The standard technique for the relative calibration in present Thomson scattering diagnostics, can be used in ITER only if the full collection path is included in the calibration: indeed, the in-vessel optics will be exposed to neutron and gamma irradiation and particle flux, that will likely cause a distortion of the spectral transmission curve. The standard scheme would ask to position a diffuser in front of the first collection mirror, e.g. on the protective shutter, and to illuminate it with a light source nearby. Alternatively, a back illumination scheme could be used, with a more efficient retroreflector array. A completely different approach is based on TS measurements from two lasers with different wavelengths: this self-calibrating method does not require any in-vessel tool and will provide both the electron temperature and the relative sensitivity of spectral channels. © 2010 IOP Publishing Ltd.
|Publication status||Published - 2010|
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)