Total Absorption Spectroscopy and its Applications in Nuclear Astrophysics

The astrophysical rapid neutron-capture process (r-process) and proton-capture process (pprocess) are responsible for the synthesis of about half of the heavy elements. Despite the importance, our understanding of these two processes is limited. Few of the important inputs required to model the r- and p-process include β-decay strength distributions on the neutron-rich side and nuclear cross sections. In an effort to provide the models with these quantities, experiments were performed using the Total Absorption Spectroscopy (TAS) to extract the particle capture cross sections and β-decay strength distributions in the mass region around
A = 70.

The experiment aimed at measuring the 72Ge(p,γ) 73As cross section was performed at the University of Notre Dame using a 1.8 to 3.6 MeV proton beam. The γ-summing technique was employed using the Summing NaI(Tl) detector (SuN) from the National Superconducting Cyclotron Laboratory. The results from this experiment will be reported in the first part of the talk. The second part will focus on the experiment done for measuring the β-decay strength distributions in neutron-rich Cu isotopes and extracting the neutron capture cross-sections of Ni isotopes. The experiment was performed at the National Superconducting Cyclotron Laboratory (NSCL) using the fragmentation of a 86Kr primary beam. 

In the final part of the talk, a future perspective with respect to building a new TAS detector at TIFR and using it for measuring the nuclear cross sections relevant for predicting the r- and p-process paths will be explored.