Radiation produced by the LEP superconducting RF cavities

The LEP superconducting RF cavities present an important radiation source both during the conditioning and during normal working conditions. Before their installation in the accelerator the cavities are tested and conditioned in a laboratory bunker up to their maximum achievable field, which in some cases can be as high as 9 MV m−1. This paper discusses radiation measurements carried out on both single cavities and standard 4-cavity modules. Following a brief description of the processes underlying the emission of radiation, the results of photon and neutron measurements are given. The induced radioactivity in various materials is also evaluated; shielding guidelines and radiation protection procedures are briefly discussed.