Total Absorption Sepctroscopy of 69,71Co Beta-Decay

Abstract:  S. Lyons, A. Spyrou, S.N. Liddick, B.P. Crider, F. Naqvi, A.C. Dombos, D.L. Bleuel, B.A. Brown, A. Couture, L. Crespo Campo, J. Engel, M. Guttormsen, A.C. Larsen, R. Lewis, P. Moller, S. Mosby, M. R. Mumpower, E. Ney, A. Palmisano, G. Perdikakis, C.J. Prokop, T. Renstrom, S. Siem, M. K. Smith, and S. J. Quinn The rapid neutron-capture process, or r process, is known to produce roughly half of the isotopes of heavy elements. Sensitivity studies have shown that the final abundance distributions of r-process nuclei are greatly impacted by uncertainties in nuclear masses, neutron-capture rates, and β-decay properties. For this reason, β-decay intensities for 69,71Co were measured using the technique of total absorption spectroscopy at the NSCL. This technique allows us to overcome the so-called “pandemonium effect,” which can cause β-feeding intensities to high-lying excitation energies to be missed in traditional β-decay experiments. The high Q-value of these isotopes allows for the study of β-decay properties over a broad energy range. The resultant β-decay intensities and deduced Gamow-Teller strengths will be compared to theoretical models, which are commonly used in r-process calculations.