Energy Dissipation and Nucleon Transfer in Heavy-Ion Reactions

Abstract

We report a correlation between the kinetic energy loss and nucleon diffusion for Krand Xe-induced reactions on heavy targets. Although this correlation suggests that these two phenomena occur on the same general time scale, the rate of kinetic energy loss decreases with interaction time. Evidence is presented to show that the initial energy dissipation rate is consistent with a frictional force which is proportional to the relative velocity.

Pre-equilibrium alpha emission accompanying deep-inelastic16O+58Ni collisions

“…However, very little is known about the mechanism of energy dissipation and the time scales involved. Recent data on the correlation of the energy loss and the variance of the fragment Z distribution indicate that the rate of energy loss is initially very large [5] as compared to later stages where diffusion models seem to apply [6]. In contrast to 7-rays, the emission of light particles occurs in a time span many orders of magnitude shorter.…”

Analysis of relaxation phenomena in heavy-ion collisions

“…The method introduced here for the determination of transport coefficients has some considerable advantages over methods which have been used so far in the literature: In contrast to the rough estimate of interaction times used in [-6, 8, 9] we get now much more accurate values and hence, a high reliability for the extracted values of the transport coefficients. As compared to the method used by Huizenga et al [15,16] we determine the deflection function from the angular distribution only. In calculating the mean interaction times -tin t (1) we carefully take into account the gradual dissipation of angular momentum as well as the energy loss during the rotation of the composite system.…”

“…The model is applied to two representative reactions between very heavy ions exhibiting a strongly focussed Csideways-peaked") and a weakly focussed C forward-peaked") angular distribution. An alternative method has recently been employed by Huizenga et al [15,16] who use the combination of energy distributions and angular distributions to obtain the deflection function. In Section 3 we investigate the time evolution of the element distribution and determine the mass transport coefficients.…”

Studies of heavy ion reactions and transuranic nuclei. Progress report, August 1, 1979-July 31, 1980. [Univ. of Rochester, New York, 8/1/79-7/31/80]

“…The well-known 21 Goulard-Primakoff formalism has been proven useful in pre-22 dieting muon capture rates over a wide range of isotopes and provides a closed-form equation for the total muon capture GP. This model has been applied to the nuclei under investigation (Table II), and the agreement between theory and experiment is 2 7 16 excellent.…”

“…The well established correlation 21 between the energy loss and the second moment of the charge or mass distribution is illustrated in (Fig. 9) Fig.…”