Penning-trap mass measurements of Zn and Cu isotopes relevant for the astrophysical rp-process

CERN INTC proposal INTC-P-475: Penning-trap masses of ⁵⁸Zn and ⁵⁶Cu, the two nuclei that decide how the rp-process passes the ⁵⁶Ni waiting point in type-I X-ray bursts.

Twelve ISOLDE shifts on a ZrO₂ target with RILIS, measuring both species with Penning trap and/or MR-ToF.

Proton-capture rates depend exponentially on the proton separation energy, hence on the mass. The ⁵⁶Cu Q-value was only a 200 keV extrapolation; ⁵⁸Zn was measured but not well enough for modern burst models.