Neutron Thresholds in the Deuteron Bombardment of Neon

The counter ratio technique has been used to detect neutron thresholds in the deuteron bombardment of neon. Energy levels in ${\mathrm{Na}}^{21}$, observed in the ${\mathrm{Ne}}^{20}(d, n){\mathrm{Na}}^{21}$ reaction, were found at 1.46±0.04 and 2.426±0.037 Mev. The latter state is bound by only 26±8 kev from dissociation into ${\mathrm{Ne}}^{20}$+$p$ and will influence the cross section for the ${\mathrm{Ne}}^{20}(p, \gamma ){\mathrm{Na}}^{21}$ reaction at low energies. Two additional thresholds were observed which are attributed to the ${\mathrm{Ne}}^{22}(d, n){\mathrm{Na}}^{23}$ reaction. The neutron yield indicates that for bombarding energies above 2.5 Mev a large fraction of the neutrons from the ${\mathrm{Ne}}^{20}(d, n){\mathrm{Na}}^{21}$ reaction leave ${\mathrm{Na}}^{21}$ in the excited state at 2.43 Mev.