THERMAL-NEUTRON CAPTURE IN SILICON

The prompt gamma-rays from thermal nuteron capture in Si28,29,30 have been studied and the radiative capture cross sections determined as 2074, 1203 and 1072 mb, respectively. There has been a marked increase in the number of transitions observed in Si29 and a complete decay scheme for this nucleus is presented. Two primary E2 transitions in Si29 have been observed and their partial cross sections are compared with the prediction of the direct capture formalism. The measured neutron separation energies are Sn(29Si)=8473.610.04 keV, Sn(30Si)=10 609.210.04 keV, and Sn(31Si)=6587.320.20 keV. © 1990 The American Physical Society.