Real-time electron density measurements from Cotton-Mouton effect in JET machine
- Consorzio RFX, Associazione EURATOM-ENEA, Corso Stati Uniti 4, 35127 Padova (Italy)
- EURATOM/UKAEA Fusion Association, Culham Science Centre, OX14 3DB Abingdon (United Kingdom)
Real-time density profile measurements are essential for advanced fusion tokamak operation and interferometry is a proven method for this task. Nevertheless, as a consequence of edge localized modes, pellet injections, fast density increases, or disruptions, the interferometer is subject to fringe jumps, which produce loss of the signal preventing reliable use of the measured density in a real-time feedback controller. An alternative method to measure the density is polarimetry based on the Cotton-Mouton effect, which is proportional to the line-integrated electron density. A new analysis approach has been implemented and tested to verify the reliability of the Cotton-Mouton measurements for a wide range of plasma parameters and to compare the density evaluated from polarimetry with that from interferometry. The density measurements based on polarimetry are going to be integrated in the real-time control system of JET since the difference with the interferometry is within one fringe for more than 90% of the cases.
- OSTI ID:
- 21266543
- Journal Information:
- Review of Scientific Instruments, Vol. 79, Issue 10; Other Information: DOI: 10.1063/1.2956831; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
- Country of Publication:
- United States
- Language:
- English
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