The excitation energy of the second excited state of ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ has been measured to be 3562.88±0.10 keV by comparing the energy of resonance fluorescence radiation from this state to calibration lines from a ${}_{}{}^{56}{}_{}{}^{}\mathrm{Co}$ source. Also the $Q$ value of the ${}_{}{}^6{}_{}{}^{}\mathrm{Li}(p,\alpha ){}_{}{}^3{}_{}{}^{}\mathrm{He}$ reaction has been determined relative to the ${}_{}{}^{19}{}_{}{}^{}\mathrm{F}(p,\alpha ){}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ reaction, giving a result for the ground state mass excess of ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ of 14 085.5±1.1 keV, somewhat below the tabulated value of 14 087.3±0.8 keV. These measurements improve the sensitivity of experiments searching for isovector parity violation in ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$.

NUCLEAR REACTIONS ${}_{}{}^6{}_{}{}^{}\mathrm{Li}(\gamma ,\gamma ){}_{}{}^6{}_{}{}^{}\mathrm{Li}$, bremsstrahlung source, $E_x=3.56\mathrm{}$ MeV, measured $E_x$. Ge(Li) detector. ${}_{}{}^6{}_{}{}^{}\mathrm{Li}(p,\alpha ){}_{}{}^3{}_{}{}^{}\mathrm{He}$, $E_p=10.5\mathrm{}$ MeV, measured $Q$. Magnetic spectrograph.

• Received 30 October 1980

DOI:https://doi.org/10.1103/PhysRevC.23.973