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Title: Reaction mechanism in the {sup 20}Ne+{sup 59}Co system at 3-7 MeV/nucleon, and observation of entrance-channel mass-asymmetry of the incomplete fusion fraction

Abstract

Incomplete fusion of {sup 20}Ne with {sup 59}Co has been investigated at 3-7 MeV/nucleon using the measurement and analysis of excitation functions. The recoil-catcher technique followed by offline gamma-ray spectroscopy has been employed. Evaporation residues are found to have contributions from precursor decays, which have been separated out from the measured cumulative cross sections of evaporation residues. Measured independent cross sections are compared with PACE-2 predictions. The PACE-2 calculations are carried out for evaporation residues formed in complete fusion (CF), and the parameters are optimized so as to reproduce the cross section of evaporation residues produced exclusively in CF, e.g., xn and pxn products. With these parameters, the predicted CF cross sections for alpha emission products are calculated. Any substantial enhancement in the experimental cross section over the PACE-2 prediction is taken as a signature of incomplete fusion (ICF). The analysis indicates the occurrence of incomplete fusion involving the breakup of {sup 20}Ne into {sup 16}O + {sup 4}He and/or {sup 12}C + {sup 8}Be(2{alpha}) followed by fusion of one of the fragments with the target nucleus {sup 59}Co. These data also suggest that the probability of incomplete fusion increases with the projectile energy. Moreover, the ICF probability is foundmore » to increase with entrance-channel mass-asymmetry of the projectile-target systems.« less

Authors:
 [1]; ;  [2];  [3]; ; ;  [4]
  1. Nuclear Physics Division, Inter University Accelerator Centre, New Delhi-110067 (India)
  2. Nuclear Physics Laboratory, Department of Physics, Aligarh Muslim University, Aligarh-202002 (India)
  3. Radio-chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400085 (India)
  4. Variable Energy Cyclotron Centre, 1/AF, Bidhan Nagar, Kolkata-700064 (India)
Publication Date:
OSTI Identifier:
21502475
Resource Type:
Journal Article
Journal Name:
Physical Review. C, Nuclear Physics
Additional Journal Information:
Journal Volume: 83; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevC.83.054604; (c) 2011 American Institute of Physics; Journal ID: ISSN 0556-2813
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ASYMMETRY; BERYLLIUM 8; CARBON 12; COBALT 59; EMISSION; EVAPORATION; EXCITATION FUNCTIONS; FORECASTING; GAMMA SPECTROSCOPY; HELIUM 4; MASS; MEV RANGE 01-10; NEON 20; NUCLEAR REACTIONS; NUCLEONS; OXYGEN 16; PRECURSOR; REACTION KINETICS; ALKALINE EARTH ISOTOPES; ALPHA DECAY RADIOISOTOPES; BARYONS; BERYLLIUM ISOTOPES; CARBON ISOTOPES; COBALT ISOTOPES; CROSS SECTIONS; DIFFERENTIAL CROSS SECTIONS; ELEMENTARY PARTICLES; ENERGY RANGE; EVEN-EVEN NUCLEI; FERMIONS; FUNCTIONS; HADRONS; HELIUM ISOTOPES; INTERMEDIATE MASS NUCLEI; ISOTOPES; KINETICS; LIGHT NUCLEI; MEV RANGE; NEON ISOTOPES; NUCLEI; ODD-EVEN NUCLEI; OXYGEN ISOTOPES; PHASE TRANSFORMATIONS; RADIOISOTOPES; SPECTROSCOPY; STABLE ISOTOPES

Citation Formats

Singh, D, Nuclear Physics Laboratory, Department of Physics, Aligarh Muslim University, Aligarh-202002, Ali, R, Afzal Ansari, M, Tomar, B S, Rashid, M H, Guin, R, and Das, S K. Reaction mechanism in the {sup 20}Ne+{sup 59}Co system at 3-7 MeV/nucleon, and observation of entrance-channel mass-asymmetry of the incomplete fusion fraction. United States: N. p., 2011. Web. doi:10.1103/PHYSREVC.83.054604.
Singh, D, Nuclear Physics Laboratory, Department of Physics, Aligarh Muslim University, Aligarh-202002, Ali, R, Afzal Ansari, M, Tomar, B S, Rashid, M H, Guin, R, & Das, S K. Reaction mechanism in the {sup 20}Ne+{sup 59}Co system at 3-7 MeV/nucleon, and observation of entrance-channel mass-asymmetry of the incomplete fusion fraction. United States. https://doi.org/10.1103/PHYSREVC.83.054604
Singh, D, Nuclear Physics Laboratory, Department of Physics, Aligarh Muslim University, Aligarh-202002, Ali, R, Afzal Ansari, M, Tomar, B S, Rashid, M H, Guin, R, and Das, S K. 2011. "Reaction mechanism in the {sup 20}Ne+{sup 59}Co system at 3-7 MeV/nucleon, and observation of entrance-channel mass-asymmetry of the incomplete fusion fraction". United States. https://doi.org/10.1103/PHYSREVC.83.054604.
@article{osti_21502475,
title = {Reaction mechanism in the {sup 20}Ne+{sup 59}Co system at 3-7 MeV/nucleon, and observation of entrance-channel mass-asymmetry of the incomplete fusion fraction},
author = {Singh, D and Nuclear Physics Laboratory, Department of Physics, Aligarh Muslim University, Aligarh-202002 and Ali, R and Afzal Ansari, M and Tomar, B S and Rashid, M H and Guin, R and Das, S K},
abstractNote = {Incomplete fusion of {sup 20}Ne with {sup 59}Co has been investigated at 3-7 MeV/nucleon using the measurement and analysis of excitation functions. The recoil-catcher technique followed by offline gamma-ray spectroscopy has been employed. Evaporation residues are found to have contributions from precursor decays, which have been separated out from the measured cumulative cross sections of evaporation residues. Measured independent cross sections are compared with PACE-2 predictions. The PACE-2 calculations are carried out for evaporation residues formed in complete fusion (CF), and the parameters are optimized so as to reproduce the cross section of evaporation residues produced exclusively in CF, e.g., xn and pxn products. With these parameters, the predicted CF cross sections for alpha emission products are calculated. Any substantial enhancement in the experimental cross section over the PACE-2 prediction is taken as a signature of incomplete fusion (ICF). The analysis indicates the occurrence of incomplete fusion involving the breakup of {sup 20}Ne into {sup 16}O + {sup 4}He and/or {sup 12}C + {sup 8}Be(2{alpha}) followed by fusion of one of the fragments with the target nucleus {sup 59}Co. These data also suggest that the probability of incomplete fusion increases with the projectile energy. Moreover, the ICF probability is found to increase with entrance-channel mass-asymmetry of the projectile-target systems.},
doi = {10.1103/PHYSREVC.83.054604},
url = {https://www.osti.gov/biblio/21502475}, journal = {Physical Review. C, Nuclear Physics},
issn = {0556-2813},
number = 5,
volume = 83,
place = {United States},
year = {Sun May 15 00:00:00 EDT 2011},
month = {Sun May 15 00:00:00 EDT 2011}
}