Abstract:
A systematic analysis of the experimental cross-section data in odd mass number (A) and odd atomic number
(Z) nuclei is reported to reveal a novel mass-energy systematics for the pre-compound emission of fast neutrons
in α-induced reactions at low energies. The experimental excitation functions have been analyzed within the
framework of statistical model predictions to get information regarding pre-compound emission. The present
analysis establishes for first time an interesting systematics, emphasizing that accessible excitation energy on
peripheral nucleons of the systems is an exponential function of atomic mass number (A) of target nuclei.
One of the most important features of this systematics is to provide a precise estimation of the pre-compound
contribution for any nuclei, except closed-shell ones, over a wide range of mass number 63 A 109 in the
nuclear landscape. New results of the present analysis emphasize an additional subtle interconnection between
the structure of nuclei and the nuclear reaction mechanism of the pre-compound emission process at low energies,
where the compound nucleus process is more likely to be dominant.
