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Title: Role of dynamical deformation in pre-scission neutron multiplicity

Authors:
; ; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1393699
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physical Review C
Additional Journal Information:
Journal Volume: 96; Journal Issue: 3; Related Information: CHORUS Timestamp: 2017-09-21 10:15:00; Journal ID: ISSN 2469-9985
Publisher:
American Physical Society
Country of Publication:
United States
Language:
English

Citation Formats

Kumar, Neeraj, Mohsina, Shabnam, Sadhukhan, Jhilam, and Verma, Shashi. Role of dynamical deformation in pre-scission neutron multiplicity. United States: N. p., 2017. Web. doi:10.1103/PhysRevC.96.034614.
Kumar, Neeraj, Mohsina, Shabnam, Sadhukhan, Jhilam, & Verma, Shashi. Role of dynamical deformation in pre-scission neutron multiplicity. United States. doi:10.1103/PhysRevC.96.034614.
Kumar, Neeraj, Mohsina, Shabnam, Sadhukhan, Jhilam, and Verma, Shashi. 2017. "Role of dynamical deformation in pre-scission neutron multiplicity". United States. doi:10.1103/PhysRevC.96.034614.
@article{osti_1393699,
title = {Role of dynamical deformation in pre-scission neutron multiplicity},
author = {Kumar, Neeraj and Mohsina, Shabnam and Sadhukhan, Jhilam and Verma, Shashi},
abstractNote = {},
doi = {10.1103/PhysRevC.96.034614},
journal = {Physical Review C},
number = 3,
volume = 96,
place = {United States},
year = 2017,
month = 9
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on September 21, 2018
Publisher's Accepted Manuscript

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  • Pre-scission neutron multiplicities are measured for {sup 12}C + {sup 204}Pb and {sup 19}F + {sup 197}Au reactions at laboratory energies of 75-95 MeV for the {sup 12}C beam and 98-118 MeV for the {sup 19}F beam. The chosen projectile-target combinations in the present study lie on either side of the Businaro-Gallone mass asymmetry ({alpha}{sub BG}) and populate the {sup 216}Ra compound nucleus. The dissipation strength is deduced after comparing the experimentally measured neutron yield with the statistical model predictions which contains the nuclear viscosity as a free parameter. Present results demonstrate the combined effects of entrance channel mass asymmetrymore » and the dissipative property of nuclear matter on the pre-scission neutron multiplicity in fusion-fission reactions.« less
  • Pre-scission neutron multiplicities from fission of the compound nuclei 210,212,214,216Rn have been measured in order to investigate the N/Z dependence of fission hindrance. The Rn isotopes are populated through the fusion of 16,18O + 194,198Pt systems and are formed at four excitation energies in the range of 50 79 MeV. The experimental pre-scission neutron yield is compared with predictions from the statistical model of compound nuclear decay containing the strength of nuclear dissipation as a free parameter. The strength of nuclear dissipation obtained in the present analysis does not show any specific dependence on the N/Z values of the fissioningmore » nuclei at large excitation energies. The dissipation strength at the lowest excitation energy, however, indicates a shell closure effect at N = 126 for the 212Rn isotope.« less
  • Fission fragment-neutron angular correlations have been measured for the reaction 178 MeV /sup 16/O+/sup 142/Nd, allowing determination of the pre-scission and total neutron multiplicities. The total multiplicity agrees well with expectations based on energy balance, unlike the value obtained in a previous measurement. The pre-scission multiplicity of 4.2 +- 0.3 is much higher than the previous value (2.7 +- 0.4), leading to a considerably longer fission time scale and higher nuclear viscosity.
  • Pre- and post-scission {sup 4}He particle multiplicities for the {sup 19}F+{sup 197}Au reaction in the excitation energy range of 43 to 90 MeV have been measured in coincidence with fission fragments. The coincident {sup 4}He particles measured at backward angles are accounted for by evaporation from a compound nucleus and fission fragments. The most probable center-of-mass energy of the {sup 4}He particles measured at backward angles is shifted towards lower energies by {approx}2 MeV compared to a statistical model calculation performed by assuming {sup 4}He emission from a spherical compound nucleus. The observed pre-scission {sup 4}He multiplicity as a functionmore » of excitation energy is compared to a set of statistical-model calculations which also included the delayed onset of fission. The comparison shows that the observed energy dependence of the pre-scission {sup 4}He multiplicity is reproduced by the calculation without taking into account the delayed onset of fission if the reduced emission barrier for {sup 4}He is assumed in the calculation. The emission mechanism of the pre-scission {sup 4}He is discussed.« less
  • A new tool for the study of heavy-ion reactions is obtained by adapting a 4..pi..-neutron-multiplicity counter to accelerator experiments. The instrument registers almost all neutrons emitted in each single reaction event. For quasielastic reactions of 290-MeV /sup 20/Ne + /sup 197/Au the measured neutron multiplicity distributions allow a quantitative decomposition of the cross section into two contributions: one with higher Q value from transfer reactions, one with lower Q value due to the decay of the projectilelike fragments.