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Title: Fission hindrance studies in {sup 200}Pb: Evaporation residue cross section and spin distribution measurements

Abstract

Evaporation residue cross sections and spin distributions have been measured for {sup 200}Pb compound nucleus formed in {sup 16}O+{sup 184}W reaction at the laboratory beam energies of 84, 92, 100, 108, 116, and 120 MeV. The evaporation residues have been selected using the recoil mass spectrometer, HIRA and detected using a 2D position sensitive silicon detector. The evaporation residue spin distributions have been measured by detecting gamma rays with 14 element BGO multiplicity filter. Measured evaporation residue cross sections and spin distributions are compared with the values predicted by a standard statistical model code. Comparison shows that, in the energy region studied, the nuclear viscosity parameter {gamma}=3 is required to explain total evaporation residue cross sections and evaporation residue spin distributions.

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;  [1];  [2] more »;  [2];  [2];  [2];  [2];  [2];  [2];  [2] « less
  1. Department of Physics, Karnatak University, Dharwad-580003 (India)
  2. (India)
Publication Date:
OSTI Identifier:
20864208
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 74; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevC.74.064603; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; COMPARATIVE EVALUATIONS; COMPOUND NUCLEI; CROSS SECTIONS; DISTRIBUTION; ENERGY DEPENDENCE; FISSION; GAMMA RADIATION; LEAD 200; MEV RANGE; MULTIPLICITY; OXYGEN 16; OXYGEN 16 REACTIONS; RECOILS; SI SEMICONDUCTOR DETECTORS; SPIN; STATISTICAL MODELS; TUNGSTEN 184; TUNGSTEN 184 TARGET

Citation Formats

Shidling, P. D., Badiger, N. M., Nath, S., Kumar, R., Jhingan, A., Singh, R. P., Sugathan, P., Muralithar, S., Madhavan, N., Sinha, A. K., Pal, Santanu, Kailas, S., Verma, S., Kalita, K., Mandal, S., Singh, R., Behera, B. R., Varier, K. M., Radhakrishna, M. C., Inter University Accelerator Centre, New Delhi-110067, UGC-DAE Consortium for Scientific Research, Kolkata Centre, Kolkata-700098, Variable Energy Cyclotron Centre, Kolkata-700064, Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai-400085, Department of Physics and Astrophysics, Delhi University, Delhi-110007, Department of Physics, Panjab University, Chandigarh-160014, Department of Physics, Calicut University, Calicut-673635, and Department of Physics, Bangalore University, Bangalore-560056. Fission hindrance studies in {sup 200}Pb: Evaporation residue cross section and spin distribution measurements. United States: N. p., 2006. Web. doi:10.1103/PHYSREVC.74.064603.
Shidling, P. D., Badiger, N. M., Nath, S., Kumar, R., Jhingan, A., Singh, R. P., Sugathan, P., Muralithar, S., Madhavan, N., Sinha, A. K., Pal, Santanu, Kailas, S., Verma, S., Kalita, K., Mandal, S., Singh, R., Behera, B. R., Varier, K. M., Radhakrishna, M. C., Inter University Accelerator Centre, New Delhi-110067, UGC-DAE Consortium for Scientific Research, Kolkata Centre, Kolkata-700098, Variable Energy Cyclotron Centre, Kolkata-700064, Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai-400085, Department of Physics and Astrophysics, Delhi University, Delhi-110007, Department of Physics, Panjab University, Chandigarh-160014, Department of Physics, Calicut University, Calicut-673635, & Department of Physics, Bangalore University, Bangalore-560056. Fission hindrance studies in {sup 200}Pb: Evaporation residue cross section and spin distribution measurements. United States. doi:10.1103/PHYSREVC.74.064603.
Shidling, P. D., Badiger, N. M., Nath, S., Kumar, R., Jhingan, A., Singh, R. P., Sugathan, P., Muralithar, S., Madhavan, N., Sinha, A. K., Pal, Santanu, Kailas, S., Verma, S., Kalita, K., Mandal, S., Singh, R., Behera, B. R., Varier, K. M., Radhakrishna, M. C., Inter University Accelerator Centre, New Delhi-110067, UGC-DAE Consortium for Scientific Research, Kolkata Centre, Kolkata-700098, Variable Energy Cyclotron Centre, Kolkata-700064, Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai-400085, Department of Physics and Astrophysics, Delhi University, Delhi-110007, Department of Physics, Panjab University, Chandigarh-160014, Department of Physics, Calicut University, Calicut-673635, and Department of Physics, Bangalore University, Bangalore-560056. Fri . "Fission hindrance studies in {sup 200}Pb: Evaporation residue cross section and spin distribution measurements". United States. doi:10.1103/PHYSREVC.74.064603.
@article{osti_20864208,
title = {Fission hindrance studies in {sup 200}Pb: Evaporation residue cross section and spin distribution measurements},
author = {Shidling, P. D. and Badiger, N. M. and Nath, S. and Kumar, R. and Jhingan, A. and Singh, R. P. and Sugathan, P. and Muralithar, S. and Madhavan, N. and Sinha, A. K. and Pal, Santanu and Kailas, S. and Verma, S. and Kalita, K. and Mandal, S. and Singh, R. and Behera, B. R. and Varier, K. M. and Radhakrishna, M. C. and Inter University Accelerator Centre, New Delhi-110067 and UGC-DAE Consortium for Scientific Research, Kolkata Centre, Kolkata-700098 and Variable Energy Cyclotron Centre, Kolkata-700064 and Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai-400085 and Department of Physics and Astrophysics, Delhi University, Delhi-110007 and Department of Physics, Panjab University, Chandigarh-160014 and Department of Physics, Calicut University, Calicut-673635 and Department of Physics, Bangalore University, Bangalore-560056},
abstractNote = {Evaporation residue cross sections and spin distributions have been measured for {sup 200}Pb compound nucleus formed in {sup 16}O+{sup 184}W reaction at the laboratory beam energies of 84, 92, 100, 108, 116, and 120 MeV. The evaporation residues have been selected using the recoil mass spectrometer, HIRA and detected using a 2D position sensitive silicon detector. The evaporation residue spin distributions have been measured by detecting gamma rays with 14 element BGO multiplicity filter. Measured evaporation residue cross sections and spin distributions are compared with the values predicted by a standard statistical model code. Comparison shows that, in the energy region studied, the nuclear viscosity parameter {gamma}=3 is required to explain total evaporation residue cross sections and evaporation residue spin distributions.},
doi = {10.1103/PHYSREVC.74.064603},
journal = {Physical Review. C, Nuclear Physics},
number = 6,
volume = 74,
place = {United States},
year = {Fri Dec 15 00:00:00 EST 2006},
month = {Fri Dec 15 00:00:00 EST 2006}
}
  • The fusion evaporation-residue cross sections for {sup 32}S+{sup 184}W have been measured at beam energies of E{sub beam}=165, 174, 185, 196, 205, 215, 225, 236, 246, and 257 MeV using the ATLAS Fragment Mass Analyzer. The data are compared with statistical model calculations and it is found that a nuclear dissipation strength, which increases with the excitation energy, is required to reproduce the excitation function. A comparison with previously published data shows that the dissipation strength depends strongly on the shell structure of the nuclear system. thinsp {copyright} {ital 1999} {ital The American Physical Society}
  • The excitation function for production of evaporation residues from the fusion of /sup 28/Si+/sup 12/C has been studied in two experiments. In the first experiment the ..gamma..-ray yields of transitions populating final state evaporation residues were measured, thereby allowing a detailed study of the bombarding energy dependence of the production of specific isotopes. More accurate absolute cross sections for evaporation residue production were measured at several energies with a gas proportional ..delta..E solid state E telescope. In this manner absolute cross sections were determined against which the ..gamma..-ray data could be normalized. The fusion cross section is found to varymore » smoothly with bombarding energy. Further, absolute cross sections agree well with model predictions currently in vogue.« less
  • The giant resonance region in /sup 208/Pb has been studied using inelastic scattering of 200-MeV polarized and unpolarized protons. Both differential cross sections sigma(theta) and analyzing power A/sub y/(theta) measurements were made. The isoscalar giant quadrupole resonance at 10.6 +- 0.5 MeV, and the combined isovector giant dipole resonance and isoscalar giant monopole resonance at 14.0 +- 0.6 MeV are clearly observed. Within uncertainties all three giant resonances are in accord with full energy-weighted sum rule depletions, based on comparisons with macroscopic distorted wave Born approximation calculations. Data for a peak at 20.9 +- 1.0 MeV are found to bemore » consistent with an isoscalar giant octupole resonance exhausting 36 +- 12 % of the energy-weighted sum rule strength. A peak located at an excitation energy of 12.0 +- 0.7 MeV is shown to be a 2h..omega.., L = 4 transition depleting 8 +- 3 % of the hexadecapole energy-weighted sum rule strength. The measured reduced transition probability for the 3/sup -/ state at 2.614 MeV is consistent both with the accepted value and with results measured at 334 and 800 MeV. Our results for the 3/sup -/ state at 2.614 MeV and for the giant quadrupole resonance do not support the anomalous behavior found in earlier studies at 104, 156, and 201 MeV. This shows that the macroscopic distorted wave Born approximation can be used to extract deformation lengths providing meaningful comparison with electromagnetic energy-weighted sum rules for proton inelastic scattering to at least 800 MeV incident proton energy.« less
  • Fusion-evaporation excitation functions for complete fusion of {sup 16}O with {sup 197}Au and {sup 208}Pb have been measured from the barrier up to excitation energies of about 100 MeV. Using the pulsed {sup 16}O beam from the Stony Brook LINAC, the very slow evaporation residues (ER`s) were separated in an electrostatic deflector system and identified in an array of three surface barrier detectors by their time of flight and energy. While the ER cross sections in the vicinity of the fusion barrier allow the extraction of important statistical model parameters such as fission barrier heights, data at higher excitation energiesmore » can yield insight into processes beyond the statistical model regime. The results will be discussed with respect to both aspects.« less