Neutronic analysis for detailed design of ITER Edge Thomson Scattering System

Shimada, Takahiko; Ishikawa, Masao; Yatsuka, Eiichi; Hatae, Takaki; Itami, Kiyoshi

Neutronic analysis has been carried out for the detailed design of Edge Thomson Scattering System (ETS) which is procured by JAEA in the ITER project. ETS measures the profile of electron temperature and density in the edge region of the plasma and consists of the laser injection system and the optical collection system installed in the EQ port plug. The optical collection system consists of many mirrors. High nuclear heating of mirrors could distorts them and deteriorates measurement accuracy. In order to reduce nuclear heating of optical mirrors, the effect of materials on nuclear heating of the optical mirrors has been evaluated. As a result, nuclear heating rate can be reduced about 25% by replacing the material of the first mirror (plasma facing mirror) from molybdenum to SUS316. Also it was found that nuclear heating rate of other mirrors can decrease about 65% by replacing materials from SUS316 to Aluminium. As described above, the appropriate material for each optical mirrors can be selected by nutronic analysis.