JPH0368423A - Isotope separator - 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 (Objective of the Invention) (Industrial Field of Application) The present invention relates to isotope separation equipment, and particularly relates to isotope separation equipment, and particularly relates to background noise generated by collision between a heating electron beam and impurity atoms in a vapor flow. This invention relates to an isotope separation device that reduces ion generation and greatly improves isotope separation efficiency.

(Prior art) Isotope valve 1111B direct using the gas diffusion method, nozzle method, or G, t centrifugal separation method has been conventionally operated by utilizing differences in chemical properties or differences in quality layers between isotopes. However, all conventional devices have a low separation efficiency per unit, so in order to concentrate a specific isotope to a predetermined concentration level, it is necessary to repeat the same separation process in multiple stages in a cascade system.

However, the isotope valve 11 device using the laser method, which selectively ionizes specific isotopes using laser light and electrically separates the ionized isotopes, has a very high separation efficiency per unit, so compared to conventional There is little need to assemble a cascade as shown in the figure, and the entire device is compact, which is advantageous in terms of economy.

FIG. 4 is a sectional view showing the structure of isotope separation using a conventional laser method. In the figure, isotope molecule II device 1
consists of a vacuum container 2 that airtightly houses the main body and various devices that make up the main body.

A metal raw material 3 containing multiple types of isotopes is stored in an evaporation crucible 4 having thermochemical resistance. A cold M pipe 5 for adjusting the temperature of the raw material is embedded in the evaporation crucible 4.

The metal raw material 3 housed in the i-filled crucible 4 is continuously irradiated with an electron beam 7 emitted from the filament 6a of the electron gun 6. The electron beam 7 is deflected by a deflection magnetic field vtr18 provided inside the electron gun 6 and irradiated onto the molten liquid surface 9 of the metal raw material.

The metal raw material 3 irradiated with the electron beam 7 is heated and evaporated through a molten state, thereby continuously producing an isotope vapor flow 10. The generated vapor flow 10 is enclosed in an enclosure 11 formed to surround the upper space of the evaporation crucible 4,
You will be guided further upwards.

On the other hand, with respect to the vapor flow 10 that has reached the upper part, a laser beam 12 selectively excites only a specific isotope that is characterized by recovery.
is irradiated. As this laser beam 12, a monochromatic laser beam having a frequency corresponding to a resonance absorption line of a specific isotope is employed. The specific isotope irradiated with the laser beam 12 has its electrons ejected and becomes an ionized isotope 13 with a positive charge.
becomes.

This ionized isotope 13 is connected to the positive electrode 14 and the negative type Fi15.
When passing through the electric field space formed between the electrodes arranged alternately, only the ionized isotope 13 is deflected to the surface of the negative electrode 15 and is adsorbed and collected.

On the other hand, neutral atoms such as isotopes that are not ionized travel straight between the electrodes without being affected by the electric field, and are collected by the vapor flow collection plate 16 disposed above the electrodes.

(Problems to be Solved by the Invention) As described above, in the conventional isotope separation apparatus, a powerful electron beam is irradiated onto the metal raw material contained in the evaporation crucible, and the metal raw material is heated and melted by the energy retained by the electron beam. It is further evaporated to form a vapor stream.

However, in the irradiation path of the electron beam, the hot electrons of the electron beam collide with impurity atoms in the vapor flow, causing the TL detachment phenomenon, and impurity atoms that are not intended for recovery are ionized, generating a large amount of background ions 17. There are drawbacks to doing so. This generation layer of background ions 17 tends to increase rapidly in proportion to the output of the electron gun, that is, the intensity of the electron beam.

This background ion 17 is an ionized isotope 1 to be recovered that has been selectively excited by the laser beam.
3 and are deposited on the surface of the negative electrode 15 and collected. As a result, a large amount of impurity atoms are mixed into the recovered product, reducing the purity of the product and significantly deteriorating the efficiency of separating specific isotopes.

The present invention has been made to solve the above problems, and by suppressing the generation layer of background ions generated by electron beam irradiation, the separation efficiency of isotopes for the purpose of recovery can be improved. The purpose of the present invention is to provide an isotope separation device that can significantly improve the

(Structure of R-light) (Means for solving the problem) In order to achieve the above object, the isotope separation apparatus according to the present invention includes an evaporation crucible containing metal raw materials containing multiple types of isotopes, It is equipped with an electron gun that irradiates the metal raw material with an electron beam to heat and evaporate the metal raw material to form a vapor flow, and selectively ionizes a specific isotope contained in the vapor flow. An isotope separation device that performs separation and recovery using an electric field gradient is characterized in that an auxiliary heating device for heating the metal raw material is attached to the evaporation crucible, and the electron gun and the auxiliary heating device are used together as a heating source for the metal raw material. shall be.

(Function) According to the isotope valve 1111 device having the above configuration, an auxiliary heating device for heating the metal raw material is installed in the evaporation crucible, and the electron gun and the auxiliary heating device are used together as a heating source for the metal raw material. As a result, the dependence on the electron gun on the total amount of heat required to heat and evaporate the metal raw material can be relatively reduced compared to conventional devices.

That is, by replenishing the shortfall in the total calorific value due to suppressing the output ratio of the electron gun with thermal energy from the auxiliary heating device, the total calorific value necessary to heat and evaporate the metal raw material is secured.

Since the output of the electron beam from the electron gun can be reduced in this way, it is possible to reduce the amount of background ions generated due to collisions between impurity metal atoms in the vapor flow and the electron beam.

Therefore, the purity and reduction degree of the isotope to be recovered are increased, and the isotope separation and recovery efficiency can be significantly improved.

(Example) Next, an example of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a cross-sectional view showing a main part of an example of the isotope separation apparatus according to the present invention. Components that are the same as those in the conventional example shown in FIG. 4 are given the same reference numerals, and redundant explanation thereof will be omitted.

That is, the isotope separation device 2t1a according to this embodiment is? !
An evaporation crucible 4 that stores a metal raw material 3 containing several types of isotopes, and an electron gun 6 that irradiates the stored metal raw material 3 with an electron beam 7 to heat and evaporate the gold R raw material 3 to form a vapor flow 10. selectively ionizes a specific isotope contained in the vapor flow 10, and converts the ionized isotope into ff1W.
In an isotope separation device that performs separation and recovery using a gradient, an auxiliary heating device 18 for heating the metal raw material 3 is installed alongside the evaporation crucible 4, and the electron gun 6 and the auxiliary heating device 18 are used as a heating source for the metal raw material 3. Constructed in combination.

The auxiliary heating device 18 includes a high-frequency heating device 19 that heats the evaporation crucible 4 using a high-frequency heating device, and a resistance heating device 20 that heats the evaporation crucible 4 using resistance heat generated by energizing a resistance wire. Consists of.

Further, a vapor enclosure container 11 is provided so as to surround the upper space of the evaporation crucible 4 containing the metal raw material 3.
11 is housed in the vacuum container 2 together with the N5A crucible 4. Further, as shown in FIG. 2, an electron gun 6 that supplies an electron beam 7 is arranged along the longitudinal direction of the evaporation crucible 4.

On the other hand, as shown in FIGS. 2 and 3, an electron beam deflection device 21 is installed which deflects the electron beam 7 emitted from the electron gun 6 and irradiates it onto a predetermined position within the evaporation crucible 4. This electron beam deflection device 21 includes, for example, a vacuum container 2
It consists of a pair of electromagnetic coils 22 fixed annularly to the outer wall of.

The electron beam 7 emitted from the electron gun 6 is applied to the molten liquid surface 9 of the evaporation crucible 4 by a magnetic field α formed between a pair of electromagnetic coils 22 coaxially arranged as shown in FIG.
deflected in the direction The electron beam 7 irradiated onto the molten liquid surface 9 heats the metal raw material 3 with its energy.

On the other hand, as heating sources for the metal raw material 3, in addition to the electron gun 6, a high frequency heating device 19 and a resistance heating device 20 are operated in parallel. That is, the output intensity of the electron gun 6 is relatively suppressed compared to the conventional device, and the amount of heat equivalent to the shortage is absorbed by the high frequency heating device 19 and the resistance heating device ff20.
It will be operated so that it can be replenished at

Since the output of the electron beam 7 from the electron gun 6 can be reduced in this way, the amount of background ions 17 generated due to the collision between the impurity amount jI atoms in the vapor flow 10 and the electron beam 7 can be reduced. . the result,
The purity and concentration of isotopes to be recovered are improved, and the efficiency of isotope separation and recovery can be significantly improved.

(Effect of the invention) As explained above, according to the isotope separation device according to the present invention,
By installing an auxiliary heating device to heat the metal raw material in the evaporation crucible, and using the auxiliary heating device together with an electron gun as a heating source for the metal raw material, it is possible to reduce the total calorific value required to heat and evaporate the metal raw material. The dependence on the electron gun can be relatively reduced compared to conventional devices.

In other words, by replenishing the shortfall in total calorific value due to suppressing the output ratio of the electron gun with thermal energy from the auxiliary heating device, the total calorific value necessary to heat and evaporate the metal raw material is secured. .

Since the output of the electron beam from the electron gun can be reduced in this way, it is possible to reduce the generation of background ions caused by collisions between impurity metal atoms in the vapor flow and the electron beam.

Therefore, the purity and concentration of the isotope to be recovered is increased, and the efficiency of isotope separation and recovery can be greatly improved.

7...Background ion, 18...Auxiliary side J!
The equipment includes 19... high frequency heating device, 20... resistance heating device, 21... electron beam deflection device, 22... electromagnetic coil.

Claims (1)

[Claims] It is equipped with an evaporation crucible that stores metal raw materials containing multiple types of isotopes, and an electron gun that irradiates the stored metal raw materials with an electron beam to heat and evaporate the metal raw materials to form a vapor flow. In an isotope separation device that selectively ionizes a specific isotope contained in the metal and separates and recovers the ionized isotope using an electric field gradient, an auxiliary heating device for heating the metal raw material is attached to the evaporation crucible. An isotope separation apparatus characterized in that the electron gun described above as a heating source for a raw material and an auxiliary heating device are used together.