Proton-Induced Reactions inNa23,Al27, andSi29

Abstract

Cross sections and excitation functions were measured for various reactions in ${\mathrm{Na}}^{23}$, ${\mathrm{Al}}^{27}$, and ${\mathrm{Si}}^{29}$ induced by 32-Mev protons from the Berkeley linear accelerator. These are compared with measurements by Reynolds and Zucker for reactions induced by 26-Mev ${\mathrm{N}}^{14}$ ions in ${\mathrm{B}}^{10}$, ${\mathrm{N}}^{14}$, and ${\mathrm{O}}^{16}$; the same compound nuclei at the same excitation energies are involved. The ${\mathrm{N}}^{14}$-induced reactions in which nearly equal-mass nuclei are emitted have much larger cross sections than the corresponding proton-induced reactions; this indicates that the former do not proceed by fission of a compound nucleus. Various spallation reactions were observed to have comparable cross sections in the two types of bombardments.