For an improved modeling of the astrophysical nucleosynthesis of p-nuclei, low energy cross section data of alpha-induced reactions on heavy isotopes are needed. Technical difficulties hamper the experimental determination of these cross sections, therefore the relevant experimental data are almost completely missing. Here we present a new method for the cross section measurements, the activation technique based on the detection of characteristic X-ray radiation. The feasibility of the method is illustrated through the measurement of the Tm-169(alpha, gamma)Lu-173 and Tm-169(alpha, n)Lu-172 reaction cross sections. Despite the relatively long half-life of the reaction products (T-1/2 = 500 and 6.7 days, respectively) it was possible to measure the cross section of the Tm-169(alpha, gamma)Lu-173 reaction between E-c.m. = 13.16 and 17.08 MeV. The Tm-169(alpha, n)Lu-172 reaction cross section was derived from close above the threshold up to E-c.m.. = 17.08 MeV. Details of the new method and the experimental results are presented. (C) 2011 Elsevier B.V. All rights reserved.
- deduced sigma. Activation method with HPCe and LEPS detectors
- NUCLEAR REACTIONS Tm+169(alpha, gamma), (alpha, n), E=11.5-17.5 MeV
- measured E gamma, I gamma, E(K X-ray), I (K X-ray)
- SOFTWARE PACKAGE