Proton elastic recoil cross sections for 0.6-5.0 MeV He-4 ions

The cross sections for proton elastic recoil of 0.6-5.0 MeV He-4 ions have been measured at recoil angles of 10 degrees, 15 degrees, 20 degrees, 25 de grees, 30 degrees, 35 degrees and 40 degrees with the target set for transm ission geometry. Thin melamine (C3H6N6) foils (10-25 mu g/cm(2)) were used as the hydrogen target. By bombarding the He-4 ions normal to the target, b ackscattered He-4 ions from nitrogen and recoil protons at forward angles w ere detected. Hence the proton recoil cross section was determined by norma lizing to the scattering cross section of He-4 ions backscattered from nitr ogen to 165 degrees [Y. Feng, Z. Zhou, G. Zhao, F. Yang, Nucl. Instr. and M eth. B 94 (1994) 11]. The measured cross sectional data are reviewed and co mpared with calculations for the kinematic inverse reaction He-4(p,p)He-4, and with the measured results of the proton recoil cross section reported u p to now. In order to simplify the application of these results for ERD ana lysis, an arbitrary polynomial is derived by fitting the cross sectional da ta from this study. (C) 1999 Elsevier Science B.V. All rights reserved.