The program LISE: a simulation of fragment separators

This paper describes the program LISE which simulates the operation of fragment separators used to produce radioactive beams via fragmentation. Various aspects of the physical phenomena involved in the production of such radioactive beams are discussed. They include fragmentation cross-sections, energy losses in materials, ionic charge-state distributions, as well as ion optics calculations and acceptance effects. This program is highly user-friendly, and is designed not only to forecast intensities and purities for planning future experiments, but also for beam tuning during experiments where its results can be quickly compared to on-line data. In addition, several general-purpose tools such as a physical parameters calculator, a database of nuclear properties, and relativistic two-body kinematics calculations make it useful even for experiments with stable beams. After a general description of fragment separators, the principles underlying the calculations are presented, followed by a practical description of the program and its features. Finally, a few examples of calculations are compared to on-line data, both qualitatively and quantitatively.