Self-calibrating magnetic field diagnostics in beam emission spectroscopyFunded under: EAEC-FUSION 12C
Magnetic field diagnostics in tokamaks using the motional Stark effect in fast neutral beams are based on two kinds of polarimetry: static and dynamic. A detailed analysis shows that static polarimetry presents a number of advantages over dynamic polarimetry, provided a sufficient number of polarisation analysers are installed and different parts of the spectrum are explored. A detailed scheme of complete static polarimetry is proposed, including the case where an in-vessel mirror with changing characteristics (coating by impurities) is placed in front of the optical detection system. The main merit of this scheme relies on the fact that it is self-calibrating with respect to both the characteristics of the mirror and the transmission of the different polarisation channels, implying that it is uniquely based on relative measurements of spectra. Further advantages are a greater flexibility of diagnostics and simpler technical equipment.
Bibliographic Reference: Article: Review Scientific Instrumentation, Vol. 66 (1995) No. 4, pp. 2892-2903
Record Number: 199511186 / Last updated on: 1995-10-10
Original language: en
Available languages: en