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Title: Dynamical aspects of fragmentation

Abstract

No abstract prepared.

Authors:
;  [1]
  1. Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellon I, Ciudad Universitaria, Nunez, 1428, Buenos Aires (Argentina)
Publication Date:
OSTI Identifier:
21054881
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 884; Journal Issue: 1; Conference: 6. Latin American symposium on nuclear physics and applications, Iguazu (Argentina), 3-7 Oct 2005; Other Information: DOI: 10.1063/1.2710647; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CALCULATION METHODS; COMPARATIVE EVALUATIONS; DYNAMICS; NUCLEAR FRAGMENTATION; NUCLEAR FRAGMENTS

Citation Formats

Ison, M. J., and Dorso, C. O. Dynamical aspects of fragmentation. United States: N. p., 2007. Web. doi:10.1063/1.2710647.
Ison, M. J., & Dorso, C. O. Dynamical aspects of fragmentation. United States. doi:10.1063/1.2710647.
Ison, M. J., and Dorso, C. O. Mon . "Dynamical aspects of fragmentation". United States. doi:10.1063/1.2710647.
@article{osti_21054881,
title = {Dynamical aspects of fragmentation},
author = {Ison, M. J. and Dorso, C. O.},
abstractNote = {No abstract prepared.},
doi = {10.1063/1.2710647},
journal = {AIP Conference Proceedings},
number = 1,
volume = 884,
place = {United States},
year = {Mon Feb 12 00:00:00 EST 2007},
month = {Mon Feb 12 00:00:00 EST 2007}
}
  • As a first application of our fusion model, the dynamical fragmentation process of fusion and subsequent fission is analyzed in the reactions of 4.8--8 MeV/nucleon /sup 208/Pb on /sup 50/Ti, /sup 52/Cr, /sup 58/Fe, and /sup 64/Ni. In this two step model, the colliding nuclei are first shown to be captured in the pockets behind the adiabatic interaction barriers and then the composite systems so formed, being strongly excited, fission adiabatically. The calculated capture cross sections agree reasonably well with the experiments and the mass distributions are systematically symmetric, independent of the choice of relative separation distance R and themore » large structure in the cranking masses. The symmetric mass fragmentation is a (dynamical) liquid drop effect and the peaks or other detailed structure in mass distributions depend on how the temperature would modify the masses and also on the dynamical coupling of mass asymmetry with the relative motion. This demands refined measurements of the fission data for larger mass asymmetry. The calculated critical angular momentum, which refers to the vanishing of the interaction barrier, in these reactions occurs at the incident energy greater than 8 MeV/nucleon. This suggests a possible importance of extending these experiments beyond their present energy limits.« less
  • The distribution of fragments resulting from collisions between 50--200-keV C{sub 60}{sup +} ions and H{sub 2} and He is found to follow approximately a simple power law {ital I}({ital m})={ital cp}{sup {ital m}} where {ital p} is a constant depending on both energy and target gas, and {ital m} is the number of missing pairs'' of carbon atoms. Based on this observation, a new dynamical fragmentation model involving the ratio of two characteristic times is proposed. In collisions by 300-keV C{sub 60}{sup ++} ions, the singly charged products are distributed quite differently, which implies the first evidence of the presencemore » of charge-separation reactions.« less
  • A complete dynamical calculation of the /sup 84/Kr+/sup 238/U reaction is carried out within the fragmentation theory based on the two-center shell model. A time-dependent Schroedinger equation in the mass-fragmentation coordinate is solved for the collision process by using the classical orbit results. It is shown that this reaction is a peripheral collision with reaction times of the order of 6 x 10/sup -21/ sec. The mass fragmentation gives large probabilities only for a few nucleon transfer, as is observed experimentally in this reaction.
  • The effects of the Coulomb expansion on the fragment kinetic energy spectrum for a fragmentating hot nuclear system is investigated. In particular, /sup 12/C-fragment spectra are calculated and compared with those predicted by the uniform expansion approximation. The results indicate that the energy spectra of fragments are quite sensitive to the details of the Coulomb expansion treatment.