BSCAT - CODE FOR SIMULATION AND FOR ANALYSIS OF THE RBS NRA SPECTRA/

A beam of charged particles as a tool for non-destructive analysis of the structure and elemental composition of thin-surface layers is freq uently used in material investigations. Nuclear methods such as RBS or NRA techniques have a good depth resolution and sufficient mass sensi tivity. Many computer programs exist, like the RUMP [see L.R. Doolitle , Nucl. Instr. and Meth. B 9 (1985) 344] or DVBS [see V. Bohac and D.M . Shirokov, Nucl. Instr. and Meth. B 84 (1994) 497] codes, for simulat ion and for analysis of experimental results collected in measurements with beams of charged particles. A new computer code, called BSCAT (B ackSCATtering), was created at the institute of Nuclear Physics to ana lyze experimental spectra and to simulate new experiments. The BSCAT c ode, written in FORTRAN-77 and partially in C, can work on IBM persona l computers or on larger computers such as CONVEX machines. As input f or the program both Rutherford and non-Rutherford cross sections can h e used and the stopping power function can be calculated by the Ziegle r or the Montenegro formula. The program was used in the analysis of c omplex spectra of backscattered particles. Among other applications th e BSCAT code was used for analysis of the spectrum of 2100 keV protons bombarding a thin carbon foil created by the IBAD technique on the su rface of a Si[111] single crystal [C-12(p, p)C-12 and Si-28(p, p)Si-28 resonance].