Variation of variance of fission fragment mass distribution: a probe to study the dynamics of fusionfission reactions
Abstract
Fragment mass distributions in fusionfission reactions of light projectiles (12C, 16O and 19F) on thorium and bismuth targets in near and below Coulomb barrier energies are investigated. Precise and systematic measurements of mass distribution shows a sudden anomalous increase in variances of mass distributions ({sigma}{sub m}{sup 2}) near Coulomb barrier energies for all three projectiles with deformed thorium target, in contrast to a smooth variation of {sigma}{sub m}{sup 2} with energy for spherical bismuth target. Microscopic effects due to change in entrance channel shape compactness for projectiles hitting the polar region of prolate thorium target is postulated to reach a almost symmetric saddle without complete fusion for events of anomalous fragment widths.
 Authors:
 Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata 700064 (India)
 Publication Date:
 OSTI Identifier:
 21056772
 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), 58 Sep 2006; Other Information: DOI: 10.1063/1.2713547; (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; BISMUTH 209 TARGET; CARBON 12 REACTIONS; COULOMB FIELD; FISSION; FISSION FRAGMENTS; FLUORINE 19 REACTIONS; HEAVY ION FUSION REACTIONS; MASS DISTRIBUTION; OXYGEN 16 REACTIONS; THERMONUCLEAR REACTIONS; THORIUM 238 TARGET; VARIATIONS
Citation Formats
Ghosh, Tilak Kumar. Variation of variance of fission fragment mass distribution: a probe to study the dynamics of fusionfission reactions. United States: N. p., 2007.
Web. doi:10.1063/1.2713547.
Ghosh, Tilak Kumar. Variation of variance of fission fragment mass distribution: a probe to study the dynamics of fusionfission reactions. United States. doi:10.1063/1.2713547.
Ghosh, Tilak Kumar. Mon .
"Variation of variance of fission fragment mass distribution: a probe to study the dynamics of fusionfission reactions". United States.
doi:10.1063/1.2713547.
@article{osti_21056772,
title = {Variation of variance of fission fragment mass distribution: a probe to study the dynamics of fusionfission reactions},
author = {Ghosh, Tilak Kumar},
abstractNote = {Fragment mass distributions in fusionfission reactions of light projectiles (12C, 16O and 19F) on thorium and bismuth targets in near and below Coulomb barrier energies are investigated. Precise and systematic measurements of mass distribution shows a sudden anomalous increase in variances of mass distributions ({sigma}{sub m}{sup 2}) near Coulomb barrier energies for all three projectiles with deformed thorium target, in contrast to a smooth variation of {sigma}{sub m}{sup 2} with energy for spherical bismuth target. Microscopic effects due to change in entrance channel shape compactness for projectiles hitting the polar region of prolate thorium target is postulated to reach a almost symmetric saddle without complete fusion for events of anomalous fragment widths.},
doi = {10.1063/1.2713547},
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}
}

Fissionfragment mass distribution has been studied for the {sup 16}O+{sup 232}Th,{sup 209}Bi systems over an energy range of 102.878.6 MeV and 81.672.6 MeV, respectively, in a laboratory frame. The variance of the mass distribution ({sigma}{sub m}{sup 2}) for the {sup 16}O+{sup 209}Bi system varies linearly with center of mass energy, while a significant anomalous behavior is found for the system {sup 16}O+{sup 232}Th. Coupled with our earlier observation for the system {sup 19}F+{sup 232}Th [T. K. Ghosh et al., Phys. Rev. C 69, 031603(R) (2004)], we propose that the accurate measurement of mass distribution is a powerful tool to lookmore »

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