MEASUREMENT OF S-FACTOR FOR THE 11B(p, α)2α REACTION AT LOW ENERGIES: CARBON BUILD-UP EFFECT

Abstract

The astrophysical S-factor for the 11B(p, α)2α reaction has been evaluated at effective center of mass (CM) energies of 110, 113, 115, 117, 119, 121, 124, 126, 128, 131, and 133 keV. It was observed that there was a significant difference between the calculated values and the literature values. Another difference with literature is the increased yield ratio N0/N1 of the reaction channels 11B(p,α0)8Be and 11B(p,α1)8Be with increasing energy. The reason for the discrepancy was attributed to being carbon build-up on the target surface during irradiation. Due to the carbon build-up effect in the energy range studied, effective energy (Eeff) values for the 11B(p, α)2α reaction decreased by about 30 keV.