Multifragmentation near the threshold

Journal Article · Fri Nov 01 00:00:00 EST 1991 · Physical Review, C (Nuclear Physics); (United States)

DOI:https://doi.org/10.1103/PhysRevC.44.2111· OSTI ID:5022137

Bohnet, A; Aichelin, J ^[1]; Pochodzalla, J; Trautmann, W ^[2]; Peilert, G; Stoecker, H; Greiner, W ^[3]

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1. Institut fuer Theoretische Physik, Universitaet Heidelberg, Philosophenweg 19, 6900 Heidelberg (Germany) Max-Planck-Institut fuer Kernphysik, 6900 Heidelberg (Germany)
2. Gesellschaft fuer Schwerionenforschung, 6100 Darmstadt (Germany)
3. Institut fuer Theoretische Physik, J. W. Goethe-Universitaet, 6000 Frankfurt am Main (Germany)

We investigate the onset of multifragmentation employing an improved version of the {ital N}-body quantum'' molecular-dynamics approach. We study in detail the reaction {sup 18}O+{sup 197}Au at 84 MeV/nucleon and find good agreement between the calculated results and the data for the double-differential proton cross section, the mass yield, the multiplicity, the kinetic energy of the fragments, and even for the kinematic correlations between intermediate mass fragments (IMF's), which have been measured in this experiment for the first time. We observe a strong correlation between the impact parameter and both the size of the target remnant as well as the average proton multiplicity. Hence both observables can be used to determine the impact parameter experimentally. The IMF's come from the most central collisions. The calculations confirm the experimental result that they are not emitted from an equilibrated system. Although the inclusive energy spectra look thermal, we cannot identify an impact parameter-independent isotropically emitting source. Even in central collisions global equilibrium is not observed. We find that multifragment emission at this bombarding energy is caused by a process very similar to that proposed in the macroscopic cold multifragmentation model. Thus it has a different origin than at beam energies around 1 GeV/nucleon, although the mass yield has an almost identical slope.

• OSTI ID: 5022137
• Journal Information: Physical Review, C (Nuclear Physics); (United States), Vol. 44:5; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
GOLD 197 TARGET
OXYGEN 18 REACTIONS
HEAVY ION REACTIONS
NUCLEAR FRAGMENTATION
DIFFERENTIAL CROSS SECTIONS
GEV RANGE 01-10
IMPACT PARAMETER
MULTIPLICITY
NUCLEAR REACTION KINETICS
PROTONS
BARYONS
CHARGED-PARTICLE REACTIONS
CROSS SECTIONS
ELEMENTARY PARTICLES
ENERGY RANGE
FERMIONS
GEV RANGE
HADRONS
KINETICS
NUCLEAR REACTIONS
NUCLEONS
REACTION KINETICS
TARGETS
653003* - Nuclear Theory- Nuclear Reactions & Scattering