International Topical Meeting on Nuclear Research Applications and Utilization of Accelerators

4-8 May 2009, Vienna

ADS/ND-05

A Study of Pre-Equilibrium Emission in Some Proton Induced Reactions: Measurement of Cross-Sections

B.P. Singh1, M.M. Musthafa2, H.D. Bhardwaj3, D.P. Singh1, P.P. Singh1, A. Yadav1, Unnati1,
M.K. Sharma1, and R. Prasad1

1Department of Physics, Aligarh Muslim University, Aligarh, India
2Department of Physics, Calicut University, Calicut, India
3Department of Physics, D.S.N. College, Unnao, India

Corresponding Author: bpsinghamu@gmail.com

The study of nuclear reactions induced by protons has again attracted the attention of nuclear physicists due to the requirement of precise nuclear data needed for the development of recently proposed accelerator driven sub-critical (ADS) reactors. Apart from several applications of nuclear data for radio-isotope production in medical sciences, environmental sciences, transmutation of nuclear waste etc., one of the main aims has been to enhance the basic understanding of the reaction mechanism. Though, a large amount of data is now available in literature on nucleon induced reactions but, in general the measurements done by different groups have large uncertainties and do not agree with each other. Further, the reaction mechanism of such reactions at different energy regimes is still not well understood. There are indications that equilibrium and pre-equilibrium reaction mechanisms both play important role at moderate excitation energies. In view of the above, as part of a programme of precise measurement of cross-sections for the production of several radio-isotopes in proton induced reactions, excitation functions for several reactions in 63,65Cu, 113,115In, 121,123Sb, and 197Au isotopes up to 20 MeV have been carried out. The experiments have been carried out using the proton beam from the Variable Energy Cyclotron Centre, Kolkata, India. The analysis of data performed in light of several theoretical model codes clearly indicates the presence of considerable pre-equilibrium component in such reactions. An attempt has been made to determine the pre-equilibrium fraction, which is a measure of the relative strength of equilibrium and pre-equilibrium component and its energy dependence. Further details of the measurements and analysis of data will be presented.