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Houshmandyar S, Watts TA, Rowan WL, Zajac J, Veselovsky V, Ivanov V, Bogar O, Weinzettl V. Design of an electron cyclotron emission diagnostics suite for COMPASS Upgrade tokamak. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:113514. [PMID: 36461518 DOI: 10.1063/5.0101790] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 09/08/2022] [Indexed: 06/17/2023]
Abstract
COMPASS Upgrade is a medium size and high field tokamak that is capable of addressing key challenges for reactor grade tokamaks, including power exhaust and advanced confinement scenarios. Electron cyclotron emission will be available among the first diagnostics to provide measurements of high spatial and temporal resolution of electron temperature profiles and electron temperature fluctuation profiles through a radial view. A separate oblique view at 12° from normal will be utilized to study non-thermal electrons. Both the radial and oblique views are envisioned to be located in a wide-angle midplane port, which has dimensions that enable simultaneous hosting of the front-end of their quasi-optical (QO) designs. Each QO design will have an in situ hot calibration source in the front-end to provide standalone and calibrated Te (R,t) measurements. The conceptual design for each QO system, the Gaussian beam analysis, and the details of the diagnostic channels are presented.
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Affiliation(s)
| | - Thomas A Watts
- Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712, USA
| | - William L Rowan
- Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Jaromir Zajac
- Institute of Plasma Physics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Viktor Veselovsky
- Institute of Plasma Physics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Vladislav Ivanov
- Institute of Plasma Physics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Ondrej Bogar
- Institute of Plasma Physics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Vladimir Weinzettl
- Institute of Plasma Physics of the Czech Academy of Sciences, Prague, Czech Republic
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Xie R, Houshmandyar S, Austin ME. Active control of electron cyclotron emission radiometer channel frequencies for improved electron temperature measurements. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:033530. [PMID: 33820040 DOI: 10.1063/5.0043662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Accepted: 02/26/2021] [Indexed: 06/12/2023]
Abstract
As advanced scenarios are developed for tokamak operations, the demand for flexibility of the electron cyclotron emission (ECE) channels' locations has increased. The tunable feature of yttrium iron garnet (YIG) filters provides this spatial flexibility. Here, we present a method of performing ECE measurements on fixed flux surfaces instead of fixed frequencies. This is achieved by adjusting YIG filters utilized in the intermediate frequency section to frequencies associated with flux surfaces in regions of interest during the discharge. The key components are the application of tunable YIG filters and a control program that calculates the filter settings using flux information from real-time reconstruction equilibria (EFIT). This fast procedure facilitates Te measurements in regions of interest to investigate plasma dynamic behaviors.
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Affiliation(s)
- R Xie
- Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712, USA
| | - S Houshmandyar
- Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712, USA
| | - M E Austin
- Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712, USA
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Houshmandyar S, Xie R, Austin ME, Rowan WL, Zhao H. Fast modulating electron cyclotron emission (FMECE) diagnostic for tokamaks. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:033510. [PMID: 33820026 DOI: 10.1063/5.0043761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 02/16/2021] [Indexed: 06/12/2023]
Abstract
Utilizing variable-frequency channels, e.g., yttrium iron garnet (YIG) bandpass filters, in the intermediate frequency (IF) section of an electron cyclotron emission (ECE) radiometer facilitates flexibility in the volume viewed by the ECE channels as well as high resolution electron temperature and temperature fluctuation measurements in tokamaks. Fast modulating electron cyclotron emission (FMECE), a stand-alone IF section with eight channels, is a novel application of YIG filters for real-time electron temperature gradient and gradient scale length measurements. Key to FMECE is a simultaneous input/output data acquisition unit, as well as a modified type of YIG filters, which is capable of fast switching of their center (set) frequencies with a frequency slew rate of 600 µs/GHz. A new FMECE has been implemented and tested on the DIII-D tokamak, demonstrating its capability in real-time gradient measurements. The data presented here shows that FMECE can identify flattening in the electron temperature profile; the latter can be used as a sensor for real time monitoring and control of plasma instabilities. Implementation and application are planned for the EAST tokamak.
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Affiliation(s)
- Saeid Houshmandyar
- Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Ruifeng Xie
- Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Max E Austin
- Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712, USA
| | - William L Rowan
- Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Hailin Zhao
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
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A multi-channel correlation ECE system for electron temperature fluctuation measurement on EAST tokamak. FUSION ENGINEERING AND DESIGN 2019. [DOI: 10.1016/j.fusengdes.2019.111336] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Zhao H, Zhou T, Liu Y, Ti A, Ling B, Austin ME, Houshmandyar S, Huang H, Rowan WL, Hu L. Upgrade of the ECE diagnostic on EAST. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:10H111. [PMID: 30399748 DOI: 10.1063/1.5035452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 05/04/2018] [Indexed: 06/08/2023]
Abstract
The electron cyclotron emission (ECE) diagnostic on the experimental advanced superconducting tokamak (EAST) was upgraded recently to provide electron temperature profile measurement with wider radial coverage and better precision. The lower limit of the ECE detection frequency band was extended from 104 GHz to 97 GHz by adding a new 8-channel heterodyne radiometer, which ensures capability for the measurement of the second harmonic ECE with toroidal magnetic field down to 1.75 T. Also, the existing 32-channel heterodyne radiometer has been upgraded, with the frequency interval for the lower frequency range up to 120 GHz reduced from 2 GHz to 1 GHz by introducing eight channels in the intermediate frequency part. In addition, a plan is presented to incorporate tunable yttrium iron garnet filters into the existing heterodyne radiometer to obtain detailed measurements of the electron temperature gradient scale length as well as finer spatial pinpointing of magnetohydrodynamic modes. Examples from DIII-D are provided where similar ECE diagnostic allowed precise measurement of the center and width of neoclassical tearing modes.
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Affiliation(s)
- Hailin Zhao
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - Tianfu Zhou
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - Yong Liu
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - Ang Ti
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - Bili Ling
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - M E Austin
- Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712, USA
| | - Saeid Houshmandyar
- Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712, USA
| | - H Huang
- Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712, USA
| | - W L Rowan
- Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712, USA
| | - Liqun Hu
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
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