Extraction Time Simulations of a Cryogenic Gas Stopping Cell Designed to Study the Properties of Superheavy Elements

Abstact —New experimental setup for high-precision mass measurement of heavy and superheavy nuclei is being built in Flerov Laboratory of Nuclear Reactions (Dubna). It consists of target unit, gas filled separator of complete fusion products, cryogenic gas stopping cell (CGSC), a radiofrequency system for transporting and cooling a low-energy beam and a multi-reflection time-of-flight mass spectrometer. Simulations of stopping efficiency and extraction time from CGSC were performed for evaporation residues of the complete fusion reactions 40 Ar + 144 Sm → 184– x Hg + xn , 40 Ar + 166 Er → 206– x Rn + xn , 48 Ca + 208 Pb → 256– x No + xn and 48 Ca + 242 Pu → 290– x Fl + xn . Internal software based on SRIM and Geant4 was used in the simulations. Optimum parameters for the real experiment, namely, the width of entrance window, pressure of helium buffer-gas in CGSC and the choice of suitable reactions were the main motivation of these simulations.