1
|
Adamek J, Müller HW, Silva C, Schrittwieser R, Ionita C, Mehlmann F, Costea S, Horacek J, Kurzan B, Bilkova P, Böhm P, Aftanas M, Vondracek P, Stöckel J, Panek R, Fernandes H, Figueiredo H. Profile measurements of the electron temperature on the ASDEX Upgrade, COMPASS, and ISTTOK tokamak using Thomson scattering, triple, and ball-pen probes. Rev Sci Instrum 2016; 87:043510. [PMID: 27131677 DOI: 10.1063/1.4945797] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The ball-pen probe (BPP) technique is used successfully to make profile measurements of the electron temperature on the ASDEX Upgrade (Axially Symmetric Divertor Experiment), COMPASS (COMPact ASSembly), and ISTTOK (Instituto Superior Tecnico TOKamak) tokamak. The electron temperature is provided by a combination of the BPP potential (ΦBPP) and the floating potential (Vfl) of the Langmuir probe (LP), which is compared with the Thomson scattering diagnostic on ASDEX Upgrade and COMPASS. Excellent agreement between the two diagnostics is obtained for circular and diverted plasmas and different heating mechanisms (Ohmic, NBI, ECRH) in deuterium discharges with the same formula Te = (ΦBPP - Vfl)/2.2. The comparative measurements of the electron temperature using BPP/LP and triple probe (TP) techniques on the ISTTOK tokamak show good agreement of averaged values only inside the separatrix. It was also found that the TP provides the electron temperature with significantly higher standard deviation than BPP/LP. However, the resulting values of both techniques are well in the phase with the maximum of cross-correlation function being 0.8.
Collapse
Affiliation(s)
- J Adamek
- Institute of Plasma Physics, Prague, Czech Republic
| | - H W Müller
- Max-Planck-Institute for Plasma Physics, Garching near Munich, Germany
| | - C Silva
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - R Schrittwieser
- Institute for Ion Physics and Applied Physics, University of Innsbruck, Innsbruck, Austria
| | - C Ionita
- Institute for Ion Physics and Applied Physics, University of Innsbruck, Innsbruck, Austria
| | - F Mehlmann
- Institute for Ion Physics and Applied Physics, University of Innsbruck, Innsbruck, Austria
| | - S Costea
- Institute for Ion Physics and Applied Physics, University of Innsbruck, Innsbruck, Austria
| | - J Horacek
- Institute of Plasma Physics, Prague, Czech Republic
| | - B Kurzan
- Max-Planck-Institute for Plasma Physics, Garching near Munich, Germany
| | - P Bilkova
- Institute of Plasma Physics, Prague, Czech Republic
| | - P Böhm
- Institute of Plasma Physics, Prague, Czech Republic
| | - M Aftanas
- Institute of Plasma Physics, Prague, Czech Republic
| | - P Vondracek
- Institute of Plasma Physics, Prague, Czech Republic
| | - J Stöckel
- Institute of Plasma Physics, Prague, Czech Republic
| | - R Panek
- Institute of Plasma Physics, Prague, Czech Republic
| | - H Fernandes
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - H Figueiredo
- Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| |
Collapse
|
2
|
Vianello N, Naulin V, Schrittwieser R, Müller HW, Zuin M, Ionita C, Rasmussen JJ, Mehlmann F, Rohde V, Cavazzana R, Maraschek M. Direct observation of current in type-I edge-localized-mode filaments on the ASDEX Upgrade tokamak. Phys Rev Lett 2011; 106:125002. [PMID: 21517319 DOI: 10.1103/physrevlett.106.125002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2009] [Indexed: 05/30/2023]
Abstract
Magnetically confined plasmas in the high confinement regime are regularly subjected to relaxation oscillations, termed edge localized modes (ELMs), leading to large transport events. Present ELM theories rely on a combined effect of edge current and the edge pressure gradients which result in intermediate mode number (n≅10-15) structures (filaments) localized in the perpendicular plane and extended along the field lines. By detailed localized measurements of the magnetic field perturbation associated to type-I ELM filaments, it is shown that these filaments carry a substantial current.
Collapse
Affiliation(s)
- N Vianello
- Consorzio RFX, Associazione Euratom-ENEA sulla Fusione, Padova, Italy
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|