Models Of Nuclear Dynamics Research Articles

Equilibrium Structure of Beryllium Dibromide from Combined Gas Electron Diffraction and Vibrational Spectroscopy Analysis

The molecular structure of BeBr2 has been investigated by gas-phase electron diffraction at the temperature 800(10) K. The conventional analysis yielded the following values: rg(Be–Br) = 1.944(6)A, l(Be–Br) = 0.068(4)A, rg(Br–Br) = 3.848(8)A, l(Br–Br) = 0.109(3)A, k(Be–Br) = 1.1(1.1) × 10−5 A3, κ(Br–Br) = 2.1(1.0) × 10−5 A3. Three models of nuclear dynamics were used to simulate the conventional analysis values—infinitesimal vibrations and two models, which take into account the kinematic and dynamic anharmonicity of the bending vibration. All models give similar values of bond angle, amplitudes, and shrinkage, excluding the harmonic model, which yields too low value l(Br–Br). The equilibrium bond distance re(Be–Br) = 1.932(11) A was estimated, taking into account the anharmonicity corrections for stretching and bending vibrations and centrifugal distortion.

Collision rates, flows, and temperatures in heavy-ion collisions

In previous publications, we have presented a nonrelativistic model for nuclear dynamics in which the one-body density matrix is evolved in time in a mean-field theory and where two-body collisions are calculated by a relaxation-time method. To further investigate this model, the rate of two-nucleon collisions in nuclei is calculated for collisions between nuclei at laboratory energies from 30–84 MeV/ A. Nucleon-nucleon collisions are found to be enhanced in regions where nucleons collide with the nuclear wall and hot spots are formed. There appears to be a focusing by the mean field. Nuclear densities, mass currents, temperatures and Wigner functions are shown, in particular, as they relate to nucleon-nucleon collisions. Other topics discussed and illustrated by calculations are promptly emitted particles (Fermi jets) and linear momentum transfer.

LIQUID PARTICLE AND LIQUID GAS MODELS OF NUCLEAR DYNAMICS

We present a model of nuclear dynamics which combines the macroscopic aspects of a classical liquid with the characteristic behaviour of a quantal gas of nearly independent quasi-particles.

Models of nuclear dynamics at intermediate energies

A review on dynamical models and their validity limits in the energy range 100MeV<E/A<2GeV is given. Open problems are discussed.