JPH0583291B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of separating gas isotopes using sheet plasma.

[Conventional technology]

Normally, gas isotope separation is performed using ionization, magnetic field deflection, and focusing by a quadrupole lens, or when large quantities are processed and high resolution is required, 235U enrichment is used. Thermal diffusion method, which takes advantage of differences in diffusivity due to temperature, and centrifugal separation method, which takes advantage of differences in mass, are used in the case of T3, and in the case of ^T3 , cryogenic separation method, which takes advantage of differences in vapor pressure, is used.

Plasma separation is also known as an isotope separation method, and plasma separation uses ion and cyclotron resonance spectrometers to
There are cyclotron resonance and plasma rotation or plasma centrifugation that utilizes rotating plasma at high rotational speeds.

In isotope separation by ion-cyclotron resonance, ions placed in a magnetic field with a uniform magnetic flux density move circularly at an angular frequency in a plane perpendicular to the magnetic field, and at the cyclotron frequency in a direction perpendicular to the magnetic field. When an alternating current electric field with a matched frequency is applied, the ions are accelerated by the alternating electric field and their radius of rotation increases. So, for example, by applying an alternating current electric field in which only 235U ⁺ resonates, it is possible to separate 235U ⁺ from 238U ⁺ .

[Problem that the invention seeks to solve]

By the way, separation methods that utilize magnetic field deflection through ionization and focusing using a quadrupole lens cannot process large quantities, and thermal diffusion, centrifugal separation, or cryogenic separation methods have low separation power and have to be repeated many times. The same process must be repeated, which is very costly and time consuming.

In addition, isotope separation methods using ion cyclotron resonance require a highly uniform magnetic field with a magnitude larger than the maximum resonance radius to separate isotopes, and collisions with other non-resonant ions are avoided. Therefore, a low-density plasma is required. Therefore, although a large amount of power is required, the processing efficiency is poor.

Therefore, the purpose of the present invention is to solve the above-mentioned drawbacks of the conventional isotope separation method by using a sheet plasma that performs isotope separation of gases by resonance of ion-cyclotron vibrations. The purpose of the present invention is to provide a gas isotope separation method using plasma.

[Means for solving problems]

In order to achieve the above object, the gas isotope separation method according to the present invention applies a high frequency equal to the cyclotron frequency of the ions to be separated to the sheet plasma. It is characterized by colliding the body with an electrically grounded limiter provided outside the boundary of the sheet plasma region to remove the electric charge, and then sucking and separating the isotope particles that have become neutral after the electric charge has been removed. It is said that

Another feature is that an electrically grounded cryopanel is placed outside the boundary of the sheet plasma region to remove charges from the colliding gas isotopes with a larger cyclotron radius. The isotope particles that have become sexual are separated by suction.

[Effect]

In the gas isotope separation method according to the present invention,
A sheet plasma containing the isotopes to be separated is formed by a plasma source and guided into a uniform, parallel magnetic field. A high frequency equal to the cyclotron frequency of ions to be separated from the sheet plasma is applied to parallel electrodes arranged narrowly across the sheet plasma. As a result, only the ions to be separated resonate with the cyclotron frequency, increase the orbital radius of circular motion, and exit from the boundary of the plasma region of the sheet plasma. Then, the plasma collides with a separation device located outside the boundary of the plasma region of the sheet plasma and is neutralized. This isotopic particle is sucked out by a pump. In this case, since the boundaries of the plasma regions of the sheet plasma are sharp, they can be easily separated with high resolution.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 schematically shows an embodiment of the present invention,
1 generates a sheet plasma 2 containing isotopes to be separated using a plasma source of the TP-D type, for example. Parallel plate electrodes 3 are placed across the sheet plasma 2 generated from the plasma source 1 and are connected to a high frequency power source 4 to apply a high frequency equal to the cyclotron frequency of the isotope to be separated contained in the sheet plasma 2. It is made to be. A limiter 5 serving as a separation device for selecting isotopes to be separated is arranged behind the parallel plate electrode 3.
This limiter 5 is electrically grounded and acts to remove the charge of the colliding isotope. Also,
The limiter 5 is connected to a pump (not shown), and the isotope particles made neutral by the limiter 5 are sucked by the pump. Further, a uniform parallel magnetic field is applied to the whole along the direction of the sheet plasma 2 by a magnetic field generator 6 (not shown).

Now, when a high frequency equal to the cyclotron frequency of the isotope to be separated is applied to the parallel plate electrode 3 by the high frequency power source 4, the ions of the isotope to be separated in the sheet plasma 2 resonate with the applied high frequency and sign As shown by 7, the orbital radius of the circular motion increases, the sheet plasma 2 exits from the boundary of the plasma region, collides with the limiter 5 provided at a distance outside of the plasma region, and is neutralized. The remaining ions exit while moving circularly within the plasma region of the sheet plasma 2. Only the isotope ions that resonate with the applied high frequency collide with the limiter 5 and are sucked by the pump, allowing them to be efficiently separated with high resolution.

FIG. 2 shows a variant embodiment implementing the method of the invention, in which a cryopanel 8 is used as the separation means. This cryo panel 8 is arranged outside the boundary of the plasma region of the sheet plasma 2, and is connected to the ground potential similarly to the limiter 5 in FIG.

Naturally, the apparatuses shown in FIGS. 1 and 2 are placed in a vacuum atmosphere, and the limiter 5 shown in FIG. 1 and the cryopanel 8 shown in FIG. 2 are used as separation means.
Adsorbents such as molecular sieves may be used instead. It should be noted that the configurations shown in FIGS. 1 and 2 merely show the basic configuration for implementing the method of the present invention, and the specific configuration of each part can be designed in various ways.

〔Effect of the invention〕

As explained above, according to the present invention, a sheet plasma with sharp plasma region boundaries is used, and sheet plasma containing isotopes to be separated generated by a plasma source is separated. A high frequency equal to the cyclotron frequency of the ions you want to separate is applied, and only the ions you want to separate resonate with the cyclotron frequency, increasing the orbital radius of circular motion, ejecting them from the boundary of the plasma region of the sheet plasma, and bringing them to the ground potential. Since the isotope particles are made to collide with a limiter located in the chamber and are sucked out as neutral particles by a pump, gaseous isotopes can be easily and efficiently separated with high separation power. As a result, according to the method of the present invention, it is possible to separate a large amount of gaseous isotopes in a short time at low cost.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the basic configuration of an apparatus for carrying out the gas isotope separation method of the present invention;
The figure is a schematic diagram showing a modification of the implementation device. In the figure, 1...Ion source, 2...Sheet plasma, 3...Parallel plate electrode, 4...High frequency power supply, 5
... Separation device, 6 ... Vacuum container, 7 ... Ion orbit, 8 ... Cryo panel.

Claims (1)

[Claims] 1. A high frequency equal to the cyclotron frequency of the ions to be separated is applied to the sheet plasma, and a gas isotope whose cyclotron radius is increased by resonance is placed outside the boundary of the sheet plasma region. A gas isotope separation method using sheet plasma, which is characterized by colliding with an electrically grounded limiter to remove electric charge, and then suctioning and separating isotope particles that have become neutral after removing electric charge. . 2 Apply a high frequency equal to the cyclotron frequency of the ions you want to separate into the sheet plasma, and the gas isotope, which resonates and has a large cyclotron radius, is placed outside the boundary of the sheet plasma region and electrically grounded. A gas isotope separation method using sheet plasma, which is characterized by colliding with a cryopanel to remove electric charge, and then suctioning and separating the isotope particles that have become neutral after the electric charge has been removed.