Focusing magnetic lens for electron accelerator

Abstract

The utility model relates to a focusing magnetic lens used for an electron accelerator, comprising an annular first magnet yoke, an annular second magnet yoke, an annular outer magnet yoke, an annular first magnetic pole, an annular second magnetic pole and an annular solenoid, the first magnet yoke and the second magnet yoke are arranged at intervals and are respectively provided with an outer step and an inner step, and the first magnetic pole and the second magnetic pole are arranged at intervals. The upper end of the outer magnet yoke is connected with the outer step of the first magnet yoke, the lower end of the outer magnet yoke is connected with the outer step of the second magnet yoke, the upper end of the first magnetic pole is connected with the inner step of the first magnet yoke, and the lower end of the second magnetic pole is connected with the inner step of the second magnet yoke. The solenoid is disposed between the outer yoke and the first and second magnetic poles. According to the focusing magnetic lens for the electron accelerator, steps are formed on the inner sides and the outer sides of the first magnet yoke and the second magnet yoke, and the outer magnet yoke, the first magnetic pole and the second magnetic pole can be conveniently assembled with the first magnet yoke and the second magnet yoke.

Description

Technical Field

[0001] The utility model relates to ion beam focusing, and more specifically to a focusing magnetic lens used for an electron accelerator. Background Art

[0002] A focusing magnetic lens refers to an axisymmetric magnetic field that can converge a uniform charged particle beam and form an image of an object in the beam path. Such a magnetic field (focusing magnetic lens) can be generated by a solenoid, an electromagnet or a permanent magnet. In the field of electron accelerator technology, a focusing magnetic lens is generally used to control the diameter of a charged particle beam. The focusing magnetic lens of the prior art has a complex structure and parts that are difficult to locate, so the assembly of the focusing magnetic lens is relatively difficult. In addition, a large amount of heat will be generated when the focusing magnetic lens is powered on. The focusing magnetic lens of the prior art is generally provided with a complex water cooling system to cool the focusing magnetic lens, resulting in a high manufacturing cost. Utility Model Content

[0003] In order to solve the problem that the parts of the focusing magnetic lens in the prior art are difficult to position, the utility model provides a focusing magnetic lens for an electron accelerator.

[0004] According to the utility model, a focusing magnetic lens for an electron accelerator comprises a first annular magnetic yoke, a second magnetic yoke, an outer magnetic yoke, a first magnetic pole, a second magnetic pole and a solenoid, wherein the first magnetic yoke and the second magnetic yoke are spaced apart from each other and respectively have an outer step and an inner step, the first magnetic pole and the second magnetic pole are spaced apart from each other, the upper end of the outer magnetic yoke is connected to the outer step of the first magnetic yoke, the lower end of the outer magnetic yoke is connected to the outer step of the second magnetic yoke, the upper end of the first magnetic pole is connected to the inner step of the first magnetic yoke, the lower end of the second magnetic pole is connected to the inner step of the second magnetic yoke, and the solenoid is arranged between the outer magnetic yoke and the first and second magnetic poles.

[0005] Preferably, the outer magnetic yoke comprises a base and a plurality of heat sinks, wherein the base is a cylindrical structure, and each heat sink is an annular sheet structure protruding radially outward from the base.

[0006] Preferably, the cooling fins are evenly spaced apart from each other.

[0007] Preferably, the first and second yokes respectively include a body, an inner flange and an outer flange, wherein the inner flange is recessed radially inward from the inner side of the body to form the inner step, and the outer flange is recessed radially outward from the outer side of the body to form the outer step.

[0008] Preferably, the outer yoke is connected to the outer flanges of the first and second yokes on the outside of the bodies of the first and second yokes, respectively, and the first and second magnetic poles are connected to the inner flanges of the first and second yokes on the inside of the bodies of the first and second yokes, respectively.

[0009] Preferably, the outer yoke is in close contact with the outer sides of the bodies of the first and second yokes, and the first and second magnetic poles are in close contact with the inner sides of the bodies of the first and second yokes.

[0010] Preferably, the inner flange and the outer flange are respectively provided with a plurality of through holes, the outer magnetic yoke and the first and second magnetic poles are respectively provided with a plurality of screw holes, and the bolts pass through the through holes and cooperate with the screw holes.

[0011] Preferably, the focusing magnetic lens further comprises a terminal block assembly connected to the outer surface of the outer magnetic yoke, and both ends of the solenoid pass through the outer magnetic yoke and are electrically connected to the terminal block assembly.

[0012] Preferably, the first and second magnetic yokes and the outer magnetic yoke are all made of stainless steel.

[0013] Preferably, the first and second magnetic poles are both made of permanent magnetic material.

[0014] According to the focusing magnetic lens for electron accelerator of the utility model, the inner and outer sides of the first and second magnetic yokes are both formed with steps, and the outer magnetic yoke and the first and second magnetic poles can be easily assembled with the first and second magnetic yokes. In addition, the outer magnetic yoke has a heat sink protruding radially outward from the base, and through the heat sink, the focusing magnetic lens of the utility model can achieve rapid cooling, simple structure, and low manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of a focusing magnetic lens for an electron accelerator according to a preferred embodiment of the utility model.

[0016] Figure 2 yes Figure 1 sectional view of .

[0017] Figure 3 yes Figure 1 Exploded diagram. DETAILED DESCRIPTION

[0018] The preferred embodiments of the present utility model are given below in conjunction with the accompanying drawings and described in detail.

[0019] like Figure 1-Figure 3As shown, a focusing magnetic lens for an electron accelerator according to a preferred embodiment of the utility model comprises a first annular magnetic yoke 1, a second magnetic yoke 2, an outer magnetic yoke 3, a first magnetic pole 4, a second magnetic pole 5 and a solenoid 6, wherein the first magnetic yoke 1 and the second magnetic yoke 2 are spaced apart from each other, the upper end of the outer magnetic yoke 3 is connected to the outer side of the first magnetic yoke 1, and the lower end of the outer magnetic yoke 3 is connected to the outer side of the second magnetic yoke 2, the first magnetic pole 4 and the second magnetic pole 5 are spaced apart from each other, the upper end of the first magnetic pole 4 is connected to the inner side of the first magnetic yoke 1, and the lower end of the second magnetic pole 5 is connected to the inner side of the second magnetic yoke 2, and the solenoid 6 is arranged between the outer magnetic yoke 3 and the magnetic poles 4, 5.

[0020] In addition, the focusing magnetic lens for electron accelerator according to this embodiment further comprises a terminal block assembly 7 connected to the outer surface of the outer magnetic yoke 3 , and both ends of the solenoid 6 pass through the outer magnetic yoke 3 and are electrically connected to the terminal block assembly 7 .

[0021] In a specific application, the focusing magnetic lens according to the utility model is arranged on the outside of the drift tube of the electron accelerator. The accelerated electrons enter the focusing magnetic lens. The inner solenoid 6 excites a magnetic field after being energized. When the electrons pass through this magnetic field, they will be affected by the Lorentz force, and their motion trajectory will be deflected, so that the electron beam will converge and focus under the action of the magnetic field like an optical lens.

[0022] The first magnetic yoke 1 , the second magnetic yoke 2 and the outer magnetic yoke 3 are all made of stainless steel, and the first magnetic pole 4 and the second magnetic pole 5 are both made of permanent magnetic materials.

[0023] like Figure 2 As shown, the outer yoke 3 includes a base 31 and a plurality of heat sinks 32, wherein the base 31 is a cylindrical structure, and each heat sink 32 is an annular sheet structure protruding radially outward from the base 31. The heat sinks 32 are evenly spaced from each other. In this embodiment, the outer yoke 3 includes eight heat sinks 32. It should be understood that the number of heat sinks 32 can be adjusted as needed. Through the heat sink 32, the focusing magnetic lens according to the utility model can achieve rapid cooling. Moreover, the heat sink 32 has a simple structure and low manufacturing cost.

[0024] In this embodiment, the first magnetic yoke 1 and the second magnetic yoke 2 are symmetrically arranged and have the same structure. The second magnetic yoke 2 is taken as an example for detailed description. Figure 3 As shown, the second magnetic yoke 2 includes a body A, an inner flange B and an outer flange C, wherein the inner flange B is recessed radially inward from the inner side of the body A and in a direction away from the first magnetic yoke 1 to form an inner step, and the outer flange 22 is recessed radially outward from the outer side of the body A and in a direction away from the first magnetic yoke 1 to form an outer step. In addition, a plurality of through holes D are evenly distributed circumferentially on the inner flange B and the outer flange C.

[0025] like Figure 2As shown, the outer yoke 3 is connected to the outer flange C of the yoke 1, 2 on the outer side of the body A of the yoke 1, 2. In this embodiment, the outer yoke 3 is closely attached to the outer side of the body A of the yoke 1, 2 and is connected to the outer flange C of the yoke 1, 2. Specifically, screw holes 33 are respectively provided at the upper and lower ends of the outer yoke 3 (see Figure 3 ), bolts (not shown) pass through the through holes D on the outer flanges C of the yokes 1, 2 and cooperate with the screw holes 33 at the upper and lower ends of the outer yoke 3.

[0026] like Figure 2 As shown, the magnetic poles 4, 5 are connected to the inner flanges B of the magnetic yokes 1, 2 on the inner sides of the bodies A of the magnetic yokes 1, 2. In this embodiment, the magnetic poles 4, 5 are closely attached to the inner sides of the bodies A of the magnetic yokes 1, 2 and are connected to the inner flanges B of the magnetic yokes 1, 2. Specifically, the upper and lower ends of the magnetic poles 4, 5 are respectively provided with screw holes 41 (see Figure 3 ), bolts (not shown) pass through the through holes D on the inner flanges B of the yokes 1, 2 and cooperate with the screw holes 41 at the upper and lower ends of the magnetic poles 4, 5.

[0027] Thus, according to the focusing magnetic lens for electron accelerator of the utility model, an inner flange B is provided on the inner side of the main body A of the yoke 1, 2, and an outer flange C is provided on the outer side of the main body A of the yoke 1, 2, so that steps are formed on the inner and outer sides of the yokes 1, 2, and the outer yoke 3 and the magnetic poles 4, 5 can be easily assembled with the yokes 1, 2.

[0028] The above is only a preferred embodiment of the utility model, and is not intended to limit the scope of the utility model. The above embodiments of the utility model can also be modified in various ways. That is, all simple, equivalent changes and modifications made according to the claims and the contents of the specification of the utility model application fall within the scope of protection of the claims of the utility model patent. The conventional technical contents are not described in detail in the utility model.

Claims

1. A focusing magnetic lens for an electron accelerator, characterized in that: The focusing magnetic lens includes a first annular magnetic yoke, a second magnetic yoke, an outer magnetic yoke, a first magnetic pole, a second magnetic pole and a solenoid, wherein the first magnetic yoke and the second magnetic yoke are spaced apart from each other and have an outer step and an inner step respectively, the first magnetic pole and the second magnetic pole are spaced apart from each other, the upper end of the outer magnetic yoke is connected to the outer step of the first magnetic yoke, the lower end of the outer magnetic yoke is connected to the outer step of the second magnetic yoke, the upper end of the first magnetic pole is connected to the inner step of the first magnetic yoke, the lower end of the second magnetic pole is connected to the inner step of the second magnetic yoke, and the solenoid is arranged between the outer magnetic yoke and the first and second magnetic poles.

2. The focusing magnetic lens according to claim 1, characterized in that: The outer magnetic yoke comprises a base body and a plurality of heat sinks, wherein the base body is a cylindrical structure, and each heat sink is an annular sheet structure protruding radially outward from the base body.

3. The focusing magnetic lens according to claim 2, characterized in that: The cooling fins are evenly spaced apart from each other.

4. The focusing magnetic lens according to claim 1, characterized in that: The first and second yokes respectively include a body, an inner flange and an outer flange, wherein the inner flange is recessed radially inward from the inner side of the body to form the inner step, and the outer flange is recessed radially outward from the outer side of the body to form the outer step.

5. The focusing magnetic lens according to claim 4, characterized in that: The outer yoke is connected to the outer flanges of the first and second yokes at the outer sides of the bodies of the first and second yokes, respectively, and the first and second magnetic poles are connected to the inner flanges of the first and second yokes at the inner sides of the bodies of the first and second yokes, respectively.

6. The focusing magnetic lens according to claim 5, characterized in that: The outer yoke is closely attached to the outer sides of the bodies of the first and second yokes, and the first and second magnetic poles are closely attached to the inner sides of the bodies of the first and second yokes.

7. The focusing magnetic lens according to claim 5, characterized in that: The inner flange and the outer flange are respectively provided with a plurality of through holes, and the outer magnetic yoke and the first and second magnetic poles are respectively provided with a plurality of screw holes, and bolts pass through the through holes and cooperate with the screw holes.

8. The focusing magnetic lens according to claim 1, characterized in that: The focusing magnetic lens further comprises a terminal block assembly connected to the outer surface of the outer magnetic yoke, and both ends of the solenoid pass through the outer magnetic yoke and are electrically connected to the terminal block assembly.

9. The focusing magnetic lens according to claim 1, characterized in that: The first and second magnetic yokes and the outer magnetic yoke are all made of stainless steel.

10. The focusing magnetic lens according to claim 1, characterized in that: The first and second magnetic poles are both made of permanent magnetic material.

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