Study of Heavy-Ion-Induced Reactions on Uranium with Use of Mica Detectors

Multifragment reactions are directly observed in heavy-ion-induced reactions using mica track detectors in $2\pi$ geometry. Sequential fission is found to be the major reaction channel in the reaction 800-MeV ${}_{}{}^{84}{}_{}{}^{}\mathrm{Kr}$+U; however, binary decay can still be identified. A small contribution of reactions with four fragments is observed for the first time in ${}_{}{}^{84}{}_{}{}^{}\mathrm{Kr}$- and ${}_{}{}^{136}{}_{}{}^{}\mathrm{Xe}$-induced reactions with uranium.