The Q value of the ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$${(}^7$Li, ${}_{}{}^8{}_{}{}^{}\mathrm{He}$) ${}_{}{}^{39}{}_{}{}^{}\mathrm{Sc}$ reaction has been measured, and a value of -37.40(4) MeV was obtained. The corresponding mass excess of ${}_{}{}^{39}{}_{}{}^{}\mathrm{Sc}$ is -14.14(4) MeV, which makes ${}_{}{}^{39}{}_{}{}^{}\mathrm{Sc}$ proton unbound by 630(40) keV. Under the assumption of a quadratic form, the b and c coefficients of the isobaric multiplet mass equation for 39 (T=(3/2) were obtained. They agree well with systematics and the predictions of the isospin-nonconserving Hamiltonian model of Ormand and Brown.

• Received 26 January 1988

DOI:https://doi.org/10.1103/PhysRevC.38.737