Abstract: Apparatus for the distribution of laser beams used during a selective reaction in a process for isotope separation by lasers. The system comprises in an enclosure (10), a material in the form of a vapor flow, from which it is wished to extract one species, and laser sources (12) supplying pulses along beams S1 . . . Sn at selective excitation wavelengths .lambda.1 . . . .lambda.n and along a beam St at wavelength .lambda.t permitting a transforming of said excited species. The system incorporates partial reflection mirrors (Mi) arranged in such a way that the transmitted and reflected beams S1 . . . Sn, St are superimposed. A first part (P1) of these beams is directed to the enclosure and a second part (P2) to the mirror (Mi+1). Return means (14) make it possible to adjust the length of the path in enclosure (10) between two mirrors (Mi) and (Mi+1).

Abstract: The invention relates to a system making it possible to obtain a selective reaction in photochemical processes from laser beams, comprising means for distributing said beams permitting a good utilization of the light energies.This system comprises in a sealed enclosure: the matter being in the state of a vapor from which it is wished to extract a chemical or isotopic species, laser sources emitting into said enclosure; a beam S.sub.1 permitting a selective excitation of the species to be extracted and a beam S.sub.2 permitting a transformation of said excited species. This system also comprises means for distributing the beams and incorporating means for superimposing the beams S'.sub.1 . . . S.sub.1.sup.(n) with n being an interger at least equal to 1 and for forming several beams S.sub.1 which it is wished to introduce at several points through the vapor to be treated, means for introducing beams S.sub.1 and beam S.sub.

Abstract: The invention relates to a method of separating isotopes from a gas mixture, of once ionized uranium the isotopes being separated by the combined effect of photon irradiation by laser light followed by Penning ionization of ions selectively excited by the laser light.According to the invention a gas of once ionized uranium isotopes is irradiated with laser light made up of photons having an energy which resonates with an excitation level of an isotope of the gas mixture. Metastable atoms or molecules are simultaneously introduced into the mixture and have an excitation energy which is less than the energy for a further ionization of the constituents of the mixture and greater than the energy gap between the energy for a further ionization of the isotope excited by the laser light and the energy of the excitation level of the same isotope.

Abstract: In a method of excitation and selective dissociation by absorption of the monochromatic light emitted by a high-power laser, the laser light is sent at a frequency .nu..sub.1 into an isotopic mixture of gaseous molecules in which a certain number of molecules exhibit transitions between two vibrational levels corresponding to a predetermined isotope and separated by an energy interval .DELTA.E.sub.1 =2h.nu..sub.1. The molecules of a predetermined isotopic species are thus excited preferentially until subsequent dissociation into a number of constituents.

Abstract: In a method of excitation and selective dissociation by absorption of the monochromatic light emitted by a high-power laser, the laser light is sent at a frequency .nu..sub.1 into an isotopic mixture of gaseous molecules in which a certain number of molecules exhibit transitions between two vibrational levels corresponding to a predetermined isotope and separated by an energy interval .DELTA.E.sub.1 = 2h.nu..sub.1. The molecules of a predetermined isotopic species are thus excited preferentially until subsequent dissociation into a number of constituents.