Development of the gas-puff imaging diagnostic in the TEXTOR tokamak
- Laboratoire de Physique des Plasmas - Laboratorium voor Plasmafysica, Association 'Euratom-Belgian state', Ecole Royale Militaire - Koninklijke Militaire School, Trilateral Euregio Cluster, B-1000 Brussels (Belgium)
- Institut fuer Energie- und Klimaforschung - Plasmaphysik, Forschungszentrum Juelich GmbH EURATOM-Association, Trilateral Euregio Cluster, D-52425 Juelich (Germany)
- Department of Applied Physics, Ghent University, B-9000 Ghent (Belgium)
Gas puff imaging (GPI) [S. J. Zweben, D. P. Stotler et al., Phys. Plasmas 9, 1981 (2002); R. J. Maqueda, G. A. Wurden et al., Rev. Sci. Instrum. 74, 2020 (2003)] is a powerful diagnostic that permits a two-dimensional measurement of turbulence in the edge region of a fusion plasma and is based on the observation of the local emission of a neutral gas, actively puffed into the periphery of the plasma. The developed in-vessel GPI telescope observes the emission from the puffed gas along local (at the puff) magnetic field lines. The GPI telescope is specially designed to operate in severe TEXTOR conditions and can be treated as a prototype for the GPI systems on next generation machines. Also, the gas puff nozzle is designed to have a lower divergence of the gas flow than previous GPI diagnostics. The resulting images show poloidally and radially propagating structures, which are associated with plasma blobs. We demonstrate that the local gas puff does not disturb plasma properties. Our results indicate also that the neutral gas emission intensity is more sensitive to the electron density than the electron temperature. Here, we present implementation details of the GPI system on TEXTOR and discuss some design and diagnostic issues related to the development of GPI systems in general.
- OSTI ID:
- 22118557
- Journal Information:
- Review of Scientific Instruments, Vol. 84, Issue 5; Other Information: (c) 2013 Euratom; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
- Country of Publication:
- United States
- Language:
- English
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