Mass Measurements of Proton-Rich Isotopes between Mo and Pd using the Canadian Penning Trap Mass Spectrometer

In our understanding of the origin of elemental abundances the means of producing the observed abundances of $^{92}$Mo and $^{94}$Mo have long been unknown. These ``light p'' nuclei cannot be adequately produced by the classic p-process alone. The $\nu$p-process however, which occurs due to the neutrino wind in core collapse supernovae explosions, involves both proton-capture and neutron-capture reactions and can produce $^{92}$Mo and $^{94}$Mo. The final abundances of these isotopes depend directly on the values of the proton separation energies, S$_{p}$, along the reaction path of this process. Recent mass measurements performed with the Canadian Penning Trap Mass Spectrometer have dramatically reduced the uncertainties of S$_{p}$ values of proton-rich nuclei between Mo and Pd. These measurements and the resulting implications for both the $\nu$p-process path and the $^{92}$Mo/$^{94}$Mo abundance ratio will be discussed. This work was supported by grants from NSERC, Canada and the U.S. DOE, Nucl. Phys. Div.,under Contract W-31-109-ENG-38