Under bombardment by 2.6-Mev deuterons, neon is observed to emit a large yield of protons which fall into at least four groups of energy change values 1.02, 2.15, 3.13, and 4.88 Mev. To assign these to the appropriate isotope, samples of neon enriched in ${\mathrm{Ne}}^{22}$ and ${\mathrm{Ne}}^{20}$ prepared by the thermal diffusion method were bombarded with the result that all groups are found to correspond to excited states of ${\mathrm{Ne}}^{21}$. The reaction involved is ${\mathrm{Ne}}^{20}\mathrm{}\left(\mathrm{dp}\right)\mathrm{}{\mathrm{Ne}}^{21}$. The maximum energy of the protons leads to the value 21.00017 for the mass of ${\mathrm{Ne}}^{21}$. The bombarded gas was found to be radioactive and the presence of ${\mathrm{Ne}}^{23}$ due to ${\mathrm{Ne}}^{22}\mathrm{}\left(\mathrm{dp}\right)\mathrm{}{\mathrm{Ne}}^{23}$ and ${\mathrm{Na}}^{21}$ due to ${\mathrm{Ne}}^{20}\mathrm{}\left(\mathrm{dn}\right)\mathrm{}{\mathrm{Na}}^{21}$ was established. By absorption the beta-rays from ${\mathrm{Ne}}^{23}$ were found to consist of a single group of maximum energy 4.1 Mev which leads to a probable value of 23.0010 for the mass of ${\mathrm{Ne}}^{23}$.

• Received 15 May 1940

DOI:https://doi.org/10.1103/PhysRev.58.12