The cross sections for proton elastic recoil of 0.6–5.0 MeV 4He ions have been measured at recoil angles of 10°, 15°, 20°, 25°, 30°, 35° and 40° with the target set for transmission geometry. Thin melamine (C 3H 6N 6) foils (10–25 μg/cm 2) were used as the hydrogen target. By bombarding the 4He ions normal to the target, backscattered 4He ions from nitrogen and recoil protons at forward angles were detected. Hence the proton recoil cross section was determined by normalizing to the scattering cross section of 4He ions backscattered from nitrogen to 165° [Y. Feng, Z. Zhou, G. Zhao, F. Yang, Nucl. Instr. and Meth. B 94 (1994) 11]. The measured cross sectional data are reviewed and compared with calculations for the kinematic inverse reaction 4He(p,p) 4He, and with the measured results of the proton recoil cross section reported up to now. In order to simplify the application of these results for ERD analysis, an arbitrary polynomial is derived by fitting the cross sectional data from this study.
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