Pre-equilibrium cross section calculations in alpha induced reactions on 65 Cu and 209 Bi A. Aydin a, * , E. Tel b , A. Kaplan c , H. Büyükuslu c a Kirikkale University, Faculty of Arts and Sciences, Department of Physics, Kirikkale, Turkey b Gazi University, Faculty of Arts and Sciences, Department of Physics, Ankara, Turkey c Süleyman Demirel University, Faculty of Arts and Sciences, Department of Physics, Isparta, Turkey article info Article history: Received 10 March 2010 Received in revised form 11 May 2010 Accepted 24 May 2010 Available online 19 June 2010 Keywords: Alpha induced reactions Excitation function Pre-equilibrium reactions abstract The nuclear data on (a, xn) reactions are very important in the fields of radiation shielding, long-term safe handling of spent fuel and spallation neutron-production. In this study, neutron-production cross sec- tions have been calculated for some target nuclei such as 65 Cu and 209 Bi. Hybrid model and geometry dependent hybrid model have been used to calculate the pre-equilibrium neutron-production cross sec- tions. The mean free path parameter’s effect for (a, xn) neutron-production cross section has been exam- ined. The obtained results have been discussed and compared with the available experimental data. Ó 2010 Elsevier Ltd. All rights reserved. 1. Introduction Knowledge of the cross sections for charged particle induced reactions on different target material leading to the isotopes of interest (and possible contaminants) is needed if optimization of production routes has to be performed (Király et al., 2008). During the last few decades several pre-equilibrium reaction mechanisms have been developed in order to explain a wide range of charged particle spectra and excitation functions induced by alpha particles in the energy region of 20–200 MeV, in target nuclei spanning the entire periodic table (Mukherjee and Singh, 1996). The observation of a forward peaked hard component in the continuous spectra of light ejectiles and the high energy tails seen in the excitation func- tions of activation cross sections induced by a-particles, contains important information about the reaction mechanism. Several models (Blann, 1971, 1975; Cline and Blann, 1971; Griffin, 1966; Harp et al., 1968; Harp and Miller, 1971) have been proposed to ex- plain the emission of energetic light particles by the equilibration process (pre-equilibrium emission) from the nuclear system ex- cited at medium energies. Predictions from these models as to the excitation functions and the energy spectra of the emitted par- ticles compared well with the existing experimental data. This has prompted a continued interest in these models as tools both to pre- dict cross sections for a number of practical purposes and to test the adequacy of the underlying physics (Ismail, 1989). Alpha induced reactions could be efficiently used to solve ana- lytical problems via charged particle activation analysis (Dmitriev, 1986). The long-term safe handling of spent fuel from fission reac- tors also requires knowledge of the neutron flux produced by (a, n) reactions following the alpha-decay (West and Sherwood, 1982; Matsunobu and Yamamuro, 2002). There are neutron background problems in many cases originating from the presence of the al- pha-decay from certain naturally occurring elements (Heaton et al., 1989). The knowledge of alpha activation products is impor- tant in many other nuclear technologies, like fusion, accelerator technology, dosimetry, etc. (Daruga and Matusevich, 1972; Ger- jacks and Ehrlich, 1992; Tárkányi et al., 2003). With the development of nuclear science and technology, the accelerator-driven clean nuclear power system (ADS) has been an interesting focus in nuclear physics. They require accurate nuclear reaction data of common cross sections and especially need the data of neutron and proton induced energy-angle correlated spec- tra of secondary light particles as well as double differential cross sections (Han et al., 2005). The nuclear data requirements for the accelerator driven technologies are extreme with respect to both the target element coverage and type of reaction data. As such, more detailed and accurate measurements are needed to provide these data. Efforts have been made to obtain the estimates of basic nuclear reaction cross sections for a number of elements both experimentally as well as theoretically (Singh et al., 2006). In this study, neutron-production cross sections for some target nuclei such as 65 Cu and 209 Bi have been investigated up to 100 MeV alpha energy. The excitation functions for (a, xn) reactions (x = 1,2,3, ...) have been calculated by pre-equilibrium reaction 0306-4549/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.anucene.2010.05.016 * Corresponding author. Tel.: +90 542 6758736; fax: +90 318 3572460. E-mail address: aaydin@kku.edu.tr (A. Aydin). Annals of Nuclear Energy 37 (2010) 1316–1320 Contents lists available at ScienceDirect Annals of Nuclear Energy journal homepage: www.elsevier.com/locate/anucene