JPH0415009B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a collection plate for isotopic separation of metal atoms by laser method.

(Conventional technology) The separation and concentration technology of metal atomic isotopes using the laser method has a very high separation efficiency compared to the conventional gas diffusion method, nozzle method, chemical exchange method, centrifugation method, etc. It is said that it is not necessary.

By the way, an atomic method using metal atoms is known as a method for concentrating and separating isotopes using a laser method.

FIG. 3 is a schematic diagram conceptually showing an example of an apparatus for concentrating metal atoms using a laser method in the atomic method.

That is, in FIG. 3, reference numeral 1 indicates a container of the concentrator, and a metal melting crucible 3 containing metal atoms 2 to be separated is placed in the container 1, and the metal atoms 2 are heated. When the atomic beam 4 is generated, the atomic beam 4 advances upward. In this atomic beam 4, one isotope atom 5
and other isotopic atoms 6 are in a mixed state. Therefore, a selective excitation laser 7 having a frequency corresponding to the absorption line of one isotope atom 5 in this atomic beam 4 is irradiated. Only one isotope atom 6 to be separated is excited by this selective excitation laser beam.

Next, an ionizing laser 8 is irradiated to ionize the excited isotope atoms. The beams of these two types of lasers 7 and 8 ionize one of the isotope atoms in the atomic beam 4 that is intended to be separated, and change them into positive ions 9.

Now, the atomic beam 4 containing this positive ion 9
When an electric field is created using the ground electrode 10 and cathode 11,
Only the positive ions 9 of the ionized isotope atoms are electrostatically attracted to the cathode 11 and finally adsorbed on the surface of the cathode 11.

On the other hand, other isotopic neutral atoms 6 that are not ionized travel straight without being affected by this electric field, and are collected and collected by the neutral atom collection plate 12.

(Problem to be solved by the invention) In the method of separating isotopes, it is necessary to continuously collect neutral atoms attached to the collection plate 12 in order to operate the separation device efficiently such as continuous operation. There is. A liquid recovery method can be considered as a method for continuous recovery.

In this recovery method, the collection plate 12 is heated to a temperature higher than the melting point of the neutral atoms to turn the neutral atoms attached to the plate 12 into a liquid state, and the liquid is allowed to flow down and collected in a recovery device. That is, FIG. 4 schematically shows an example of the above-mentioned flow recovery method, in which the collection plate 12 is placed facing the crucible 3, and the vapor of neutral atoms is collected on the bottom surface of the collection plate 12. adhere to. The attached neutral atoms are collected by the collection plate 12
When the neutral atoms are heated and maintained above their melting point, they flow along the inclined surface of the collection plate 12 and are collected in the collection devices 13 disposed at both ends of the plate 12.

However, some liquid neutral atoms have a large surface tension and a large specific gravity, so the collection plate 1
2, and if more than a certain amount collects, it will drip directly from the surface of the collection plate 12 to the lower crucible 3 side while flowing along the slope of the collection plate 12, making it impossible to collect it. It was hot.

The present invention has been made to solve the above problems, and has a structure in which isotope-separated neutral atoms are efficiently collected on a collection plate and do not drop directly from the collection plate. The object of the present invention is to provide a collection plate for

[Structure of the invention] (Means for solving the problem) The present invention evaporates metal atoms to generate an atomic beam, irradiates the atomic beam with a laser, and separates isotopes to obtain isotopically neutral atoms. A collection plate for isotope separation, characterized in that the main body of the neutral atom collection plate is divided into a plurality of parts, and the ends of the divided pieces are arranged so as to overlap each other. This is a collection plate for separation.

(Function) In order to prevent the neutral atoms in liquid state adhering to the plate that collects neutral atoms from dripping, the surface of the plate is formed in a structure and surface condition that makes it easy for liquid neutral atoms to wet. The amount of adhesion is less than the size of dropping neutral atoms, and the structure is such that even if liquid neutral atoms drop, they can be recovered.

Therefore, according to the present invention, neutral atoms can be reliably recovered without the dropping limit amount of liquid neutral atoms adhering to the lower surface of the plate.

(Example) Hereinafter, an example of a collection plate for isotope separation according to the present invention will be described with reference to FIG. Note that FIG. 1 only shows the main parts of the present invention, that is, the neutral atom collection plate and its recovery device, and the other parts are the same as in FIG. Omitted.

In FIG. 1, reference numeral 14 indicates a neutral atom collecting plate main body used in the present invention, and this plate main body 14 has a plurality of divided pieces 15 formed by dividing an integrated plate into a plurality of pieces at apex a. They are arranged in the same shape on the left and right, with a downward slope bordering on . Further, the ends of the respective divided pieces 15 are arranged so as to overlap each other, and the respective overlapping surfaces have a gap large enough to form a gas flow path b.
Therefore, when the collection plate 14 is incorporated into the isotope separation device shown in FIG. Adheres to the underside. Here, each divided piece 15 is heated and maintained above the melting point of neutral atoms, so that the neutral atoms attached to the divided piece 15 become liquid, and the lower surface of each divided piece 15 is heated along the inclined surface. run down. The liquid neutral atoms 16 that have reached the lower end of the divided piece 15 turn into droplets and flow down onto the upper surface of the next divided piece 15. The liquid neutral atoms 16 that have flown down to the upper surface of the divided piece flow over the next divided piece, and further flow down one after another to the upper surface of the next divided piece. In this way, the liquid neutral atoms 16 flow one after another over the upper surface of the next-stage divided piece 15 and are collected in the collection device 13 disposed at the end.

In the collection plate configured in this way, the liquid neutral atoms adhering to the lower surface of the divided piece 15 increase in size while falling, and move to the upper surface of the next divided piece before reaching the dropping limit amount. Become. When the liquid flows on the upper surface of the divided piece, no matter how large the droplets are, they do not directly fall downward.

According to this embodiment, the neutral atoms separated from the neutral atom collection plate will not drip down to the crucible side, making it possible to reliably collect the neutral atoms and improve the concentration and separation efficiency. It has the effect of increasing.

FIG. 2 shows another embodiment of the invention.

In this embodiment, both ends of the divided piece 15 shown in FIG. 1 are bent in opposite directions to form a vertical portion 17,
The divided pieces 15 are sequentially arranged in lower stages so as to have a downward slope with the uppermost divided piece 15a as the center, and the vertical portions 17 of the divided pieces 15 are opposed to each other.

The effects of this embodiment are almost the same as those of the embodiment shown in FIG. 1, so the explanation thereof will be omitted.

[Effects of the Invention] According to the present invention, since all neutral atoms can be recovered, the concentration separation efficiency is not only increased, but also
By dividing one collection plate body into a plurality of parts, thermal stress at high temperatures can be reduced.

In addition, the production of the neutral atom trapping plate is easier than that of an integrated plate, which has the effect of reducing production costs.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are longitudinal sectional views showing respective embodiments of the collection plate for isotope separation according to the present invention,
FIG. 3 is a longitudinal sectional view conceptually showing a conventional isotope separation device, and FIG. 4 is a longitudinal sectional view schematically showing the collection plate and its vicinity in FIG. 3. 1... Container, 2... Metal atom, 3... Crucible,
4... Atomic beam, 5... One isotope, 6...
The other isotope, 7... Excitation laser, 8... Ionization laser, 9... Positive ions, 10... Ground electrode, 11... Cathode, 12... Neutral atom collection plate, 13... Recovery device, 14... Collection plate main body, 15... Division piece, 16... Liquid neutral atom, 1
7...Vertical part.

Claims (1)

[Claims] 1. In a collection plate for isotope separation, which evaporates metal atoms to generate an atomic beam, irradiates the atomic beam with a laser, and separates isotopes to obtain neutral atoms of the isotope, the neutral atom collection A collection plate for isotope separation, characterized in that the main body of the plate is divided into a plurality of parts, and the ends of the divided pieces are arranged one on top of the other.