CN103943304A - Magnetic flux density continuously adjustable even axial magnetic field producing device and method for producing continuously adjustable even axial magnetic field of device - Google Patents

Abstract

A device for generating a continuously adjustable uniform axial magnetic field with a magnetic flux density and a method for generating a continuously adjustable uniform axial magnetic field by the device relate to the technical field of constructing a special configuration magnetic field. The problem of complex structure of the existing magnetic flux density axial magnetic field generating device and unstable and non-adjustable magnetic field generated by the existing magnetic flux density axial magnetic field generating device and method are solved. The inner coil of the present invention is wound on the cylindrical iron core, the two circular inner magnetic poles are respectively fixed on the two ends of the cylindrical iron core, the two outer magnetic poles of the circular ring are respectively fixed on the two ends of the cylindrical shell, and the outer coil is fixed on the The inner side of the cylindrical shell, and the outer coils are wound and arranged in a circular ring. The cylindrical shell is coaxially sleeved on the outer side of the cylindrical iron core. The two circular outer magnetic poles are respectively located on the same plane as the two circular inner magnetic poles. And the two circular ring outer magnetic poles are not connected to the two circular inner magnetic poles; the power supply provides current for the outer coil and the inner coil at the same time. The invention is suitable for generating continuously adjustable uniform axial magnetic field.

Description

Device for generating continuously adjustable uniform axial magnetic field with magnetic flux density and method for generating continuously adjustable uniform axial magnetic field with the device

technical field

The invention relates to the technical field of constructing a special configuration magnetic field.

Background technique

The magnetic field is a special substance that has a magnetic force on the magnet placed in it. Its basic feature is that it can exert a force on the moving charge, that is, the current-carrying conductor or the moving charged particle is subjected to the force of the magnetic field in the magnetic field, and the charged particle is affected by the force. The acting force is called the Lorentz force, and its magnitude and direction are given by the formula is the Lorentz force on the charged particle, q is the electric charge of the charged particle, v is the velocity of the charged particle, Determined by the magnetic flux density. In particular, it is pointed out that plasma is a multi-particle system composed of charged particles in an unbound state, and electromagnetic interaction is the decisive factor governing the motion of the system. Therefore, constructing an electromagnetic field with a specific configuration is the main method to control the motion state of plasma charged particles . In the cylindrical coordinate system, the axial magnetic field is radial to the Lorentz force of the charged particles moving in the circumferential direction, that is, the charged particles obtain radial centripetal force under the action of the axial magnetic field and move in a circle. This effect is applied in many engineering fields, such as plasma mass separators, so designing a device that can generate a continuously adjustable uniform axial magnetic field has great application value. However, it is very difficult to construct an axial magnetic field that meets engineering requirements, because:

1. In order to flexibly and effectively control the motion state of charged particles, the magnetic flux density of the axial magnetic field in the working area needs to be continuously adjustable within the range of 0 Gauss to 2000 Gauss 0.2T, and the axial magnetic field only exists in the working area, and the magnetic flux density outside the area needs to be continuously adjusted. decline;

2. In order to make the charged particles obtain a more uniform angular velocity, the non-uniformity of the axial magnetic flux density in the working area must be limited within the allowable range of the design;

3. In order not to affect the circular motion of charged particles, the acceleration in other directions should be much smaller than the radial acceleration, that is, the radial and circumferential magnetic flux density components in the working area should be much smaller than the axial component.

Contents of the invention

In order to solve the problem that the structure of the existing magnetic flux density axial magnetic field generating device is complex and the magnetic field generated by the existing magnetic flux density axial magnetic field generating device and method is unstable and cannot be adjusted, the present invention proposes a continuously adjustable magnetic flux density A device for generating a uniform axial magnetic field and a method for generating a continuously adjustable uniform axial magnetic field by the device.

The device for generating a uniform axial magnetic field with continuously adjustable magnetic flux density in the present invention includes two circular inner magnetic poles, a cylindrical iron core, two circular ring outer magnetic poles, a cylindrical shell, an outer coil, and an inner coil and power supply;

The inner coil surrounds the cylindrical iron core, the two circular inner magnetic poles are respectively fixed at both ends of the cylindrical iron core, the two circular ring outer magnetic poles are respectively fixed at both ends of the cylindrical shell, and the outer coil is fixed on the cylindrical The inner side of the shell, and the outer coils are wound and arranged in a circular ring. The cylindrical shell is coaxially sleeved on the outside of the cylindrical iron core. The two circular outer magnetic poles are respectively located on the same plane as the two circular inner magnetic poles, and the two The outer magnetic pole of the circular ring is not connected to the two circular inner magnetic poles; the working area is between the inner coil and the outer coil, and the power supply provides current for the outer coil and the inner coil at the same time.

A device for generating a continuously adjustable uniform axial magnetic field with magnetic flux density A method for generating a continuously adjustable uniform axial magnetic field: the method is:

Turn on the power supply, the power supply provides current for the inner coil and the outer coil, so that the inner coil and the outer coil generate a magnetic field in the same direction, and change the magnitude of the current provided by the power supply, so that the axial magnetic field density generated by the inner coil and the outer coil is at 0 in the working area The range of Gauss to 2000 Gauss is varied, so that the non-uniformity of the magnetic flux density of the axial magnetic field generated by the inner coil and the outer coil is within 10%, and the generation of a continuously adjustable and uniform axial magnetic field is realized.

The present invention uses a power supply to pass current through the inner coil to excite a magnetic field. The magnetic flux density is determined by the Biot-Savat law. The inner and outer coils are charged through the power supply. The magnetic field excited by the coil is not affected by temperature and has strong controllability, and the structure of the invention is simple. Compared with the existing axial magnetic field generation device, the structural complexity is reduced by 20% year-on-year, and at the same time, it can generate stable current, and the magnetic field can be adjusted by changing the current, so that the generated magnetic field has strong stability, and the magnetic field can be adjusted by adjusting the current, and the stability is increased by 10% compared with the existing axial magnetic field generation device.

Description of drawings

Fig. 1 is a schematic diagram of the device structure of the present invention;

Fig. 2 is a side view of the device of the present invention;

Figure 3 is the radial, angular and axial magnetic flux density configuration curves of the working area. The three curves in the figure are the radial component curve, angular component curve and axial component curve of the magnetic flux density from top to bottom. .

Detailed ways

Specific Embodiments 1. This embodiment is described in conjunction with FIG. 1 and FIG. 2. The device for generating a uniform axial magnetic field with continuously adjustable magnetic flux density described in this embodiment includes two circular inner magnetic poles 1 and a cylindrical iron core 2. , two circular ring outer magnetic poles 3, a cylindrical shell 4, an outer coil 6, an inner coil 7 and a power supply;

The inner coil 7 is wound around the cylindrical iron core 2, two circular inner magnetic poles 1 are respectively fixed at both ends of the cylindrical iron core 2, two circular outer magnetic poles 3 are respectively fixed at both ends of the cylindrical shell 4, and the outer The coil 6 is fixed on the inner side of the cylindrical shell 4, and the outer coil 6 is wound and arranged in a circular ring, the cylindrical shell 4 is coaxially sleeved on the outside of the cylindrical iron core 2, and the two circular outer magnetic poles 3 are respectively connected to the two The two circular inner magnetic poles 1 are located on the same plane, and the two circular outer magnetic poles 3 are not connected to the two circular inner magnetic poles 1; the working area 5 is between the inner coil 7 and the outer coil 6, and the power supply is the outer coil 6 at the same time. and inner coil 7 to supply current.

The object of the present invention is to design a device capable of producing a specific magnetic field configuration that meets the requirements. The method of generating a magnetic field is to use a permanent magnet or an excitation coil. The advantage of permanent magnets is that the magnetic field is relatively stable and is not prone to fluctuations. However, the plasma temperature is very high. When the permanent magnet is heated by the plasma to exceed the Curie temperature, it will lose its magnetism, which will affect the trajectory of charged particles and lead to control failure. . The magnetic field can be excited by passing current through the excitation coil, and the magnetic flux density is determined by the Biot-Savat law.

The device of the invention consists of a working area, an iron core and an inner coil. By changing the size and direction of the inner coil current, the magnetic field in the working area can be continuously adjusted in a large range, which meets the task requirements of controlling charged particles with different masses. The device of the invention has the advantages of simple structure, easy processing and long service life, and is of great significance to the successful development of various engineering equipment such as plasma mass separators.

Embodiment 2. This embodiment is a further description of the device for generating a continuously adjustable and uniform axial magnetic field with magnetic flux density described in Embodiment 1. Both the inner coil 7 and the outer coil 6 use paint with a bare wire diameter of 1mm. Round copper wire with 54,000 winding turns and a cross-sectional area of 100cm×5.4cm.

Embodiment 3. This embodiment is a further description of the device for generating a continuously adjustable and uniform axial magnetic field with magnetic flux density described in Embodiment 1. The circular inner magnetic pole 1 has a radius of 11 cm and an axial thickness of 3 cm.

Embodiment 4. This embodiment is a further description of the device for generating a continuously adjustable uniform axial magnetic field with magnetic flux density described in Embodiment 1. The inner radius of the outer magnetic pole 3 of the circular ring is 12 cm, and the outer radius is 24 cm. , the axial thickness is 19cm.

Embodiment 5. This embodiment is a further description of the device for generating a continuously adjustable and uniform axial magnetic field with magnetic flux density described in Embodiment 1. The radius of the cylindrical iron core 2 is 3 cm, and the axial length is 100 cm.

Embodiment 6. This embodiment is a further description of the device for generating a continuously adjustable uniform axial magnetic field with magnetic flux density described in Embodiment 1. The inner radius of the cylindrical shell 4 is 19 cm, the outer radius is 20 cm, and the axis The length is 100cm.

Embodiment 7. This embodiment is a further description of the device for generating a continuously adjustable and uniform axial magnetic field with magnetic flux density described in Embodiment 1. The cylindrical shell 4 is made of soft iron material DT3.

Embodiment 8. This embodiment is a further description of the device for generating a continuously adjustable and uniform axial magnetic field with magnetic flux density described in Embodiment 1. The material of the middle cylindrical iron core 1 is soft magnetic alloy with high saturation magnetic flux density. 1J22.

Specific Embodiment 9. This embodiment is a method for generating a continuously adjustable uniform axial magnetic field by the device for generating a continuously adjustable uniform axial magnetic field with a magnetic flux density described in Embodiment 1: the method is as follows:

Turn on the power supply, the power supply provides current for the inner coil 7 and the outer coil 6, so that the inner coil 7 and the outer coil 6 generate a magnetic field in the same direction, change the magnitude of the current provided by the power supply, and make the axial magnetic field generated by the inner coil 7 and the outer coil 6 The density changes within the range of 0 Gauss to 2000 Gauss in the working area, so that the non-uniformity of the magnetic flux density of the axial magnetic field generated by the inner coil 7 and the outer coil 6 is within 10%, and the magnetic flux density can be continuously adjusted and uniform in the axial direction. The generation of a magnetic field.

design concept:

Since the magnetic permeability of the iron core material is much greater than that of vacuum, it can be known from the refraction theorem of the magnetic field tanα ₁ tanα ₂ = μ ₁ μ ₂ that the magnetic flux density lines generated by the excitation coil in the iron core can be considered to be parallel to the surface of the iron core, There is little leakage to the outside, that is, the iron core is the main channel of the magnetic flux density line, and this channel is called a magnetic circuit. In the magnetic circuit system of the device of the present invention, the cross-sectional area of the central cylindrical iron core is the smallest, and its magnetic flux density is the largest according to Ohm's law of a closed magnetic circuit, so the magnetic flux that can pass through the central cylindrical iron core when it reaches magnetic saturation determines the The maximum magnetic flux density of the gap. High saturation magnetic flux density soft magnetic alloy 1J22 has a relative magnetic permeability of 900 when the magnetic flux density is 20000 Gauss, and still has a strong magnetic field ability, which can be calculated from the size of the iron core structure. At this time, the magnetic flux density in the working area is 2500 Gauss , to meet the design requirements of 2000 Gauss. The excitation coil is made of enamelled round copper wire with a bare wire diameter of 1mm, and the cross-sectional area of the coil is 100cm×5.4cm when winding 54000 turns. When the coil current is 3.3A, the magnetic flux density in the working area is greater than 2000 Gauss, and the air gap magnetic flux density can be continuously adjusted within the range of 0 Gauss to 2000 Gauss (0.2T) by adjusting the current. When the magnetic flux density line enters the vacuum from the iron core in the working area, it can be known from the boundary condition B _1n = B _2n of the magnetic field on the interface of the two media that at the interface of different media, the normal component of the magnetic flux density vector Continuous, that is, the magnetic flux density in the working area is mainly axial, with small radial and circumferential components. Figure 3 can be obtained through ansys simulation. It can be seen from Fig. 3 that the magnetic flux density at abscissa 0.06cm-1.06cm in the working area of the present invention is greater than 2000 Gauss, the magnetic flux density outside the working area decreases rapidly, and the uniformity of the axial magnetic flux density in the working area is very good , the radial and circumferential flux densities are small. Therefore, the configuration of the magnetic field generated by the device of the present invention meets the design requirements.

The power supply system provides current to the inner coil to generate magnetic flux. By changing the magnitude and direction of the inner coil current, the magnetic field in the working area can be continuously adjusted in a wide range; the axial magnetic flux density in the working area of the magnetic field generating device is between 0 Gauss and Continuously adjustable within the range of 2000 Gauss (0.2T), the magnetic flux density 3cm outside the working area is rapidly reduced to within 30% of the working area;

The non-uniformity of the axial magnetic flux density in the working area of the magnetic field generating device of the present invention is within 10%, and the axial and circumferential magnetic flux density is less than 5% of the axial component.

Claims (9)

1. the continuous generation device of adjustable even axial magnetic field of magnetic flux density, it is characterized in that, this device comprises two circular Inner magnetic poles (1), cylinder iron core (2), two circular rings outer magnetic poles (3), cylindrical housing (4), exterior loop (6), interior loop (7) and power supply;

Interior loop (7) is looped around on cylinder iron core (2), two circular Inner magnetic poles (1) are separately fixed at the two ends of cylinder iron core (2), two circular rings outer magnetic poles (3) are separately fixed at the two ends of cylindrical housing (4), exterior loop (6) is fixed on the inner side of cylindrical housing (4), and exterior loop (6) becomes annular to be wound around arrangement, cylindrical housing (4) coaxial sleeve is in the outside of cylinder iron core (2), two circular rings outer magnetic poles (3) are positioned at same plane with two circular Inner magnetic poles (1) respectively, and two circular rings outer magnetic poles (3) are not connected with two circular Inner magnetic poles (1), between interior loop (7) and exterior loop (6), be service area (5), power supply is simultaneously for exterior loop (6) and interior loop (7) provide electric current.

2. the continuous generation device of adjustable even axial magnetic field of magnetic flux density according to claim 1, it is characterized in that, it is the enamel insulated round copper wire of 1mm that interior loop (7) and exterior loop (6) all adopt bare wire diameter, wound convolution numerical digit 54000 circles, and coil section amasss as 100cm * 5.4cm.

3. the generation device of the continuous adjustable even axial magnetic field of magnetic flux density according to claim 1, is characterized in that, the radius of circular Inner magnetic pole (1) is 11cm, and axial width is 3cm.

4. the generation device of the continuous adjustable even axial magnetic field of magnetic flux density according to claim 1, is characterized in that, the inside radius of circular rings outer magnetic pole (3) is 12cm, and outer radius is 24cm, and axial width is 19cm.

5. the generation device of the continuous adjustable even axial magnetic field of magnetic flux density according to claim 1, is characterized in that, the radius of cylinder iron core (2) is 3cm, and axial length is 100cm.

6. the generation device of the continuous adjustable even axial magnetic field of magnetic flux density according to claim 1, is characterized in that, the inside radius of cylindrical housing (4) is 19cm, outer radius 20cm, and axial length is 100cm.

7. the generation device of the continuous adjustable even axial magnetic field of magnetic flux density according to claim 1, is characterized in that, the material of cylindrical housing (4) is soft iron material DT3.

8. the generation device of the continuous adjustable even axial magnetic field of magnetic flux density according to claim 1, is characterized in that, the material of intermediate cylindrical iron core (1) is high saturation magnetic flux density magnetically soft alloy 1J22.

9. the generation device of the continuous adjustable even axial magnetic field of magnetic flux density claimed in claim 1 produces adjustable even axial magnetic field method continuously, it is characterized in that, the method is:

Switch on power, power supply is that interior loop (7) and exterior loop (6) provide electric current, make interior loop (7) and exterior loop (6) produce equidirectional magnetic field, the size of the electric current that change power supply provides, the axial magnetic field density that interior loop (7) and exterior loop (6) are produced changes in 0 Gauss～2000 Gauss's scope in service area, make the magnetic flux density non-uniformity of the axial magnetic field that interior loop (7) and exterior loop (6) produce in 10%, realize the magnetic flux density generation of adjustable even axial magnetic field continuously.