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Stefanikova E, Peterka M, Bohm P, Bilkova P, Aftanas M, Sos M, Urban J, Hron M, Panek R. Fitting of the Thomson scattering density and temperature profiles on the COMPASS tokamak. Rev Sci Instrum 2016; 87:11E536. [PMID: 27910584 DOI: 10.1063/1.4961554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A new technique for fitting the full radial profiles of electron density and temperature obtained by the Thomson scattering diagnostic in H-mode discharges on the COMPASS tokamak is described. The technique combines the conventionally used modified hyperbolic tangent function for the edge transport barrier (pedestal) fitting and a modification of a Gaussian function for fitting the core plasma. Low number of parameters of this combined function and their straightforward interpretability and controllability provide a robust method for obtaining physically reasonable profile fits. Deconvolution with the diagnostic instrument function is applied on the profile fit, taking into account the dependence on the actual magnetic configuration.
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Affiliation(s)
- E Stefanikova
- Institute of Plasma Physics of the CAS, Za Slovankou 1782/3, 180 00 Prague, Czech Republic
| | - M Peterka
- Institute of Plasma Physics of the CAS, Za Slovankou 1782/3, 180 00 Prague, Czech Republic
| | - P Bohm
- Institute of Plasma Physics of the CAS, Za Slovankou 1782/3, 180 00 Prague, Czech Republic
| | - P Bilkova
- Institute of Plasma Physics of the CAS, Za Slovankou 1782/3, 180 00 Prague, Czech Republic
| | - M Aftanas
- Institute of Plasma Physics of the CAS, Za Slovankou 1782/3, 180 00 Prague, Czech Republic
| | - M Sos
- Institute of Plasma Physics of the CAS, Za Slovankou 1782/3, 180 00 Prague, Czech Republic
| | - J Urban
- Institute of Plasma Physics of the CAS, Za Slovankou 1782/3, 180 00 Prague, Czech Republic
| | - M Hron
- Institute of Plasma Physics of the CAS, Za Slovankou 1782/3, 180 00 Prague, Czech Republic
| | - R Panek
- Institute of Plasma Physics of the CAS, Za Slovankou 1782/3, 180 00 Prague, Czech Republic
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Zubek JP, Aftanas M, Hasek J, Schludermann E, Wilgosh L, Winocur G, Sansom W. Intellectual and Perceptual Changes during Prolonged Perceptual Deprivation: Low Illumination and Noise Level. Percept Mot Skills 2016. [DOI: 10.2466/pms.1962.15.1.171] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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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.
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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
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Bohm P, Aftanas M, Bilkova P, Stefanikova E, Mikulin O, Melich R, Janky F, Havlicek J, Sestak D, Weinzettl V, Stockel J, Hron M, Panek R, Scannell R, Frassinetti L, Fassina A, Naylor G, Walsh MJ. Edge Thomson scattering diagnostic on COMPASS tokamak: installation, calibration, operation, improvements. Rev Sci Instrum 2014; 85:11E431. [PMID: 25430338 DOI: 10.1063/1.4893995] [Citation(s) in RCA: 3] [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: 06/04/2023]
Abstract
The core Thomson scattering diagnostic (TS) on the COMPASS tokamak was put in operation and reported earlier. Implementation of edge TS, with spatial resolution along the laser beam up to ∼1/100 of the tokamak minor radius, is presented now. The procedure for spatial calibration and alignment of both core and edge systems is described. Several further upgrades of the TS system, like a triggering unit and piezo motor driven vacuum window shutter, are introduced as well. The edge TS system, together with the core TS, is now in routine operation and provides electron temperature and density profiles.
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Affiliation(s)
- P Bohm
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - M Aftanas
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - P Bilkova
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - E Stefanikova
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - O Mikulin
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - R Melich
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - F Janky
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - J Havlicek
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - D Sestak
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - V Weinzettl
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - J Stockel
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - M Hron
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - R Panek
- Institute of Plasma Physics ASCR, Za Slovankou 1782/3, 18200 Prague, Czech Republic
| | - R Scannell
- CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, United Kingdom
| | - L Frassinetti
- School of Electrical Engineering, Division of Fusion Plasma Physics, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden
| | - A Fassina
- Consorzio RFX, Corso Stati Uniti, 4-35127 Padua, Italy
| | - G Naylor
- CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB, United Kingdom
| | - M J Walsh
- ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St Paul lez Durance, France
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Hron M, Janky F, Pipek J, Sousa J, Carvalho B, Fernandes H, Vondracek P, Cahyna P, Urban J, Paprok R, Mikulín O, Aftanas M, Panek R, Havlicek J, Fortunato J, Batista A, Santos B, Duarte A, Pereira T, Valcarcel D. Overview of the COMPASS CODAC system. Fusion Engineering and Design 2014. [DOI: 10.1016/j.fusengdes.2013.09.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Zajac J, Preinhaelter J, Urban J, Aftanas M, Bílková P, Böhm P, Fuchs V, Nanobashvili S, Weinzettl V, Zácek F. First results from EBW emission diagnostics on COMPASS. Rev Sci Instrum 2012; 83:10E327. [PMID: 23126985 DOI: 10.1063/1.4733530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
COMPASS tokamak shots at low magnetic field feature overdense plasmas during the extended current flat-top phase. The first harmonic of the electron cyclotron emission is completely cutoff for O and X modes and so the emission caused by electron Bernstein waves (EBWs) propagating obliquely with respect to the magnetic field and undergoing so called EBW-X-O conversion process can be observed. We perform an angular scan of the EBW emission during a set of comparable shots in order to determine the optimum antenna direction. A weak dependence of the radiative temperature on the antenna angles indicates an influence of multiple reflections from the vessel wall. The low temperature at the mode conversion region is responsible for the collisional damping of EBW, which can explain several times lower measured radiative temperature than the electron temperature measured by the Thomson scattering system.
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Affiliation(s)
- J Zajac
- Institute of Plasma Physics AS CR, vvi, Association EURATOM∕IPP.CR, Prague, Czech Republic.
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Aftanas M, Bohm P, Bilkova P, Weinzettl V, Zajac J, Zacek F, Stockel J, Hron M, Panek R, Scannell R, Walsh MJ. High-resolution Thomson scattering system on the COMPASS tokamak: evaluation of plasma parameters and error analysis. Rev Sci Instrum 2012; 83:10E350. [PMID: 23127007 DOI: 10.1063/1.4743956] [Citation(s) in RCA: 3] [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: 06/01/2023]
Abstract
The electron density and temperature profiles measured by the Thomson scattering diagnostic on the COMPASS tokamak are used for estimation of electron kinetic energy, energy confinement time, and effective charge number Z(eff). Data are compared with the line-integrated electron density measured by a microwave interferometer in an ohmically heated plasma with a circular cross section. An error analysis of both electron temperature and density are performed by two methods-a constant chi-square boundaries method and a Monte Carlo simulation, determining asymmetrical error bars for the electron temperature.
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Affiliation(s)
- M Aftanas
- Institute of Plasma Physics AS CR, vvi, Prague 8, Czech Republic.
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Bohm P, Hron M, Kovar J, Sova J, Zvolanek M, Aftanas M, Bilkova P, Panek R, Walsh M. Personnel protection during the operation of Thomson scattering laser system on COMPASS tokamak. Fusion Engineering and Design 2011. [DOI: 10.1016/j.fusengdes.2011.02.073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Bilkova P, Melich R, Aftanas M, Böhm P, Sestak D, Jares D, Weinzettl V, Stöckel J, Hron M, Panek R, Scannell R, Walsh MJ. Progress of development of Thomson scattering diagnostic system on COMPASS. Rev Sci Instrum 2010; 81:10D531. [PMID: 21033886 DOI: 10.1063/1.3494378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A new Thomson scattering diagnostic system has been designed and is being built now on the COMPASS tokamak at the Institute of Plasma Physics ASCR in Prague (IPP Prague) in the Czech Republic. This contribution focuses on design, development, and installation of the light collection and detection system. High spatial resolution of 3 mm will be achieved by a combination of design of collection optics and connected polychromators. Imaging characteristics of both core and edge plasma collection objectives are described and fiber backplane design is presented. Several calibration procedures are discussed. The operational deployment of the Thomson scattering diagnostic is planned by the end of 2010.
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Affiliation(s)
- P Bilkova
- Institute of Plasma Physics AS CR, v.v.i., Association EURATOM/IPP.CR, Za Slovankou 3, Prague 8 182 00, Czech Republic.
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Bohm P, Sestak D, Bilkova P, Aftanas M, Weinzettl V, Hron M, Panek R, Baillon L, Dunstan MR, Naylor G, Walsh MJ. Laser system for high resolution Thomson scattering diagnostics on the COMPASS tokamak. Rev Sci Instrum 2010; 81:10D511. [PMID: 21033866 DOI: 10.1063/1.3460450] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A new Thomson scattering diagnostic has been designed and is currently being installed on the COMPASS tokamak in IPP Prague in the Czech Republic. The requirements for this system are very stringent with approximately 3 mm spatial resolution at the plasma edge. A critical part of this diagnostic is the laser source. To achieve the specified parameters, a multilaser solution is utilized. Two 30 Hz 1.5 J Nd:YAG laser systems, used at the fundamental wavelength of 1064 nm, are located outside the tokamak area at a distance of 20 m from the tokamak. The design of the laser beam transport path is presented. The approach leading to a final choice of optimal focusing optics is given. As well as the beam path to the tokamak, a test path of the same optical length was built. Performance tests of the laser system carried out using the test path are described.
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Affiliation(s)
- P Bohm
- Institute of Plasma Physics AS CR, v.v.i., EURATOM IPP.CR, Za Slovankou 1782/3, 18200 Prague 8, Czech Republic.
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Šesták D, Weinzettl V, Bílková P, Böhm P, Aftanas M, Naydenkova D, Stöckel J, Ďuran I, Walsh M. Design and engineering of optical diagnostics for COMPASS. Fusion Engineering and Design 2009. [DOI: 10.1016/j.fusengdes.2009.01.058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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