Optimization of ISOL targets based on Monte-Carlo simulations of ion release curves

A detailed model for simulating release curves from ISOL targets has been developed. The full 3D geometry is implemented using Geant-4. Produced particles are followed individually from production to release. The delay time is computed event by event. All processes involved: diffusion, effusion and decay are included to obtain the overall release curve. By fitting to the experimental data, important parameters of the release process (diffusion coefficient, sticking time,...) are extracted. They can be used to improve the efficiency of existing targets and design new ones more suitable to produce beams of rare isotopes. (C) 2003 Elsevier Science B.V. All rights reserved.