The $Q$ values of the reactions ${}_{}{}^{96}{}_{}{}^{}\mathrm{Ru}$(${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{14-12}{}_{}{}^{}\mathrm{C}$)${}_{}{}^{98-100}{}_{}{}^{}\mathrm{Pd}$ have been simultaneously measured using a quadrupole-dipole-dipole-dipole magnetic spectrometer. The result for the (${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$) reaction is $Q=-12.529\mathrm{}\pm 0.020$ MeV, from which we deduce the first measured mass excess of ${}_{}{}^{98}{}_{}{}^{}\mathrm{Pd}$: -81.303±0.022 MeV. The $Q$ value for the (${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$) reaction is determined to be -11.723±0.020 MeV, from which we obtain -82.214±0.022 MeV for the mass excess of ${}_{}{}^{99}{}_{}{}^{}\mathrm{Pd}$. This value is the first direct measurement of the mass of ${}_{}{}^{99}{}_{}{}^{}\mathrm{Pd}$, and disagrees with a previously tabulated value. For the (${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$) reaction, $Q=-5.599\mathrm{}\pm 0.026$ MeV, which leads to a mass excess for ${}_{}{}^{100}{}_{}{}^{}\mathrm{Pd}$ of -85.213±0.027 MeV, in agreement with a previous measurement using light ions. A mass excess of -87.138±0.022 MeV for ${}_{}{}^{106}{}_{}{}^{}\mathrm{Cd}$, measured with the ${}_{}{}^{104}{}_{}{}^{}\mathrm{Pd}$(${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$) reaction, is also in excellent agreement with a tabulated value.

NUCLEAR REACTIONS ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ + ${}_{}{}^{96}{}_{}{}^{}\mathrm{Ru}$, $E=70\mathrm{}$ MeV; measured $E_{{}_{}{}^{14}{}_{}{}^{}\mathrm{C}}$, $E_{{}_{}{}^{13}{}_{}{}^{}\mathrm{C}}$, $E_{{}_{}{}^{12}{}_{}{}^{}\mathrm{C}}$; ${}_{}{}^{98}{}_{}{}^{}\mathrm{Pd}$, ${}_{}{}^{99}{}_{}{}^{}\mathrm{Pd}$, ${}_{}{}^{100}{}_{}{}^{}\mathrm{Pd}$ deduced level, $Q$, masses; QDDD magnetic spectrometer.

• Received 15 July 1981

DOI:https://doi.org/10.1103/PhysRevC.25.331