Protons from the Deuteron Bombardment of Enriched Silicon and Related Atomic Masses

Abstract

Enriched samples of silicon have been bombarded with 3.8 Mev deuterons and 17 proton groups have been assigned to the ${\mathrm{Si}}^{28}\mathrm{}(d,p)\mathrm{}{\mathrm{Si}}^{29}$, ${\mathrm{Si}}^{29}\mathrm{}(d,p)\mathrm{}{\mathrm{Si}}^{30}$ and ${\mathrm{Si}}^{30}\mathrm{}(d,p)\mathrm{}{\mathrm{Si}}^{31}$ reactions. The ground state transitions for ${\mathrm{Si}}^{28}\mathrm{}(d,p)\mathrm{}{\mathrm{Si}}^{29}$ and ${\mathrm{Si}}^{29}\mathrm{}(d,p)\mathrm{}{\mathrm{Si}}^{30}$ are found to be 6.18±0.09 Mev and 8.36±0.10 Mev. Seven proton groups corresponding to excited states in ${\mathrm{Si}}^{29}$ and three groups leading to excited states in ${\mathrm{Si}}^{30}$ have been observed. Five groups are found to be associated with ${\mathrm{Si}}^{30}\mathrm{}(d,p)\mathrm{}{\mathrm{Si}}^{31}$, with a sixth in doubt. A method for using extrapolated range measurements to obtain mean ranges is described. The published transition energies of reactions possibly involving ground states of aluminum, silicon and phosphorus isotopes are tabulated. These energies are converted to mass differences which are presented on a diagram. The lack of satisfactory consistency of these mass differences is discussed and the discrepancy of reaction data and mass spectroscopic data between aluminum and sulphur is outlined.