JPH0546245B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a crucible for an isotope separation device that has little thermal deformation and is easy to cool.

(Prior Art) An isotope separation device for metal atoms using a laser beam has a much higher separation efficiency than a conventional isotope separation device using a gas diffusion method or a centrifugation method. Therefore, there is less need to repeat the same separation process in multiple stages in a cascade system until a specific isotope reaches a predetermined concentration level.
Furthermore, the entire isotope separation device is small and economical.

FIG. 4 is a conceptual diagram of a conventional laser method-based metal atom isotope separation apparatus.

In FIG. 4, the isotope separation apparatus 1 consists of a separation cell 2 that airtightly houses the main body, and various devices constituting the main body.

A metal raw material 3 containing multiple types of isotopes is housed in an evaporation crucible 4 having thermochemical resistance. Water holes 7 for cooling are buried inside the crucible 4.

An electron beam 6 emitted from a filament 5a of a linear electron gun 5 is deflected by a deflection magnetic field 8 and irradiated onto a metal raw material 3 in a crucible 4. The metal raw material 3 irradiated with the electron beam 6 is heated to a high temperature, evaporates through a molten state, and forms a vapor flow 9.

In this vapor stream 9, a specific isotope 10 to be recovered and other isotopes 11 are mixed. This vapor flow 9 is irradiated with an excitation laser beam 12 that selectively excites only a specific isotope 10 to be recovered. As the excitation laser beam 12, a laser beam having a wavelength corresponding to the absorption line of the specific isotope 10 is employed. The excited specific isotope is further irradiated with an ionizing laser beam 13, at which time electrons are ejected and the specific isotope 1
0 becomes an ionized isotope 14 with a positive charge.

When the vapor flow 9 containing this ionized isotope 14 passes through an electric field space formed by applying a voltage between the ground electrode 15 and the negative electrode 16, only the ionized isotope 14 is transferred to the negative electrode. 16 and are attracted to the surface and collected by adsorption.

On the other hand, neutral atoms such as non-ionized isotopes 17
travels straight between the electrodes without being affected by the electric field,
The neutral atom collecting plate 18 arranged on the secondary side of the electrode is configured to attract and collect the atom.

(Problems to be Solved by the Invention) In order to increase the size of these isotope separation devices, it is necessary to lengthen the crucible and evaporate the metal raw material using this lengthened crucible. . By irradiating the laser beam along the longitudinal direction of the elongated crucible, a large amount of vapor flow can be irradiated, and isotope separation can be performed efficiently.

On the other hand, crucibles currently in use do not have this concept, and merely water-cooled copper crucibles are used. However, in order to make the crucible longer than several meters, it is essential to form water cooling holes to reduce thermal deformation, and it is essential that the crucible be reliable in that the cooling medium does not leak out of the crucible. Furthermore, in order to improve the beam input of the linear electron gun 5, it is necessary to develop a crucible with good thermal efficiency, that is, excellent heat insulation.

The present invention has been made in order to satisfy the above-mentioned needs and solve the problems, and it is an object of the present invention to provide a crucible for an isotope separation device that is long, has excellent thermal efficiency, and can contribute to separation efficiency.

[Structure of the invention]

(Means for Solving the Problems) The present invention stores a metal raw material containing multiple types of isotopes in a crucible, heats and evaporates the metal raw material to generate a vapor flow, and laser beams a laser beam onto this vapor flow. In a crucible for an isotope separation device in which a specific isotope in a vapor flow is selectively ionized by irradiation with water and the ionized isotope is separated by an electric field, the crucible body has a main body extending longitudinally around the outer periphery. A metal outer layer body divided into a plurality of pieces along the length is provided, and this outer layer body is provided with a cooling mechanism.

The plurality of divided metal outer layer bodies are connected to each other by cooling mechanism pipes.

An inner layer is provided between the crucible body and the outer layer.

(Function) The crucible body is made of a single piece, is forcibly cooled by a heat-resistant and corrosion-resistant outer layer, and has a composite structure of outer layers divided in the longitudinal direction.
It is possible to machine the water holes in the outer layer unit, which reduces thermal deformation during operation. On the other hand, it is also possible to connect the outer layer by providing a cooling pipe in the water passage hole. A plurality of inner layers are further provided between the inner crucible and the outer layer to reduce the amount of radiant heat transferred to the outer layer and increase reliability.

(Example) A first example of a crucible for an isotope separation device according to the present invention will be described with reference to FIGS. 1 and 2. Note that FIG. 2 is a longitudinal sectional view taken along the line A--A in FIG. 1.

In FIGS. 1 and 2, reference numeral 20 indicates a long main body of the crucible, and a metal outer layer body 21 divided into a plurality of elongated pieces along the longitudinal direction is provided around the outer periphery of the main body 20 as a support. 22. A cooling pipe 23 having water passage holes 24 is inserted into the outer layer body 21 .

The main body 20 accommodates the metal raw material 3, and melts and evaporates the metal raw material using a linear electron gun. Therefore, it is heated to a considerably high temperature (〓), so it is made of heat-resistant and corrosion-resistant materials.

The outer layer body 21 provided on the outer periphery of this main body 20 is 1 to
Since it is 2m long, it has been divided into multiple parts. Further, in order to provide a water passage hole 24 in the outer layer body 21, a hole is formed by machining, and a cooling pipe 23 is inserted.
The outer layer body 21 divided into a plurality of parts by 3 is also connected.

FIG. 3 is a longitudinal section showing a second embodiment of the present invention. That is, in this embodiment, the body 2 of the crucible
0 and the outer layer body 21, the first inner layer body 25 and the second
In addition, two inner layer bodies are provided, and supports 27 and 28 are interposed in each inner layer body.

The embodiment shown in FIG. 1 shows an example in which a plurality of outer layer bodies 21 are connected by cooling pipes 23, but in this embodiment, the cooling pipes may be inserted and removed for each individual unit. .

By dividing the outer layer body 21 into a plurality of pieces as shown in FIG. 1, the following effects can be obtained. If these outer layers are made in one piece, the crucible body 2
Since the temperature is naturally higher on the 0 side, the outer layer body is deformed in a warped (arcuous) manner. By dividing this, deformation can be reduced.

Furthermore, by dividing the unit, it becomes possible to form water holes in each unit, and it is possible to embed cooling pipes. The outer layer is usually made of a material with good thermal conductivity, such as copper. Materials with good thermal conductivity, such as copper, generally have poor weldability, so it is also possible to use cooling pipes made of stainless steel, which has excellent weldability, and reduces the risk of cooling water leaks. , highly reliable.

In addition, by using an inner layer between the main body and the outer layer of the crucible as shown in Figure 3, it is possible to protect the crucible in the event that the main body cracks, and it also prevents radiant heat from reaching the outer layer. It also helps to reduce This makes the input by the electron gun efficient and useful for evaporating the metal raw material.

[Effects of the Invention] The crucible for an isotope separation device according to the present invention comprises a crucible main body that accommodates a metal raw material, and an outer layer body outside the crucible body that supports and cools the main body, and divides the outer layer body in the longitudinal direction. This facilitates machining of cooling holes and reduces thermal deformation during operation.

In addition, by inserting multiple inner layers between the main body and the outer layer to reduce the amount of radiant heat transferred to the outer layer,
A crucible with excellent thermal efficiency can be provided. Additionally, the inner layer also serves to prevent molten metal from leaking if the crucible body cracks, thereby improving safety and reliability.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view showing a first embodiment of a crucible for an isotope separation device according to the present invention;
The figure is a sectional view taken along the line A-A in FIG. FIG. 2 is a configuration diagram conceptually showing a body separation device. 3...Metal raw material, 4...Crucible, 7...Water hole, 20...Main body of crucible, 21...Outer layer body, 2
2... Support body, 23... Cooling pipe, 24... Water passage hole, 25... First inner layer body, 26... Second inner layer body, 27, 28... Support body.

Claims (1)

[Claims] 1. A metal raw material containing multiple types of isotopes is stored in a crucible, the metal raw material is heated and evaporated to generate a vapor flow, and a laser beam is irradiated to this vapor flow to create a vapor flow. In a crucible for an isotope separation device that selectively ionizes a specific isotope and separates the ionized isotope using an electric field, the main body of the crucible is divided into a plurality of pieces along the longitudinal direction around the outer periphery. 1. A crucible for an isotope separation device, characterized in that a metal outer layer body is provided, and the outer layer body is provided with a cooling mechanism. 2. The crucible for an isotope separation device according to claim 1, wherein the plurality of divided metal outer layer bodies are connected by a cooling mechanism pipe. 3. The crucible for an isotope separation device according to claim 1, wherein an inner layer is provided between the crucible main body and the outer layer.