MODEX - A Program for Calculation of the Energy Spectra of Particle Emitted in the Reactions of Pre-Equilibrium and Equilibrium Statistical Decays

The program is described intended for calculation of the energy distribution of particles, emitted by excited nucleus, using the Modified Exciton Model (MEM). The complete text of the program is presented in FORTRAN66 language. We reproduce here this 1974 JINR Communication as it was never published in a journal but it represents a historical interest as the first (in the world) Monte Carlo realization of the preequilibrium plus evaporation model, and was and still is used in dozens of countries all over the world. E.g., the current CEM03.03 and LAQGSM03.03 event-generators of the latest LANL Monte Carlo transport code MCNP6 have today modified parts from MODEX, the first Monte Carlo preequilibrium code in the world. * Current and permanent address: XCP-3, Computational Physics Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA # Current and permanent address: Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980 Dubna, Moscow region, Russia