A simulation tool for Recoil Distance Method lifetime measurements at NSCL

A detailed, universal simulation tool for the Recoil Distance Method lifetime measurements at the National Superconducting Cyclotron Laboratory (NSCL) is presented. The measurements are made with the Köln-NSCL plunger-SeGA setup and utilize fast, secondary beams of exotic nuclei provided by the Coupled Cyclotron Facility and the A1900 fragment separator. The simulation tool, built upon GEANT4 and Root toolkits, incorporates all relevant aspects of a plunger experiment. The tool is applied in two ways. First, to aid in the design of new experiments by facilitating the choice of optimal experimental conditions. Second, to aid in off-line analysis of the experimental data and in particular to deduce the lifetime by comparison of experimental and simulated peak shapes in the γγ-ray energy spectra. All the important features of the simulation tool are described, followed by examples of the application of the tool in the cases of real experiments completed or proposed at NSCL.