Exploitation of Avalanche Photodiodes for Thomson Scattering Diagnostics in Tokamaks

The COMPASS tokamak, originally from UKAEA, Culham laboratory, U.K., will be reinstalled at Institute of Plasma Physics, Prague. The scientific programme is focused mainly on the investigation of the edge plasma region with high temperature and density gradients called pedestal. Many innovations will be done and new diagnostics have to be constructed. One of the key diagnostics is an incoherent Thomson scattering for measurements of electron temperature Te and density ne with a high spatial resolution. Several construction options are considered. In this paper a possibility of using a Nd:YAG laser in combination with a detection system based on Avalanche Photodiodes is discussed.