Laser isotope separation

The laser isotope separation method is reviewed. The infrared multiphoton dissociation can be made by using CO2 or TEA laser. These laser make the pulse oscillation within about 100 nsec at the power of 1 J. The wavelength of oscillation is usually around 10.6 μm. The photon density at the target is 3 x 1021 photon/cm2. The molecules irradiated by this laser beam absorb energy and make dissociation. CDF3 makes absorption at 971 and 980/cm, which are the oscillation region of CO2 laser. However, the CHF3 does not. Then, the irradiation of CO2 laser beam on CDF3 causes dissociation, but not on CHF3. The selectivity S is expressed by the ratio of reactivity. The vibrational excitation method, in which laser beam excites a specified isotopes to a vibration level, is applied for the separation of Br-79 and Br-81. The two-step photoionization is applied for the separation of the isotopes of metal elements. The photo predissociation by laser is used for the separation of light elements. The separation of I37 Cl can be made by using dye laser. A table of the laser isotope separation is presented in this paper. In the table, the method of separation suitable for each element is shown. (Kato, T.)