Relevance of equilibrium in multifragmentation

Journal Article · Thu Jan 15 04:00:00 EST 2009 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.79.014608· OSTI ID:21199506

Furuta, Takuya ^[1]; Ono, Akira ^[2]

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1. GANIL (DSM-CEA/IN2P3-CNRS), Boite Postal 55027, F-14076 Caen (France)
2. Department of Physics, Tohoku University, Sendai 980-8578 (Japan)

The relevance of equilibrium in a multifragmentation reaction of very central {sup 40}Ca + {sup 40}Ca collisions at 35 MeV/nucleon is investigated by using simulations of antisymmetrized molecular dynamics (AMD). Two types of ensembles are compared. One is the reaction ensemble of the states at each reaction time t in collision events simulated by AMD, and the other is the equilibrium ensemble prepared by solving the AMD equation of motion for a many-nucleon system confined in a container for a long time. The comparison of the ensembles is performed for the fragment charge distribution and the excitation energies. Our calculations show that there exists an equilibrium ensemble that well reproduces the reaction ensemble at each reaction time t for the investigated period 80{<=}t{<=}300 fm/c. However, there are some other observables that show discrepancies between the reaction and equilibrium ensembles. These may be interpreted as dynamical effects in the reaction. The usual static equilibrium at each instant is not realized since any equilibrium ensemble with the same volume as that of the reaction system cannot reproduce the fragment observables.

• OSTI ID: 21199506
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 1 Vol. 79; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ATOM-ATOM COLLISIONS
CALCIUM 40
CHARGE DISTRIBUTION
COLLISIONS
COMPARATIVE EVALUATIONS
CONTAINERS
EQUATIONS OF MOTION
EQUILIBRIUM
EXCITATION
MEV RANGE 10-100
MOLECULAR DYNAMICS METHOD
NUCLEAR FRAGMENTATION
NUCLEONS
SIMULATION