skip to main content

Title: Experimental studies of quasi-fission reactions

A large number of recent experimental studies have shown that a substantial fraction of the total reaction cross section in heavy-ion reactions is found in fission-like processes, which do not result from the fission decay of a completely fused system. Following the suggestion of Swiatecki such processes, which represents a complete relaxation of the relative kinetic energy and a substantial amount of net mass transfer between the two fragments, are denoted quasi-fission reactions. They are distinct from compound fission reactions by bypassing the stage of a completely fused-system. This typically means that they are associated with short reaction times, which results in several measurable characteristics such as broken forward-backward symmetries, large anisotropies of the angular distributions and increased widths of the fragment mass distributions. The distinction between quasi-fission and deep inelastic reactions is less stringent and has the character of a gradual evolution from one reaction type to the other, as found also as quasi-elastic reaction evolves into deeply inelastic processes as a function of the total kinetic energy loss. In the present paper some of the experimental data characterizing quasi-fission reactions are reviewed and discussed. 22 refs., 6 figs.
Authors:
Publication Date:
OSTI Identifier:
6573147
Report Number(s):
CONF-880896-5
ON: DE89003968
DOE Contract Number:
W-31109-ENG-38
Resource Type:
Conference
Resource Relation:
Conference: Symposium on heavy-ion reaction dynamics in tandem energy region, Hitachi, Japan, 1 Aug 1988; Other Information: Portions of this document are illegible in microfiche products
Research Org:
Argonne National Lab., IL (USA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; LEAD 208 TARGET; HEAVY ION REACTIONS; QUASI-FISSION; SAMARIUM 154 TARGET; THORIUM 232 TARGET; URANIUM 238 TARGET; ANGULAR DISTRIBUTION; ANGULAR MOMENTUM; DEEP INELASTIC SCATTERING; EXPERIMENTAL DATA; FISSION FRAGMENTS; FLUORINE 19 REACTIONS; MAGNESIUM 24 REACTIONS; MASS DISTRIBUTION; NICKEL 60 REACTIONS; OXYGEN 16 REACTIONS; CHARGED-PARTICLE REACTIONS; DATA; DISTRIBUTION; INELASTIC SCATTERING; INFORMATION; INTERACTIONS; LEPTON-BARYON INTERACTIONS; LEPTON-HADRON INTERACTIONS; LEPTON-NUCLEON INTERACTIONS; NUCLEAR FRAGMENTS; NUCLEAR REACTIONS; NUMERICAL DATA; PARTICLE INTERACTIONS; SCATTERING; SPATIAL DISTRIBUTION; TARGETS 651820* -- Nuclear Properties & Reactions, A=150-189, Experimental; 651920 -- Nuclear Properties & Reactions, A=190-219, Experimental; 652020 -- Nuclear Properties & Reactions, A=220 & above, Experimental