ABSTRACT
This paper presents designs of collection optics for a JT-60SA Thomson scattering system. By using tangential (to the toroidal direction) YAG laser injection, three collection optics without strong chromatic aberration generated by the wide viewing angle and small design volume were found to measure almost all the radial space. For edge plasma measurements, the authors optimized the channel number and wavelength ranges of band-pass filters in a polychromator to reduce the relative error in T(e) by considering all spatial channels and a double-pass laser system with different geometric parameters.
ABSTRACT
Neutron and gamma-ray irradiation complicates the design of the edge Thomson scattering (TS) system in ITER. The TS light is relayed through the relaying optics with labyrinth and fiber coupling optics. Electron density of 2×10(19) m(-3) is sufficient to measure T(e) and n(e) within a 10% and 5% margin of error, respectively, with a spatial resolution of 5 mm. This system can cover from 0.85 to 1 of the normalized minor radius. The time resolution is 10 ms, which is determined by the repetition rate of the laser device. A super-Gaussian is the ideal laser profile for the laser injection optics to avoid a breakdown of the filling gas used in density calibration through Raman scattering.