cw __ __ i!iB zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA NUCLEAR PHYSICS A zyxwvutsrq EISNIER Nuclear Physics A573 (1994) 291-305 Determination of the 35Cl(n, pJ3?3 reaction cross and its astrophysical implications S. Druyts section zyxwvutsrqpo Institute of Reference Materials and Measurements (IRMM/ CBNM), Joint Research Centre, B-2440 Geel, Belgium C. Wagemans ’ Nuclear Physics Laboratory, University of Gent, B-9000 Gent, Belgium P. Geltenbort Institut LawLangevin, F-38042 Grenoble, France Received 2 December 1993 zyxwvutsrqponmlkjihgfedcbaZYXWVUTS Abstract The zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA 35Cl(n, P)~% reaction cross section has been measured with thermal neutrons at the High Flux Reactor of the ILL (Grenoble) and with resonance neutrons at the linear accelerator GELINA of the IRMM (Gee0 For the thermal cross section, a precise value of 440 k 10 mb was obtained. In the region up to about 100 keV neutron energy, several resonances were determined with high resolution. These data were used to calculate the maxwellian averaged cross section at various temperatures. Their impact on stellar-nucleo- synthesis calculations is discussed. Key words: NUCLEAR REACTIONS 35Cl(n, p); E = thermal-100 keV; measured proton yield vs E; deduced reaction, maxwellian averaged u; calculated (n, p)/(n, y) branching ratio. 1. Introduction Important discrepancies (up to a factor of three) exist between the 35Cl(n,,, pj3?3 reaction cross-section values reported in the literature [l-9]. These data were ’ Supported by the National Fund for Scientific Research, Belgium. 03759474/94/$07.00 0 1994 Elsevier Science B.V. All rights reserved SSDZ 0375-9474(94)00043-M