Application of Monte Carlo methods in accelerator safety

Particle accelerators of varying energies and intensities are increasingly used for different technological and research purposes and there is widespread use of Monte Carlo techniques related to radiation protection in such accelerators. This is mainly because of the complexity of the problem together with some unique challenges posed to radiation protection and dosimetry in the accelerator environment, mainly because the source of radiation are directional, dynamic, pulsed and a mixture of different types. Technological and theoretical developments necessary for a more precise radiation protection practices are non-trivial in nature and are different from conventional radiological safety requirements. Production of radiation source from high energy electron and positive ion accelerators are complex in space (large fluence gradients), time (duty factor), and composition (e.g., photons, neutrons and muons are the principal components of concern for radiological protection). Operational flexibility, such as high beam current and multi-beam capability together with research-oriented developments like the Spallation Neutron Source (SNS), Accelerator Driven Sub-critical Systems (ADSS) and Radioactive Ion Beam (RIB) facilities, has placed new demands on radiation protection systems. Fortunately, development of sophisticated computational techniques, particularly those based on Monte Carlo simulations, has made it possible to undertake otherwise intractable calculations