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Title: Fission fragment mass distribution for nuclei in the r-process region

Abstract

The fission fragment mass distribution is estimated theoretically on about 2000 nuclides which might have a critical role on the r-process nucleosynthesis through fission (Z>85). The mass distribution of fission fragment is derived by considering the location and the depth of valleys of potential energy surface near scission point of nuclei calculated by means of the liquid drop model with the shell energy correction by the Two-Center shell model. The guiding principle of determining the fission mass asymmetry is the behavior of the fission paths from the saddle to the scission point given by the Langevin calculation.

Authors:
; ; ;  [1];  [2];  [3];  [4]; ;  [5];  [6]
  1. Department of Physics, Konan University, 8-9-1 Okamoto, Kobe 658-8501 (Japan)
  2. Numazu College of Technology, NAO (Japan)
  3. Univ. of Chicago (United States)
  4. NAO, GUSA, Univ. of Tokyo (Japan)
  5. JAEA (Japan)
  6. FLNR (JINR) (United States)
Publication Date:
OSTI Identifier:
21056773
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 891; Journal Issue: 1; Conference: 6. Symposium on nuclear physics, Tours (France), 5-8 Sep 2006; Other Information: DOI: 10.1063/1.2713548; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ASYMMETRY; CORRECTIONS; FISSION; FISSION FRAGMENTS; LIQUID DROP MODEL; MASS; MASS DISTRIBUTION; NUCLEAR FRAGMENTATION; NUCLEI; NUCLEOSYNTHESIS; POTENTIAL ENERGY; R PROCESS; SCISSION-POINT MODEL; SHELL MODELS

Citation Formats

Tatsuda, S., Hashizume, K., Wada, T., Ohta, M., Sumiyoshi, K., Otsuki, K., Kajino, T., Koura, H., Chiba, S., and Aritomo, Y. Fission fragment mass distribution for nuclei in the r-process region. United States: N. p., 2007. Web. doi:10.1063/1.2713548.
Tatsuda, S., Hashizume, K., Wada, T., Ohta, M., Sumiyoshi, K., Otsuki, K., Kajino, T., Koura, H., Chiba, S., & Aritomo, Y. Fission fragment mass distribution for nuclei in the r-process region. United States. doi:10.1063/1.2713548.
Tatsuda, S., Hashizume, K., Wada, T., Ohta, M., Sumiyoshi, K., Otsuki, K., Kajino, T., Koura, H., Chiba, S., and Aritomo, Y. Mon . "Fission fragment mass distribution for nuclei in the r-process region". United States. doi:10.1063/1.2713548.
@article{osti_21056773,
title = {Fission fragment mass distribution for nuclei in the r-process region},
author = {Tatsuda, S. and Hashizume, K. and Wada, T. and Ohta, M. and Sumiyoshi, K. and Otsuki, K. and Kajino, T. and Koura, H. and Chiba, S. and Aritomo, Y.},
abstractNote = {The fission fragment mass distribution is estimated theoretically on about 2000 nuclides which might have a critical role on the r-process nucleosynthesis through fission (Z>85). The mass distribution of fission fragment is derived by considering the location and the depth of valleys of potential energy surface near scission point of nuclei calculated by means of the liquid drop model with the shell energy correction by the Two-Center shell model. The guiding principle of determining the fission mass asymmetry is the behavior of the fission paths from the saddle to the scission point given by the Langevin calculation.},
doi = {10.1063/1.2713548},
journal = {AIP Conference Proceedings},
number = 1,
volume = 891,
place = {United States},
year = {Mon Feb 26 00:00:00 EST 2007},
month = {Mon Feb 26 00:00:00 EST 2007}
}
  • Effect of the {beta}-delayed fission in r-process abundance is investigated with a realistic model for the fission fragment mass distribution (FFMD). The data base for the FFMD is constructed based on the two-center shell model and multi-dimensional Langevin calculation. The {beta}-decay rates including neutron emission and {beta}-delayed fission are also newly calculated with 2nd version of the the gross theory. The differences appeared in the final element abundance calculated with and without fission process, with different {beta}-delayed fission rates are demonstrated.
  • Recently our FLNR theoretical group completes a calculation model to treat all reaction processes in heavy and superheavy mass region, which is so called 'Unified model'. Using a lot of available experimental data, we verify the validity of our model and establish a reliable model to describe the whole reaction process. As examples of the application of our model, we discuss two cases that are quasi-fission process and deep inelastic collision. We show the calculation results of the mass distribution of fission fragments in the reaction {sup 36}S+{sup 236}U. Also, we discuss the possibility for the production of new heavymore » neutron-rich nuclei in the low-energy multi-neutron transfer process.« less
  • A phenomenological approach to description of fission-fragment mass distribution Y(M) for nuclei in the vicinity of Pb is developed and used to extract from the experimental Y(M) data the nuclear deformation potential energy V(M) and its components: the macroscopic (liquid-drop) part and the shell correction in the transition state. The results of the analysis are compared with the theoretically obtained V(M) and Y(M). The three-hump fragment-mass distributions observed in Ra fission are satisfactorily described within the framework of the approach developed. The properties of the symmetric and asymmetric fission valleys and the related Y(M) components are discussed.