Protons from the Separated Isotopes of Carbon and Neon under Deuteron Bombardment

The protons arising from the bombardment by 2.54-Mev deuterons of CH₄ gas enriched in C¹³ isotope and neon enriched in Ne²² have been studied with a cloud chamber. It is shown that the yield of long range protons from the C¹³(dp)C¹⁴ reaction is less than four percent of the yield of shorter range protons from the C¹²(dp)C¹³ reaction at this deuteron energy. This low yield means that the half-life of C¹⁴ discovered by Ruben and Kamen is considerably less than their estimate and is probably about 100 years. In neon the longest range group of protons discovered by Pollard and Watson is shown to be complex, with an indicated doublet width of the ground state of Ne²¹ of 0.44 Mev. The only proton group definitely indicated for the Ne²² bombardment occurs at about 30 cm range.