Friction coefficients for deep inelastic heavy-ion collisions

Abstract

The friction coefficients for deep inelastic collisions are re-evaluated microscopically in the framework of the linear response theory, adopting the cutoff procedure of Jensen et al. to take account of lifetime of particle-hole excitations. They have the same order of magnitude as the previous ones with a constant time cutoff parameters.

Neck Formation in Fusion Dynamics of Massive Nuclei

“…2. Here, the shape of nuclei is described by the two-center shell parametrization 18,19 with two collective variables {z, ε}, where z is the relative distance of two nuclei and ε the neck parameter.…”

Variation of transport coefficients for average fission dynamics with temperature and shape

“…This model has been developed some time ago [17], (see also [19]) and has been applied successfully to heavy ion collisions and fission. It is comparatively simple numerically but nevertheless is able to describe quite well [18] the single particle energies and wave functions near the Fermi level.…”

“…A detailed description of the construction of V can be found in [17] and [19]. As basic shape parameters there are the distance z 0 = z 2 − z 1 between the centers z i of the two potential wells, a neck-parameter ǫ, a mass ratio α and deformations δ 1 , δ 2 of the two fragments.…”

“…For a given shape the Hamiltonian (2.28) is diagonalized within the basis of eigen-functions constructed for the the two-center potential without a "neck-correction term"; hereto states up to energies of (N 0 + 3/2)hω 0 are taken into account, with N 0 = 20. The "neck-correction term" is used to remove the cusp which naturally arises at z = 0 if one just puts together two oscillator potentials (see Fig.2; for more details we refer to [17] [19]). The deformations δ i of the fragments are described by the ratio of the semi-axes a i and b i as a i /b i = (1 + 2/3δ i )/ (1 − 4/3δ i ), with i = 1 and 2 for the left and right fragments.…”

Friction coefficient for deep-inelastic heavy-ion collisions

“…The results of the classical model of D.H.E. Gross and Kalinowski [33] (dashed curves with stars) are shown for comparison, along with the results of the microscopic model developed in [15] which are obtained with a constant temperature (dashed curve without stars). The curves correspond to different temperatures which increase from 0.5 MeV (bottom curve) to 2 MeV (upper curve).…”