Dynamic and quasistatic trajectories in quasifission reactions and particle emission

Abstract

We show that the quasifission paths predicted by the one-body dissipation dynamics, in the slowest phase of a binary reaction, follow a quasistatic path, which represents a sequence of states of thermal equilibrium at a fixed value of the deformation coordinate. This establishes the use of the statistical particle-evaporation model in the case of dynamical time-evolving systems. Pre-and post-scission multiplicities of neutrons and total multiplicities of protons and α particles in fission reactions of 63 Cu+ 92 Mo, 60 Ni+ 100 Mo, 63 Cu+ 100 Mo at 10 MeV/u and 20 Ne+ 144,148,154 Sm at 20 MeV/u are reproduced reasonably well with statistical model calculations performed along dynamic trajectories whose slow stage (from the most compact configuration up to the point where the neck starts to develop) lasts some 35 × 10 −21 s.

A self-confined Fermi-gas model for nuclear collective motion

“…( 139), are capable to account for though small but finite compressibility of the nucleus. In order to illustrate this, consider the density distributions ρ x obtained in ETF calculations [46,47] performed for 160 Yb with a realistic Skyrme interaction, namely SkM * [23]. The Y x function was taken in the form Y x = 2z 2 − r 2 , with r = x 2 1 + x 2 2 , z = x 3 , where x i are the Cartesian coordinates of x.…”

The thermo field theory of nuclear collective motion

“…First suggested in the context of neutron-induced fission, Eq. (1), after coupling to particle evaporation from deformed nuclei [4,5] and completing by a random force [6][7][8][9][10], turned eventually into a vital tool for extracting empirical values of M, f , γ from fusion, fusion-fission, and quasifission processes following nucleus-nucleus collisions at the energies per nucleon well below the Fermi-energy [11][12][13][14].…”