The energy distributions of charged particles emitted in the bombardment of ${\mathrm{Li}}^6$ and ${\mathrm{Li}}^7$ by 0.24-Mev tritons have been obtained by magnetic analysis and by measuring pulse heights in a proportional counter. $Q$ values for the reactions ${\mathrm{Li}}^6(t, d){\mathrm{Li}}^7$, ${\mathrm{Li}}^6(t, p){\mathrm{Li}}^8$, and ${\mathrm{Li}}^7(t, \alpha ){\mathrm{He}}^6$ were found to be 0.986±0.007 Mev, 0.790±0.011 Mev and 9.79±0.03 Mev, respectively. The latter, when combined with other accurately measured $Q$ values, leads to a ${\mathrm{He}}^6$—${\mathrm{Li}}^6$ mass difference of 3.55±0.03 Mev, which is in agreement with the most recent $\beta$-ray measurements. Evidence is also presented for an excited state of ${\mathrm{He}}^6$ at 1.71±0.01 Mev above the ground state.

• Received 28 July 1954

DOI:https://doi.org/10.1103/PhysRev.96.684