Production cross sections of elements near the N=126 shell in Ca48-induced reactions with Gd154,Tb159,Dy162, and Ho165 targets Academic Article uri icon

abstract

  • Excitation functions for shell-stabilized evaporation residues produced in Ca48-induced reactions with Gd154,Tb159,Dy162, and Ho165 targets have been measured in experiments performed at the Cyclotron Institute at Texas A&M University. The examined energy range predominantly covers the 3n and 4n evaporation channels with higher cross sections measured for the 4n products. The σ4n are nearly invariant within experimental uncertainty in reactions with Tb159,Dy162, and Ho165 with the maxima at 12.6 ± 1.9, 12.6 ± 1.7, and 9.4 ± 1.3 mb, respectively. For the reaction with Gd154, 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 Światecki [Phys. Rev. C 71, 014602 (2005)].PRVCAN0556-281310.1103/PhysRevC.71.014602 The fusion probability was estimated by using a phenomenological expression presented by Siwek-Wilczyńska [Int. J. Mod. Phys. E 17, 12 (2008)].IMPEER0218-301310. 1142/S0218301308009501 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. © 2014 American Physical Society.

author list (cited authors)

  • Mayorov, D. A., Werke, T. A., Alfonso, M. C., Bennett, M. E., & Folden, C. M.

citation count

  • 15

publication date

  • August 2014