Twenty years of visual Monte Carlo

The development of Visual Monte Carlo (VMC) started in 1993 at the Instituto de Radioprotecao e Dosimetria (lRD), Rio de Janeiro, RJ, Brazil. The twenty years of development has produced a robust, well documented and fully benchmarked Monte Carlo program VMC has been applied to the calculation of gamma spectrometry systems and for dose calculations involving the transport of photons, alpha particles and protons. VMC is written in the Visual Basic language which provides a friendly graphics interface with the user. VMC developed into two main software: VMC in-vivo for simulation of whole body counter laboratories, and VMC dose calculation, for dose calculations due to exposure to radionuclides or X-rays. The two main VMC programs are freely available for download at the site http://www.vmcsoftware.com/lndex.html. VMC can be considered a 'specialized' Monte Carlo program as it is designed specifically to solve radiation protection problems, and the main geometry used is the voxel matrix. However, VMC can be programmed to perform calculations which would be difficult to execute using more 'generic' Monte Carlo programs such as MCNP or GEANT. For example, matrices containing two or more anthropomorphic phantoms and special geometries for source tissues, such as the endosteum/cortical bone interface may be simulated. The development of VMC continues, and the next twenty years shows much promise. (author)