Fission-product formation in the thermal-neutron-induced fission of odd Cm isotopes

Abstract

Thermal-neutron-induced fission of $^{243}\mathrm{Cm}$ was studied at the Lohengrin mass separator. The light-mass peak of the fission-yield curve was investigated, and yields of masses from $A=72$ to $A=120$ were obtained. Independent-product yields were determined for nuclear charges $Z=28--37$. The yield of masses in the superasymmetric region was found to be identical to other fission reactions studied at Lohengrin. The multimodal approach to fission and the macroscopic-microscopic method for the calculation of charge-distribution parameters in isobaric chains were used to analyze experimental results from the fission of $^{243}\mathrm{Cm}$ and $^{245}\mathrm{Cm}$. A systematics on fission modes was derived from the analysis and extended to the $^{247}\mathrm{Cm}$ case. The weight of the $^{132}\mathrm{Sn}$ mode was found to decrease in $^{243}\mathrm{Cm}$, relative to the $^{245}\mathrm{Cm}$ nucleus. A prediction of the $^{78}\mathrm{Ni}$ yield in the fission of Cm isotopes was made. The feasibility of the study of $^{78}\mathrm{Ni}$ at Lohengrin has been demonstrated.