Simulation software of radioactive decay, ß and γ disintegration of cesium137

We present a software dedicated to radioactivity studies, in particular to radioactive decays. The software has been developed to model the C.R.A.B. (Compteur de Radioactivité Alpha Béta) counter, a device constructed by the C.E.A. in the seventies for use as an educational support for radioactive studies in french schools. The evolution of safety rules prevents nowadays the use of such educational devices in schools. At the origin, the software was developed to train students before a tutorial session using a real radioactive source of Cesium 237 and now the software substitutes entirely the experiments. Indeed, the simulation reassures parents and students who are always afraid of radioactivity. Various studies are proposed: study of the exponential nuclear radioactive decay on a network of radioactive nuclei and roll of dices, Poisson and Gauss distributions, influence of the source-detector distance, radiation absorption by aluminum or by lead. This software is currently used either in the last year of high school or at the University for students in their 1st year.