Eur. Phys. J. A (2020) 56: 247
https://doi.org/10.1140/epja/s10050-020-00238-1

Regular Article - Experimental Physics

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

¹ Department of Physics, Shri Varshney College, Aligarh, 202 001, India
² Accelerator Laboratory, Physics Department, Aligarh Muslim University, Aligarh, 202 002, India
³ Instituto de Física, Universidad Nacional Autónoma de México, Av. Universidad 3000, 04510, Ciudad de México, Mexico
⁴ Physics Department, Jamia Millia Islamia (A Central University), New Delhi, 110 025, India
⁵ Department of Physics, Indian Institute of Technology Ropar, Rupnagar, Punjab, 140 001, India
⁶ Department of Physics, University of Petroleum and Energy Studies, Dehradun, 248007, India

^* e-mail: manojamu76@gmail.com

Received: 30 July 2020
Accepted: 28 August 2020
Published online: 3 October 2020

Abstract

The compound and pre-compound emission processes have been established as two main competing de-excitation modes of an excited nucleus by-dint-of evaporation and emission of light fast particles in low energy $$\alpha $$-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 $$\alpha $$-particle induced reactions on odd Z and odd A isotopic target nuclei viz., $$^{103}$$Rh, $$^{107}$$Ag, $$^{109}$$Ag, $$^{113}$$In, $$^{115}$$In, $$^{121}$$Sb, and $$^{123}$$Sb, 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 $$^{107}$$Ag, $$^{109}$$Ag, $$^{113}$$In, $$^{115}$$In, $$^{121}$$Sb, and $$^{123}$$Sb, respectively, where role of the Coulomb barrier V$$_b$$ 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).