Mass measurement of proton-rich, medium-weight nuclei by the (He3,He6) reaction

The (${}_{}{}^3{}_{}{}^{}\mathrm{He}$,${}_{}{}^6{}_{}{}^{}\mathrm{He}$) reaction at 70 MeV on ${}_{}{}^{70}{}_{}{}^{}\mathrm{Ge}$, ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$, ${}_{}{}^{106}{}_{}{}^{}\mathrm{Cd}$, ${}_{}{}^{112}{}_{}{}^{}\mathrm{Sn}$, and ${}_{}{}^{144}{}_{}{}^{}\mathrm{Sm}$ has been used to study the protonrich nuclei ${}_{}{}^{67}{}_{}{}^{}\mathrm{Ge}$, ${}_{}{}^{87}{}_{}{}^{}\mathrm{Zr}$, ${}_{}{}^{103}{}_{}{}^{}\mathrm{Cd}$, ${}_{}{}^{109}{}_{}{}^{}\mathrm{Sn}$, and ${}_{}{}^{141}{}_{}{}^{}\mathrm{Sm}$. The observed ground state mass excesses have been determined to be -62.65±0.03, -79.344±0.009, -80.620±0.018, -82.634±0.011, -75.933±0.016 MeV, respectively. Excited states observed in these reactions are also reported. The cross sections for the (${}_{}{}^3{}_{}{}^{}\mathrm{He}$, ${}_{}{}^6{}_{}{}^{}\mathrm{He}$) reaction decrease with increasing $A$ but not as dramatically as has been observed with the (${}_{}{}^3{}_{}{}^{}\mathrm{He}$,${}_{}{}^7{}_{}{}^{}\mathrm{Be}$) reaction.