Relativistic nuclear fluid dynamics. [250 MeV, 2. 1 GeV]

Journal Article · Wed Jun 01 00:00:00 EDT 1977 · Phys. Rev., C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.15.2059· OSTI ID:7256163

Amsden, A A; Harlow, F H; Nix, J R

By use of finite-difference methods we solve in three spatial dimensions the classical relativistic equations of motion for the collision of two heavy nuclei. These equations express the conservation of nucleon number, momentum, and energy for a specified nuclear equation of state. For /sup 20/Ne + /sup 238/U at laboratory bombarding energies per nucleon of 250 MeV and 2.1 GeV, we calculate the time evolution of the matter distribution for several impact parameters. Nearly central collisions deform and compress the system enormously, whereas in peripheral collisions the projectile is fragmented into a portion that proceeds roughly straight ahead at its original velocity and another portion that deposits its energy in the target. For a given impact parameter we construct from the velocity vectors at some large time the energy and angular distributions for the expanding matter. An integration of these results over impact parameter then gives us the double differential cross section d/sup 2/sigma/dEd..cap omega... For the 250-MeV case we compare calculated and experimental results in the form of proton energy spectra for four laboratory angles ranging from 30/sup 0/ to 120/sup 0/. The calculations reproduce correctly the experimental slopes at each angle, as well as the overall decrease in the experimental cross section from forward to backward angles. However, at 30/sup 0/ the calculated values are only one-half the experimental ones, whereas at 120/sup 0/ they are twice as large. These comparisons, together with comparisons of calculations done by other workers, suggest that heavy nuclei are partially transparent to each other during collisions at high energy, but that the process is not solely a superposition of individual nucleon-nucleon collisions. Instead, coherent collective-field effects play some role.

• Research Organization: Theoretical Division Los Alamos Scientific Laboratory, University of California, Los Alamos, New Mexico 87545
• OSTI ID: 7256163
• Journal Information: Phys. Rev., C; (United States), Vol. 15:6
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
HYDRODYNAMIC MODEL
EQUATIONS OF MOTION
NEON 20 REACTIONS
NUCLEAR REACTION KINETICS
URANIUM 238 TARGET
ANGULAR DISTRIBUTION
CONSERVATION LAWS
DIFFERENTIAL CROSS SECTIONS
EQUATIONS OF STATE
FINITE DIFFERENCE METHOD
FLUID FLOW
GEV RANGE 01-10
GEV RANGE 10-100
MANY-BODY PROBLEM
PROTON SPECTRA
RELATIVISTIC RANGE
THREE-DIMENSIONAL CALCULATIONS
CHARGED-PARTICLE REACTIONS
CROSS SECTIONS
DIFFERENTIAL EQUATIONS
DISTRIBUTION
ENERGY RANGE
EQUATIONS
GEV RANGE
HEAVY ION REACTIONS
ITERATIVE METHODS
KINETICS
MATHEMATICAL MODELS
NUCLEAR REACTIONS
NUMERICAL SOLUTION
PARTICLE MODELS
REACTION KINETICS
SPECTRA
STATISTICAL MODELS
TARGETS
THERMODYNAMIC MODEL
653003* - Nuclear Theory- Nuclear Reactions & Scattering
651915 - Nuclear Properties & Reactions
A=190-219
Theoretical- Nuclear Reactions & Scattering- (-1987)