A Resonance Process in the Disintegration of Boron by Protons

Abstract

An experimental investigation of the efficiency of production of $\ensuremath{\alpha}$-particles from boron as a function of the energy of the bombarding protons is reported. Of the two established processes, $_{5}\mathrm{B}^{11}+_{1}\mathrm{H}^{1}\ensuremath{\rightarrow}3_{2}\mathrm{He}^{4}+{Q}_{1}$ and $_{5}\mathrm{B}^{11}+_{1}\mathrm{H}^{1}\ensuremath{\rightarrow}_{4}\mathrm{Be}^{8}+_{2}\mathrm{He}^{4}+{Q}_{2},$ the second exhibits peculiarities in its efficiency curve whereas the first increases exponentially with proton energy. This irregularity is interpreted as the occurrence of a resonance process in the second disintegration, the resonance peak occurring at 180 kv. A discussion of the possible theoretical interpretations of the process is given. Absolute yields for a thick boron target at various proton energies are given.