UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

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2024-11-23 18:07
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Conference: Bucharest University Faculty of Physics 2009 Meeting


Section: Nuclear and Elementary Particles Physics


Title:
Cross Section Evaluation of the (n,alpha) reaction with fast neutrons on 64Zn, 137Sm using the Hauser-Feshbach Approach


Authors:
A. I. Oprea*, Yu. M. Gledenov, P.V. Sedyshev, M. V. Sedysheva, C. Oprea, C.Pirvutoiu**, D. Vladoiu**


Affiliation:
*141980 Dubna, Russian Federation, Frank Laboratory for Neutron Physics, Joint Institute for Nuclear Research Dubna

** University of Bucharest, Faculty of Physics, Atomic and Nuclear Physics Chair, ROMANIA


E-mail


Keywords:
fast neutrons, penetrabilities, cross sections


Abstract:
In the (n,alpha) reactions induced by neutrons with energy about some MeV the experimental data are very poor due to the difficulty of the measurement of the cross section. In this energy region of the incident neutrons the cross section is of order of tens mb or lower for emission of charged particles. It is supposed for both nuclei that the nuclear reaction is going by formation of an intermediate compound nucleus and this is suggested by the differential cross section experimental data. For the theoretical evaluation it was used the Hauser-Feshbach approach. In this approach it is important to obtain the penetrabilities for neutron in the entrance channel and for charged particles (protons, alphas) in the exit channels. We have obtained the penetrabilities starting from quantum mechanical considerations and after that using them for obtaining the cross section. For this purpose we realized computer programs where it was implemented the regular an irregular functions in the integral form without any approximation. The theoretical and experimental evaluations of the 64Zn and 137Sm are important from theoretical point of view, nuclear reactor materials studies and astrophysical researches. Experimental data were measured using a double gridded ionisation chambers at electrostatic generators of LNF-JINR Dubna (Russia) and Institute of Heavy Ions Physics from Pekin University (China).