Compact neutron generator based on all-glass helicon ion source

Abstract

A compact neutron generator based on an all-glass helicon ion source. The compact neutron generator comprises a helicon ion source part (1), a chamber part (2) and a target part (3). First, deuterium gas is introduced into an ion source chamber (106), and the deuterium gas is then excited by means of an antenna (107), so as to generate helicon plasma; under magnetic field confinement, ions are first extracted as a beam by means of the potential difference between an extraction electrode and an ion source cover plate (109), and are then accelerated by an electric field between the extraction electrode and a titanium target (306); and finally, the deuterium ion beam bombards the titanium target (306), such that neutrons are produced by means of a deuterium-deuterium fusion reaction. In addition, an arc-shaped magnet (303) and a resistor (307) are also used to suppress secondary electrons, which are produced during target bombardment, thereby preventing the secondary electrons from being accelerated backward into the ion source chamber (106).

Description

A compact neutron generator based on an all-glass helical wave ion source Technical Field

[0001] This invention belongs to the field of accelerator neutron sources, and particularly relates to a compact neutron generator based on an all-glass spiral wave ion source. Background Technology

[0002] A deuterium-deuterium neutron generator is a nuclear technology device that produces neutrons through deuterium fusion. It generates high-energy neutrons by accelerating deuterium ions and colliding them with a target material. The technical principle of a deuterium-deuterium neutron generator mainly involves three aspects: ion source technology, accelerator technology, and fusion reaction. The accelerator neutron source uses an accelerator ion source to generate ions, which are then accelerated by a high-voltage electric field to bombard the target material. The target material, after being bombarded by a high-energy proton beam, undergoes a deuterium-deuterium fusion reaction, releasing neutrons in the 4π direction. Compared to radioactive neutron sources that use radioactive nuclides to produce neutrons, accelerator neutron sources have advantages such as higher safety, better controllability, and longer lifespan. However, improving the beam intensity and neutron yield of neutron generators remains a challenge. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a compact neutron generator based on an all-glass spiral wave ion source. This device uses an all-glass spiral wave ion source to increase plasma density and uses a copper-based solid deuterium self-target. Simultaneously, magnets and resistors are used to suppress secondary electrons, ensuring that the overall device is compact, simple in structure, and easy to process components. It also satisfies the requirements of confining the ion beam and suppressing secondary electrons, thereby obtaining a high-current ion beam and increasing neutron yield.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] A compact neutron generator based on an all-glass spiral wave ion source is disclosed. The neutron generator includes an ion source section, a chamber section, a target section, and associated vacuum pumping system, high-voltage feed system, radio frequency system, cooling system, and gas supply system. The ion source section, chamber section, and target section are connected sequentially from top to bottom.

[0006] The ion source section is used to receive the gas fed in by the gas supply system. Based on the matching connection between the antenna and the radio frequency system, the antenna is excited to generate spiral wave plasma by controlling the radio frequency power.

[0007] The extraction section is used to introduce the plasma into the chamber section in the form of an ion beam;

[0008] The chamber section is used in conjunction with a matching vacuum system to create a vacuum environment for the ion beam;

[0009] The target portion is used to concentrate the ion beam in a vacuum environment, and the deuterium-deuterium fusion reaction is generated through a high-voltage feed system to produce neutrons;

[0010] The cooling system provides cooling channels for the ion source and the target.

[0011] Furthermore, the ion source is fixed by bolts connecting the ion source cover plate and the chamber cover plate. The ion source chamber is a cylindrical body with an upper round cover, a small protruding hollow cylinder, and a lower opening. The ion source chamber is fixed by bolts connecting the glass cover plate and the ion source cover plate. An antenna and a magnet are placed outside the ion source chamber. After the coil is connected to the radio frequency system, it excites the gas inside the ion source chamber to generate spiral wave plasma. The magnet confines the spiral wave plasma.

[0012] Furthermore, the main body of the chamber is cylindrical in shape, and the upper cover plate and the lower cover plate of the chamber are connected by bolts. The upper and lower cover plates and the chamber are vacuum sealed with sealing rings. There are air extraction ports around the chamber, and a vacuum system is installed at the air extraction ports to provide a vacuum environment for the inside of the chamber.

[0013] Furthermore, the target body includes a coaxial lead-out electrode, a target, a connecting frame, a target support column, and a target base. The target support column is fixed to the target base by fixing screws on its bottom edge. The connecting frame is fixed to the target support column by bolts. The target is fixed to the connecting frame by bolts. The lead-out electrode is fixed to the connecting frame by embedding. The target base is bolted to the lower cover plate of the chamber. A magnet is placed inside the lead-out electrode to suppress secondary electrons. A resistor is placed at the connecting frame to suppress secondary electrons as well. A high-voltage channel is opened inside the target base for the high-voltage feed system to feed high voltage to the target through a high-voltage feed line.

[0014] Furthermore, the chamber is made of metal, and its shape and size are determined according to the target diameter and installation environment. Functional ports are opened around the chamber for evacuation, observation, and measurement, and flanges are welded to both ends of the chamber.

[0015] Furthermore, the chamber cover plate is an integral flange with a central opening. The diameter of the central opening is larger than the diameter of the lead-out tube head and smaller than the outer diameter of the ion source cover plate. The chamber cover plate is made of the same material as the chamber portion.

[0016] Furthermore, the ion source chamber is made of non-metallic material, with a round cap at the top and a protruding hollow cylinder. A container is placed on top of the cylinder to allow the reaction gas to enter the ion source chamber. The middle part is a hollow cylinder, and the lower end is a disc that extends outward and has a partial protrusion at the bottom. The shape of the end face is changed according to the sealing method. The upper and lower surfaces of the lower end are in contact with the glass cover plate and the ion source cover plate, respectively.

[0017] Furthermore, the ion source chamber is fixed by compression between the glass cover plate and the ion source cover plate, and the ion source vacuum seal is formed by the compression deformation of the sealing ring.

[0018] Furthermore, the antenna is a Helicon type antenna.

[0019] Furthermore, the antenna is made of materials with excellent thermal conductivity and high electrical conductivity, and has a cooling channel inside. The antenna cross-section is a hollow ring inside.

[0020] Furthermore, the gas is deuterium, which is stored in a gas storage container, the container itself having a gas pressure gauge, a needle valve, and a pressure reducing valve.

[0021] Furthermore, an air inlet pipe is provided at the upper end of the ion source chamber, and a gas controller is installed on the air inlet pipe to control the flow rate of deuterium gas released into the ion source chamber and the opening and closing of the gas path.

[0022] Furthermore, the upper end face of the glass cover plate has three centrally symmetrical threaded holes and an L-shaped groove, which are used to screw in the threaded support and fix the annular magnet and make it coaxial with the ion source chamber, respectively. The lower end face has two sealing grooves.

[0023] Furthermore, the protruding magnet chuck has a round hole for the ion source chamber to pass through, and three through holes corresponding to the three threaded holes of the glass cover plate are machined at the edge. One end face has a raised ring for fixing the antenna and making the antenna and the ion source chamber coaxial. The other end face has an L-shaped groove for fixing the ring magnet and making it coaxial with the ion source chamber.

[0024] Furthermore, the planar magnetic chuck has a central circular hole for the ion source chamber to pass through, three through holes corresponding to the three threaded holes in the glass cover plate at the edge, an L-shaped groove on one end face for fixing the magnet and making it coaxial with the ion source chamber, and a flat surface on the other end face.

[0025] Furthermore, the ion source cover plate is made of a metal material with good thermal conductivity, and is in the shape of a disc with a straight ion beam extraction hole in the center, which serves as a plasma electrode. It forms a vacuum seal by sealing with a sealing ring between itself and the upper cover plate of the chamber.

[0026] Furthermore, the ion source cover plate has a hollow annular cooling channel inside, and a protruding cylindrical internal threaded hole is welded on the upper end face.

[0027] Furthermore, the ion source components, including the threaded support, nut, glass cover, bolt, protruding magnetic chuck, and flat magnetic chuck, are made of PEEK material.

[0028] Furthermore, the target base and the lower cover plate of the chamber are fixed together by bolts.

[0029] Furthermore, the target base is made of insulating material and is composed of a small concave hollow cylinder at the top, a large cylinder at the bottom, and a convex disc edge at the junction of the top and bottom. Twelve through holes are machined on the convex disc edge, and an L-shaped circular channel is provided inside.

[0030] Furthermore, the lower end face of the target base is machined with a high-pressure feed channel, which is cylindrical in shape and has internal threads at the lower end.

[0031] Furthermore, the high-pressure sealing pipe is a cylindrical plate with two ends and a regular hexagonal plate in the middle. The cylinders are threaded on the outside, the upper cylinder has a cylindrical hole, and the lower cylinder has a conical hole. The high-pressure sealing cover is a regular hexagonal cylinder with a hollow internal thread and a circular hole on the end face. The conical rubber plug has a circular through hole in the middle.

[0032] Furthermore, the target support column is cylindrical in shape, with a protruding edge at the lower end and a circular through channel inside. The protruding edge has circumferentially distributed through holes, and the upper end face has circumferentially distributed threaded holes. The target support column is fixed to the target base by connecting with screws, and the lower end face has threaded holes.

[0033] Furthermore, the high-pressure sealing pipe is fastened to the target base by threads, the high-pressure line is inserted into the high-pressure feed channel, and the high-pressure line head wire is fixed by the connection between the threaded hole on the lower end face of the bolt target support column. Then, it is fixed to the target base by the radial force of the conical rubber plug and the axial force of the high-pressure sealing cover. The side of the high-pressure sealing pipe that contacts the target base has a sealing groove.

[0034] Furthermore, the upper and lower ends of the connecting frame are disc-shaped, each with circumferentially distributed through holes. The middle part is a cuboid with rounded corners, inside which there are two circular through channels. The connecting frame is fixed by screw connection with the target support column.

[0035] Furthermore, the lower shield is an L-shaped cylinder with a lower opening and an upper end extending inward, and has circumferentially distributed through holes machined on the upper end. The lower shield is fixed to the lower end of the connecting frame by bolts. The upper shield is an L-shaped cylinder with a lower opening and an upper end extending outward, and has circumferentially distributed through holes machined on it. The upper shield is fixed to the upper end of the connecting frame by bolts.

[0036] Furthermore, the resistive element is fixed by bolts between the upper and lower ends of the connecting bracket.

[0037] Furthermore, the target is based on oxygen-free copper and coated with a titanium film. The area and thickness of the coating are set according to the ion beam and neutron parameters.

[0038] Furthermore, the target and the connecting frame are fixed by means of bolt connection.

[0039] Furthermore, the high-pressure sealing cover and high-pressure sealing tube are made of insulating material and are used to press the high-pressure feed line onto the target support.

[0040] Furthermore, the lead-out electrode is divided into two parts: the lead-out electrode head and the lead-out electrode straight cylinder. The two parts are fixed together by a slot. The lead-out electrode head has a circular hole, and the upper end of the lead-out electrode straight cylinder has a concave ring.

[0041] Furthermore, the magnet holder is fixed by being placed on a concave ring inside the straight cylinder of the lead electrode, and the magnet holder has two symmetrical square holes.

[0042] Furthermore, the magnet box is a rectangular prism with a hollow interior and no top cover, and has a protruding frame on the top. The magnet box cover is a rectangular prism with no top cover and a hollow interior.

[0043] Furthermore, the electrode cylinder is fixedly engaged with the target support column via a slot.

[0044] Furthermore, the ring magnet is made of neodymium iron boron or samarium cobalt, with a core providing a 1.1T magnetic field and the upper and lower end faces being magnetized surfaces; the rectangular magnet is made of neodymium iron boron or samarium cobalt, with a core providing a 1.1T magnetic field and the two largest rectangular faces being magnetized surfaces.

[0045] Furthermore, in the target body portion, the target support column, connecting frame, target body, and lead-out electrode are all made of materials with good conductivity, while the high-pressure sealing cover and high-pressure sealing tube are made of insulating materials.

[0046] Furthermore, a 90kV high voltage is applied to the target support column, which is then transmitted to the target and the extraction electrode. The potential on the target and the extraction electrode is 90kV. No high voltage is applied to the ion source cover plate (plasma electrode), and the potential is 0. An electric field is generated between the extraction electrode and the target and the ion source cover plate (plasma electrode), and the extracted ion beam enters the chamber and bombards the target.

[0047] Furthermore, an inclined fluorinated liquid inlet channel and a horizontal fluorinated liquid outlet channel are provided on the side of the high-pressure channel.

[0048] Furthermore, the cooling system for the ion source includes cooling for the antenna and the ion source cover plate.

[0049] Furthermore, the target cooling system includes target cooling, with coolant entering through a coolant inlet channel and exiting through a coolant outlet channel, flowing through the target base, target support column, connecting frame, and target. The channels between the target base and target support column, the target support column and connecting frame, and the connecting frame and target are water-sealed by sealing rings to prevent coolant leakage.

[0050] Furthermore, the resistivity of the coolant is greater than or equal to 4 MΩ·cm, ensuring that the target surface temperature is less than 120°C and the overall coil temperature is less than 50°C. The coolant is pumped into the cooling section through a cooling machine, and the coolant pressure, flow rate, and temperature are set by the cooling machine.

[0051] Furthermore, the sealing ring is made of fluororubber with a circular or rectangular cross-section. It is placed in the sealing groove and, after being squeezed by pressure, fills the sealing groove to form a vacuum seal. A cooling circulation channel is set between the ion source chamber and the plasma water-cooled cover to achieve cooling of the upper and lower cover plates of the ion source, the ion source chamber and the coil.

[0052] The beneficial effects of this invention are as follows:

[0053] 1. This invention employs an all-glass helical wave ion source and uses a copper-based solid deuterium self-target. This ensures a compact overall device with low energy consumption and a simple structure, while also increasing plasma density to obtain a high-current ion beam and increase neutron yield.

[0054] 2. This invention uses a combination of magnets and resistors to suppress secondary electrons, which greatly enhances the effect of suppressing secondary electrons.

[0055] 2. This invention can extract a 10mA beam current under a high voltage of 90kV, and the neutron yield can reach more than 2E9n / s;

[0056] 3. The present invention adopts common sealing methods, convenient quick-connect fittings, and convenient threaded connections, which can be easily assembled and replaced with later parts, reducing production and usage costs and facilitating commercialization. Attached Figure Description

[0057] Figure 1 is a cross-sectional schematic diagram of a compact neutron generator based on an all-glass spiral wave ion source according to the present invention;

[0058] Figure 2 is a schematic diagram of the ion source assembly.

[0059] Figure 3 is a partial cross-sectional view of the ion source;

[0060] Figure 4 is a schematic diagram of the antenna;

[0061] Figure 5 is a schematic diagram of the chamber;

[0062] Figure 6 shows one of the cross-sectional views of the target.

[0063] Figure 7 is a schematic diagram of the rectangular magnet fixing assembly;

[0064] Figure 8 is the second cross-sectional view of the target;

[0065] Figure 9 shows the third cross-sectional view of the target.

[0066] Figure 10 shows the cross-sectional view of the connecting frame, target and shielding cover in combination;

[0067] Figure 11 is the fourth cross-sectional view of the target.

[0068] Reference numerals: 1. Ion source section; 2. Chamber section; 3. Target section; 101. Inlet pipe; 102. Flow meter; 103. Quartz tube sleeve; 104. Threaded support; 105. Planar magnetic chuck; 106. Ion source chamber; 107. Antenna; 108. Glass cover plate; 109. Ion source cover plate; 110. Protruding magnetic chuck; 111. Ring magnet; 201. Upper cover plate of chamber; 202. Chamber; 203. Lower cover plate of chamber; 204. Molecular pump; 301. Lead-out electrode head; 302. 303. Magnet bracket; 304. Rectangular magnet; 305. Upper shielding cover; 306. Lead-out electrode cylinder; 307. Target; 308. Resistor element; 309. Connecting frame; 310. High-pressure sealing tube; 311. High-pressure sealing cover; 312. Conical rubber plug; 313. Target base; 314. Target support column; 315. Lower shielding cover; 316. Magnet box cover; 317. Magnet box; 318. Coolant inlet channel; 319. Coolant outlet channel; 320. Fluoride inlet channel; 311. Fluoride outlet channel. Detailed Implementation

[0069] The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings:

[0070] As shown in Figure 1, this invention provides a compact neutron generator based on an all-glass spiral wave ion source. From top to bottom, it is mainly divided into an ion source part 1, a chamber part 2, a target part 3, and its supporting vacuum system, high-voltage feed system, radio frequency system, cooling system, and gas supply system. Its working principle is as follows: First, the gas supply system introduces reactive gas into the ion source. Then, the ion source ionizes the gas through the radio frequency system to generate an ion beam. The ion beam is guided into the chamber by the levitation potential of the extraction electrode. Finally, the target part accelerates and confines the ion beam with the help of the accelerating electrode and the high voltage on the target, and then bombards the target to produce a deuterium-deuterium fusion reaction.

[0071] Referring to Figures 1 and 5, the main body of the neutron generator is a cylindrical chamber 202. The upper and lower ends of the chamber 202 are respectively bolted to the upper cover plate 201 and the lower cover plate 203, and are vacuum-sealed using sealing rings. The chamber 202 has extraction ports around its perimeter, which are bolted to the molecular pump 204 using copper ring seals.

[0072] Referring to Figures 1, 2, 3, and 4, the ion source chamber 106 has a round cap at the top with a protruding hollow cylinder. A hollow cylinder is placed on top of this cylinder, allowing the reaction gas to enter the ion source chamber 106. The middle section is a hollow cylinder, and the lower end is a partially protruding disc with a raised section at the bottom. The shape of the end face varies depending on the sealing method. Gas is supplied by the gas supply system via an inlet pipe 101. A flow meter 102 is connected to the inlet pipe 101 to control the gas intake. The inlet pipe 101 and the ion source chamber 106 are connected by a quartz tube sleeve 103. The protruding disc at the lower end of the ion source chamber 106 is pressed against both sides by a glass cover plate 108 and an ion source cover plate 109. The pressing force comes from the bolt connection that secures the glass cover plate 108 and the ion source cover plate 109. Furthermore, the contact points between the glass cover plate 108 and the ion source cover plate 109 and the ion source chamber 106 are sealed with sealing rings. One annular magnet 111 is placed in a groove on the upper surface of the glass cover plate 108, and is secured above it by a protruding magnetic chuck 110 and a threaded support 104 and their matching nuts. The other annular magnet is secured by a threaded support 104, a protruding magnetic chuck 110, a flat magnetic chuck 105, and their matching nuts. The antenna 107 is secured by two protruding magnetic chucks. Quartz tube sleeves 103 are installed at the coolant inlet and outlet of the antenna 107 for inserting water pipes and allowing coolant to flow through. The ion source cover plate 109 has an annular coolant channel machined inside, and a protruding internally threaded ring is welded to its upper surface, on which a quick-connect plug is fitted for inserting water pipes and allowing coolant to flow through.

[0073] Referring to Figures 1, 6, 7, 8, 9, 10, and 11, the target body 3 is composed of a target base 312, a target support column 313, a connecting frame 308, a target 306, and lead-out electrodes. The lead-out electrodes are divided into two parts: an upper lead-out electrode head 301 and a lower lead-out electrode cylinder 305, which are fixed together by a locking groove. The lead-out electrodes and the target support column 313 are also fixed together by the locking groove. A rectangular magnet 303 is fixed to the lead-out electrode cylinder 305 by a magnet bracket 302, which is fixed by contact with a protruding ring inside the lead-out electrode cylinder 305. The rectangular magnet 303 is placed in a magnet box 316, which is then covered with a magnet box cover 315. The magnet box 316 is fixed by contact between its convex edge and the edge of the rectangular hole in the magnet bracket 302. The connecting frame 308 is fixed to the target support column 313 via a through hole at its bottom edge using bolts. The target 306 is fixed to the connecting frame 308 via a through hole at its edge using bolts. The upper shield 304 is fixed to the connecting frame 308 and the target 306 using fixing bolts. The lower shield 314 is fixed to the connecting frame 308 and the target support column 313 using fixing bolts. The resistor element 307 is fixed to the connecting frame 308, the target 306, and the target support column 313 using fixing bolts. The target support column 313 is fixed to the target base 312 via a through hole at its edge using screws. The target base 312 and the lower cover plate 203 of the chamber are fixed together using bolts. The high-pressure sealing tube 309 is screwed into the target base 312 via its external thread for threaded connection and fixation. The high-pressure wire is inserted into the high-pressure sealing cap 310 and the conical rubber plug 311. The head of the high-pressure wire is fixed to the target support column 313 by bolt connection. The high-pressure sealing cap 310 is screwed onto the high-pressure sealing tube 309, so that the high-pressure wire is fixed to the target base 312 by the radial force of the conical rubber plug 311 and the axial force of the high-pressure sealing cap 310. The target base 312 has stepped channels machined inside, with inclined fluorinated liquid inflow channels 319 and horizontal fluorinated liquid outflow channels 320 machined on both sides of the channels. The internal carriage of the target base 312 has two L-shaped channels, which together with the internal channels between the target support column 313, the connecting frame 308 and the target 306 form the coolant inflow channel 317 and the coolant outflow channel 318. The contact surfaces between each pair of the target base 312, the target support column 313, the connecting frame 308 and the target 306 are sealed with sealing rings to prevent coolant leakage.

[0074] Preferably, the chamber 202 is made of a metal with certain strength and good machinability, such as SUS304 / SUS316 / aluminum. The chamber 202 can withstand pressure changes and has a low leakage rate. The chamber 202 is provided with extraction ports, observation ports, and measurement ports as needed. The specifications of the functional ports and flanges at both ends conform to GB / T 6070-2007 and GB / T 6071-2003. The diameter of the chamber 202 can be varied according to the target diameter and installation environment; in this example, the diameter is 250 mm and the length is 472 mm.

[0075] Preferably, the vacuum system consists of a molecular pump 204 and a chamber 202, etc. The molecular pump 204 extracts the air from the chamber 202 to achieve a vacuum environment.

[0076] Preferably, the chamber cover plate 201 is made of the same material as the chamber 202, and is an integral flange with a central opening. The flange specifications refer to GB / T 6070-2007. The diameter of the central through hole needs to be much larger than the diameter of the lead-out electrode head 301, and smaller than the outer diameter of the ion source cover plate 109, which is 250 mm in this example.

[0077] Preferably, the ion source chamber 106 is made of non-metallic materials, such as quartz glass or boron nitride. The inner diameter of the ion source chamber 106 is 40 mm. To meet the requirements of pressure resistance and sealing, the wall thickness should not be too thick; in this example, the wall thickness is 5 mm.

[0078] Preferably, the antenna 107 has an outer diameter of 6 mm and an inner diameter of 3 mm, and is a Helicon type antenna. The antenna diameter and height affect the electron density of the excited plasma and can be adjusted according to the required ion beam performance and the diameter of the chamber 202. The antenna 107 should be made of a material with excellent thermal conductivity and high electrical conductivity; in this example, the material is copper.

[0079] Preferably, the radio frequency system is connected to the antenna 107 by a matching unit, and the radio frequency power is adjusted by a radio frequency power supply.

[0080] Preferably, in the gas supply system, the gas introduced through the gas inlet pipe 101 is deuterium gas, which is stored in a gas storage bottle and flows into the ion source chamber 106 through the gas inlet pipe 101.

[0081] Preferably, the flow meter 102 is mounted on the inlet pipe 101 to control the flow rate of hydrogen isotope gas released into the ion source chamber 106, in this example the flow rate is 15 SCCM.

[0082] Preferably, the upper end face of the glass cover plate 108 has three centrally symmetrical threaded holes and an L-shaped groove, which are used to screw in the threaded support 104 and fix the annular magnet 111 and make it coaxial with the ion source chamber 106, respectively. The lower end face has two sealing grooves for sealing the vacuum.

[0083] Preferably, the protruding magnetic chuck 110 has a round hole for the ion source chamber 106 to pass through, and three through holes corresponding to the three threaded holes of the glass cover plate 108 are machined at the edge. One end face has a protruding ring for fixing the antenna 107 and making the antenna 107 and the ion source chamber 106 coaxial. The other end face has an L-shaped groove for fixing the ring magnet 111 and making it coaxial with the ion source chamber 106.

[0084] Preferably, the planar magnetic chuck 105 has a central hole for the ion source chamber 106 to pass through, and three through holes corresponding to the three threaded holes of the glass cover plate 108 are machined at the edge. One end face has an L-shaped groove for fixing the annular magnet 111 and making it coaxial with the ion source chamber 106, and the other end face is flat.

[0085] Preferably, the ion source cover plate 109 is made of 304 stainless steel and is disc-shaped. A straight ion beam extraction hole with a diameter of 6mm is opened in the center, which serves as a plasma electrode. A vacuum seal is formed by sealing the cover plate 201 of the chamber with a sealing ring. The ion source cover plate 109 has a hollow annular cooling channel inside. The cooling channel has a rectangular cross-section of 8mm×15mm and a protruding cylindrical internal threaded hole welded on the upper end face.

[0086] Preferably, the ion source part 1, the threaded support 104, the nut, the glass cover plate 108, the bolt, the protruding magnetic chuck 110, and the flat magnetic chuck 105 are made of PEEK material.

[0087] Preferably, the target base 312 is made of polyoxymethylene material and is an overall small concave hollow cylinder at the upper end, a large cylinder at the lower end, and a convex disc edge at the junction of the upper and lower ends. Twelve through holes are machined on the convex disc edge, and an L-shaped circular channel is provided inside.

[0088] Preferably, the target base 312 has a high-pressure feed channel machined on its lower end face. The high-pressure channel is cylindrical in shape and has internal threads at its lower end.

[0089] Preferably, the high-pressure sealing tube 309 is a cylindrical tube with two cylindrical ends and a regular hexagonal plate in the middle. The cylinder has threads on the outside, a cylindrical hole at the upper end, and a tapered hole at the lower end. The high-pressure sealing cover 310 is a regular hexagonal tube with a hollow internally threaded cylinder and a circular hole at the end. The tapered rubber plug 311 has a circular through hole in the middle with a diameter of 8.8 mm.

[0090] Preferably, the target support column 313 is cylindrical in shape, with a protruding edge at the lower end and a circular through channel inside. The protruding edge has circumferentially distributed through holes, and the upper end face has circumferentially distributed threaded holes. The target support column 313 is fixed to the target base 312 by screws, and the lower end face has threaded holes.

[0091] Preferably, the high-pressure sealing pipe 309 is fastened to the target base 312 by threads, the high-pressure wire is inserted into the high-pressure feed channel, and the high-pressure wire head is fixed by the connection between the threaded hole on the lower end face of the bolt target support column 313. Then, it is fixed to the target base 312 by the radial force of the conical rubber plug 311 and the axial force of the high-pressure sealing cover 310. The side of the high-pressure sealing pipe that contacts the target base 312 has a sealing groove.

[0092] Preferably, the upper and lower ends of the connecting frame 308 are disc-shaped, each with circumferentially distributed through holes, and the middle part is a cuboid with rounded corners, with two circular through channels inside. The connecting frame 308 is fixed by screw connection with the target support column 313.

[0093] Preferably, the lower shield 314 is an L-shaped cylinder with a lower opening and an upper end extending inward, and has circumferentially distributed through holes machined on the upper end. The lower shield 314 is fixed to the lower end of the connecting frame 308 by bolts. The upper shield 304 is an L-shaped cylinder with a lower opening and an upper end extending outward, and has circumferentially distributed through holes machined on it. The upper shield 304 is fixed to the upper end of the connecting frame 308 by bolts.

[0094] Preferably, the resistor element 307 is fixed by bolts between the upper and lower ends of the connecting bracket 308. The resistor element 307 is a resistor with a resistance value of 601kΩ, and there are 12 of them.

[0095] Preferably, the target 306 is based on oxygen-free copper and has a coating on its surface. The coating is a titanium film with a diameter of 58 mm and a thickness of 10 μm.

[0096] Preferably, the high-pressure sealing cap 310 and the high-pressure sealing tube 309 are made of PEEK material and are used to press the high-pressure feed line onto the target support.

[0097] Preferably, the lead-out electrode is divided into two parts: lead-out electrode head 301 and lead-out electrode cylinder 305. The two parts are fixed together by a slot. The lead-out electrode head 301 has a circular hole with a diameter of 12mm. The upper end of the lead-out electrode cylinder 305 is provided with a concave ring.

[0098] Preferably, the magnet bracket 302 is fixed by being placed on the concave ring inside the lead electrode cylinder 305, and the magnet bracket 302 has two symmetrical square holes.

[0099] Preferably, the magnet box 316 is a rectangular parallelepiped with a hollow interior and no top cover, and has a protruding frame on the upper part. The magnet box cover 315 is a rectangular parallelepiped with no top cover and a hollow interior.

[0100] Preferably, the annular magnet 111 is made of neodymium iron boron or samarium cobalt, with a core providing a magnetic field of 1.1T, and the upper and lower end faces being magnetized surfaces. The magnetic field at the center of the ion source chamber 106 is 400Gs. The rectangular magnet 303 is made of neodymium iron boron or samarium cobalt, with a core providing a magnetic field of 1.1T, and the two largest rectangular faces being magnetized surfaces. The magnetic field at the center of the lead-out electrode cylinder 305 is 30Gs.

[0101] Preferably, the target body part 3, the target support column 313, the connecting frame 308, the target 306, and the lead-out electrode are all made of 304 stainless steel.

[0102] Preferably, a 90kV high voltage is applied to the target support column 313, and the high voltage is further transmitted to the target 306 and the extraction electrode. The potential on the target 306 and the extraction electrode is 90kV. No high voltage is applied to the ion source cover plate 109 (plasma electrode), and the potential is 0. An electric field is generated between the extraction electrode and the target 306 and the ion source cover plate 109 (plasma electrode), and the extracted ion beam enters the chamber and bombards the target.

[0103] Preferably, the high-voltage channel has an inclined fluorinated liquid inlet channel 319 and a horizontal fluorinated liquid outlet channel 320 on its side, immersing the high-voltage wire in the flowing fluorinated liquid to achieve high-voltage arc extinguishing and prevent sparking. In this example, the coolant velocity at the inlet of the fluorinated liquid channel is 15 L / min.

[0104] Preferably, the cooling system of the ion source section 1 includes the antenna 107 and the ion source cover plate 109 for cooling. In this example, the coolant velocity at the inlet of the coolant channel is 15 L / min.

[0105] Preferably, the target cooling system includes target cooling. Coolant enters through coolant inlet channel 317 and exits through coolant outlet channel 318, flowing through target base 312, target support column 313, connecting frame 308, and target 306. The channels between target base 312 and target support column 313, target support column 313 and connecting frame 308, and connecting frame 308 and target 306 are water-sealed by sealing rings to prevent coolant leakage. In this example, the coolant velocity at the coolant inlet is 15 L / min.

[0106] Preferably, the coolant is deionized water with a resistivity greater than or equal to 16, ensuring that the surface temperature of the target 306 is less than 120°C and the overall temperature of the antenna 107 is less than 50°C. The coolant is pumped into the cooling section through a cooling machine, and the coolant pressure, flow rate, and temperature can be set by the cooling machine.

[0107] Preferably, the sealing ring is made of fluororubber and has a circular or rectangular cross-section. Placed within the sealing groove, it fills the groove and forms a vacuum seal when compressed under pressure.

[0108] In summary, this invention presents an all-glass spiral wave ion source. It eliminates the traditional stainless steel ion source cover and the double-ended through-hole ion source chamber 106, instead employing a novel ion source chamber with one end through-hole and the other connected to the gas supply system. A glass cover 108 made of PEEK material and an ion source cover 109 made of metal material are used to press and fix the ion source chamber 106 together, eliminating the capacitance at both ends of the ion source chamber 106 and making radio frequency matching easier.

[0109] The target part 3 is equipped with a magnet and a resistor to achieve dual suppression of secondary electrons, thereby enhancing the suppression effect of secondary electrons.

[0110] An active cooling system is installed in the ion source section 1 and the target section 3.

[0111] Insulation conditions are set for high-voltage channels. Insulation is achieved by immersing the high-voltage lines in a flowing fluorinated solution.

[0112] This invention has advantages such as low energy consumption, compact structure, high plasma density, good secondary electron suppression effect, high beam intensity, and high neutron yield. Furthermore, the device employs simple threaded connections and quick-connect couplings to link components, facilitating assembly and subsequent maintenance, and reducing production and operating costs.

[0113] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A compact neutron generator based on an all-glass helical wave ion source, characterized in that: It includes an ion source section, a chamber section, and a target section; the ion source section, chamber section, and target section are connected sequentially from top to bottom; The ion source section is used to receive the fed gas. By controlling the radio frequency power, the antenna is used to excite the fed gas to generate spiral wave plasma. The ion source section is fixed by bolts between the ion source cover plate and the upper cover plate of the chamber. The ion source chamber is a cylindrical body with a top cover, a small protruding hollow cylinder, and a lower opening. The ion source chamber is fixed by bolts between the glass cover plate and the ion source cover plate. The antenna and magnet are placed outside the ion source chamber. The chamber section is used to create a vacuum environment for the ion beam; the main body of the chamber section is cylindrical in shape, and the upper cover plate and the lower cover plate of the chamber are connected by bolts. The upper cover plate, the lower cover plate of the chamber and the main body of the chamber are vacuum sealed with sealing rings. There are air extraction ports around the main body of the chamber, and a vacuum system is installed at the air extraction ports. The target section is used to extract plasma from the ion source chamber and concentrate the ion beam in a vacuum environment to produce neutrons through deuterium-deuterium fusion reaction. The target section includes a coaxial extraction electrode, a target, a connecting frame, a target support column, and a target base. The target support column is fixed to the target base by fixing screws on the bottom edge. The connecting frame is fixed to the target support column by bolts. The target is fixed to the connecting frame by bolts. The extraction electrode is fixed to the connecting frame by embedding. The target base is bolted to the lower cover plate of the chamber. A magnet is placed inside the extraction electrode. A resistor is placed at the connecting frame. A high-voltage channel is opened inside the target base.

2. A compact neutron generator based on an all-glass helical wave ion source according to claim 1, characterized in that: The gas is deuterium, which is stored in a gas storage container equipped with a gas pressure gauge, needle valve, and pressure reducing valve.

3. A compact neutron generator based on an all-glass helical wave ion source according to claim 1, characterized in that: The upper end face of the glass cover has three centrally symmetrical threaded holes and an L-shaped groove, which are used to screw in the threaded support and fix the magnet and make it coaxial with the ion source chamber, respectively. The lower end face has two sealing grooves.

4. A compact neutron generator based on an all-glass helical wave ion source according to claim 1, characterized in that: Functional openings are provided around the main body of the chamber for evacuation, observation, and measurement. Flanges are welded to both ends of the chamber.

5. A compact neutron generator based on an all-glass helical wave ion source according to claim 1, characterized in that: The upper and lower ends of the connecting frame are disc-shaped, each with circumferentially distributed through holes. The middle part is a rectangular prism with rounded corners, inside which there are two circular through channels. The connecting frame is fixed to the target support column by screws.

6. A compact neutron generator based on an all-glass helical wave ion source according to claim 1, characterized in that: The lower shield is an L-shaped cylinder with a lower opening and an upper end extending inward. The upper end has circumferentially distributed through holes. The lower shield is fixed to the lower end of the connecting frame by bolts. The upper shield is an L-shaped cylinder with a lower opening and an upper end extending outward. It has circumferentially distributed through holes. The upper shield is fixed to the upper end of the connecting frame by bolts.

7. A compact neutron generator based on an all-glass helical wave ion source according to claim 1, characterized in that: The lead-out electrode is divided into two parts: the lead-out electrode head and the lead-out electrode straight cylinder. The two parts are fixed together by a slot. The lead-out electrode head has a circular hole, and the upper end of the lead-out electrode straight cylinder has a concave ring.

8. A compact neutron generator based on an all-glass helical wave ion source according to claim 1, characterized in that: A high voltage is supplied to the target support column, and the high voltage is further transmitted to the target and the extraction electrode. An electric field is generated between the extraction electrode, the target and the ion source cover plate electrode, and the extracted ion beam enters the chamber and bombards the target.

9. A compact neutron generator based on an all-glass helical wave ion source according to claim 1, characterized in that: There is an inclined fluorinated liquid inlet channel and a horizontal fluorinated liquid outlet channel on the side of the high-pressure channel.

10. A compact neutron generator based on an all-glass helical wave ion source according to claim 1, characterized in that: The coolant in the target body's cooling system enters through the coolant inlet channel and exits through the coolant outlet channel, flowing through the target base, target support column, connecting frame, and target. The channels between the target base and target support column, the target support column and connecting frame, and the connecting frame and target are water-sealed by sealing rings to prevent coolant leakage.

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