Fusion-induced fission measurements with the MUSIC active target detector

Abstract

The rapid neutron capture process (r-process) is believed to be responsible for about half of the production of the elements heavier than iron and it may also contribute to abundances of some lighter nuclides. Great excitement was recently generated by evidence for r-process nucleosynthesis in binary neutron star mergers via multi-wavelength observations of kilonova emission and gravitational waves. In order to interpret the observations and validate theoretical predictions, an understanding of the fission process, in particular of the evolution of fission barrier heights, is needed. An experimental study of fusioninduced fission cross sections using active-target detectors is a promising idea since the fission excitation function can be studied with a single beam energy. The Multi-Sampling Ionization Chamber (MUSIC) is an active-target detector in which a gas serves as both, counting gas and target nuclei. A proof-of principle experiment to explore the ability to identify fission events with MUSIC was recently performed at Argonne National Laboratory. In this work, ideas, results and perspectives will be discussed.