Savrasov A. Study of reactions mechanism with γ-rays and light particles by using of activation method

Thesis is devoted to the experimental investigation of reactions with γ-rays and light particles by activation method. A flux-weighted average yields have been obtained for the first time for the reactions with bremsstrahlung γ-rays at ten nuclei both in the giant dipole resonance region and for higher energies. The domination of the statistical mechanism has been shown for the most of the photonuclear reactions with escaping of neutrons and γ-rays and nonstatistical mechanisms for reactions with escaping of charged particles. For the first time the cross-sections and isomeric cross-section ratios have been measured for the thirteen nuclei in reactions with light particles and neutrons. The measurement of isomeric yields ratios has been performed for the twelve photofission fragments, created in reactions on six heavy actinides. For these fragments the average angular moments have been obtained based on the statistical model which used in the free codes. There is no increasing of the average angular moments values at increasing of atomic number for odd-even heavy nuclei as opposed to even-odd ones. The precise measurement of the excitation energy of the first excited levels has been obtained for two nuclei. It is important both for defining of the lowest beta-decay energy value and for more accurate definition of the end-point energy for atomic-nuclei process.