How signatures of quasifission evolve in reactions forming Curium

Abstract

Quasifission, a fission-like reaction outcome in which no compound nucleus forms, is an important competitor to fusion in reactions used for super-heavy element formation. The precise mechanisms driving the competition between quasifission and fusion are poorly understood. To explore the influence reaction parameters have on quasifission probabilities, an investigation into the evolution of quasifission signatures as a function of entrance channel parameters is required. Using the Australian National University’s 14UD tandem accelerator and CUBE detector for two-body fission studies, measurements were made for a diverse range of reactions forming isotopes of Curium. Observables known to reveal signs of quasifission—namely mass ratio spectra, mass-angle distributions, and angular anisotropies—were extracted. Evidence of quasifission was observed in all reactions, but the observables showing evidence of quasifission were not the same for all reactions. A link between this evolution and reaction timescales will be discussed.