Accelerator Shielding Design: From Protons to Electrons, from America to Europe and Back
A. Fasso, Morgan Lecture (Stanford Linear Accelerator Center)
During the past 30 years of experience in radiation protection and shielding design at high-energy accelerators, I have witnessed many changes in the techniques used to solve problems of radiation transport and dosimetry. These changes have been primarily linked to the computer revolution which has radically transformed not just how accelerator shielding is designed but also our everyday lives, touching all aspects of our society. An important role in the technical progress in this field has been played by a long-standing collaboration between the Radiation Protection Groups of CERN (European Center for Nuclear Research) and SLAC (Stanford Linear Accelerator Center), respectively the largest proton and electron accelerator centers in the world. Such a collaboration, informal and unofficial, has developed over many years as a result of frequent exchanges of experts and of know-how between the two laboratories, which are still continuing today. These exchanges have contributed to the establishment of a new, global way to handle radiation shielding problems, common to both laboratories despite the apparently different environments. This approach has first propagated to similar laboratories and then has been progressively extended to other types of accelerators, including synchrotron radiation sources and other machines of lower energy. The new calculation techniques have also affected other aspects of radiation protection and safety, such as the exposure of aircrew members and astronauts to natural cosmic radiation, the activation of machine components and environment, radiation damage, and accelerator decommissioning.