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Title: Production cross sections of elements near the N = 126 shell in Ca 48 -induced reactions with Gd 154 , Tb 159 , Dy 162 , and Ho 165 targets

Abstract

Excitation functions for shell-stabilized evaporation residues produced in 48 Ca -induced reactions with 154 Gd , 159 Tb , 162 Dy , and 165 Ho targets have been measured in experiments performed at the Cyclotron Institute at Texas A&M University. The examined energy range predominantly covers the 3 n and 4 n evaporation channels with higher cross sections measured for the 4 n products. The σ 4 n are nearly invariant within experimental uncertainty in reactions with 159 Tb , 162 Dy , and 165 Ho with the maxima at 12.6 ± 1.9, 12.6 ± 1.7, and 9.4 ± 1.3 mb, respectively. For the reaction with 154 Gd , the maximum is slightly lower at 4.0 ± 0.6 mb. A simple model to describe the measured production cross sections was employed. Capture was estimated by using the “diffused barrier formula” from the “fusion by diffusion” model proposed by Swiatecki et al. [Phys. Rev. C 71, 014602 (2005)]. The fusion probability was estimated by using a phenomenological expression presented by Siwek-Wilczynska et al. [Int. J. Mod. Phys. E 17, 12 (2008)]. The survival probability was calculated according to the formula of Vandenbosch and Huizenga [Nuclear Fission (Academic, New York, 1973)], derivedmore » from transition-state theory. The best agreement is reached between calculation and experiment upon inclusion of collective effects in the calculation of the survival probability, shown previously to be important for production of weakly deformed nuclei. This, in turn, challenges the expectation that strong shell stabilization benefits the production cross section. The present data are compared with earlier studies on production of neutron-deficient nuclei in Ca-induced reactions with lanthanide targets.« less

Authors:
; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science - Office of Nuclear Physics
OSTI Identifier:
1392003
DOE Contract Number:  
AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 90; Journal Issue: 2
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS

Citation Formats

Mayorov, D. A., Werke, T. A., Alfonso, M. C., Bennett, M. E., and Folden, C. M. Production cross sections of elements near the N=126 shell in Ca48 -induced reactions with Gd154,Tb159,Dy162 , and Ho165 targets. United States: N. p., 2014. Web. doi:10.1103/PhysRevC.90.024602.
Mayorov, D. A., Werke, T. A., Alfonso, M. C., Bennett, M. E., & Folden, C. M. Production cross sections of elements near the N=126 shell in Ca48 -induced reactions with Gd154,Tb159,Dy162 , and Ho165 targets. United States. doi:10.1103/PhysRevC.90.024602.
Mayorov, D. A., Werke, T. A., Alfonso, M. C., Bennett, M. E., and Folden, C. M. Fri . "Production cross sections of elements near the N=126 shell in Ca48 -induced reactions with Gd154,Tb159,Dy162 , and Ho165 targets". United States. doi:10.1103/PhysRevC.90.024602.
@article{osti_1392003,
title = {Production cross sections of elements near the N=126 shell in Ca48 -induced reactions with Gd154,Tb159,Dy162 , and Ho165 targets},
author = {Mayorov, D. A. and Werke, T. A. and Alfonso, M. C. and Bennett, M. E. and Folden, C. M.},
abstractNote = {Excitation functions for shell-stabilized evaporation residues produced in 48 Ca -induced reactions with 154 Gd , 159 Tb , 162 Dy , and 165 Ho targets have been measured in experiments performed at the Cyclotron Institute at Texas A&M University. The examined energy range predominantly covers the 3 n and 4 n evaporation channels with higher cross sections measured for the 4 n products. The σ 4 n are nearly invariant within experimental uncertainty in reactions with 159 Tb , 162 Dy , and 165 Ho with the maxima at 12.6 ± 1.9, 12.6 ± 1.7, and 9.4 ± 1.3 mb, respectively. For the reaction with 154 Gd , the maximum is slightly lower at 4.0 ± 0.6 mb. A simple model to describe the measured production cross sections was employed. Capture was estimated by using the “diffused barrier formula” from the “fusion by diffusion” model proposed by Swiatecki et al. [Phys. Rev. C 71, 014602 (2005)]. The fusion probability was estimated by using a phenomenological expression presented by Siwek-Wilczynska et al. [Int. J. Mod. Phys. E 17, 12 (2008)]. The survival probability was calculated according to the formula of Vandenbosch and Huizenga [Nuclear Fission (Academic, New York, 1973)], derived from transition-state theory. The best agreement is reached between calculation and experiment upon inclusion of collective effects in the calculation of the survival probability, shown previously to be important for production of weakly deformed nuclei. This, in turn, challenges the expectation that strong shell stabilization benefits the production cross section. The present data are compared with earlier studies on production of neutron-deficient nuclei in Ca-induced reactions with lanthanide targets.},
doi = {10.1103/PhysRevC.90.024602},
journal = {Physical Review. C, Nuclear Physics},
number = 2,
volume = 90,
place = {United States},
year = {Fri Aug 01 00:00:00 EDT 2014},
month = {Fri Aug 01 00:00:00 EDT 2014}
}