Half-Life Measurement for the r p-Process Waiting Point Nuclide 80Zr

X-ray bursts have been suggested as a possible site for the astrophysical rp-process. The time scale for the process is governed by β-decay half-lives of several even-even N = Z waiting point nuclei, in particular, N = Z = 40 80Zr. A 4.1(+0.8-0.6)-s β+/EC half-life for 80Zr was determined by observing delayed 84-keV γ rays depopulating a T1/2 = 4-μs isomer at 312 keV in the daughter 80Y. As this half-life is lower than many previously predicted values, the calculated excessive production of A = 80 nuclides in astrophysical x-ray burst scenarios is reduced, and less extreme conditions are necessary for the production of heavier nuclides