Studies of heavy-ion reactions and transuranic nuclei: Progress report, September 1, 1987--August 31, 1988
The effect of successively increasing gradients of the potential energy surface on mass and charge transport was studied experimentally and theoretically with a series of damped reactions induced by /sup 48/Ca, /sup 64/Ni, /sup 58/Ni, and /sup 40/Ca projectiles on /sup 238/U targets. Combined transport-evaporation calculations that were performed for the interpretation of data demonstrate a systematic deficiency of quantitative reaction theory. A new type of experimental method has been employed to study several moments of the energy partition in damped reactions, measuring multiplicity correlations of neutrons emitted from the asymptotic fragments with a specially designed, directionally sensitive multiplicity counter. First results indicate significant departures of damped reaction systems from thermal equilibrium. Employing realistic Monte Carlo simulation of published experiments, it was demonstrated that the directions of net mass transfer and energy deposit are uncorrelated in damped reactions. Evaporative and preequilibrium neutron emission has been studied for the asymmetric heavy-ion system /sup 139/La + /sup 40/Ar. The disequilibrium energy transport phenomena observed in the experiment are quantitatively reproduced by model calculations. A strong impact-parameter dependence of preequilibrium emission is demonstrated. The emission patterns of ..cap alpha.. particles evaporated from high spin compound nuclei, previously attributed to exotic nuclear shapes, have been explained in realistic statistical model calculations for nuclei with conventional shapes. A new octal digital delay module has been designed and tested.
- Research Organization:
- Rochester Univ., NY (USA). Dept. of Chemistry and Physics
- DOE Contract Number:
- FG02-88ER40414
- OSTI ID:
- 6986006
- Report Number(s):
- DOE/ER/40414-1; ON: DE89002732; TRN: 88-038320
- Resource Relation:
- Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
Similar Records
Studies of heavy ion reactions and transuranic nuclei: Progress report for period September 1, 1986-August 31, 1987
Limiting excitation energy in fusion-evaporation reactions?
Related Subjects
HOLMIUM 165 TARGET
IRON 56 REACTIONS
LANTHANUM 139 TARGET
ARGON 40 REACTIONS
URANIUM 238 TARGET
NUCLEAR REACTIONS
CALCIUM 40 REACTIONS
CALCIUM 48 REACTIONS
FISSION FRAGMENTS
HEAVY ION FUSION REACTIONS
MONTE CARLO METHOD
NICKEL 58 REACTIONS
NICKEL 64 REACTIONS
PROGRESS REPORT
RESEARCH PROGRAMS
CHARGED-PARTICLE REACTIONS
DOCUMENT TYPES
HEAVY ION REACTIONS
NUCLEAR FRAGMENTS
TARGETS
652020* - Nuclear Properties & Reactions
A=220 & above
Experimental
651720 - Nuclear Properties & Reactions
A=90-149
Experimental
651820 - Nuclear Properties & Reactions
A=150-189
Experimental