JPS59177121A - Isotope separation apparatus - Google Patents

Abstract

PURPOSE:To provide the titled apparatus low in power consumption and easy to handle, constituted so as to separate an isotope by allowing gas in a plasma state ionized by a high frequency source for an electronic cyclotron to resonate to the electromagnetic wave of the high frequency source of the electronic cyclotron. CONSTITUTION:In an isotope separation apparatus wherein a DC magnetic field is generated by the super-conductive coil 1 provided around a cylindrical vacuum container 7, the gas generating part 11 for generating gas containing an atom to be separated such as uranium provided in the above-mentioned container 7 is heated by an electromagnetic induction heating coil 21 and laser 20 and an electromagnetic wave is applied to the gas in the generated magnetic field through an antenna 13 by the high frequency source of resonance frequency or the higher harmonic thereof of an electronic cyclotron to generate ionized plasma which is, in turn, resonated to the electromagnetic wave applied through an antenna 15 by the high frequency source 14 of ion cyclotron resonance frequency or the higher harmonic thereof and isotopes having different masses such as uranium 235 or 238 are respectively separated by collectors 5, 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an isotope separation device for dregs-like substances, and particularly to a device suitable for isotope separation in a plasma state.

[Prior art]

Conventional isotope separation devices include the gas diffusion method and the centrifugation method, both of which have been put into practical use to separate uranium isotopes.

Recently, a review of isotope separation methods has been underway, mainly in the United States. American Nuclear 5oci
Conference Proceedings published by ety
dings on UraniumFuel 5u
pply at Monterrey on Jan.
.

23-26.1977 P, 332
According to FLW's evaluation, the plasma separation method is less than 1/4 of the separation cost of the gas diffusion method and centrifugation method, and the equipment cost is also less than 1/4.

The details are not clear, but according to the figure on page 350 of the same document, the principle is as follows.

FIG. 1 is a diagram showing its principle. A superconducting coil 1' for generating a DC magnetic field is placed around the cylindrical vacuum vessel 7! i=install. Broken lines 8 in the vacuum vessel 7 indicate lines of magnetic force generated. There is a uranium ion source on the left side of the figure, and uranium ions are implanted into the vacuum vessel 7. Broken lines 8 are lines of magnetic force. Uranium ions travel along magnetic lines of force 8. Here, a high frequency electric field crossing the lines of magnetic force 8 is applied. High frequency frequency -1l-f
i(H2), the strength of the magnetic field tBT (Te5la), the mass number FM of the ion, and the number of charges Z, the relationship is '1ffA When 1ffA is added, a resonance phenomenon occurs and the radius of rotation increases. Here n is an integer. f when n=l
i is said to be the ion cyclotron resonance frequency, and n=2
When it is above, it is called its harmonic.

3 in Figure 1 is the ion cyclotron resonance frequency, and 2 is the movement of ions that resonates with its harmonics? 4 is the motion of ions that resonate at other frequencies? show. uranium-23
5, when an electric field of the same wave number that satisfies equation (1) k is applied. In the case of mixed ions of uranium-235 and uranium-238, most of the uranium-238 reaches the collector 6 , and most of the uranium-235 reaches the collector 5 .

The plasma separation method achieves the isotope separation of uranium as described above.

In this plasma separation method, an ion source is used to inject ions. However, high current ion sources require a vacuum pump due to poor gas efficiency (ion yield/gas inflow). In addition, there are many factors that reduce operating efficiency and power efficiency, such as requiring water cooling to counter heat generated by the ion source, replacing filaments, and soiling extraction electrodes.

Since the extraction voltage of the large current ion source is fully equipped with a voltage of at least IK, V or more, for example, to generate an ion beam of 100 A, a power source of at least 100 W or more is required.

[Purpose of the invention]

An object of the present invention is to provide a novel apparatus for plasma separation that eliminates the need for an ion source that reduces efficiency and availability.

[Summary of the invention]

The key point of the present invention is that instead of generating all ions from a gas using an ion source, the electron-ion cyclotron resonance frequency or the high frequency of its harmonics is generated in the gas in a magnetic field. The purpose is to generate ions in a plasma state from the gas by applying and ionizing the gas.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be explained with reference to FIG. A superconducting coil 1 for generating a DC magnetic field is installed around the cylindrical X-empty container 7. The magnetic field lines generated are similar to FIG. At the bottom of the figure is a gas generating section 11 containing all separated atoms such as uranium.

The saturated vapor pressure of metallic uranium is shown in Figure 3. The vertical axis is the saturated vapor pressure (1 mm Hg), and the horizontal axis is the absolute temperature (0K).

In order to vaporize metallic uranium, a heating laser 20 is installed at the top of the vacuum container 7, and the laser light is used to heat the gas generating part lit.
Heat. The gas generating section 11 includes an electromagnetic induction heating coil 21
It is preheated by.

fe = 2.8X10"mBT ・" (2) From Ryo Takatsutsuha 12 for electron cyclotrons with all grooves,
High frequency waves are introduced into the vacuum vessel 7 through the entire antenna 13, and the uranium-235 and uranium-238 gases are ionized. Here rTl is an integer.

When Il+-1, fe is the electronic cyclotron resonance wave number, and when m = '2, fe is its harmonic and r
L is said.

When ionizing at the gas all-electron cyclotron resonance frequency or its harmonics, an energy of 100 eV is sufficient in winter to generate individual ions. In the case of a mixture of two or more types of gas, ions ionized by electron cyclotron resonance collide with the gas, and gases that do not have electron cyclotron resonance are also ionized.

This energy of 100 eV is an order of magnitude lower than the extraction voltage IKV of the ion source. This means that compared to an ion source type device, the electron cyclotron resonance type requires an order of magnitude less power for ionization.

Reference numeral 14 in FIG. 2 is a frequency source having a frequency fiO of the ion cyclotron resonance frequency of uranium-235 or its harmonics, and 15 is an antenna as its load. The radius of rotation of the uranium 235 within this antenna increases, and more uranium 235 reaches the collector 5. On the other hand, uranium 2
38 has a large amount reaching collector 6 8 d of uranium that reached collector 5! If the degree of shrinkage does not reach the target value, this device may be used again, or a process similar to this device may be used in multiple stages as necessary. In this way, complete isotopic separation of uranium is possible.

In the above explanation, all examples of helical coil antennas were shown as loads for high-frequency sources for ion cyclotrons, but the antennas may also use all the so-called "D-type electrodes" used in cyclotron accelerators. A so-called "loop antenna" or "waveguide antenna" used in nuclear fusion plasma experimental equipment may also be used.

In addition, although all examples of uranium-235 and '77-238 are shown as isotopes to be separated, the present invention is not limited to these.
For example, it may be applied to the separation of hydrogen, deuterium, tritium, etc.

In FIG. 2, the electromagnetic induction heating coil 21 and the laser 20 are used all around the uranium to heat the metal uranium, but the present invention is not limited thereto, and conventionally known heating methods such as electric,
Sound may also be used, such as air resistance direct heating, electric resistance indirect heating, induction heating, solar heating, and chemical reaction heat.

〔Effect of the invention〕

According to the present invention, a large-capacity ion source that is inefficient and difficult to handle? Instead, it is possible to realize an entire isotope separation device using a radio frequency source and antenna for an electron cyclotron, which consumes less power and is easy to handle.

[Brief explanation of drawings]

FIG. 1 is a principle diagram of a plasma separation method using a conventional ion source, FIG. 2 is a sectional view of a plasma separation apparatus of the present invention, and FIG. 3 is a temperature versus saturated vapor pressure diagram of metallic uranium. 12... High frequency source of electron cyclotron resonance frequency or its harmonics, 14... Ion cyclotron resonance/
Illustration

Claims (1)

[Claims] 1. All gaseous substances in a magnetic field, means for ionizing with electromagnetic waves at the electron cyclotron resonance frequency, or electromagnetic waves in the harmonic frequency band thereof, plasma k generated, electromagnetic waves at the ion cyclotron resonance frequency, or harmonics thereof. An isotope separation device characterized by comprising means for resonating with electromagnetic waves in the frequency band.