Determination of the proton separation energy of Rh93 from mass measurements

The proposed {nu}p process, which occurs in the early time proton-rich neutrino winds of core-collapse supernovae, has the potential to resolve the long-standing uncertainty in the production of the light p-nuclei {sup 92}Mo and {sup 94}Mo. A recent study incorporating this {nu}p process has indicated that the proton separation energy S{sub p} of {sup 93}Rh is especially important in determining the relative production of these two isotopes. To reproduce the observed solar {sup 92}Mo/{sup 94}Mo abundance ratio of 1.57 a S{sub p} value for {sup 93}Rh of 1.64 {+-} 0.1 MeV is required. The previously unknown masses of {sup 92}Ru and {sup 93}Rh have been measured with the Canadian Penning Trap mass spectrometer resulting in an experimental value for S{sub p}({sup 93}Rh) of 2.007 {+-} 0.009 MeV. This implies that with our current understanding of the conditions in core-collapse supernova explosions the {nu}p process is not solely responsible for the observed solar {sup 92}Mo/{sup 94}Mo abundance ratio.