Compact magnetic deflection system for neutral beam injection

Abstract

The invention discloses a compact magnetic deflection system for neutral beam injection. The compact magnetic deflection system comprises an iron yoke assembly, two magnet assemblies with the same structure and a magnet protection assembly, the iron yoke assembly is of a rectangular frame structure and forms a complete magnetic loop, the two magnet assemblies are oppositely arranged in the iron yoke assembly, and a channel is reserved between the two magnet assemblies. The magnet protection assembly surrounds the two magnet assemblies; the magnet assembly comprises a magnet exciting coil box, an iron core and an electrified coil, two space grooves are formed in the excitation coil box in a rectangular-ambulatory-plane mode, the iron core is located in the space groove in the inner layer, the electrified coil is located in the space groove in the outer layer, and the head end and the tail end of the electrified coil extend out of the side edge of the excitation coil box in the same direction; charged ions flexibly deflect out of an original beam line channel by changing the current of the electrified coil or the number of turns of the coil. According to the invention, mixed charged ion beams can be effectively filtered out, and purified neutral beam injection is realized.

Description

Technical Field

[0001] The invention relates to the technical field of high energy neutral beam injectors, in particular to a compact magnetic deflection system for neutral beam injection. Background Art

[0002] Charged particle and neutral particle implantation are widely used. In the semiconductor field, the type and effect of ion implantation determine the core performance of the internal structure devices of semiconductor chips, and it is a very important link in the integrated circuit manufacturing process. In the field of vacuum coating, the direction and sensitivity of the ion beam determine the film thickness and density. In the field of magnetic confinement fusion and high-energy particles, ions are neutralized to produce neutral particles and other charged ion components. High-energy neutral atom beams can be effectively injected into confined plasma and collide with background plasma, so they are often used for auxiliary heating and neutron source generation. Differences in ion types, ion beam transmission and neutralization efficiency will lead to complex beam composition, so an effective deflection system is required to filter out charged ions.

[0003] Common charged ion deflection systems include electric deflection and magnetic deflection. Electric deflection mainly utilizes the electric field force between the electrode plates. When charged ions hit the electrode plates, it is easy to cause the deposition of ion sheaths and secondary electron emission, resulting in damage to the electrode plates and weakening of the electric field force. Therefore, there are more requirements for the pressure resistance, mechanical and thermal transfer capabilities of the deflection plate materials, and it is not suitable for high-energy ions. Magnetic deflection utilizes the Lorentz force provided by the magnetic field. The direction of the force is always perpendicular to the tangent of the deflection direction of the charged ions. Different charged ions have different deflection radii. The deflected remaining ions can be received by related devices after the magnetic deflection system, and the collision heat energy is taken away by cooling water. It is more suitable for high-energy particle screening and deflection.

[0004] At present, magnetic deflection devices are mainly used in large scientific research equipment. The entire system is accompanied by additional water cooling and winding coils, which is very large in size and has complicated manufacturing and use processes. In fact, with the demand for high-energy particle beams in various industries, miniaturized ion implantation devices are gradually becoming commercialized, so miniaturized and compact magnetic deflection devices have broad application prospects.

[0005] The demand for miniaturization, flexibility and high precision of particle beam injection devices is gradually increasing, and the deflection device that effectively separates and deflects charged ions is a core component. The current magnetic deflection device used for charged particle deflection is bulky and equipped with an internal water-cooled conductive coil. It takes a longer time to adjust the magnetic field and causes greater current heat. It is complex to manufacture, use and maintain, so it is not suitable for the needs of miniaturized high-energy ion beam devices.

[0006] In the prior art, the invention patent with the patent publication number CN117292866A discloses a residual charged particle electric deflection system of a negative ion source neutral beam injector, including electric deflection plates, a main support structure, an adjustable support base, a protective shell, a hanger and a thermocouple. The electric deflection plates are used to form an electric field between the plates and absorb the energy of high-energy charged particles; the main support structure is used to support and position the plate body; the adjustable support base is used to install and position the electric deflector inside the beam line vacuum chamber; the protective shell is used to form a potential protection between the high-potential plate and the remaining components of the beam line, and a trumpet-shaped beam limiter with a water-cooled pipeline is used at the entrance and exit of the protective shell to limit the beam to a spatial size; the hanger is used to hang the main body of the electric deflector. The present invention realizes the stripping of residual charged particles in the negative ion source neutral beam injection system by the method of electric deflection, and realizes the neutralization of the beam. However, the deflection system is applied in the field of nuclear fusion technology and 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] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0009] A compact magnetic deflection system for neutral beam injection comprises: an iron yoke assembly 100, two magnet assemblies 200 of the same structure and a magnet protection assembly 300; the iron yoke assembly 100 is a rectangular frame structure, forming a complete magnetic circuit, the two magnet assemblies 200 are arranged relatively in the iron yoke assembly 100, and a channel is left in the middle; the magnet protection assembly 300 surrounds the two magnet assemblies 200; wherein,

[0010] The magnet assembly 200 includes: an excitation coil box 210, an iron core 220 and a power coil 230; two U-shaped space slots are arranged inside the excitation coil box 210, the iron core 220 is located in the inner space slot, the power coil 230 is located in the outer space slot, and the head and tail ends of the power 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 power coil 230, the charged ions can be flexibly deflected out of the original beam line channel.

[0011] In one embodiment of the present invention, the magnet protection assembly 300 includes an entrance beam collimator 310 and a turn-port beam limiter 320; the entrance beam collimator 310 is arranged at the entrance of the deflection magnet, and the turn-port beam limiter 320 is arranged at the exit of the deflection magnet;

[0012] The entrance beam collimator 310 includes an upper limiting baffle 311 and a lower limiting baffle 312, which are respectively arranged at the top and bottom of the deflection magnet entrance and present a trumpet shape;

[0013] The turn port beam limiter 320 includes an upper beam baffle and a lower beam baffle, which are respectively arranged at the top and bottom of the deflection magnet exit.

[0014] In one embodiment of the present invention, the magnet protection assembly 300 includes a magnet upper guard plate 331, a magnet lower guard plate 332, a magnet left guard plate 333, a magnet right guard plate 334 and a magnetic pole inner 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] Two sets of magnet left guard plates 333 and magnet right guard plates 334 are respectively located on the sides of the two magnet assemblies 200, and are respectively connected to the entrance beam collimator 310 and the return port beam limiter 320; at the same time, the magnet left guard plate 333 and the magnet right guard plate 334 are provided with coil through slots, and the head and tail ends of the energized coil 230 extend from the coil through slots;

[0018] The two magnetic pole inner shields 335 are respectively relatively 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 iron yoke assembly 100, and the input and output ports of the cooling pipes 410 of the cooling assemblies 400 are arranged in the same direction and on the same side as the head and tail ends of the energized coil 230.

[0020] In one embodiment of the present invention, the cooling pipe 410 is closely attached to the back side of the excitation coil box 210 .

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

[0022] In one embodiment of the present invention, the energized coil 230 is wound in a continuous pancake-like manner and has multiple layers wound along the direction of the deflection magnetic field.

[0023] In one embodiment of the present invention, the current of the energized coil 230 or the number of coil turns is changed to flexibly deflect the charged ions out of the original beam line channel, including:

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

[0025]

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

[0027]

[0028] Among them, the uniform strong magnetic field magnetic induction intensity B is obtained by the following formula:

[0029]

[0030] In the formula, m represents the mass of the ion, e represents the charge of one charge, Q represents the excitation ampere-turns, N represents the total number of turns of the energized coil, I represents the current passed through the energized coil, f represents the frequency of the alternating current, g represents the air gap height, a represents the current surface 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 as follows: the present invention designs a compact magnetic deflection system, which is suitable for miniaturized high-energy particle injection of various beam shapes, can effectively filter out various types of energy charged ion components, flexibly adjust the magnetic field size, and effectively remove the heat of the conductive coil current. It is simple to manufacture and easy to maintain, so that it can be widely used in various scenarios.

[0032] The present invention can achieve the purpose of effectively filtering and purifying neutral beams by changing the current of the energized coil or the number of coil turns so as to deflect the charged ions out of the original beam line channel.

[0033] The energized coil is led out from the side, with external water cooling and installation of protective components, making the replacement process of the main components simple, convenient for processing, and highly flexible, and convenient for installation and matching with other components of the high-energy particle injection beam line.

[0034] The present invention controls the current to make the deflection radius smaller, so L z It will be smaller, which will eventually make the size of the entire beam line in the Z direction much smaller. The design and assembly of the entire magnetic deflection system can effectively shorten the size Lz in the beam line transmission direction, greatly reducing the impact of vacuum differences in different sections of the beam line. In addition, the charged ions can be controlled to hit the receiving components at fixed positions, meeting the needs of compact, high-precision, and flexible neutral beam injection.

[0035] The overall design of the invention is simple, the manufacturing cost is low, and the whole set of equipment is highly practicable. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The figure 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 It is a schematic diagram of an iron yoke assembly and a magnet protection assembly according to an embodiment of the present invention.

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

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

[0040] Figure 5 FIG. 2 is a schematic diagram of the working process of the magnetic deflection system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0041] In order to facilitate those skilled in the art to understand the technical solution of the present invention, the technical solution of the present invention is further described in conjunction with the accompanying drawings of the specification.

[0042] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0043] See also Figure 1 As shown, the present invention provides a compact magnetic deflection system for neutral beam injection, comprising an iron yoke assembly 100, two magnet assemblies 200 of the same structure, and a magnet protection assembly 300. The iron yoke assembly 100 is a rectangular frame structure, forming a complete magnetic circuit, the two magnet assemblies 200 are relatively arranged in the iron yoke assembly 100, with a channel in the middle, and the magnet protection assembly 300 surrounds the two magnet assemblies 200.

[0044] See also Figure 1 to Figure 2 As shown, in one embodiment of the present invention, the iron yoke assembly 100 includes an upper end iron yoke (not shown), a lower end iron yoke 120, a left end iron yoke 130 and a right end iron yoke 140. The upstream of the deflection system is a beam current mixed with an ion beam and a neutral beam, so the diffuse magnetic field of the magnet at the entrance is required to be small to avoid the ions from being deflected in advance and bombarding other components. Therefore, the end iron yoke and the side iron yoke are designed and manufactured to form a complete magnetic circuit, and the size parameters can be based on Kirchhoff's theorem. In order to meet the needs of iron yoke assembly and deflection magnet accessory installation, the upper end iron yoke and the lower end iron yoke 120 need to open multiple step through holes and threaded blind holes. The design structure of the left end iron yoke 130 and the right end iron yoke 140 is the same, and its main body is designed as a rectangular parallelepiped, and threaded blind holes are opened on the surface connected to other structures to install the magnet assembly 200 and its fixing and supporting structures.

[0045] See also 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 a power coil 230. Two space slots are arranged in a U-shaped manner in the excitation coil box 210, the iron core 220 is located in the inner space slot, and the power coil 230 is located in the outer space slot, and a continuous pancake winding method is adopted, and multiple layers are wound along the deflection magnetic field direction, and the head and tail ends of the power 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 power coil 230, the charged ions can be flexibly deflected out of the original beam line channel.

[0046] In this embodiment, there are two iron cores 220, the main body of which is a rounded rectangular parallelepiped, and a stepped through hole is required on the front to install the magnet protection assembly 300 and the auxiliary structure. In order to make full use of the magnetic field of the magnet and keep the size of the magnetic field area unchanged with the change of the magnetic field current, an equal B magnet design is selected, that is, the magnetic flux density on each magnetic pole cross section is a constant, so the cross section of the two iron cores 220 is designed using the Rogowski theoretical boundary curve. The power coil 230 is encapsulated in the excitation coil box 210 and assembled together with the iron core 220.

[0047] See also Figure 1 To Figure 4 As shown, in one embodiment of the present invention, the magnet protection assembly 300 is the main external heat flux bearing component of the deflection magnet, and it needs to use a material with a large thermal conductivity and a high melting point. According to the influence of beam divergence and diffuse magnetic field on ion beam and the working principle of the magnet, the design of the magnet protection assembly 300 includes the design of the entrance beam collimator 310, the return port beam limiter 320, the magnet upper guard plate 331, the magnet lower guard plate 332, the magnet left guard plate 333, the magnet right guard plate 334 and the pole inner guard plate 335.

[0048] In this embodiment, the magnet protection assembly 300 includes an entrance beam collimator 310 and a turn port beam limiter 320. The entrance beam collimator 310 is disposed at the entrance of the deflection magnet, and the turn port beam limiter 320 is disposed at the exit of the deflection magnet.

[0049] In order to meet the requirement of adjustable beam size, the entrance beam collimator 310 includes an upper limiting baffle 311 and a lower limiting baffle 312, which are respectively arranged at the top and bottom of the deflection magnet entrance, and are in a trumpet shape. The main body is a rectangular parallelepiped structure with long sides and rounded corners, 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, in order to provide a flexible selection method for the deflection radius of charged ions, the turning port beam limiter 320 includes an upper beam baffle and a lower beam baffle, which are respectively arranged at the top and bottom of the deflection magnet outlet. A stepped conical blind hole is opened on the back side near the center of the beam side for installing a thermocouple (not shown in the figure), and two elliptical through holes are opened away from the beam side for the combined installation of the baffle and the iron yoke.

[0051] In this embodiment, the upper magnet guard plate 331 is located on the upper end iron yoke of the iron yoke assembly 100. After the upper magnet 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 lower magnet guard plate 332 is located on the upper end iron yoke of the iron yoke assembly 100 and below the magnet assembly 200. Two groups of magnet left guard plates 333 and magnet right guard plates 334 are respectively located on the sides of the two magnet assemblies 200, and are respectively connected to the entrance beam collimator 310 and the return port beam limiter 320. At the same time, the left magnet guard plate 333 and the right magnet guard plate 334 are provided with coil through grooves, and the head and tail ends of the energized coil 230 extend from the coil through grooves. And, the two pole inner guard plates 335 are respectively relatively fixed on the iron cores 220 of the two magnet assemblies 200.

[0052] In this embodiment, the upper magnet guard plate 331, the lower magnet guard plate 332, the left magnet guard plate 333, the right magnet guard plate 334 and the inner pole guard plate 335 are mainly used to receive the heat load generated by the beam divergence and the bombardment of the magnet by the charged ions of unknown components. The upper magnet guard plate 331, the lower magnet guard plate 332, the left magnet guard plate 333, the right magnet guard plate 334 and the inner pole guard plate 335 are made of similar materials, all of which are chromium zirconium copper plates. When the particle energy is too high, a water cooling pipe 410 can be added to the inner design. The inner pole guard plate 335 is fastened to the magnetic pole by bolts, the upper magnet guard plate 331 uses the threaded blind hole on the screw and the iron yoke to realize the combined installation of the guard plate and the iron yoke, and the lower magnet guard plate 332 is directly supported by two mounting brackets and fixed to the end iron yoke. The two sets of magnet left guard plates 333 and magnet right guard plates 334 are composed of four limiting baffles, each of which is a rectangular parallelepiped structure with long sides and rounded corners. A blind hole is opened near the beam side to install a thermocouple for temperature measurement, and a groove is opened to weld a water cooling pipe 410 when necessary. At the same time, the magnet left guard plate 333 and the magnet right guard plate 334 are provided with coil through grooves, and the first and tail ends of the energized coil 230 extend from the coil through grooves.

[0053] See also 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 the same structure are respectively located between the magnet assembly 200 and the iron yoke assembly 100, and the input and output ports of the cooling pipes 410 of the cooling assemblies 400 are arranged in the same direction and on the same side as the head and tail ends of the energized coil 230.

[0054] In this embodiment, the cooling assembly 400 includes a cold water cover 420, and two cold water covers 420 are respectively located between the excitation coil box 210 and the left magnet guard plate 333, and between the other excitation coil box 210 and the right magnet guard plate 334. A hanging support component is provided in the cold water cover 420, and the cooling assembly 400 is connected to the excitation coil box 210 and the magnet guard plate through the hanging support component, and the cooling pipe 410 is supported, and the cooling pipe 410 is close to the back of the excitation coil box 210.

[0055] In this embodiment, the cold water cover 420 and the cooling pipe 410 are both made of oxygen-free copper, and the hoisting support parts are made of 304 austenitic non-magnetic stainless steel. From the physical design example calculation, it can be seen that the circuit heat brought by the common small-sized neutral beam injection is about several kilowatts, so the water cooling design is a water channel close to the stainless steel box, and the silver welding process is used between the cooling pipe 410 and the 10 coil slots to withstand higher temperature changes.

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

[0057] The deflection magnet uses the Lorentz force on charged particles when they move in a uniform magnetic field to deviate the ions from the beam channel. When a charged ion with a charge of q moves at a speed of υ in a transverse magnetic field of uniform strength B, the Lorentz force on the ion is F, and its direction is perpendicular to the plane determined by the direction of ion movement and the uniform magnetic field. Under the action of the Lorentz force, the ion will move in a circular motion, and the formula is as follows:

[0058]

[0059] It can be obtained that when ions move in a uniform transverse deflection magnetic field, the relationship between the deflection radius and the magnetic field strength is:

[0060]

[0061] In the formula, R is the radius of the circular motion of the charged ions, the unit is m, υ represents the speed of the charged ions, the unit is m / s; B represents the magnetic induction intensity of the uniform magnetic field, the unit is T.

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

[0063]

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

[0065]

[0066] For H- ions with energy E, the deflection radius is:

[0067]

[0068] Here, m represents the mass of the ion and e represents the charge of one electric charge.

[0069] In this embodiment, the deflection magnet generates a uniform magnetic field region of a certain intensity on the beam transmission path, so that the high-energy charged ions in the beam line that have not been neutralized deviate from the neutral beam line channel in the process of passing through the uniform magnetic field region and emerge from the magnetic field region at a certain angle. Considering the effective use of the installation space inside the beam line transmission channel and the distribution of the internal vacuum gradient, the magnitude of the magnetic field strength B is designed to be adjustable, and the specific strength is determined by the energy of the high-energy charged ions during the experiment. For compact magnetic deflection systems, the focus is on flexibility. Generally, the energy E is given. According to the above formulas (1-4) and (1-5), by controlling the magnetic field strength B, the deflection radius of the charged ions can be controlled. In this way, the deflection position of the charged ions can be set. If you want to hit the charged ions to a certain position, you can set the ion eater at the corresponding position.

[0070] In this embodiment, the working principle of changing the current of the energized coil 230 or the number of coil turns to change the magnetic field strength B and thus flexibly deflecting the charged ions out of the original beam line channel is described below.

[0071] Take a hydrogen ion source with an energy of 30keV and a beam diameter of 0.2m as an example. Due to the way hydrogen ions are generated, they usually contain charged particles with other energies, with energy values ​​of E2. Usually, the minimum E2 is E1 / 3. According to formula (1-2), the deflection radii are R, Depend on Figure 5 It can be seen that in order to prevent all charged ions from being deflected to the magnet itself, the deflection radius of E / 3 ions should not be less than D / 2. In addition, the deflection magnet design needs to meet the following conditions:

[0072]

[0073] Where Lz,Ly represents the beam channel size on the magnet ZOY surface, θ represents the deflection angle of the charged ions, and β represents the angle between the line connecting the exit point of the charged ions and the center of the deflection circle and the incident surface of the deflection magnet; l y1 ,l z1 Respectively represent the distance of full energy ions in the Lz and Ly directions. R2 represents E / 3 particles. There will only be particles of three energies, E, E / 2 and E / 3, on the beam source side. In the figure, R1 represents full energy ions. Correspondingly, θ1 and θ2 represent the deflection angles of charged ions in two energy states, and β1 and β2 represent the angles between the line connecting the exit point of charged ions and the center of the deflection circle in two energy states and the incident surface of the deflection magnet.

[0074] Substituting the numerical values, we can obtain that when the magnetic field B is not greater than 1500 Gs, the beam channel size in the deflection magnet is Lz = 0.1m, Ly = 0.3m, Lx = 0.2m, where Lx represents the beam channel size in the X direction.

[0075] According to the empirical formula of magnetic pole utilization:

[0076]

[0077] In the formula, ξ is the magnetic pole utilization coefficient, which is generally 0.78 to 0.91, r m The deflection radius is expressed as the theoretical calculation, and R is expressed as the actual deflection radius. Because the magnetic field between the magnetic poles is not uniform, the design of the magnetic pole tip distance (in the Z direction and the Y direction) needs to take this additional increment into account.

[0078] In addition, the beam transmission process will be affected by the space charge effect and the extraction geometry, making the half-divergence angles of the beam in the horizontal direction (XOZ plane) and the vertical direction (YOZ plane) α and γ respectively. Assuming that the divergence angle of the high-energy ion beam does not change during the deflection process, the increase in its width (X direction) after the beam is deflected 180° is l = 2πRtanα, and in order to meet the protection requirements of the deflection magnet, the shimming height of the magnetic pole is designed to be d, then 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 dipole electromagnets are compared.

[0080] The deflection magnet of the present invention is more suitable for a combined H-type two-pole electromagnet design structure, such as Figure 3 The energized coil 230 is the core component of the deflection magnet. By changing the current in the energized coil 230, the magnetic field B is changed. The excitation ampere-turns Q can be obtained according to the formula:

[0081] Q = NI = 80·fgB, (1-8);

[0082] In the formula, the AC frequency f = 1.05 ~ 1.10, g is the air gap height, usually represented by Lx, the unit is m, N is the total number of turns of the energized coil, and I is the current passing through the energized coil, the unit is A.

[0083] Therefore, the total number of turns N of the energized coil of the deflection magnet is:

[0084]

[0085] Where a is the conductor current surface density, unit A / m 2, S represents the cross-sectional area of ​​the conductor, unit is m 2 The internal water-cooled wire has a strong current carrying capacity, but it is very troublesome to maintain and is not suitable for miniaturized and compact deflection systems. Therefore, in the case of short pulses, according to the "Electrical Engineering Handbook", it is decided to use external water cooling, and the coil current density is 3A / mm 2 The coil itself is a cylindrical oxygen-free copper wire with a radius of 4mm. The outer side of the wire is covered 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, and 52 turns are taken, that is, 26 turns on each side.

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

[0087] In one embodiment of the present invention, according to the design requirements of the magnetic field space and the preliminary results of the magnet design, the total length l of the wire of the single-side coil of the deflection magnet is about 21m. According to the design structure of the energized coil 230, the energized coil 230 of the deflection magnet of each beam channel adopts a series structure, and the heat generation power of the energized coil 230 on each beam channel is 2.1kW. This part of heat and the heat generated by the beam power deposited on the magnetic pole guard plate need to be removed from the deflection magnet by cooling water to maintain its operating temperature within a limited range.

[0088] In one embodiment of the present invention, considering the limitation of installation space and the need of current lead of the deflection magnet, the iron yoke assembly 100 of the deflection magnet is designed to include two end iron yokes and side iron yokes. The processing of the iron yoke requires high flatness and verticality to meet the need of forming a uniform magnetic field between the magnetic poles.

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

[0090] In one embodiment of the present invention, the beam of mixed components enters the compact magnetic deflection system vertically, and the beam size can be changed by the entrance beam collimator 310 at the entrance. The charged particles are deflected by the Lorentz force in the magnetic field region generated by the energized coil 230. Most of the charged ions are deflected to the lower right of the magnet and received by subsequent receiving devices, such as ion eaters, and a small number of charged ions hit the magnet protection assembly 300 and the return port beam limiter 320. The current I of the energized wire can be adjusted, and thus the magnetic field strength B can be adjusted. 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 ion eater. z1 If the experiment needs to be carried out for a long time, the current heat generated by the winding coil in the external water cooling method will affect the current carrying capacity of the wire itself, which can be taken away by the circulating cooling water in the cooling assembly 400 to achieve efficient and safe operation. The deflected charged particles need to be received. The size of the miniaturized beam line device is generally compact. Where is the ion eater designed? The present invention can control the deflection radius, and then can direct the deflected ions to hit the ion eater.

[0091] It is obvious 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 present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-limiting from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any reference numerals in the claims should not be regarded as limiting the claims involved.

[0092] The above-described embodiments merely represent implementation methods of the invention. The protection scope of the present invention is not limited to the above-described embodiments. For those skilled in the art, several modifications and improvements may be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A compact magnetic deflection system for neutral beam injection, characterized in that: include: An iron yoke assembly (100), two magnet assemblies (200) of the same structure, and a magnet protection assembly (300); the iron yoke assembly (100) is a rectangular frame structure, forming a complete magnetic circuit, the two magnet assemblies (200) are arranged relatively inside the iron yoke assembly (100), and a channel is left in the middle; the magnet protection assembly (300) surrounds the two magnet assemblies (200); wherein, The magnet assembly (200) comprises: an excitation coil box (210), an iron core (220) and an energized coil (230); two space slots are arranged in a U-shaped manner in the excitation coil box (210), the iron core (220) is located in the inner space slot, the energized coil (230) is located in the outer space slot, and the head and tail ends 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 coil turns of the energized coil (230), the charged ions can be flexibly deflected out of the original beam line channel.

2. The compact magnetic deflection system for neutral beam injection according to claim 1, characterized in that The magnet protection assembly (300) comprises an entrance beam collimator (310) and a rotation port beam limiter (320); the entrance beam collimator (310) is arranged at the entrance of the deflection magnet, and the rotation port beam limiter (320) is arranged at the exit of the deflection magnet; The entrance beam collimator (310) comprises an upper limiting baffle (311) and a lower limiting baffle (312), which are respectively arranged at the top and bottom of the deflection magnet entrance and present a trumpet-mouth shape; The turn-port beam limiter (320) comprises an upper beam baffle and a lower beam baffle, which are respectively arranged at the top and bottom of the deflection magnet exit.

3. The compact magnetic deflection system for neutral beam injection according to claim 2, characterized in that The magnet protection assembly (300) comprises a magnet upper guard plate (331), a magnet lower guard plate (332), a magnet left guard plate (333), a magnet right guard plate (334) and a magnetic pole inner 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 respectively connected to the left end iron yoke (130) and the right end iron yoke (140) of the iron yoke assembly (100); 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 groups of magnet left guard plates (333) and magnet right guard plates (334) are respectively located on the sides of the two magnet assemblies (200), and are respectively connected to the entrance beam collimator (310) and the rotation port beam limiter (320); at the same time, the magnet left guard plate (333) and the magnet right guard plate (334) are provided with coil through slots, and the head and tail ends of the energized coil (230) extend out from the coil through slots; The two magnetic pole inner guard plates (335) are respectively relatively fixedly located on the iron cores (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 cooling assemblies (400) with the same structure are respectively located between the magnet assembly (200) and the iron yoke assembly (100), and the input and output ports of the cooling pipes (410) of the cooling assemblies (400) are arranged in the same direction and on the same side as the head and tail ends 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 closely attached to the back side of the excitation coil box (210).

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

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 pancake-like manner and has multiple layers wound along the direction of the deflection magnetic field.

8. The compact magnetic deflection system for neutral beam injection according to claim 1, characterized in that By changing the current of the energized coil (230) or the number of coil turns, the charged ions are flexibly deflected out of the original beam line channel, including: Deflection radius of D-ions with energy E for: Deflection radius of H- ions with energy E for: Among them, the uniform strong magnetic field magnetic induction intensity B is obtained by the following formula: In the formula, m represents the mass of the ion, e represents the amount of charge, Q It is expressed as the excitation ampere-turns, N is the total number of turns of the energized coil, I is the current passed through the energized coil, f is the frequency of the alternating current, g is the air gap height, a is the conductor current surface density, and S is the conductor cross-sectional area.

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