New possibilities in the study of the photofission process using backscattered laser photons

Until now the photofission of nuclei has been studied mainly by means of bremsstrahlung photons having the continuous energy spectrum. At low energies (E approx-lt 20 MeV) the valuable information was obtained about multipolarity of excitations, quantum numbers of transition states, fission barriers and widths of actinides. In the intermediate and high energy region the fission decay becomes possible for any nuclei and the subject of nuclear fission includes the problem of fragmentation, symmetric and asymmetric decay modes probability etc. This paper reports that improve the experimental accuracy of photofission experiments many efforts have been made using the quasimonochromatic gamma beams obtained by different techniques. Among them: the annihilation of positrons in flight, coherent radiation from the crystal, energy tagging by means of the coincidence registration of fission fragments and scattered electrons and the backward Compton scattering of laser photons on high energy electrons