MOCADI_FUSION: Extension of the Monte-Carlo code MOCADI to heavy-ion fusion–evaporation reactions

We have recently developed a code, called MOCADI_FUSION, for tracing fusion–evaporation residues (ERs) through matter within ion-optical systems. The program is based on the existing Monte-Carlo code MOCADI, which has been extended by including the kinematics of fusion–evaporation reactions and the atomic interaction of the ERs with the target atoms. The ion optics of the experimental set-up used for the selection of the desired species is combined with the phase-space distribution of the ERs at the target exit into MOCADI to evaluate the secondary beam properties (beam profile, separation quality, transmission, etc.) along the separator. The code has been tested for the velocity filter SHIP at GSI, and it reproduces the set-up characteristics (angular, charge state and velocity acceptances) and the experimental transmission data. MOCADI_FUSION has been also used for the SHIPTRAP experiment to evaluate the range distribution of the ERs in the gas cell and to estimate the overall SHIPTRAP efficiency.

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