First superheavy element experiments at the GSI recoil separator TASCA: The production and decay of element 114 in the $^{244}\mathrm{Pu}$($^{48}\mathrm{Ca}$,3-4$n$) reaction

First superheavy element experiments at the GSI recoil separator TASCA: The production and decay of element 114 in the ${}^{244}{Pu}$ ( ${}^{48}{Ca}$ ,3-4 $n$ ) reaction

J. M. Gates et al.

Phys. Rev. C 83, 054618 – Published 27 May 2011

Abstract

Experiments with the new recoil separator, Transactinide Separator and Chemistry Apparatus (TASCA), at the GSI were performed by using beams of ${}^{48}{Ca}$ to irradiate targets of ${}^{206 - 208}{Pb}$ , which led to the production of ${}^{252 - 254}{No}$ isotopes. These studies allowed for evaluation of the performance of TASCA when coupled to a new detector and electronics system. By following these studies, the isotopes of element 114 ( $^{288 - 291}$ 114) were produced in irradiations of ${}^{244}{Pu}$ targets with ${}^{48}{Ca}$ beams at compound nucleus excitation energies around 41.7 and 37.5 MeV, demonstrating TASCA's ability to perform experiments with picobarn-level cross sections. A total of 15 decay chains were observed and were assigned to the decay of $^{288 - 291}$ 114. A new α-decay branch in ${}^{281}{Ds}$ was observed, leading to the new nucleus ${}^{277}{Hs}$ .