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 α-
induced 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).
