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Dreier H, Dinklage A, Fischer R, Hirsch M, Kornejew P, Pasch E. Bayesian Design of Diagnostics: Case Studies for Wendelstein 7-X. Fusion Science and Technology 2017. [DOI: 10.13182/fst06-a1244] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- H. Dreier
- Max-Planck-Institut für Plasmaphysik, EURATOM Association Teilinstitut Greifswald, D-17491 Greifswald, Germany
| | - A. Dinklage
- Max-Planck-Institut für Plasmaphysik, EURATOM Association Teilinstitut Greifswald, D-17491 Greifswald, Germany
| | - R. Fischer
- Max-Planck-Institut für Plasmaphysik, EURATOM Association Teilinstitut Greifswald, D-17491 Greifswald, Germany
| | - M. Hirsch
- Max-Planck-Institut für Plasmaphysik, EURATOM Association Teilinstitut Greifswald, D-17491 Greifswald, Germany
| | - P. Kornejew
- Max-Planck-Institut für Plasmaphysik, EURATOM Association Teilinstitut Greifswald, D-17491 Greifswald, Germany
| | - E. Pasch
- Max-Planck-Institut für Plasmaphysik, EURATOM Association Teilinstitut Greifswald, D-17491 Greifswald, Germany
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Dreier H, Bagryansky P, Baumgarten N, Biel W, Lambertz HT, Lehnen M, Lizunov A, Solomakhin A. First results from the modular multi-channel dispersion interferometer at the TEXTOR tokamak. Rev Sci Instrum 2011; 82:063509. [PMID: 21721693 DOI: 10.1063/1.3600896] [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] [Indexed: 05/31/2023]
Abstract
At the TEXTOR tokamak in Jülich, Germany, a modular dispersion interferometer was installed and operated for the first time. Equipped with four lines of sight, the line-integrated density could be measured in parallel at different major radii with a resolution of better than 3 × 10(17) m(-2). This paper will describe the setup and show the first measurement results. Among others, it was possible to detect the evolution of a disruption with a time resolution of 4 μs. The movement of the runaway beam following the disruption could be resolved spatially and temporarily.
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Affiliation(s)
- H Dreier
- Max-Planck-Institut für Plasmaphysik, EURATOM Association, Wendelsteinstr. 1, D-17491 Greifswald, Germany
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Solomakhin AL, Bagryansky PA, Biel W, Dreier H, Ivanenko SV, Khilchenko AD, Kovalenko YV, Kvashnin AN, Lambertz HT, Lizunov AA, Lvovskiy AV, Savkin VY. Measurement of Plasma Density in Modern Fusion Devices by Dispersion Interferometer. Fusion Science and Technology 2011. [DOI: 10.13182/fst11-a11588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- A. L. Solomakhin
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
- Novosibirsk State University, 630090, Novosibirsk, Russia
| | - P. A. Bagryansky
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
- Novosibirsk State University, 630090, Novosibirsk, Russia
| | - W. Biel
- Forschungszentrum Jülich GmbH, Association EURATOM-FZ Jülich, Institut für Plasmaphysik, Trilateral Euregio Cluster, 52425 Jülich, Germany
| | - H. Dreier
- Max-Planck-Institut für Plasmaphysik, EURATOM Association, Wendelsteinstr. 1, D-17491 Greifswald, Germany
| | - S. V. Ivanenko
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
| | - A. D. Khilchenko
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
| | - Yu. V. Kovalenko
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
- Novosibirsk State University, 630090, Novosibirsk, Russia
| | - A. N. Kvashnin
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
| | - H. T. Lambertz
- Forschungszentrum Jülich GmbH, Association EURATOM-FZ Jülich, Institut für Plasmaphysik, Trilateral Euregio Cluster, 52425 Jülich, Germany
| | - A. A. Lizunov
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
- Novosibirsk State University, 630090, Novosibirsk, Russia
| | - A. V. Lvovskiy
- Novosibirsk State University, 630090, Novosibirsk, Russia
| | - V. Ya. Savkin
- Budker Institute of Nuclear Physics, 630090, Novosibirsk, Russia
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König R, Baldzuhn J, Biel W, Biedermann C, Burhenn R, Bozhenkov S, Cantarini J, Dreier H, Endler M, Hartfuss HJ, Hildebrandt D, Hirsch M, Jakubowski M, Jimenez-Gomez R, Kocsis G, Kornejev P, Krychowiak M, Laqua HP, Laux M, Oosterbeek JW, Pasch E, Richert T, Schneider W, Schweer B, Svensson J, Thomsen H, Weller A, Werner A, Wolf R, Zhang D, Zoletnik S. Diagnostics design for steady-state operation of the Wendelstein 7-X stellarator. Rev Sci Instrum 2010; 81:10E133. [PMID: 21033995 DOI: 10.1063/1.3483210] [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
The status of the diagnostic developments for the quasistationary operable stellarator Wendelstein 7-X (maximum pulse length of 30 min at 10 MW ECRH heating at 140 GHz) will be reported on. Significant emphasis is being given to the issue of ECRH stray radiation shielding of in-vessel diagnostic components, which will be critical at high density operation requiring O2 and OXB heating.
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Affiliation(s)
- R König
- Max-Planck-Institute für Plasmaphysik, EURATOM Association, Greifswald D-1749, Germany.
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König R, Cantarini J, Dreier H, Erckmann V, Hildebrandt D, Hirsch M, Kocsis G, Kornejew P, Laux M, Laqua H, Pasch E, Recsei S, Szabó V, Thomsen H, Weller A, Werner A, Wolf R, Ye MY, Zoletnik S. Diagnostic developments for quasicontinuous operation of the Wendelstein 7-X stellarator. Rev Sci Instrum 2008; 79:10F337. [PMID: 19044644 DOI: 10.1063/1.2964998] [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] [Indexed: 05/27/2023]
Abstract
The stellarator Wendelstein 7-X will allow for quasicontinuous operation with the duration only being limited to two 30 min discharges per day, at a continuous heating power of 10 MW electron cyclotron resonance heating (ECRH) at 140 GHz, by the capacity of the cooling water reservoir. This will result in high thermal loads on all plasma facing components of 50-100 kW/m(2) from radiation alone and of up to about 500 kW/m(2) on components additionally exposed to convective loads. In high density scenarios toroidally varying ECRH stray radiation levels of 50-200 kW/m(2) need to be coped with, requiring careful material selection and different shielding and hardening techniques. Furthermore, a gradual buildup of coatings on plasma facing optical components, which without any measures being taken, would lead to high transmission losses already within a few days of long pulse operation (equivalent to about 1 year of operation in pulsed devices like JET or ASDEX-upgrade) and therefore needs to be prevented as much as possible. In addition in situ cleaning as well as absolute calibration techniques need to be developed for all plasma facing optical systems. Here we report about some of our efforts to find, for various types of diagnostics, ways to cope with these adverse effects. Moreover, we give a few examples for individual diagnostic specific issues with respect to quasicontinuous operation, such as the development of a special integrator for the magnetic diagnostics as well as special interferometer types which can cope with unavoidable vibrations and slow path length changes due to, e.g., thermal expansion of the plasma vessel.
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Affiliation(s)
- R König
- Euratom Association, Max-Planck-Institut fur Plasmaphysik, Wendelsteinstr. 1, 17491 Greifswald, Germany
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Lizunov A, Bagryansky P, Khilchenko A, Kovalenko YV, Solomakhin A, Biel W, Lambertz HT, Krasikov Y, Mitri M, Schweer B, Dreier H. Development of a multichannel dispersion interferometer at TEXTOR. Rev Sci Instrum 2008; 79:10E708. [PMID: 19044526 DOI: 10.1063/1.2969466] [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: 05/27/2023]
Abstract
The design and main characteristics of 14-channel dispersion interferometer for plasma profile measurement and control in TEXTOR tokamak are presented. The diagnostic is engineered on the basis of modular concept, the 10.6 microm CO(2) laser source and all optical and mechanical elements of each module are arranged in a compact housing. A set of mirrors and retroreflectors inside the TEXTOR vacuum vessel provides full coverage of the torus cross section with 12 vertical and two diagonal lines of sight, no rigid frame for vibration isolation is required. Results of testing of the single-channel prototype diagnostic and the pilot module of the multichannel dispersion interferometer are presented.
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Affiliation(s)
- A Lizunov
- Budker Institute of Nuclear Physics, Novosibirsk 630090, Russia
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Krychowiak M, Dodt D, Dreier H, König R, Wolf R. Development of a virtual Z(eff) diagnostic for the W7-X stellarator. Rev Sci Instrum 2008; 79:10F512. [PMID: 19044657 DOI: 10.1063/1.2956826] [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: 05/27/2023]
Abstract
For the W7-X stellarator a diagnostic system for measurement of local Z(eff) values from the visible bremsstrahlung continuum is foreseen. The method is based on passive, absolute measurement of the bremsstrahlung intensity along several lines of sight. In order to eliminate the spurious impact of other radiation sources of different spectral intensity distribution than the bremsstrahlung, like the line radiation, it is intended to spectrally resolve the detected radiation, e.g., by use of microspectrometers. The visible bremsstrahlung background can be extracted by making use of the 1/lambda(2) dependence of its intensity (expressed in unit Wm(3) sr nm) in the high temperature plasmas by using Bayesian data analysis techniques. In a second step, the local values of Z(eff) as a function of the effective plasma radius are derived by inversion, using different regularization methods, of the line-integrated bremsstrahlung signals with the knowledge of the magnetic flux surfaces. Inversion of the full model based on statistical methods allows taking into account all conceivable uncertainties accompanying Z(eff) measurement and provides uncertainties of the local Z(eff) values and valuable information on other uncertain parameters of the model. In this paper we show the first steps in developing a virtual Z(eff) diagnostic for W7-X which allows the optimization of the statistical model as well as of the future diagnostic setup.
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Affiliation(s)
- M Krychowiak
- Max-Planck-Institut fur Plasmaphysik, Euratom Association, Wendelsteinstr. 1, 17491 Greifswald, Germany
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Dreier H, Dinklage A, Fischer R, Hirsch M, Kornejew P. Bayesian experimental design of a multichannel interferometer for Wendelstein 7-X. Rev Sci Instrum 2008; 79:10E712. [PMID: 19044530 DOI: 10.1063/1.2956962] [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] [Indexed: 05/27/2023]
Abstract
Bayesian experimental design (BED) is a framework for the optimization of diagnostics basing on probability theory. In this work it is applied to the design of a multichannel interferometer at the Wendelstein 7-X stellarator experiment. BED offers the possibility to compare diverse designs quantitatively, which will be shown for beam-line designs resulting from different plasma configurations. The applicability of this method is discussed with respect to its computational effort.
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Affiliation(s)
- H Dreier
- Max-Planck-Institut für Plasmaphysik, EURATOM Association, Teilinstitut Greifswald, D-174891 Greifswald, Germany
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Dreier H, Dinklage A, Fischer R, Hirsch M, Kornejew P, Hartfuss HJ, Dudeck M, Musielok J, Sadowski MJ. Comparative studies to the design of the interferometer at W7-X with respect to technical boundary conditions. ACTA ACUST UNITED AC 2008. [DOI: 10.1063/1.2909104] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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