MCPR -- A Monte Carlo model for studies of Fragmentation Reactions

Fragmentation reactions are nowadays one of the most successful mechanisms to produce new unknown nuclear species. Nuclear reactions have the standard direct and compound-nucleus reactions components. Also there exists abundant evidence of an intermediate process that seems to fall in between these two types, and is more than just a combination of them. This in between state, the so-called pre-equilibrium stage, is less clearly understood. So, there are many models to describe pre- equilibrium reactions. In the present work, a systematic study of fragmentation-reaction data has been carried out, using the new Monte Carlo Pre-equilibrium code MCPR. The model combines a pre-equilibrium stage with the ABLA evaporation model, based on the statistical de-excitation model. Particle spectra; angular distributions; fragment distributions; excitation functions, along with production cross sections, were calculated for a large group of reactions. We particularly are interested in energies and elements studied at the National Superconducting Cyclotron Laboratory, NSCL. Here energies of 80 to 150 MeV/u and masses $\sim$ A=20-200 are typically used.