A systematic experimental study of pre-compound emission in α-particle induced reactions on odd mass nuclei A = 103–123

Abstract

The compound and pre-compound emission processes have been established as two main competing deexcitation modes of an excited nucleus by-dint-of evaporation and emission of light fast particles in low energy αinduced reactions, respectively. An existence of the plenty experimental data on above established processes for a wide range of mass nuclei coerces to drive for some systematic trends in such reactions with excitation energy and mass number (A). Present work is an attempt to develop a systematics on the pre-compound emission process by analysing consistent experimental cross-section data of α-particle induced reactions on odd Z and odd A isotopic target nuclei viz., 103Rh, 107Ag, 109Ag, 113In, 115In, 121Sb, and 123Sb, respectively. The analysis of data indicates sarcastic deviation in the experimental cross-section data with respect to calculations performed by the statistical Monte-Carlo code pace4 beyond the peak region. Such deviation becomes more prominent towards tail portion of excitation functions, which is regarded as a significant contribution of the pre-compound emission process. Observed energy dependent uniformity of such deviation for all studied reactions gives a clue for existing some systematics on concerning process with atomic mass number (A). Present study is an extension of previous work [Eur. Phys. J. A 54, 205 (2018)], but rather in more precise way for nearby isotopic target mass nuclei 107Ag, 109Ag, 113In, 115In, 121Sb, and 123Sb, respectively, where role of the Coulomb barrier Vb and target deformation is found to be significantly important in the systematic decay of excited nuclei through emission of light fast particles in pre-compound process with mass number (A).