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
Academic Article
Overview
Research
Identity
Additional Document Info
Other
View All
Overview
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 4n 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 wiatecki [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-Wilczyska [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.
