JAPANESE CONTRIBUTION TO ITER TASK OF IRRADIATION TESTS ON DIAGNOSTICS COMPONENTS

As an R&D task of the ITER engineering design activities (EDA), we car ried out the irradiation tests on the basic materials of transmission components such as ceramics, windows, fiber optics and mirrors, and in -vessel diagnostics sensors such as magnetic probes and bolometers. Ce ramics will be used as general insulating materials. Here we investiga ted the radiation induced conductivity (RIC) of ceramics for 14 MeV ne utrons. Optical elements are the most sensitive to radiation damages a mong the transmission components. Radiation induce transmission loss o f window materials and fiber optics have been measured in the Japan ma terial testing reactor (JMTR). Off line irradiation tests were carried out for molybdenum corner cube reflector (CCR) and gold coated mirror s in JMTR also. Fourteen MeV-neutron-induce luminescence of window mat erial was evaluated in the fusion neutronics source (FNS). Bolometers should be installed inside the vacuum vessel to measure the radiation losses in the infra red to soft X-ray range. We demonstrated the perfo rmance of the JT 60 type bolometer under Co-60 gamma-rays. (C) 1998 El sevier Science S.A. All rights reserved.