JPS62172699A - Magnetic field generator for plasma confinement - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a magnetic field generator capable of stably confining plasma.

(Prior Art) Generating plasma and utilizing ions or electrons in the plasma is now widely practiced in various fields.

(Problems to be Solved by the Invention) However, a magnetic field generator for plasma confinement that is capable of retaining plasma in a highly stable manner and is suitable for miniaturization has not been proposed in the past. An object of the present invention is to provide a magnetic field generator for plasma confinement that can maintain plasma in a highly stable manner and is suitable for downsizing.

(Means for solving the problem) The above object consists of a pair of magnetic force line generating means composed of permanent magnets that form magnetic force lines connecting an outer end surface and an inner end surface. This is achieved by the magnetic field generating device for plasma confinement of the present invention, in which the respective outer end faces and inner end faces are opposed to each other, and the magnetic poles of the opposed outer end faces and inner end faces are the same. According to the present invention, a cusp magnetic field is formed in a space facing the magnetic field line generating means, and plasma is confined in a highly stable manner.

The present invention is particularly effective when used as a plasma generator that generates plasma by electron cyclotron resonance.

(Effects of the Invention) According to the present invention, a strong cusp-shaped plasma confinement magnetic field space of 1 can be created using a relatively small-sized device. Plasma is stably confined within this magnetic field space, making it possible to generate high-temperature, high-density plasma.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of a first embodiment of the invention. This first embodiment can be used as an electron cyclotron resonance type plasma generator. Forming lines of magnetic force 3.3'' connecting the outer end surfaces 1, 1'' and the inner end surfaces 2, 2',
A pair of magnetic field line generating means 6, 6'', which are composed of permanent magnets 4.5'' and 4.5'', are shown. The outer end surfaces 1 and 1' and the inner end surfaces 2 and 2' of each of the pair of magnetic force line generating means 6.6'' are perpendicularly opposed to each other. .2's magnetic poles are the same. In this embodiment, the outer end surfaces 1.1' and the inner end surfaces 2, 2' of the magnetic force line generating means 6, 6' have an annular shape with their centers coincident with the legs 7-7°. , along with this, the magnetic field line 3.3" is the axis 7-7
It is formed in a ring shape that is symmetrical with respect to °. Inner end surface 2
．． 2" is set back from the outer end surface 1.1°, and a gap is provided between the outer end surface 1.1° of each of the magnetic force line generating means 6, 6" and the inner end surface 2, 2" of each. The space thus formed facing the magnetic force line generating means 6,6' is used as a space for plasma confinement and plasma generation. The outer end surfaces 1.1'' are opposed to each other with a yoke 8 interposed therebetween.

At the center of the inner end surface 2.2° is an opening 10 that leads to the outside.
11 is provided, and an insulating window 13 and an antenna 16 for inputting electromagnetic waves are inserted into the opening 10.
An electrode 14 for extracting the ion beam is inserted into the electrode 1 . A commutating pole 15 is installed outwardly between the outer end surfaces 1.1' so that magnetic poles of the same polarity as those of the outer end surfaces 1 and 1' are close to each other, and this prevents the outer end surface from leaking outward. The lines of magnetic force from 1.1° are pushed back inward, allowing the lines of magnetic force to be more effectively arranged from the outer end face 1.1°. A magnetic field line shield 17 is provided around the insulator window 13 for electromagnetic wave input to demagnetize or shield the magnetic field lines, and the electromagnetic waves are transmitted to a desired position in the facing space 12 without losing energy during transmission. can be transmitted. When electromagnetic waves are introduced from the outside into the facing space 12 via the antenna 16 while the inside of the apparatus configured in this manner is filled with an atmosphere of a desired element at a predetermined pressure, plasma is generated by an electron cyclotron resonance phenomenon. . The plasma thus generated is extracted to the outside by the ion extraction electrode 14. In addition, magnets 4, 4' and magnet 5
, 5° are interpolations that increase the strength of the magnetic field around the inner wall of the device. In this embodiment, the vacuum container 22 is provided in the opposing space 12, and the inside thereof is kept in a high vacuum state. Needless to say, it is okay to be left alone. In either case, it is preferable that the cavity be designed so that the electromagnetic waves propagated in from the outside resonate in the cavity, so that the electromagnetic wave energy can be used effectively.

2 and 3 are diagrams showing the magnetic field line arrangement and magnetic flux density contour diagram, respectively, in the first example of the actual anchor described above, and FIGS. 4 and 5 show the magnet 15 in the first example. FIG. 7 is a diagram showing the configuration of magnetic lines of force when removed, and a contour diagram of magnetic flux density. From these figures, the desired magnetic field configuration is formed in the facing space 12 regardless of the presence or absence of the magnetic pole I5, but by adding the magnetic pole 15, the magnetic field strength near the inner wall surface becomes higher, and the plasma It can be seen that it is possible to confine more effectively.

FIG. 6 is a cross-sectional perspective view of a second embodiment of the invention. In this embodiment, a pair of magnetic force line generating means 6, 6' is generated from a cylindrical permanent magnet 4.4' having outer end faces l, 1' and a cylindrical permanent magnet 21, 21° having inner end faces 2, 2". The magnetic poles of the opposing end surfaces are the same as in the first embodiment.In this embodiment, the inner end surface 2
, 2° is not provided with an opening leading to the outside, and the electromagnetic waves are brought in and the ion beam is extracted from the axis 2.
3-23' between the opposing end faces 24.
This is done via 25. That is, an insulating window 13 for electromagnetic wave input and an antenna 16 are inserted into the opening 24, and an ion extraction electrode 14 is suppressed in the opening 25. A vacuum container 22 is provided in the opposing space 12, and a part of the vacuum container 22 is guided into the opening 24.25, and a part of the vacuum container guided into the opening 24 is ,
The electromagnetic wave input window 13 is surrounded to shield or demagnetize the surrounding magnetic field so that a strong magnetic field does not reach the antenna 16.

FIG. 7 is a side view of a third embodiment of the present invention.

In this embodiment, the outer and inner parts of the integrally formed magnet are magnetized in opposite directions, so that the magnetic poles of the outer end face 1.1° and the inner end face 2°2° are different. It is like that.

FIG. 8 is a plan view showing an end face of the magnetic force line generating means 6 according to the fourth embodiment of the present invention. In this embodiment, protruding portions 1a and 2a are formed on the outer end face 1 and the inner end face 2, and the lines of magnetic force formed by these end faces are not axially symmetrical. The lines of magnetic force formed in this protruding portion form exactly a four-electrode magnetic field, and ions can be extracted from this portion.

FIG. 9 is a plan view showing an end face of the magnetic force line generating means 6 according to the fifth embodiment of the present invention. In this embodiment, the outer end surface 1 and the inner end surface 2 have an oval shape, and the lines of magnetic force formed between these end surfaces are also formed so as to surround a space in an oval shape along these end surfaces.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional perspective view of the first embodiment of the present invention, FIGS. 2 and 3 are magnetic field line arrangement diagrams and magnetic flux density contour diagrams of the first embodiment, respectively. FIG. 6 is a cross-sectional perspective view of the second embodiment of the present invention, and FIG. 7 is a third embodiment of the present invention. FIG. 8 is a plan view of a fourth embodiment of the present invention, and FIG. 9 is a plan view of a fifth embodiment of the present invention. 1.1゛・・・・・・Outer end surface, 2.2゛・・・・・・
Inner end face, 3.3°... Lines of magnetic force, 4.4", 5.5', 18.18", 21.21'...
...Permanent magnet, 6...Magnetic field line generating means, 7.7', 23.23'...Axis, 8.9.9
'... Yoke, 10.11, 24.25... Opening, 12...
...Opposing space, 13...Window for electromagnetic wave human power,
14... Electrode, 15... Magnetic pole, 16.
...Antenna, 17...Magnetic field line shield,
18.18'...Commuting electrode, 22...Vacuum container.

Claims (11)

[Claims] (1) Consisting of a pair of magnetic force line generating means made of permanent magnets that form lines of magnetic force connecting the outer end surface and the inner end surface, and the outer end surface and inner end surface of each of the pair of magnetic force line generating means are opposed to each other. A magnetic field generator for plasma confinement, in which the magnetic poles of the opposing outer end faces and inner end faces are the same. (2) The plasma confinement magnetic field generating device according to claim (1), wherein the magnetic lines of force are formed axially symmetrically. (3) The plasma confinement magnetic field generating device according to claim (2), wherein the magnetic lines of force are formed in an annular shape. (4) A magnetic field generating device for plasma confinement according to claim (1), wherein a gap is provided between the outer end surface and the inner end surface of each of the magnetic force line generating means. (5) The plasma confinement magnetic field generating device according to claim 1, wherein a gap is formed between the opposing end surfaces of the pair of magnetic force line generating means. (6) The magnetic field generating device for plasma confinement according to claim 1 or 4, wherein the inner end surface is set back from the outer end surface. (7) The plasma confinement magnetic field generating device according to claim (6), wherein the opposing outer end surfaces are in close contact with each other. (8) The magnetic field generating device for plasma confinement according to claim (1), wherein an opening leading to the outside is provided in the center of the inner end surface. (9) A magnetic pole having the same polarity as the magnetic pole of the outer end surface is provided adjacent to the outer side between the outer end surfaces.
1) The magnetic field generator for plasma confinement as described in item 1). (10) A magnetic field generating device for plasma confinement according to claim (1), in which electromagnetic waves propagated from the outside resonate inside a cavity. A magnetic field generating device for plasma confinement according to claim 1, wherein a magnetic field line shield is provided around a communication point with the outside. (11) The outer end face and the inner end face are end faces of separate permanent magnets, a gap is formed between each magnet, and a gap is formed between the magnets along a magnetic path on the opposite side from the end face of the magnet. A magnetic field generating device for plasma confinement according to claim (1), wherein a magnetized permanent magnet is installed.