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Title: Classical microscopic calculations of high-energy collisions of heavy ions

Abstract

Nonrelativistic classical microscopic (equations of motion) calculations have been made for collisions between nuclei mostly with 50 nucleons each and for relative velocities of 0.5c and 0.8c (nonrelativistic laboratory energies of 117 and 300 MeV/nucleon, respectively). The trajectories of all the nucleons are calculated with two-body forces between all pairs of nucleons. The potentials are sums of attractive and repulsive Yukawa potentials of reasonable ranges and are adjusted to give reasonable binding and kinetic energies and to fit the NN cross section sigma/sub ..nu../ appropriate for the viscosity and thus for shock phenomena; sigma/sub ..nu../ strongly emphasizes transverse momentum transfers. Ensemble averages are taken over (10) initial distributions and care is taken to monitor the relatively minor effects of evaporation of the individual noninteracting nuclei. Central collisions corresponding to small impact parameters b (less than about a nuclear radius R) are ''explosive'' and seem fairly well equilibrated at maximum compression and subsequently. There is some similarity to development of shocks. After an initial penetration of about a mean free path, there is rapid dissipation of the collisional translational energy with associated large internal energies and large compressions (to somewhat less than twice normal density), followed finally by an explosive expansion;more » the angular distributions are roughly isotropic for quite small b but show some transverse peaking for very small b. For small b (approximately-less-than0.5R) and for v = 0.5c, but not for 0.8c, we find large fused residues with A approx. = 60. Transparency and nonequilibrium effects develop rapidly with increasing b and are somewhat more important for v = 0.8c than for 0.5c. For b approximately-greater-than R (noncentral collisions) the nuclei retain much and for b approximately-greater-than 1.5R most of their initial identity, suffering relatively little immediate mass loss.« less

Authors:
;
Publication Date:
Research Org.:
Argonne National Laboratory, Argonne, Illinois 60439
OSTI Identifier:
7308740
Resource Type:
Journal Article
Journal Name:
Phys. Rev., C; (United States)
Additional Journal Information:
Journal Volume: 15:4
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; HEAVY ION REACTIONS; ANGULAR DISTRIBUTION; CROSS SECTIONS; EQUATIONS OF MOTION; GEV RANGE; HYDRODYNAMICS; NUCLEAR RADII; NUCLEON-NUCLEON INTERACTIONS; PAULI PRINCIPLE; SHOCK WAVES; TRANSVERSE MOMENTUM; TWO-BODY PROBLEM; YUKAWA POTENTIAL; BARYON-BARYON INTERACTIONS; CHARGED-PARTICLE REACTIONS; DIFFERENTIAL EQUATIONS; DISTRIBUTION; ENERGY RANGE; EQUATIONS; FLUID MECHANICS; HADRON-HADRON INTERACTIONS; INTERACTIONS; LINEAR MOMENTUM; MANY-BODY PROBLEM; MECHANICS; NUCLEAR POTENTIAL; NUCLEAR PROPERTIES; NUCLEAR REACTIONS; PARTICLE INTERACTIONS; 653003* - Nuclear Theory- Nuclear Reactions & Scattering

Citation Formats

Bodmer, A R, and Panos, C N. Classical microscopic calculations of high-energy collisions of heavy ions. United States: N. p., 1977. Web. doi:10.1103/PhysRevC.15.1342.
Bodmer, A R, & Panos, C N. Classical microscopic calculations of high-energy collisions of heavy ions. United States. https://doi.org/10.1103/PhysRevC.15.1342
Bodmer, A R, and Panos, C N. 1977. "Classical microscopic calculations of high-energy collisions of heavy ions". United States. https://doi.org/10.1103/PhysRevC.15.1342.
@article{osti_7308740,
title = {Classical microscopic calculations of high-energy collisions of heavy ions},
author = {Bodmer, A R and Panos, C N},
abstractNote = {Nonrelativistic classical microscopic (equations of motion) calculations have been made for collisions between nuclei mostly with 50 nucleons each and for relative velocities of 0.5c and 0.8c (nonrelativistic laboratory energies of 117 and 300 MeV/nucleon, respectively). The trajectories of all the nucleons are calculated with two-body forces between all pairs of nucleons. The potentials are sums of attractive and repulsive Yukawa potentials of reasonable ranges and are adjusted to give reasonable binding and kinetic energies and to fit the NN cross section sigma/sub ..nu../ appropriate for the viscosity and thus for shock phenomena; sigma/sub ..nu../ strongly emphasizes transverse momentum transfers. Ensemble averages are taken over (10) initial distributions and care is taken to monitor the relatively minor effects of evaporation of the individual noninteracting nuclei. Central collisions corresponding to small impact parameters b (less than about a nuclear radius R) are ''explosive'' and seem fairly well equilibrated at maximum compression and subsequently. There is some similarity to development of shocks. After an initial penetration of about a mean free path, there is rapid dissipation of the collisional translational energy with associated large internal energies and large compressions (to somewhat less than twice normal density), followed finally by an explosive expansion; the angular distributions are roughly isotropic for quite small b but show some transverse peaking for very small b. For small b (approximately-less-than0.5R) and for v = 0.5c, but not for 0.8c, we find large fused residues with A approx. = 60. Transparency and nonequilibrium effects develop rapidly with increasing b and are somewhat more important for v = 0.8c than for 0.5c. For b approximately-greater-than R (noncentral collisions) the nuclei retain much and for b approximately-greater-than 1.5R most of their initial identity, suffering relatively little immediate mass loss.},
doi = {10.1103/PhysRevC.15.1342},
url = {https://www.osti.gov/biblio/7308740}, journal = {Phys. Rev., C; (United States)},
number = ,
volume = 15:4,
place = {United States},
year = {Fri Apr 01 00:00:00 EST 1977},
month = {Fri Apr 01 00:00:00 EST 1977}
}