A compact magnetic deflection system for neutral beam injection

Abstract

This invention discloses a compact magnetic deflection system for neutral beam injection, comprising: a yoke assembly, two identical magnet assemblies, and a magnet protection assembly. The yoke assembly has a rectangular frame structure, forming a complete magnetic circuit. The two magnet assemblies are arranged opposite each other within the yoke assembly, with a channel in between. The magnet protection assembly surrounds the two magnet assemblies. Each magnet assembly includes: an excitation coil box, an iron core, and a energized coil. The excitation coil box has two U-shaped slots, with the iron core located in the inner slot and the energized coil in the outer slot, with both ends of the energized coil extending from the side of the excitation coil box in the same direction. By changing the current or the number of turns of the energized coil, charged ions can be flexibly deflected out of the original beamline channel. This invention can effectively filter out mixed charged ion beams, achieving purified neutral beam injection.

Description

Technical Field

[0001] This invention relates to the field of high-energy neutral beam injector technology, specifically to a compact magnetic deflection system for neutral beam injection. Background Technology

[0002] Charged and neutral particle implantation has a wide range of applications. In the semiconductor field, the type and effectiveness of ion implantation determine the core performance of internal structural devices in semiconductor chips, making it a crucial step in integrated circuit manufacturing. In vacuum deposition, the direction and sensitivity of the ion beam determine the film thickness and density. In magnetic confinement fusion and high-energy particle fields, ion neutralization produces neutral particles and other charged ion components. High-energy neutral atom beams can be effectively injected into confined plasmas, colliding with the background plasma, and are therefore often used for auxiliary heating and neutron source generation. Differences in ion type, ion beam transport, and neutralization efficiency lead to complex beam composition, thus requiring effective deflection systems for charged ion filtering.

[0003] Common charged ion deflection systems include electrical deflection and magnetic deflection. Electrical deflection primarily utilizes the electric field between electrode plates. Charged ions hitting the electrode plates can easily cause ion sheath deposition and secondary electron emission, leading to electrode plate damage and weakening of the electric field. Therefore, it places higher demands on the pressure resistance, mechanical properties, and thermal mobility of the deflection plate material, making it unsuitable for high-energy ions. Magnetic deflection utilizes the Lorentz force provided by a magnetic field. The direction of this force is always perpendicular to the tangent of the charged ion deflection direction. Different charged ions have different deflection radii. The remaining deflected ions can be received by related devices after the magnetic deflection system, and the collision heat energy can be removed by cooling water. This is more suitable for high-energy particle screening and deflection.

[0004] Currently, magnetic deflection devices are mainly used in large-scale scientific research facilities. The entire system, along with additional water cooling and winding coils, is extremely bulky, and the manufacturing and usage processes are complex. In fact, with the increasing demand for high-energy particle beams from various industries, miniaturized ion implantation devices are gradually becoming commercialized. Therefore, miniaturized and compact magnetic deflection devices have broad application prospects.

[0005] The demand for miniaturization, flexibility, and high precision in particle beam injection devices is increasing, and deflection devices that effectively separate and deflect charged ions are core components. Currently, magnetic deflection devices used for deflecting charged particles are bulky and equipped with internally water-cooled conductive coils. Adjusting the magnetic field requires longer time and generates greater current heat, making them complex to manufacture, use, and maintain. Therefore, they are not suitable for the needs of miniaturized high-energy ion beam devices.

[0006] In the prior art, patent publication number CN117292866A discloses an electric deflection system for residual charged particles in a neutral beam injector of a negative ion source. This system includes electric deflection plates, a main support structure, an adjustable support base, a protective shell, a lifting device, and thermocouples. The electric deflection plates are used to form an inter-plate electric field and absorb the energy of high-energy charged particles; the main support structure is used for supporting and positioning the plate body; the adjustable support base is used for installing and positioning the electric deflector inside the beamline vacuum chamber; the protective shell is used to form potential protection between the high-potential plates and the rest of the beamline components. Horn-shaped beam limiters with water-cooled pipes are used at the inlet and outlet of the protective shell to confine the beam within a certain spatial dimension; the lifting device is used for hoisting the electric deflector body. This invention achieves the removal of residual charged particles in a neutral beam injector system of a negative ion source through electric deflection, thus neutralizing the beam. However, this deflection system, when applied in the field of nuclear fusion technology, cannot be small in size. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a compact magnetic deflection system for neutral beam injection.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0009] A compact magnetic deflection system for neutral beam injection includes: a yoke assembly 100, two identical magnet assemblies 200, and a magnet protection assembly 300. The yoke assembly 100 has a rectangular frame structure, forming a complete magnetic circuit. The two magnet assemblies 200 are arranged opposite each other within the yoke assembly 100, with a channel in between. The magnet protection assembly 300 surrounds the two magnet assemblies 200.

[0010] The magnet assembly 200 includes: an excitation coil box 210, an iron core 220, and an energizing coil 230; the excitation coil box 210 has two space slots arranged in a U-shape, the iron core 220 is located in the inner space slot, and the energizing coil 230 is located in the outer space slot, with the beginning and end of the energizing coil 230 extending out from the side of the excitation coil box 210 in the same direction; by changing the current of the energizing coil 230 or the number of coil turns, charged ions can be flexibly deflected out of the original wire channel.

[0011] In one embodiment of the present invention, the magnet protection assembly 300 includes an inlet beam collimator 310 and a rotary port beam limiter 320; the inlet beam collimator 310 is disposed at the inlet of the deflecting magnet, and the rotary port beam limiter 320 is disposed at the outlet of the deflecting magnet.

[0012] The inlet beam collimator 310 includes an upper limiting baffle 311 and a lower limiting baffle 312, which are respectively disposed at the top and bottom of the deflection magnet inlet, and are in the shape of a trumpet.

[0013] The rotary beam limiter 320 includes an upper beam baffle and a lower beam baffle, which are respectively disposed at the top and bottom of the deflection magnet outlet.

[0014] In one embodiment of the present invention, the magnet protection assembly 300 includes an upper magnet guard plate 331, a lower magnet guard plate 332, a left magnet guard plate 333, a right magnet guard plate 334, and an inner magnet guard plate 335.

[0015] The magnet upper guard plate 331 is located on the upper end iron yoke of the iron yoke assembly 100. After the magnet upper guard plate 331 is connected to the upper end iron yoke, its two ends are also connected to the left end iron yoke 130 and the right end iron yoke 140 of the iron yoke assembly 100, respectively.

[0016] The magnet lower guard plate 332 is located above the upper end iron yoke of the iron yoke assembly 100 and below the magnet assembly 200.

[0017] The two sets of magnet left guard plates 333 and magnet right guard plates 334 are located on the sides of the two magnet assemblies 200, and are respectively connected to the inlet beam collimator 310 and the rotary port beam limiter 320; at the same time, the magnet left guard plate 333 and magnet right guard plate 334 are provided with coil through slots, and the beginning and end of the energized coil 230 extend from the coil through slots;

[0018] The two inner protective plates 335 are respectively fixed on the iron cores 220 of the two magnet assemblies 200.

[0019] In one embodiment of the present invention, the compact magnetic deflection system further includes a cooling assembly 400; two cooling assemblies 400 with the same structure are respectively located between the magnet assembly 200 and the yoke assembly 100, and the input and output ports of the cooling pipes 410 of the cooling assembly 400 are arranged in the same direction and on the same side as the beginning and end of the energized coil 230.

[0020] In one embodiment of the present invention, the cooling pipe 410 is in close contact with the back of the excitation coil box 210.

[0021] In one embodiment of the present invention, the iron core 220 is rectangular, and the four corners are designed using the Rogowski theoretical boundary curve.

[0022] In one embodiment of the present invention, the energized coil 230 adopts a continuous disc winding method and is wound in multiple layers along the direction of the deflection magnetic field.

[0023] In one embodiment of the present invention, by changing the current or the number of turns of the energized coil 230, charged ions are flexibly deflected out of the original bundle channel, including:

[0024] Deflection radius of a D-ion with energy E for:

[0025]

[0026] Deflection radius of H- ions with energy E for:

[0027]

[0028] The magnetic induction intensity B of a uniform strong magnetic field is obtained by the following formula:

[0029]

[0030] In the formula, m represents the ion mass, e represents the charge of a single charge, Q represents the excitation ampere-turns, N represents the total number of turns of the energized coil, I represents the current flowing through the energized coil, f represents the AC frequency, g represents the air gap height, a represents the surface current density of the conductor, and S represents the cross-sectional area of ​​the conductor.

[0031] Compared with the prior art, the beneficial effects of the present invention are: the present invention designs a compact magnetic deflection system that is suitable for miniaturized high-energy particle injection of various beam shapes. It can effectively filter out various energy charged ion components, flexibly adjust the magnetic field size, and effectively remove the current heat of the conductive coil. It is simple to manufacture and easy to maintain, making it widely applicable in various scenarios.

[0032] This invention achieves the purpose of effectively filtering and purifying neutral beams by changing the current or number of turns of the energized coil to deflect charged ions out of the original beamline channel.

[0033] The energized coil is led out from the side, and the external water cooling system and protective components make the replacement of major components simple, easy to process, highly flexible, and convenient to install and match with other components of the high-energy particle injection beamline.

[0034] This invention controls the current to make the deflection radius smaller, so L z This will result in a smaller overall size in the Z-direction of the beamline, significantly reducing the overall size of the beamline. The design and assembly of the entire magnetic deflection system can effectively shorten the beamline's transmission direction dimension Lz, greatly minimizing the impact of vacuum differences between different sections of the beamline. Furthermore, it allows for the control of charged ions hitting a fixed receiving component, meeting the requirements for compact, high-precision, and flexible neutral beam injection.

[0035] The invention has a simple overall design, low cost, and high feasibility of implementation. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of a compact magnetic deflection system for neutral beam injection according to an embodiment of the present invention.

[0037] Figure 2 This is a schematic diagram of the yoke assembly and magnet protection assembly according to an embodiment of the present invention.

[0038] Figure 3 This is a schematic diagram of the magnet assembly according to an embodiment of the present invention.

[0039] Figure 4 This is a schematic diagram of the cooling assembly according to an embodiment of the present invention.

[0040] Figure 5 This is a schematic diagram of the working process of the magnetic deflection system according to an embodiment of the present invention. Detailed Implementation

[0041] To facilitate understanding of the technical solution of the present invention by those skilled in the art, the technical solution of the present invention will now be further described in conjunction with the accompanying drawings.

[0042] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0043] Please see Figure 1 As shown, the present invention provides a compact magnetic deflection system for neutral beam injection, comprising a yoke assembly 100, two identical magnet assemblies 200, and a magnet protection assembly 300. The yoke assembly 100 has a rectangular frame structure, forming a complete magnetic circuit. The two magnet assemblies 200 are arranged opposite each other within the yoke assembly 100, with a channel in the middle. The magnet protection assembly 300 surrounds the two magnet assemblies 200.

[0044] Please see Figures 1 to 2 As shown, in one embodiment of the present invention, the yoke assembly 100 includes an upper yoke (not shown), a lower yoke 120, a left yoke 130, and a right yoke 140. Upstream of the deflection system is a mixed ion beam and a neutral beam; therefore, the diffuse magnetic field at the magnet's inlet must be small to prevent premature ion deflection and bombardment of other components. Thus, the end yokes and side yokes are designed and manufactured to form a complete magnetic circuit, and their dimensional parameters can be based on Kirchhoff's laws. To meet the needs of yoke assembly and deflection magnet accessory installation, the upper and lower yokes 120 require multiple stepped through holes and threaded blind holes. The left and right yokes 130 and 140 have the same design structure; their main body is a cuboid, with threaded blind holes on the surfaces that connect with other structures for mounting the magnet assembly 200 and its fixing and supporting structures.

[0045] Please see Figures 1 to 4As shown, in one embodiment of the present invention, the magnet assembly 200 includes: an excitation coil box 210, an iron core 220, and an energized coil 230. The excitation coil box 210 has two U-shaped slots. The iron core 220 is located in the inner slot, and the energized coil 230 is located in the outer slot. The coil is wound using a continuous disc-like winding method, with multiple layers wound along the direction of the deflecting magnetic field. The beginning and end of the energized coil 230 extend from the side of the excitation coil box 210 in the same direction. By changing the current or the number of turns of the energized coil 230, charged ions can be flexibly deflected out of the original wire channel.

[0046] In this embodiment, there are two iron cores 220. The main body is a rounded cuboid, with stepped through-holes on the front for mounting the magnetic protection assembly 300 and its auxiliary structures. To fully utilize the magnetic field and maintain the size of the magnetic field region unchanged with variations in the magnetic field current, a B-type magnet design is chosen, meaning the magnetic flux density is constant across the cross-section of each magnetic pole. Therefore, the cross-sections of the two iron cores 220 are designed using the Rogowski theoretical boundary curve. The energized coil 230 is encapsulated within the excitation coil box 210 and assembled together with the iron cores 220.

[0047] Please see Figure 1 To and Figure 4 As shown, in one embodiment of the present invention, the magnet protection component 300, as the main external heat flow bearing component of the deflection magnet, needs to be made of a material with high thermal conductivity and high melting point. Based on the influence of beam divergence and diffused magnetic fields on the ion beam and the working principle of the magnet, the design of the magnet protection component 300 includes the design of an inlet beam collimator 310, a rotary inlet beam limiter 320, an upper magnet guard plate 331, a lower magnet guard plate 332, a left magnet guard plate 333, a right magnet guard plate 334, and an inner pole guard plate 335.

[0048] In this embodiment, the magnet protection assembly 300 includes an inlet beam collimator 310 and a rotary port beam limiter 320. The inlet beam collimator 310 is disposed at the inlet of the deflecting magnet, and the rotary port beam limiter 320 is disposed at the outlet of the deflecting magnet.

[0049] To meet the requirement of adjustable beam size, the inlet beam collimator 310 includes an upper limiting baffle 311 and a lower limiting baffle 312, which are respectively set at the top and bottom of the deflection magnet inlet, presenting a trumpet shape. The main body is a long-sided rounded cuboid structure, and a blind hole is opened near the center of the beam side to install a thermocouple (not shown in the figure).

[0050] In addition, to provide a flexible selection of the deflection radius of charged ions, the rotary port beam limiter 320 includes an upper beam baffle and a lower beam baffle, which are respectively set at the top and bottom of the deflection magnet outlet. A stepped conical blind hole is opened on the back of the beam near the center for installing a thermocouple (not shown in the figure), and two elliptical through holes are opened away from the beam for the combined installation of the baffle and the yoke.

[0051] In this embodiment, the upper magnet guard plate 331 is located above the upper end yoke of the yoke assembly 100. After being connected to the upper end yoke, the two ends of the upper magnet guard plate 331 are also connected to the left end yoke 130 and the right end yoke 140 of the yoke assembly 100, respectively. The lower magnet guard plate 332 is located above the upper end yoke of the yoke assembly 100 and below the magnet assembly 200. Two sets of left magnet guard plates 333 and right magnet guard plates 334 are located on the sides of the two magnet assemblies 200, respectively, and are connected to the inlet beam collimator 310 and the rotary port beam limiter 320, respectively. At the same time, the left magnet guard plate 333 and the right magnet guard plate 334 have coil through slots, and the beginning and end ends of the energized coil 230 extend from the coil through slots. In addition, the two inner pole guard plates 335 are respectively fixed on the iron cores 220 of the two magnet assemblies 200.

[0052] In this embodiment, the upper magnet guard plate 331, lower magnet guard plate 332, left magnet guard plate 333, right magnet guard plate 334, and inner pole guard plate 335 are mainly used to receive the heat load generated by beam divergence and bombardment of the magnet by charged ions of unknown composition. The upper magnet guard plate 331, lower magnet guard plate 332, left magnet guard plate 333, right magnet guard plate 334, and inner pole guard plate 335 are made of similar materials, namely chromium zirconium copper plates. When the particle energy is too high, a water cooling pipe 410 can be added internally. The inner pole guard plate 335 is fastened to the magnetic pole with bolts. The upper magnet guard plate 331 is assembled with the yoke using a screw and a threaded blind hole on the yoke. The lower magnet guard plate 332 is directly supported by two mounting brackets and fixed to the end yoke. The two sets of magnet left guard plates 333 and magnet right guard plates 334 are composed of four limiting baffles. Each limiting baffle is a rectangular structure with rounded corners on its long side. A blind hole is opened near the beam side to install a thermocouple for temperature measurement. If necessary, a groove is cut and welded to the water cooling pipe 410. At the same time, the magnet left guard plate 333 and magnet right guard plate 334 have coil through slots, and the beginning and end of the energized coil 230 extend from the coil through slots.

[0053] Please see Figures 1 to 4 As shown, in one embodiment of the present invention, the compact magnetic deflection system further includes a cooling assembly 400. Two cooling assemblies 400 with identical structures are respectively located between the magnet assembly 200 and the yoke assembly 100, and the inlet and outlet of the cooling pipe 410 of the cooling assembly 400 are arranged in the same direction and on the same side as the beginning and end of the energized coil 230.

[0054] In this embodiment, the cooling assembly 400 includes a cold water cover 420. Two cold water covers 420 are respectively located between the excitation coil box 210 and the left magnet guard plate 333, and the other excitation coil box 210 and the right magnet guard plate 334. A hoisting support component is provided inside the cold water cover 420. The hoisting support component connects the cooling assembly 400 to the excitation coil box 210 and the magnet guard plate, and supports the cooling pipe 410, which is in close contact with the back of the excitation coil box 210.

[0055] In this embodiment, both the cooling water cover 420 and the cooling pipe 410 are made of oxygen-free copper, and the hoisting support components are made of 304 austenitic non-magnetic stainless steel. As calculated by the physical design example, the circuit heat generated by a typical small-sized neutral beam injection is approximately several kilowatts. Therefore, the water cooling design is a single water channel tightly attached to the stainless steel box. The cooling pipe 410 and the 10 coil slots are connected using a silver soldering process, which can withstand high temperature variations.

[0056] Please see Figures 1 to 5 As shown, in one embodiment of the present invention, the working principle is as follows:

[0057] The deflecting magnet utilizes the Lorentz force experienced by charged particles moving in a uniform magnetic field to deflect ions away from the beam channel. When a charged ion with charge q moves at velocity υ in a uniform transverse magnetic field of strength B, the magnitude of the Lorentz force on the ion is F, and its direction is perpendicular to the plane determined by the direction of ion motion and the direction of the uniform magnetic field. Under the action of the Lorentz force, the ion will undergo circular motion, which can be expressed by the following formula:

[0058]

[0059] The relationship between the deflection radius and the magnetic field strength when an ion moves in a uniform transverse deflection magnetic field can be obtained as follows:

[0060]

[0061] In the formula, R is the radius of the circular motion of the charged ion, in meters; υ represents the velocity of the charged ion, in meters per second; and B represents the magnetic induction intensity of the uniform magnetic field, in tons.

[0062] The velocity υ of the high-energy ion beam can be expressed as:

[0063]

[0064] Therefore, combining formulas (1-1) to (1-3), the deflection radius of the D- ion with energy E can be calculated as follows:

[0065]

[0066] For an H- ion with energy E, its deflection radius is:

[0067]

[0068] Where m represents the ion mass and e represents the amount of charge.

[0069] In this embodiment, the deflecting magnet generates a uniform magnetic field region of a certain intensity along the beam transmission path. This causes the unneutralized high-energy charged ions within the beamline to deviate from the neutral beamline channel as they pass through the uniform magnetic field region, exiting from the magnetic field region at a certain angle. Considering the effective utilization of the installation space inside the beamline transmission channel and the distribution of the internal vacuum gradient, the magnitude of the magnetic field strength B is designed to be adjustable. The specific intensity is determined by the energy of the high-energy charged ions during the experiment. For a compact magnetic deflection system, flexibility is key. Generally, the energy E is given. From the above formulas (1-4) and (1-5), the deflection radius of the charged ions can be controlled by controlling the magnetic field strength B. This allows setting the deflection position of the charged ions. To target a specific position, an ion swallower can be placed at that position.

[0070] In this embodiment, the working principle of changing the magnetic field strength B by changing the current or the number of turns of the energized coil 230, thereby causing charged ions to be flexibly deflected out of the original beamline channel, will be explained below.

[0071] Taking a hydrogen ion source with an energy E1 of 30 keV and a beam diameter D of 0.2 m as an example. Due to the way hydrogen ions are generated, they usually also contain charged particles with other energies, with energies of E2, typically E2 being at least E1 / 3. According to formula (1-2), the deflection radii are R, ... Depend on Figure 5 It is known that, in order to prevent all charged ions from deflecting to the magnet itself, the deflection radius of E / 3 ions must be no less than D / 2. Furthermore, the deflecting magnet design must meet the following conditions:

[0072]

[0073] In the formula, Lz, Ly represent the beam channel dimensions on the ZOY plane of the magnet, θ represents the deflection angle of the charged ions, and β represents the angle between the line connecting the charged ion exit point and the deflection center and the incident surface of the deflecting magnet; l y1 ,l z1 The distances of the ions at full energy levels in the Lz and Ly directions are represented respectively. R2 represents the E / 3 particle; the beam source will only have particles of energy levels E, E / 2, and E / 3. In the diagram, R1 represents the full-energy ion. Correspondingly, θ1 and θ2 represent the deflection angles of the charged ions in the two energy states, respectively, and β1 and β2 represent the angles between the line connecting the exit point of the charged ion and the center of the deflection circle, and the incident surface of the deflecting magnet, respectively, in the two energy states.

[0074] Substituting the values, we can obtain the beam channel dimensions within the deflecting magnet as Lz = 0.1 m, Ly = 0.3 m, and Lx = 0.2 m when the magnetic field B is no greater than 1500 Gs. Here, Lx represents the beam channel dimension in the X direction.

[0075] Based on the empirical formula for utilizing magnetic poles:

[0076]

[0077] In the formula, ξ represents the magnetic pole utilization coefficient, which is generally taken as 0.78 to 0.91, and r m R represents the theoretically calculated deflection radius, while R represents the actual deflection radius. Since the magnetic field between the magnetic poles is not uniform, this additional increment needs to be taken into account when designing the distance between the magnetic pole ends (in the Z and Y directions).

[0078] Furthermore, the beam propagation process is affected by space charge effects and the extraction geometry, resulting in half-divergence angles of α and γ in the horizontal direction (XOZ plane) and vertical direction (YOZ plane), respectively. Assuming the divergence angle of the high-energy ion beam remains unchanged during deflection, the increase in its width (X direction) after a 180° deflection is l = 2πRtanα. To meet the protection requirements of the deflection magnet, the padding height of the magnetic poles is designed to be d. Therefore, the distance between the magnetic poles (X direction) Lx is (D + 2 × l + 2 × d).

[0079] In this embodiment, the advantages and disadvantages of C-type, H-type, WF-type, and frame-type dipolar electromagnets are compared.

[0080] The deflection magnet of this invention is best suited to a combined H-type dipolar electromagnet design, such as... Figure 3 As shown. The energized coil 230 is the core component of the deflecting magnet. By changing the current in the energized coil 230, the magnetic field strength B is changed. According to the formula, the excitation ampere-turns Q can be obtained as:

[0081] Q = NI = 80·fgB, (1-8);

[0082] In the formula, the AC frequency f = 1.05 to 1.10, g is the air gap height, usually represented by Lx in meters, N is the total number of turns of the energized coil, and I is the current flowing through the energized coil in amperes (A).

[0083] Therefore, the total number of turns N of the current-carrying coil of the deflecting magnet is:

[0084]

[0085] In the formula, 'a' represents the surface current density of the conductor, with units of A / m. 2S represents the cross-sectional area of ​​the conductor, in meters. 2 Internally water-cooled conductors have high current-carrying capacity, but maintenance is very troublesome, making them unsuitable for miniaturized and compact deflection systems. Therefore, under short-pulse conditions, based on the "Electrical Engineering Handbook," an external water-cooling method was chosen, with a coil current density of 3A / mm². 2 The coil itself is a cylindrical oxygen-free copper wire with a radius of 4mm. The outside of the wire is wrapped with two layers of glass fiber film and polyimide film with thicknesses of 0.127mm and 0.0508mm respectively to ensure insulation. Substituting into the formula, the total number of turns of the coil in this case is 50.9 turns, taking 52 turns, that is, 26 turns on each side.

[0086] In one embodiment of the present invention, to reduce the number of connectors in the energized coil 230 and considering the production capacity of the conductor raw materials, the energized coil 230 adopts a continuous pancake winding method. Considering the requirements for installation space and installation stability of the energized coil 230, the energized coil 230 is designed as a 4×7 structure, with 4 layers along the direction of the deflecting magnetic field. Therefore, the detailed design structure of the energized coil 230 of the deflecting magnet is 4 layers on each side, with 7 coils in each layer, all connected in series. Each coil on each side requires two power connectors, and the entire deflecting magnet requires a total of 4 connectors, all of which are led out from the side.

[0087] In one embodiment of the present invention, based on the design requirements of the magnetic field space and the preliminary results of the above magnet design, the total wire length l of the single-sided coil of the deflecting magnet is approximately 21m. According to the design structure of the energized coil 230, the energized coil 230 of the deflecting magnet in each beam channel adopts a series structure, resulting in a heating power of 2.1kW for the energized coil 230 in each beam channel. This heat, along with the heat generated by the beam power deposited on the magnetic pole protector, needs to be carried away by cooling water to maintain the operating temperature of the deflecting magnet within a defined range.

[0088] In one embodiment of the present invention, considering the limitations of installation space and the need for deflection magnet current leads, the yoke assembly 100 of the deflection magnet is designed to include two end yokes and a side yoke. The yokes require high flatness and perpendicularity in their machining to meet the need for forming a uniform magnetic field between the magnetic poles.

[0089] In one embodiment of the present invention, according to Kirchhoff's law of magnetic circuits, the B of general industrial soft iron... m The thickness is 2T, therefore, in this case, the thickness L of the yoke surrounding the magnet is... thick The thickness of the end yoke 120 should not be less than 0.0046 mm. Based on the installation space requirements, the magnetic path design requirements of the yoke, and the need for space for the uniform magnet design, the main body of the upper and lower end yokes is a rectangular structure with corners removed, measuring 300 mm in length (X direction), 240 mm in width (Z direction), and 5 mm in thickness (Y direction).

[0090] In one embodiment of the invention, the mixed-component beam enters the compact magnetic deflection system perpendicularly, and the beam size can be altered by the inlet beam collimator 310 at the inlet. Charged particles are deflected by the Lorentz force in the magnetic field region generated by the energized coil 230. The vast majority of charged ions are deflected to the lower right of the magnet and received by subsequent receiving devices, such as an ionizer; a small portion of charged ions hit the magnet protection assembly 300 and the rotating port beam limiter 320. The current I in the energized conductor can be adjusted, thereby adjusting the magnetic field strength B. The specific strength depends on the energy E of the high-energy ion beam during the experiment and the position l of the lower right ionizer. z1 The decision is made. If the experiment needs to be carried out for a long time, the current heat generated by the externally water-cooled winding coil will affect the current-carrying capacity of the wire itself. This can be removed by the circulating cooling water in the cooling component 400, achieving efficient and safe operation. The deflected charged particles need to be received. Miniaturized wire-beam devices are generally quite compact. Where is the ion swallower designed? This invention can control the deflection radius, thereby directing the deflected ions to hit the ion swallower.

[0091] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0092] The above embodiments are merely examples of implementation methods of the invention. The scope of protection of the present invention is not limited to the above embodiments. For those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A compact magnetic deflection system for neutral beam injection, characterized in that, include: The system comprises an iron yoke assembly (100), two identical magnet assemblies (200), and a magnet protection assembly (300). The iron yoke assembly (100) has a rectangular frame structure, forming a complete magnetic circuit. The two magnet assemblies (200) are arranged opposite each other within the iron yoke assembly (100), with a channel in between. The magnet protection assembly (300) surrounds the two magnet assemblies (200). The magnet assembly (200) includes: an excitation coil box (210), an iron core (220), and a energizing coil (230); the excitation coil box (210) has two U-shaped slots, with the iron core (220) located in the inner slot and the energizing coil (230) located in the outer slot, and the beginning and end of the energizing coil (230) extending from the side of the excitation coil box (210) in the same direction; by changing the current or the number of turns of the energizing coil (230), charged ions can be flexibly deflected out of the original wire channel, including: Deflection radius of a D-ion with energy E for: The deflection radius R of an H- ion with energy E H- for: The magnetic induction intensity B of a uniform strong magnetic field is obtained by the following formula: In the formula, m represents the ion mass, e represents the charge of a single charge, Q represents the excitation ampere-turns, N represents the total number of turns of the energized coil, I represents the current flowing through the energized coil, f represents the AC frequency, g represents the air gap height, a represents the surface current density of the conductor, and S represents the cross-sectional area of ​​the conductor; wherein, the iron core (220) is rectangular.

2. The compact magnetic deflection system for neutral beam injection according to claim 1, characterized in that, The magnet protection assembly (300) includes an inlet beam collimator (310) and a rotary port beam limiter (320); the inlet beam collimator (310) is located at the inlet of the deflecting magnet, and the rotary port beam limiter (320) is located at the outlet of the deflecting magnet. The inlet beam collimator (310) includes an upper limiting baffle (311) and a lower limiting baffle (312), which are respectively disposed at the top and bottom of the deflection magnet inlet, and are in the shape of a trumpet. The rotating port beam limiter (320) includes an upper beam baffle and a lower beam baffle, which are respectively disposed at the top and bottom of the deflection magnet outlet.

3. The compact magnetic deflection system for neutral beam injection according to claim 2, characterized in that, The magnet protection assembly (300) includes an upper magnet guard plate (331), a lower magnet guard plate (332), a left magnet guard plate (333), a right magnet guard plate (334), and an inner magnet guard plate (335); The magnet upper guard plate (331) is located on the upper end iron yoke of the iron yoke assembly (100). After the magnet upper guard plate (331) is connected to the upper end iron yoke, its two ends are also connected to the left end iron yoke (130) and the right end iron yoke (140) of the iron yoke assembly (100), respectively. The magnet lower guard plate (332) is located above the upper end iron yoke of the iron yoke assembly (100) and below the magnet assembly (200); Two sets of magnet left guard plates (333) and magnet right guard plates (334) are located on the sides of the two magnet assemblies (200) respectively, and are connected to the inlet beam collimator (310) and the rotary port beam limiter (320) respectively; at the same time, the magnet left guard plate (333) and magnet right guard plate (334) are provided with coil through slots, and the beginning and end of the energized coil (230) extend from the coil through slots; The two inner protective plates (335) are respectively fixed on the iron core (220) of the two magnet assemblies (200).

4. The compact magnetic deflection system for neutral beam injection according to claim 1, characterized in that, The compact magnetic deflection system also includes a cooling assembly (400); two identical cooling assemblies (400) are located between the magnet assembly (200) and the yoke assembly (100), and the inlet and outlet of the cooling pipe (410) of the cooling assembly (400) are arranged in the same direction and on the same side as the beginning and end of the energized coil (230).

5. The compact magnetic deflection system for neutral beam injection according to claim 4, characterized in that, The cooling pipe (410) is attached to the back of the excitation coil box (210).

6. The compact magnetic deflection system for neutral beam injection according to claim 1, characterized in that, The four corners of the iron core (220) are designed using the boundary curves of the Rogosky theory.

7. The compact magnetic deflection system for neutral beam injection according to claim 1, characterized in that, The energized coil (230) is wound in a continuous disc-shaped manner and is wound in multiple layers along the direction of the deflecting magnetic field.

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