Hammerton, K. M.Morrissey, D. J.Kohley, Z.Wakhle, A.Stiefel, K.Hinde, DavidDasgupta, M.Williams, E.Carter, I. P.Cook, K. J.Jeong, D. Y.Luong, D. H.McNeil, S. D.Palshetkar, C.Rafferty, D. C.Simenel, C.Greene, J.2018-11-052018-11-05978-981-322-941-9http://hdl.handle.net/1885/148872Superheavy elements are primarily formed through heavy ion fusion reactions. Formation of a fully equilibrated compound nucleus is a critical step in this reaction mechanism but can be hindered by orders of magnitude by quasifission, a process in which the dinuclear system breaks apart prior to full equilibration. To provide a complete description of heavy-ion fusion it is important to characterize the quasifission process. The interplay between the fusion-fission and quasifission reaction channels was explored by measuring fission mass distributions in eight different combinations of Cr+W reactions, with varying neutron-richness, at the Australian National University. The reactions were measured in two energy regimes: one at 13% above the Bass fusion barrier and one at 52.0 MeV of excitation energy in the compound nucleus, ECN*. For the systems measured at Ec.m./ VBass = 1.13 the dependence on the neutron-richness is clear. However, for the reactions at ECN* = 52.0 MeV, the dependence is less clear and additional factors are shown to play a vital role, especially the influence of deformation on the effective fusion barrier. The present work demonstrates that quasifission is an important process in competition with heavy-ion fusion in reactions with intermediate mass projectiles, particularly with more neutron-rich systems.application/pdf© World Scientific201710.1142/9789813229426_0053