YAHFC-MC: A Monte Carlo based Hauser-Feshbach Reaction Code System

A computer code system, YAHFC-MC, for treating nuclear reactions within the statistical decay framework, i.e., Hauser-Feshbach, and its extensions will be presented. The code system is based on a Monte Carlo, event-by-event simulation of the nuclear reaction, which allows for the study of spectral correlations between emitted particles. The code system is flexible and controlled by a series of input commands allowing access to all reaction parameters. The code system supports both traditional reaction calculations, as well as decays from initial populations, which is useful for the analysis of surrogate reaction experiments. YAHFC-MC is written in FORTRAN 95 making use of dynamic memory allocation and derived types. The code is interfaced with the optical model computer codes FRESCO and ECIS, which allows easy access to a wide range of direct processes. Reaction calculations generate nuclear data libraries that are suitable for insertion into the Generalized Nuclear Data (GND) structure. Examples of calculations contained in a recent evaluation for ^240-242Am will be presented.