Energy Levels ofNa21andMg22

Abstract

Neon gas has been bombarded with 2.4, 3.1, 4.6, and 6.1-Mev deuterons and with 3.4- and 4.5-Mev ${\mathrm{He}}^3$ particles. Time-of-flight measurements of neutron groups indicate excited states of ${\mathrm{Na}}^{21}$ at 0.37±0.04, 1.69±0.05, 2.83±0.04, 3.89±0.05, 4.86±0.06, and 5.01±0.05 Mev, in addition to the well-known states at 2.43, 3.57, 4.18, 4.31, and 4.49 Mev. Angular distributions show strong direct interaction features. ${\mathrm{Mg}}^{22}$, here reported for the first time, has a mass excess ($M-A$) of -0.14±0.08 Mev (${\mathrm{C}}^{12}$ reference) from $Q=-0.043\mathrm{}\pm 0.08$ Mev for ${\mathrm{Ne}}^{20}({\mathrm{He}}^3, n){\mathrm{Mg}}^{22}$. The first excited state is at 0.995±0.04 Mev. No other states are observed with $E_x<2.5\mathrm{}$ Mev.