheet (24) is a disc-shaped molybdenum sheet, the diameter of the target sheet is smaller than that of the groove, and one surface of the target sheet (24) is plated with titanium and then adsorbs deuterium or tritium to form a deuterium target or a tritium target;

clamping ring (23) are stainless steel ring, the external diameter with target piece (24) constant diameter, the internal diameter is greater than the active area of target piece (24), the anchor ring of clamping ring (23) is equipped with and is used for installing the screw through-hole of screw (22).

4. The double-quartz glass tube type high voltage unit for a small neutron generator of claim 2, wherein: the cooling liquid guide pipe (2) comprises an outer pipe (15) and an inner pipe (16) arranged in the outer pipe (15), the outer pipe (15) and the inner pipe (16) form a sleeve structure, the top end of the inner pipe (16) is located inside the outer pipe (15), and a space between the inner wall of the outer pipe (15) and the outer wall of the inner pipe (16) and an inner space of the inner pipe (16) jointly form the circulating flow channel; the outer wall of the top end of the inner tube (16) is connected with the inner wall of the outer tube (15) in a sealing mode, the tail ends of the inner tube (16) and the outer tube (15) are arranged on the target electrode (3), and the outer tube (15) is connected with the target electrode (3) in a sealing mode and used for supporting the target electrode (3); the outer tube (15) and the inner tube (16) are made of quartz glass;

the tail end of the outer pipe (15) is arranged in the cooling liquid channel (29), and the outer wall of the opening at the tail end of the outer pipe (15) is in sealing connection with the cooling liquid channel (29); the opening of the tail end of the inner tube (16) extends into the target base inner cavity (33);

the main body of the high-pressure connecting rod (20) penetrates through the inner pipe (16), and the high-pressure joint (17) at the top end of the high-pressure connecting rod (20) extends out of the top end of the outer pipe (15);

the insulation device is characterized by further comprising an insulation external thread ring (12) arranged on the outer wall of the top end of the outer pipe (15), wherein an external thread is arranged on the outer wall of the insulation external thread ring (12);

the high-voltage connector (17) at the top end of the high-voltage connecting rod (20) penetrates through the insulating threaded plug (11) to extend out of the top end of the outer tube (15), the insulating threaded plug (11) is used for plugging the top end of the outer tube (15), and the insulating threaded plug (11) is in sealing connection with the high-voltage connecting rod (20);

the insulating gland (9) is used for matching with the external thread of the insulating external thread ring (12) to press the insulating threaded plug (11) on the top end of the outer pipe (15);

the sealing structure further comprises a first sealing ring (10) arranged between the insulating gland (9) and the insulating external thread ring (12) and used for realizing sealing between the insulating gland (9) and the insulating external thread ring (12);

the cooling system is characterized by further comprising a cooling liquid input pipe (13), wherein one end of the cooling liquid input pipe (13) penetrates through the side wall of the outer pipe (15) to be communicated with the inner pipe (16), the other end of the cooling liquid input pipe is used for being connected with an outlet of an external circulating cooler, and the cooling liquid input pipe (13) is hermetically connected with the side wall of the outer pipe (15); the cooling system also comprises a cooling liquid output pipe (14), one end of the cooling liquid output pipe (14) is communicated with the outer pipe (15), and the other end of the cooling liquid output pipe is used for being connected with an inlet of an external circulating cooler;

the cooling liquid input pipe (13) and the cooling liquid output pipe (14) are arranged at positions close to the top end of the inner pipe (16), and the cooling liquid input pipe (13) and the cooling liquid output pipe (14) are perpendicular to the outer pipe (15) and are oppositely positioned on two sides of the outer pipe (15).

5. The double-layer quartz glass tube type high voltage unit for a small neutron generator of claim 4, wherein: the insulating threaded plug (11) and the insulating gland (9) are made of polytetrafluoroethylene, and the insulating external thread ring (12) is made of organic glass; the cooling liquid input pipe (13) and the cooling liquid output pipe (14) are made of quartz glass; the cooling liquid is fluorinated liquid.

6. The double-layer quartz glass tube type high voltage unit for a small neutron generator of claim 4, wherein: the high-voltage input module (1) comprises a T-shaped insulator (8) with a high-voltage wire (4) arranged inside, and the high-voltage connector (17) at the top end of the high-voltage connecting rod (20) is arranged in the T-shaped insulator (8) and connected with the high-voltage wire (4).

7. The double-layer quartz glass tube type high voltage unit for a small neutron generator of claim 6, wherein: the high-voltage connector (17) is hermetically connected with the T-shaped insulator (8) through the insulating threaded plug (11) and the threads of the T-shaped insulator (8); a groove is formed in the side surface of the high-pressure joint (17); the top end of the high-voltage wire (4) is provided with a round-head copper cap (7), the high-voltage wire (4) is arranged in the T-shaped insulator (8) through a piston sleeve plug (5), and the round-head copper cap (7) is fixed in the T-shaped insulator (8) through an insulating fixing plug (6); the round-head copper cap (7) is arranged in the groove of the high-voltage connector (17) to realize the connection between the high-voltage connector (17) and the high-voltage wire (4); the piston sleeve plug (5) is connected with the T-shaped insulator (8) in a sealing mode through threads.

8. The double-layer quartz glass tube type high voltage unit for a small neutron generator of claim 6, wherein: the T-shaped insulator (8), the insulating fixing plug (6) and the piston sleeve plug (5) are made of polytetrafluoroethylene.

Technical Field

The invention belongs to the technical field of neutron generators, and particularly relates to a double-layer quartz glass tube type high-voltage unit for a small neutron generator.

Background

The small neutron generator is distinguished by small size, light weight, easy movement and practical use, which requires small size and compact structure of the individual units constituting the generator. The small neutron generator mainly comprises an ion source, a high-voltage unit, a vacuum unit and an electric unit, and the basic working principle is that the ion source generates D⁺Lifting D by means of an acceleration unit⁺The energy of the energy is used for target shooting to generate nuclear reaction and generate neutrons, and the high voltage required to be loaded by the acceleration unit is generally over 100 kV. Lifting D⁺The energy of (A) is determined by placing the ion source at a high potential, the target at ground potential, and applying a positive high voltage to the ion source to cause D⁺Accelerating under the action of electric field to raise its energy, placing ion source at ground potential, placing target at high potential, and loading high negative voltage to target to raise D⁺The energy of the electric field is increased by the forced acceleration under the action of the electric field. In the first method, the power supply, the gas supply device and the cooling device related to the ion source are required to be installed at a high potential which is the same as the potential of the ion source, the ion source is required to be insulated, an accelerating unit and insulators are required to be installed between the ion source and the target, the insulation grade in the atmosphere reaches more than 100kV, and the length of each insulator is equal to or more than 100kVReaching more than dozens of centimeters, resulting in large volume of the whole device. The second method is that since the ion source is at ground potential, its associated power supply and the like can be installed at ground potential without insulation, and further, this method can place the target in a vacuum chamber, D⁺The energy boost of (2) can be accelerated by adopting a gap, the insulation between the ion source and the target can be vacuum insulation, the size of the gap only needs a few centimeters, and the problems of high-voltage insulation, cooling, supporting and high-voltage feed-in between the target and the ground in vacuum need to be solved.

Disclosure of Invention

The invention aims to research a compact high-voltage unit structure aiming at the technical requirements of a small neutron generator and solve the problems of high-voltage feeding, supporting, insulating and cooling at a high-potential target end.

In order to achieve the purposes, the technical scheme adopted by the invention is a double-layer quartz glass tube type high-voltage unit for a small neutron generator, wherein the double-layer quartz glass tube type high-voltage unit comprises a high-voltage input module and a target electrode which are arranged at two ends of a straight-tube type cooling liquid guide tube, the outside of the target electrode is a smooth outer shell, a target sheet is arranged inside the target electrode, and a circulating flow passage capable of passing through cooling liquid is arranged inside the cooling liquid guide tube and used for refrigerating the target sheet; the high-voltage input module provides high-voltage electricity to the target electrode through a high-voltage connecting rod penetrating through the cooling liquid guide pipe.

Furthermore, the target electrode comprises a cylindrical outer shell which is composed of a target base and an electrode and has a smooth surface, and a target sheet which is arranged on the target base and is positioned in the outer shell, wherein the target base is provided with a cooling liquid channel, and the electrode is provided with a beam channel;

the target base is made of copper materials and is cylindrical, one end of the target base is provided with the cooling liquid channel, the other end of the target base is an inclined plane provided with a target sheet opening, and a target base inner cavity is formed between the inclined plane and the cooling liquid channel; one end of the cooling liquid channel, which is positioned at the outer shell, is an arc-shaped opening, and the surface of the cooling liquid channel is smooth and has no sharp edges; the electrode is a stainless steel cylinder, one end of the electrode is the beam channel, is an arc-shaped opening, has a smooth surface without sharp edges and corners, and the other end of the electrode is an opening with internal threads and is connected with the target base through threads;

the angle of the inclined plane is 45 degrees, the target sheet is arranged on the opening of the target sheet in a sealing mode, and the target sheet is connected with the inclined plane in an insulating and sealing mode;

the edge of one side of the target sheet opening, which faces the beam current channel, is provided with a groove, and the target sheet is arranged in the groove; a second sealing ring is arranged between the target sheet and the groove, and the target sheet is tightly pressed on the second sealing ring through a pressing ring so as to realize the insulating sealing connection between the target sheet and the inclined plane;

the tail end of the high-pressure connecting rod penetrates through the cooling liquid channel to extend into the target base inner cavity, and the tail end of the high-pressure connecting rod is L-shaped and connected to the side wall of the target base; the high-pressure connecting rod is made of stainless steel; the top end of the high-voltage connecting rod is provided with a high-voltage connector for connecting high-voltage electricity; the high-voltage connector is made of copper;

the resistance is connected between the pressure ring and the target base;

the permanent magnet is a rectangular thin sheet and is arranged in the electrode through an iron sheet support, the permanent magnet is positioned on the inclined plane and between the beam current channels, and the N pole and the S pole of the permanent magnet are arranged oppositely.

Furthermore, the second sealing ring is made of polytetrafluoroethylene, and the thickness of the second sealing ring is larger than the depth of the groove; the inclined plane is provided with a plurality of threaded holes, the compression ring is connected with the inclined plane through screws and the threaded holes, and bakelite insulating sleeves are sleeved on the peripheries of the screws;

the target sheet is a disc-shaped molybdenum sheet, the diameter of the target sheet is smaller than that of the groove, and deuterium or tritium is adsorbed on one surface of the target sheet after titanium plating to form a deuterium target or tritium target;

the clamping ring is a stainless steel circular ring, the outer diameter of the clamping ring is equal to the diameter of the target sheet, the inner diameter of the clamping ring is larger than the active area of the target sheet, and the annular surface of the clamping ring is provided with a screw through hole for mounting the screw.

Further, the cooling liquid guide pipe comprises an outer pipe and an inner pipe arranged in the outer pipe, the outer pipe and the inner pipe form a sleeve structure, the top end of the inner pipe is positioned in the outer pipe, and a space between the inner wall of the outer pipe and the outer wall of the inner pipe and an inner space of the inner pipe jointly form the circulating flow channel; the outer wall of the top end of the inner tube is hermetically connected with the inner wall of the outer tube, the tail ends of the inner tube and the outer tube are arranged on the target electrode, and the outer tube is hermetically connected with the target electrode and used for supporting the target electrode; the outer tube and the inner tube are made of quartz glass;

the tail end of the outer pipe is arranged in the cooling liquid channel, and the outer wall of the opening at the tail end of the outer pipe is in sealing connection with the cooling liquid channel; the opening at the tail end of the inner tube extends into the target substrate inner cavity;

the main body of the high-pressure connecting rod penetrates through the inner pipe, and the high-pressure joint at the top end of the high-pressure connecting rod extends out of the top end of the outer pipe;

the outer tube is characterized by also comprising an insulating external thread ring arranged on the outer wall of the top end of the outer tube, wherein the outer wall of the insulating external thread ring is provided with an external thread;

the high-voltage connector at the top end of the high-voltage connecting rod penetrates through the insulating threaded plug and extends out of the top end of the outer tube, the insulating threaded plug is used for plugging the top end of the outer tube, and the insulating threaded plug is in sealing connection with the high-voltage connecting rod;

the insulating gland is used for matching with the external thread of the insulating external thread ring to press the insulating threaded plug on the top end of the outer tube;

the first sealing ring is arranged between the insulating gland and the insulating external thread ring and used for realizing sealing between the insulating gland and the insulating external thread ring;

the cooling system further comprises a cooling liquid input pipe, one end of the cooling liquid input pipe penetrates through the side wall of the outer pipe to be communicated with the inner pipe, the other end of the cooling liquid input pipe is used for being connected with an outlet of an external circulating cooler, and the cooling liquid input pipe is in sealing connection with the side wall of the outer pipe; the cooling system also comprises a cooling liquid output pipe, wherein one end of the cooling liquid output pipe is communicated with the outer pipe, and the other end of the cooling liquid output pipe is used for connecting an inlet of an external circulating cooler;

the cooling liquid input pipe and the cooling liquid output pipe are arranged at positions close to the top end of the inner pipe, and the cooling liquid input pipe and the cooling liquid output pipe are perpendicular to the outer pipe and are oppositely located on two sides of the outer pipe.

Furthermore, the insulating threaded plug and the insulating gland are made of polytetrafluoroethylene, and the insulating external thread ring is made of organic glass; the cooling liquid input pipe and the cooling liquid output pipe are made of quartz glass; the cooling liquid is fluorinated liquid.

Further, the high-voltage input module comprises a T-shaped insulator, a high-voltage wire is arranged in the T-shaped insulator, and the high-voltage connector at the top end of the high-voltage connecting rod is arranged in the T-shaped insulator and connected with the high-voltage wire.

Further, the high-voltage connector is hermetically connected with the T-shaped insulator through the insulating threaded plug and the threads of the T-shaped insulator; a groove is formed in the side face of the high-pressure joint; the top end of the high-voltage wire is provided with a round-head copper cap, the high-voltage wire is arranged in the T-shaped insulator through a piston sleeve plug, and the round-head copper cap is fixed in the T-shaped insulator through an insulating fixing plug; the round-head copper cap is arranged in the groove of the high-voltage connector, so that the high-voltage connector is connected with the high-voltage wire; the piston sleeve plug is connected with the T-shaped insulator in a sealing mode through threads.

Furthermore, the T-shaped insulator, the insulating fixing plug and the piston sleeve plug are made of polytetrafluoroethylene.

The invention has the beneficial effects that:

1. the polytetrafluoroethylene has the insulation grade equivalent to that of ceramic, the machining performance is superior to that of ceramic, and the polytetrafluoroethylene is soft in material and beneficial to thread sealing. The polytetrafluoroethylene is used as the main materials of the T-shaped insulator 8, the insulating fixing plug 6 and the loop plug 5 in the high-voltage input module 1, so that the high-voltage input module 1 has a simple structure and a small size, avoids high-voltage ignition during high-voltage input and has high safety performance.

2. Because the target electrode 3 needs to be arranged in the vacuum chamber, the cross section size of the high-voltage input module 1 made of polytetrafluoroethylene as a main material is smaller than that of a structure made of other materials such as ceramic, water and transformer oil, so that the size of the target electrode 3 is reduced, the size of the vacuum chamber is reduced, the overall structure is simplified, and the system size of the neutron generator is reduced.

3. The high voltage input module 1 can carry a high voltage of 130 kV.

4. The cooling liquid guide pipe 2 is made of quartz glass, because the quartz glass is equivalent to ceramic and polytetrafluoroethylene in insulation grade, the mechanical strength and the vacuum performance are equivalent to ceramic and superior to those of the polytetrafluoroethylene, the electric breakdown voltage reaches 35kV/mm, the welding is facilitated, the mechanical strength is high, and the structure of a small-size circulating flow channel required by the cooling liquid guide pipe 2 is easy to process. In addition, the quartz glass and the metal are easy to be bonded to form a firm whole, so that the quartz glass and the metal are easy to be connected with the target electrode 3 in a sealing way.

5. The fluorinated liquid has good insulating property, flowing property and heat-conducting property, the three properties are superior to those of transformer oil, the flowing property is equivalent to that of water, and the heat-conducting property is inferior to that of water. No poison, odour, no volatilization and corrosion. Is an excellent insulating cooling liquid, and can reduce and simplify the system structure and volume.

6. The target electrode 3 is a cylinder with an arc-shaped end face after being assembled, and all irregular structures and tips are arranged inside the target electrode 3, so that the uniformity of electric field distribution is ensured.

7. The target base 18 is bonded with the cooling liquid guide pipe 2, the cooling liquid is guided to the target piece 24 through the inner tube 16 of the cooling liquid guide pipe 2, the target piece 24 is cooled, and then the cooling liquid flows into a circulating flow channel between the inner tube 16 and the outer tube 15 of the cooling liquid guide pipe 2 through the target base inner cavity 33 below the target piece 24 to be guided out, so that the target piece 24 is cooled circularly.

8. The beam current is D⁺Particles, positive charges impinging on the target surface of the target 24 will flow through the resistor 26 to the electrodesThe electrode 19 forms a voltage difference between the target surface and the electrode 19, generates a power line with a direction pointing from the target surface to the inner wall of the electrode 19, forms a self-suppression electric field, and secondary electrons generated on the target surface reversely move under the action of the electric field and hit the target surface to be lost. Secondary electrons are prevented from moving toward the acceleration field region.

9. The transverse magnetic field generated by the permanent magnet 27 on the inner wall of the electrode 19 deflects the secondary electrons generated by the target surface in the process of moving to the acceleration field region, and the secondary electrons strike the inner wall of the electrode 19 and are eliminated, so that the secondary electrons are prevented from entering the acceleration field region.

10. The self-suppression electric field and the transverse magnetic field generated by the permanent magnet 27 play a double-layer suppression role on secondary electrons, the suppression effect is very good, and the double-insurance effect can be played, namely, one fails and the other also plays a role.

11. The target electrode 3 has small size, complete functions and obvious effect of inhibiting secondary electrons.

12. The target 24 can bear D + beam current with energy of 130keV and above 3.5 mA.

Drawings

FIG. 1 is a schematic view of a double-layer quartz glass tube type high voltage unit for a small neutron generator according to an embodiment of the present invention;

FIG. 2 is a schematic view of a target electrode 3 according to an embodiment of the present invention;

FIG. 3 is an enlarged partial view of the dielectric seal of the portion of the target 24 described in the embodiments of the present invention;

FIG. 4 is a partially enlarged view showing the position of the top end of the coolant guide pipe 2 (the position where the coolant input pipe 13 and the coolant output pipe 14 are provided) in the embodiment of the present invention;

FIG. 5 is a partially enlarged view showing the position of the rear end of the cooling liquid guide pipe 2 (the position where the cooling liquid guide pipe 2 and the cooling liquid passage 29 are connected) in the embodiment of the present invention;

in the figure: 1-high voltage input module, 2-cooling liquid guide pipe, 3-target electrode, 4-high voltage wire, 5-piston sleeve plug, 6-insulating fixed plug, 7-round head copper cap, 8-T-shaped insulator, 9-insulating gland, 10-first sealing ring, 11-insulating threaded plug, 12-insulating external thread ring, 13-cooling liquid input pipe, 14-cooling liquid output pipe, 15-external pipe, 16-internal pipe, 17-high voltage joint, 18-target base, 19-electrode, 20-high voltage connecting rod, 21-bakelite insulating sleeve, 22-screw, 23-press ring, 24-target sheet, 25-second sealing ring, 26-resistor, 27-permanent magnet, 28-iron sheet bracket, 29-cooling liquid channel, 30-beam channel, 31-inclined plane, 32-target sheet opening and 33-target base inner cavity.

Detailed Description

The invention is further described below with reference to the figures and examples.

As shown in FIG. 1, the invention provides a double-layer quartz glass tube type high-voltage unit for a small neutron generator, which comprises a high-voltage input module 1, a cooling liquid guide tube 2 and a target electrode 3. The cooling liquid guide pipe 2 is a straight pipe type, the high-voltage input module 1 is arranged at the top end of the cooling liquid guide pipe 2, and the target electrode 3 is arranged at the tail end of the cooling liquid guide pipe 2. The outer part of the target electrode 3 is a smooth outer shell, the target sheet 24 is arranged in the target electrode, and a circulating flow passage capable of passing through cooling liquid is arranged in the cooling liquid guide pipe 2 and used for refrigerating the target sheet 24; the high voltage input module 1 supplies high voltage electricity to the target electrode 3 through a high voltage connection rod 20 penetrating inside the coolant flow guide pipe 2.

As shown in fig. 1 and 2, the target electrode 3 includes a high voltage connecting rod 20, a target base 18, a target piece 24, a resistor 26, an electrode 19, a permanent magnet 27, and the like.

The target base 18 and the electrode 19 form a cylindrical outer shell with smooth appearance, the target sheet 24 is arranged on the target base 18 and positioned in the outer shell, the target base 18 is provided with a cooling liquid channel 29, the electrode 19 is provided with a beam channel 30 for passing through D generated by the ion source⁺And (4) beam current.

The target base 18 is made of copper material and is cylindrical, one end of the target base is provided with a cooling liquid channel 29 (the cooling liquid channel 29 is used for being bonded with the insulated cooling liquid guide pipe 2, conveying cooling liquid to the target sheet 24 on the target base 18 and cooling the target sheet 24), and the other end of the target base is provided with an inclined plane 31 with a target sheet opening 32 and external threads; a target base inner cavity 33 is formed between the inclined surface 31 and the cooling liquid channel 29; the cooling liquid channel 29 is an arc-shaped opening at one end of the outer shell, and has a smooth surface and no sharp edges.

The electrode 19 is a stainless steel cylinder (formed by processing a cylindrical stainless steel bar), one end of the electrode is a beam channel 30 which is an arc-shaped opening with a smooth surface and no sharp edges, and the other end of the electrode is an opening with internal threads (adapted to the external threads of the target base 18) and is connected with the target base 18 through threads.

The angle of the inclined plane 31 is 45 degrees, the target sheet 24 is hermetically arranged on the target sheet opening 32, and the target sheet 24 is in insulating and sealing connection with the inclined plane 31; the diameter of the target 24 is 40mm, the diameter of the cooling liquid channel 29 is 30mm, the diameter of the beam channel 30 is 18mm, the outer diameter of the outer shell is 52mm, the inner diameter is 46mm, and the electrode 19 with the length of 150mm forms the main part of the outer shell (namely, the outer diameter of the electrode 19 is 52mm, and the inner diameter is 46 mm).

As shown in fig. 3, the edge of the target opening 32 facing the beam passage 30 is provided with a groove, and the target 24 is arranged in the groove; a second sealing ring 25 is arranged between the target sheet 24 and the groove, the target sheet 24 is pressed on the second sealing ring 25 through a pressing ring 23, the insulating and sealing connection between the target sheet 24 and the inclined plane 31 is realized (the target sheet 24 is not contacted with the inclined plane 31), the second sealing ring 25, the target sheet 24 and the pressing ring 23 are sequentially arranged in the groove in the mounting sequence, the pressing ring 23 is connected with the target base 18 through an insulating screw 22, and the insulating and sealing between the target sheet 24 and the inclined plane 31 (namely the target base 18) is realized.

The second sealing ring 25 is an insulating sealing ring made of polytetrafluoroethylene and has a thickness larger than the depth of the groove.

The inclined plane 31 is provided with a plurality of threaded holes which are uniformly arranged.

The target piece 24 is a circular molybdenum piece, the diameter of the circular molybdenum piece is smaller than that of the groove, and deuterium or tritium is adsorbed on one surface of the target piece 24 after titanium plating to form a deuterium target or a tritium target.

The press ring 23 is a stainless steel circular ring, the outer diameter of the press ring is equal to the diameter of the target sheet 24, the inner diameter of the press ring is larger than the active area of the target sheet 24, and a screw through hole for mounting the screw 22 is formed in the annular surface of the press ring 23.

The pressing ring 23 is connected with the inclined plane 31 through a screw 22 and a threaded hole, and a bakelite insulating sleeve 21 is sleeved on the periphery of the screw 22. When the target sheet 24 is installed, the target sheet does not contact the target base 18, the bakelite insulating sleeve 21 is placed in the screw through hole of the pressing ring 23, and finally the pressing ring 23 is pressed by the screw 22, so that the target sheet 24 and the target base 18 are insulated and sealed.

A resistor 26 is connected between the pressure ring 23 and the target base 18, and the resistance of the resistor 26 is 300k omega.

The tail end of the high-pressure connecting rod 20 passes through the cooling liquid channel 29 of the target base 18 and extends into the inner cavity 33 of the target base, and the tail end of the high-pressure connecting rod 20 is L-shaped and is connected to the side wall of the target base 18 through welding; the high-voltage connecting rod 20 is made of stainless steel and is used for being connected with the high-voltage wire 4 and conveying accelerating high voltage to the target electrode 3. The top end of the high-voltage connecting rod 20 is provided with a high-voltage connector 17 for connecting high-voltage electricity; the high voltage connection 17 is copper.

The permanent magnets 27 are two pieces in the shape of rectangular thin pieces, and are arranged in the electrodes 19 through semicircular iron piece brackets 28, and the magnetic field intensity is 200 gauss. The permanent magnet 27 is located between the inclined surface 31 and the beam passage 30, and the N pole and the S pole of the permanent magnet 27 are opposite.

As shown in fig. 1, the coolant flow guide pipe 2 includes an insulating threaded plug 11, an insulating gland 9, a coolant delivery pipe 14, an insulating externally threaded ring 12, a first seal ring 10, a coolant delivery pipe 13, an outer pipe 15, an inner pipe 16, and the like.

The inner tube 16 is arranged in the outer tube 15, the outer tube 15 and the inner tube 16 form a sleeve structure, the top end (i.e. the end far away from the target electrode 3) of the inner tube 16 is positioned in the outer tube 15 (close to the top end of the outer tube 15), and the space between the inner wall of the outer tube 15 and the outer wall of the inner tube 16 and the inner space of the inner tube 16 jointly form a circulating flow channel; the outer wall of the top end of the inner tube 16 is hermetically connected with the inner wall (near the top end) of the outer tube 15 (i.e., one end of the circulating flow passage is sealed), the tail ends of the inner tube 16 and the outer tube 15 are arranged on the target electrode 3, and the outer tube 15 is hermetically connected with the target electrode 3 and used for supporting the target electrode 3; the outer tube 15 and the inner tube 16 are made of quartz glass.

The outer diameter of the outer tube 15 is 20mm, the inner diameter is 14mm, the thickness of the tube wall is 3mm, the length is more than or equal to 500mm, and openings at two ends are ground flat; the outer diameter of the inner tube 16 is 10mm, the inner diameter is 6mm, the thickness of the tube wall is 2mm, the length is more than or equal to 490mm, and openings at two ends are ground flat.

As shown in fig. 5, the tail end of the outer tube 15 is disposed in the cooling liquid channel 29 of the target electrode 3, and the outer wall of the opening at the tail end of the outer tube 15 is hermetically connected with the cooling liquid channel 29 by bonding with an AB glue; the opening at the tail end of the inner tube 16 extends into the target base inner cavity 33, and the distance between the opening at the tail end of the inner tube 16 and the opening at the tail end of the outer tube 15 is about 20 mm.

The body of the high-voltage connecting rod 20 on the target 3 penetrates inside the inner tube 16, and the high-voltage joint 17 at the tip of the high-voltage connecting rod 20 extends beyond the tip of the outer tube 15 (i.e., beyond the tip of the cooling liquid guiding tube 2).

The insulating threaded plug 11, the insulating gland 9 and the insulating external thread ring 12 are arranged at the top end of the outer tube 15 and used for sealing the top end of the outer tube 15 and fixing the high-voltage connecting rod 20;

the insulating external thread ring 12 is arranged on the outer wall of the top end of the outer tube 15, and external threads are arranged on the outer wall of the insulating external thread ring 12;

the insulating threaded plug 11 is arranged on the top end of the outer tube 15, a high-voltage connector 17 at the top end of the high-voltage connecting rod 20 penetrates through the insulating threaded plug 11 and extends out of the top end of the outer tube 15, the insulating threaded plug 11 is used for plugging the top end of the outer tube 15, and the insulating threaded plug 11 is in sealing connection with the high-voltage connecting rod 20;

the insulation gland 9 is used for matching with the external thread of the insulation external thread ring 12 to press the insulation threaded plug 11 on the top end of the outer tube 15;

the first sealing ring 10 is arranged between the insulating gland 9 and the insulating external thread ring 12 and used for sealing between the insulating gland 9 and the insulating external thread ring 12.

The material of insulating screw stopper 11 and insulating gland 9 is polytetrafluoroethylene, and the material of insulating external screw thread ring 12 is organic glass, and insulating external screw thread ring 12 sets up on outer tube 15 through bonding.

As shown in fig. 4, one end of the cooling liquid input pipe 13 passes through the side wall of the outer pipe 15 to communicate with the inner pipe 16, the other end is used for connecting an outlet of an external circulation cooler, and the cooling liquid input pipe 13 is hermetically connected with the side wall of the outer pipe 15; one end of the coolant outlet pipe 14 is communicated with the outer pipe 15, and the other end is used for connecting an inlet of an external circulating cooler. The cooling liquid firstly enters the inner tube 16 through the cooling liquid input tube 13 and is guided to the target substrate inner cavity 33 to cool the target piece 24, and then flows to the cooling liquid output tube 14 through the circulating flow channel between the inner tube 16 and the outer tube 15 to flow back to the circulating cooling machine, so as to form a cooling liquid guiding loop.

The coolant inlet pipe 13 and the coolant outlet pipe 14 are disposed near the top end of the inner pipe 16, and the coolant inlet pipe 13 and the coolant outlet pipe 14 are perpendicular to the outer pipe 15 and are oppositely disposed at both sides of the outer pipe 15.

The cooling liquid input pipe 13 and the cooling liquid output pipe 14 are made of quartz glass, the outer diameter is 10mm, the inner diameter is 6mm, the pipe wall thickness is 2mm, and the length is more than or equal to 100 mm; the cooling liquid is fluorinated liquid with high fluidity and insulating property.

As shown in fig. 1, the high voltage input module 1 includes a T-shaped insulator 8 having a high voltage line 4 therein, and a high voltage connector 17 at a top end of a high voltage connection rod 20 is disposed in the T-shaped insulator 8 and connected to the high voltage line 4.

The high-voltage connector 17 is hermetically connected with the T-shaped insulator 8 through the insulating threaded plug 11 and the threads of the T-shaped insulator 8; the side surface of the high-pressure joint 17 is provided with a semicircular groove; the top end of the high-voltage wire 4 is provided with a round-head copper cap 7 (namely, a plurality of strands of metal wire cores of the high-voltage wire 4 are sleeved with the round-head copper cap 7 and are firmly welded), the high-voltage wire 4 is arranged in a T-shaped insulator 8 through a piston sleeve plug 5, and the round-head copper cap 7 is fixed in the T-shaped insulator 8 through an insulating fixing plug 6; the round-head copper cap 7 is arranged in the groove of the high-voltage connector 17, so that the high-voltage connector 17 is connected with the high-voltage wire 4; the piston sleeve plug 5 is connected with the T-shaped insulator 8 in a sealing way through threads; the high voltage line 4, the T-insulator 8 and the high voltage connector 17 are integrated.

The T-shaped insulator 8, the insulating fixing plug 6 and the loop plug 5 are made of polytetrafluoroethylene.

The working principle and the effect of the double-layer quartz glass tube type high-voltage unit for the small neutron generator provided by the invention are as follows: the cooling liquid is guided into the cooling liquid input pipe 13 from the outlet of the circulating cooling machine, flows into the inner pipe 16 and then is sprayed to the back surface of the target piece 24, the cooling liquid flows back to the circulating flow channel between the inner pipe 16 and the outer pipe 15 after filling the target substrate inner cavity 33, and flows back into the circulating cooling machine through the cooling liquid output pipe 14, so that a cooling liquid loop is formed. The high-voltage connecting rod 20 passes through the inner tube 16 to be connected with the target base 18 of the target electrode 3, is connected with the high-voltage wire 4 through the high-voltage connector 17, and feeds the high voltage of about-100 kV to the target electrode 3. The total thickness of the quartz glass tube constituting the cooling liquid guide tube 2 is 5mm (the sum of the wall thicknesses of the outer tube 15 and the inner tube 16), the thickness of the cooling liquid layer is 3mm, and the breakdown voltage of the cooling liquid and the breakdown voltage of the quartz glass tube can both reach 30kV/mm, so that the bulk breakdown voltage of the cooling liquid guide tube 2 can reach more than 200 kV.

The device according to the present invention is not limited to the embodiments described in the specific embodiments, and those skilled in the art can derive other embodiments according to the technical solutions of the present invention, and also belong to the technical innovation scope of the present invention.