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Danani S, Pandya HKB, Vaghashiya P, Padasalagi S, Kumar R, Rowan WL, Ziegel JP, Kumar V. Physics Studies for Assessment of Requirement of Displacement Compensation System for ITER ECE Diagnostic. EPJ Web Conf 2023. [DOI: 10.1051/epjconf/202327703011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023] Open
Abstract
The Electron Cyclotron Emission (ECE) diagnostic has the key function of measuring the core electron temperature profile and electron temperature fluctuation, from the intensity of electron cyclotron radiation emitted from the plasma along the major radius. The ECE diagnostic consists of three main systems: (1) front-end optics, which collects the radiation from the plasma, (2) transmission lines including polarizer splitter unit, which transports the ordinary and extraordinary ECE emission modes separately from the front-end and distributes it to the instrumentation, and (3) detection and analysis instrumentation which is housed at a distance from the tokamak, in the diagnostics building [1]. With its high electron temperatures and harsh environment, ITER presents various challenges for the diagnostic system. One of the most insidious is the misalignment between the in-vessel front-end optics and the ex-vessel transmission line which is caused by vibration of the vacuum vessel during operational and baking phases. Since the electron temperature is inferred from the intensity of the ECE, transient misalignment may lead to poor accuracy in this critical measurement. These displacements are expected to be ~ 15 mm in vertical (z) and horizontal (x) directions, and ~ 5 mm in the toroidal (y) direction. It is important to minimize the effect of these displacements, so that the system maintains alignment during operation, and reliable temperature information is attained. Our objective is to first study the coupling losses due to imperfect coupling of Gaussian beams owing to port plug displacements. Measurements are done to determine the power loss due to coupling of offset beams experimentally. The measured value for coupling loss is ~2 dB at 120 GHz, which is quite high, and it is therefore concluded that a mechanism is needed to compensate for the displacements.
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2
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Udintsev V, Danani S, Taylor G, Giacomin T, Guirao J, Pak S, Hughes S, Worth L, Vayakis G, Walsh M, Schneider M, Pandya H, Kumar R, Kumar V, Jha S, Thomas S, Padasalagi SB, Kumar S, Phillips PE, Rowan WL, Austin M, Khodak A, Feder R, Neilson H, Basile A, Hubbard AE, Saxena A, Nazare C, Maquet P, Gimbert N. Progress in ITER ECE Diagnostic Design and Integration. EPJ Web Conf 2019. [DOI: 10.1051/epjconf/201920303003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The ITER Electron Cyclotron Emission (ECE) diagnostic is progressing towards its Preliminary Design Review (PDR). In parallel, the diagnostic integration in the Equatorial Port is ongoing. Port Integration has to address the structural integrity to withstand various loads, maintenance and the safety aspects of ECE diagnostic. The ITER ECE system includes radial and oblique lines-of-sight. Recently, a successful peer-review of the in-port plug Hot Calibration Source has taken place and its performance and integration feasibility has been demonstrated. Four 45-meter long low-loss transmission lines are designed to transmit mm-wave power in the frequency range of 70- 1000 GHz in both X- and O-mode polarization from the port plug to the ECE instrumentation room in the diagnostic building. Prototype transmission lines are being tested [1]. A prototype polarizing Martin-Puplett type Fourier Transform Spectrometer (FTS) operating in the frequency range 70-1000 GHz, has a fast scanning mechanism and a cryo-cooled dual-channel THz detector system. Its performance has been tested as per ITER requirements. Assessment of the instrumentation and control requirements, functional and non-functional requirements, operation procedures, plant automation are ongoing for the PDR. The current status of the diagnostic, together with integration activities, is presented.
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Houshmandyar S, Austin ME, Brookman MW, Liu Y, Rowan WL, Zhao H. Variable location channels to improve efficiency and precision for direct ∇ T e measurements and high spatial resolution T e -profile measurements using electron cyclotron emission. Rev Sci Instrum 2018; 89:10H109. [PMID: 30399714 DOI: 10.1063/1.5035429] [Citation(s) in RCA: 1] [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: 04/15/2018] [Accepted: 06/20/2018] [Indexed: 06/08/2023]
Abstract
Electron cyclotron emission (ECE) diagnostics that use variable location channels based on yttrium iron garnet (YIG) bandpass filters improve the precision and the efficiency of measurements of electron temperature (T e ) profiles and fluctuations (δT e ). These variable frequency filters were substituted for fixed frequency filters in the intermediate frequency section to achieve the required higher resolution over a target radial range, just before the experiment. Here, we present the proof-of-principle for high temporal resolution measurement of the electron temperature gradient, via real-time slewing of a YIG filter for relocation of an ECE channel during a long pulse. The key component is the application of YIG tunable filters with their narrow bandwidth and capability for a high slew rate of their center frequency. This application permits fast relocation of the ECE channels for direct measurement of the gradient and close spacing of channels to investigate the magnetic island's dynamic behavior.
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Affiliation(s)
- 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
| | - M W Brookman
- Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Y Liu
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - W L Rowan
- Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712, USA
| | - H Zhao
- Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712, USA
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4
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Liao KT, Austin ME, Rowan WL, Thomas DM, Zhao BZ. Estimating the performance of lithium beam measurements of current density and electron density in an H-mode pedestal. Rev Sci Instrum 2018; 89:10D135. [PMID: 30399706 DOI: 10.1063/1.5035294] [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] [Received: 04/13/2018] [Accepted: 06/22/2018] [Indexed: 06/08/2023]
Abstract
The lithium beam is an effective diagnostic tool for investigation of stability and particle transport in the pedestal. It was used successfully to measure edge current density on DIII-D, achieving qualitative agreement with neoclassical models. Electron density profiles were also measured. Proposed upgrades will continue these measurements with higher reliability as well as explore edge current measurements using spectroscopy. The optics will be redesigned to optimize throughput and aperture broadening and to replace the photomultiplier tubes with avalanche photodiodes. The new system will yield detailed measurements of the pedestal, complementing existing diagnostics for investigating pedestal stability, edge localized mode cycle, and particle transport through the pedestal.
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Affiliation(s)
- K T Liao
- Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78702, USA
| | - M E Austin
- Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78702, USA
| | - W L Rowan
- Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78702, USA
| | - D M Thomas
- General Atomics, San Diego, California 92186, USA
| | - B Z Zhao
- Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78702, USA
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5
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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. Rev Sci Instrum 2018; 89:10H111. [PMID: 30399748 DOI: 10.1063/1.5035452] [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] [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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6
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Huang X, Liu DM, Liu C, Fu J, Wan BN, Lyu B, Wu ZW, Holcomb CT, Ko J, Rowan WL, Huang H, Miao GZ. Four-dimensional calibration turntable of the motional Stark effect diagnostic on EAST. Rev Sci Instrum 2018; 89:10B108. [PMID: 30399705 DOI: 10.1063/1.5036938] [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] [Received: 04/19/2018] [Accepted: 07/11/2018] [Indexed: 06/08/2023]
Abstract
The motional Stark effect (MSE) diagnostic is applied to measure the safety factor q and current density profile of a tokamak device, which are important parameters in realizing the high-performance and long-pulse steady state of a tokamak. A single-channel MSE diagnostic based on dual photoelastic modulators, whose sightline meets with the neutral beam injection at a major radius of R = 2.12 m, has been built for the D window of the Experimental Advanced Superconducting Tokamak (EAST). According to the requirements of MSE diagnostic polarimetric calibration, a high-precision four-dimensional calibration turntable, driven by four stepping motors and controlled by software running on the computer, was designed for EAST. The turntable allows us to rapidly calibrate the MSE diagnostic in a series of positions and angles during EAST maintenance. The turntable can move in four dimensions of translation, yaw, pitch, and roll of the polarizer and can create linearly polarized light at any given angle with accuracy of ∼0.05° for the MSE system offline calibration. The experimental results of the MSE diagnostic calibration in the laboratory show that the turntable has the advantages of high positioning accuracy, flexible spatial movement, and convenient control and fully meets the calibration requirements of an MSE diagnosis system.
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Affiliation(s)
- X Huang
- School of Electrical Engineering and Automation, Hefei University of Technology, Hefei 230009, China
| | - D M Liu
- School of Electrical Engineering and Automation, Hefei University of Technology, Hefei 230009, China
| | - C Liu
- School of Electrical Engineering and Automation, Hefei University of Technology, Hefei 230009, China
| | - J Fu
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - B N Wan
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - B Lyu
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - Z W Wu
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - C T Holcomb
- Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94550, USA
| | - J Ko
- National Fusion Research Institute, Yuseong, Daejeon 305-333, South Korea
| | - W L Rowan
- Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712, USA
| | - H Huang
- Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712, USA
| | - G Z Miao
- School of Electrical Engineering and Automation, Hefei University of Technology, Hefei 230009, China
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7
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Taylor G, Austin ME, Basile A, Beno JH, Danani S, Feder R, Houshmandyar S, Hubbard AE, Johnson DW, Khodak A, Kumar R, Kumar S, Ouroua A, Padasalagi SB, Pandya HKB, Phillips PE, Rowan WL, Stillerman J, Thomas S, Udintsev VS, Vayakis G, Walsh M, Weeks D. Update on the status of the ITER ECE diagnostic design. EPJ Web Conf 2017. [DOI: 10.1051/epjconf/201714702003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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8
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Basse NP, Dominguez A, Edlund EM, Fiore CL, Granetz RS, Hubbard AE, Hughes JW, Hutchinson IH, Irby JH, LaBombard B, Lin L, Lin Y, Lipschultz B, Liptac JE, Marmar ES, Mossessian DA, Parker RR, Porkolab M, Rice JE, Snipes JA, Tang V, Terry JL, Wolfe SM, Wukitch SJ, Zhurovich K, Bravenec RV, Phillips PE, Rowan WL, Kramer GJ, Schilling G, Scott SD, Zweben SJ. Diagnostic Systems on Alcator C-Mod. Fusion Science and Technology 2017. [DOI: 10.13182/fst07-a1434] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [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)
- N. P. Basse
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - A. Dominguez
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - E. M. Edlund
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - C. L. Fiore
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - R. S. Granetz
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - A. E. Hubbard
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - J. W. Hughes
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - I. H. Hutchinson
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - J. H. Irby
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - B. LaBombard
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - L. Lin
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - Y. Lin
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - B. Lipschultz
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - J. E. Liptac
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - E. S. Marmar
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - D. A. Mossessian
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - R. R. Parker
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - M. Porkolab
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - J. E. Rice
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - J. A. Snipes
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - V. Tang
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - J. L. Terry
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - S. M. Wolfe
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - S. J. Wukitch
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - K. Zhurovich
- Massachusetts Institute of Technology, Plasma Science and Fusion Center, Cambridge, Massachusetts 02139
| | - R. V. Bravenec
- Fusion Research Center, University of Texas, Austin, Texas 78712
| | - P. E. Phillips
- Fusion Research Center, University of Texas, Austin, Texas 78712
| | - W. L. Rowan
- Fusion Research Center, University of Texas, Austin, Texas 78712
| | - G. J. Kramer
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543
| | - G. Schilling
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543
| | - S. D. Scott
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543
| | - S. J. Zweben
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543
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9
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Austin ME, Brookman MW, Rowan WL, Danani S, Bryerton EW, Dougherty P. Design and first plasma measurements of the ITER-ECE prototype radiometer. Rev Sci Instrum 2016; 87:11E111. [PMID: 27910542 DOI: 10.1063/1.4960163] [Citation(s) in RCA: 1] [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: 06/06/2023]
Abstract
On ITER, second harmonic optically thick electron cyclotron emission (ECE) in the range of 220-340 GHz will supply the electron temperature (Te). To investigate the requirements and capabilities prescribed for the ITER system, a prototype radiometer covering this frequency range has been developed by Virginia Diodes, Inc. The first plasma measurements with this instrument have been carried out on the DIII-D tokamak, with lab bench tests and measurements of third through fifth harmonic ECE from high Te plasmas. At DIII-D the instrument shares the transmission line of the Michelson interferometer and can simultaneously acquire data. Comparison of the ECE radiation temperature from the absolutely calibrated Michelson and the prototype receiver shows that the ITER radiometer provides accurate measurements of the millimeter radiation across the instrument band.
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Affiliation(s)
- M E Austin
- Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712, USA
| | - M W Brookman
- 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
| | - S Danani
- ITER-India/Institute for Plasma Research, Bhat, Gandhinagar 382428, India
| | - E W Bryerton
- Virginia Diodes, Inc., Charlottesville, Virginia 22902, USA
| | - P Dougherty
- Virginia Diodes, Inc., Charlottesville, Virginia 22902, USA
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10
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Rowan WL, Houshmandyar S, Phillips PE, Austin ME, Beno JH, Hubbard AE, Khodak A, Ouroua A, Taylor G. Physics design of the in-vessel collection optics for the ITER electron cyclotron emission diagnostic. Rev Sci Instrum 2016; 87:11E132. [PMID: 27910318 DOI: 10.1063/1.4960420] [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
Measurement of the electron cyclotron emission (ECE) is one of the primary diagnostics for electron temperature in ITER. In-vessel, in-vacuum, and quasi-optical antennas capture sufficient ECE to achieve large signal to noise with microsecond temporal resolution and high spatial resolution while maintaining polarization fidelity. Two similar systems are required. One views the plasma radially. The other is an oblique view. Both views can be used to measure the electron temperature, while the oblique is also sensitive to non-thermal distortion in the bulk electron distribution. The in-vacuum optics for both systems are subject to degradation as they have a direct view of the ITER plasma and will not be accessible for cleaning or replacement for extended periods. Blackbody radiation sources are provided for in situ calibration.
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Affiliation(s)
- W L Rowan
- 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
| | - P E Phillips
- 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
| | - J H Beno
- Center for Electromechanics, The University of Texas at Austin, Austin, Texas 78712, USA
| | - A E Hubbard
- Plasma Science and Fusion Center, MIT, Cambridge, Massachusetts 02139, USA
| | - A Khodak
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - A Ouroua
- Center for Electromechanics, The University of Texas at Austin, Austin, Texas 78712, USA
| | - G Taylor
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
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11
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Houshmandyar S, Yang ZJ, Phillips PE, Rowan WL, Hubbard AE, Rice JE, Hughes JW, Wolfe SM. Temperature gradient scale length measurement: A high accuracy application of electron cyclotron emission without calibration. Rev Sci Instrum 2016; 87:11E101. [PMID: 27910677 DOI: 10.1063/1.4955297] [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
Calibration is a crucial procedure in electron temperature (Te) inference from a typical electron cyclotron emission (ECE) diagnostic on tokamaks. Although the calibration provides an important multiplying factor for an individual ECE channel, the parameter ΔTe/Te is independent of any calibration. Since an ECE channel measures the cyclotron emission for a particular flux surface, a non-perturbing change in toroidal magnetic field changes the view of that channel. Hence the calibration-free parameter is a measure of Te gradient. BT-jog technique is presented here which employs the parameter and the raw ECE signals for direct measurement of electron temperature gradient scale length.
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Affiliation(s)
- S Houshmandyar
- Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Z J Yang
- Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - P E Phillips
- Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712, USA
| | - W L Rowan
- Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712, USA
| | - A E Hubbard
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02129, USA
| | - J E Rice
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02129, USA
| | - J W Hughes
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02129, USA
| | - S M Wolfe
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02129, USA
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12
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Taylor G, Austin ME, Beno JH, Danani S, Ellis RF, Feder R, Hesler JL, Hubbard AE, Johnson DW, Kumar R, Kumar S, Kumar V, Ouroua A, Pandya HKB, Phillips PE, Roman C, Rowan WL, Udintsev V, Vayakis G, Walsh M. Status of the design of the ITER ECE diagnostic. EPJ Web of Conferences 2015. [DOI: 10.1051/epjconf/20158703002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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13
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Yang ZJ, Phillips PE, Zhuang G, Xiao JS, Huang H, Rowan WL, Wang ZJ. A 16-channel heterodyne electron cyclotron emission radiometer on J-TEXT. Rev Sci Instrum 2012; 83:10E313. [PMID: 23126973 DOI: 10.1063/1.4732069] [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
To study equilibrium temporal dynamics and the mechanisms of magnetohydrodynamic instabilities, a 16-channel heterodyne electron cyclotron emission (ECE) radiometer has been developed to view the J-TEXT tokamak from the low field side. The ECE radiometer detects second-harmonic extraordinary mode in the frequency band of 94-125 GHz which corresponds to resonances from 1.8 T to 2.2 T. This ECE system consists of an ECE transmission line, a radio frequency unit, and two 8-channel intermediate frequency units. An in situ blackbody calibration source is applied for system calibration by comparison of hot and cold sources in order to provide an absolute temperature measurement.
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Affiliation(s)
- Z J Yang
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
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14
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Austin ME, Pandya HKB, Beno J, Bryant AD, Danani S, Ellis RF, Feder R, Hubbard AE, Kumar S, Ouroua A, Phillips PE, Rowan WL. Conceptual Design of the ITER ECE Diagnostic – An Update. EPJ Web of Conferences 2012. [DOI: 10.1051/epjconf/20123203003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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15
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Udintsev VS, Vayakis G, Costley AE, Patel KM, Pitcher CS, Walker CI, Walsh MJ, Benchikhoune M, Bora D, Dammann A, Henderson MA, Levesy B, Tesini A, Danani S, Pandya H, Vasu P, Austin ME, Phillips PE, Rowan WL, Feder R, Johnson D. Progress in the Development of the ITER ECE Diagnostic. Fusion Science and Technology 2011. [DOI: 10.13182/fst11-a11733] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [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)
- V. S. Udintsev
- ITER Organization, Route de Vinon CS 90 046, 13067 St. Paul-lez-Durance Cedex, France
| | - G. Vayakis
- ITER Organization, Route de Vinon CS 90 046, 13067 St. Paul-lez-Durance Cedex, France
| | - A. E. Costley
- ITER Organization, Route de Vinon CS 90 046, 13067 St. Paul-lez-Durance Cedex, France
| | - K. M. Patel
- ITER Organization, Route de Vinon CS 90 046, 13067 St. Paul-lez-Durance Cedex, France
| | - C. S. Pitcher
- ITER Organization, Route de Vinon CS 90 046, 13067 St. Paul-lez-Durance Cedex, France
| | - C. I. Walker
- ITER Organization, Route de Vinon CS 90 046, 13067 St. Paul-lez-Durance Cedex, France
| | - M. J. Walsh
- ITER Organization, Route de Vinon CS 90 046, 13067 St. Paul-lez-Durance Cedex, France
| | - M. Benchikhoune
- ITER Organization, Route de Vinon CS 90 046, 13067 St. Paul-lez-Durance Cedex, France
| | - D. Bora
- ITER Organization, Route de Vinon CS 90 046, 13067 St. Paul-lez-Durance Cedex, France
| | - A. Dammann
- ITER Organization, Route de Vinon CS 90 046, 13067 St. Paul-lez-Durance Cedex, France
| | - M. A. Henderson
- ITER Organization, Route de Vinon CS 90 046, 13067 St. Paul-lez-Durance Cedex, France
| | - B. Levesy
- ITER Organization, Route de Vinon CS 90 046, 13067 St. Paul-lez-Durance Cedex, France
| | - A. Tesini
- ITER Organization, Route de Vinon CS 90 046, 13067 St. Paul-lez-Durance Cedex, France
| | - S. Danani
- Institute for Plasma Research, Bhat, Gandhinagar-382 428 India
| | - H. Pandya
- Institute for Plasma Research, Bhat, Gandhinagar-382 428 India
| | - P. Vasu
- Institute for Plasma Research, Bhat, Gandhinagar-382 428 India
| | - M. E. Austin
- Fusion Research Center, The University of Texas at Austin, Austin, Texas
| | - P. E. Phillips
- Fusion Research Center, The University of Texas at Austin, Austin, Texas
| | - W. L. Rowan
- Fusion Research Center, The University of Texas at Austin, Austin, Texas
| | - R. Feder
- Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey
| | - D. Johnson
- Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey
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Bespamyatnov IO, Rowan WL, Liao KT, Granetz RS. An integrated charge exchange recombination spectroscopy/beam emission spectroscopy diagnostic for Alcator C-Mod tokamak. Rev Sci Instrum 2010; 81:10D709. [PMID: 21033902 DOI: 10.1063/1.3475707] [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 novel integrated charge exchange recombination spectroscopy (CXRS)/beam emission spectroscopy (BES) system is proposed for C-Mod, in which both measurements are taken from a shared viewing geometry. The supplementary BES system serves to quantify local beam densities and supplants the common calculation of beam attenuation. The new system employs two optical viewing arrays, 20 poloidal and 22 toroidal channels. A dichroic filter splits the light between two spectrometers operating at different wavelengths for impurity ion and beam neutrals emission. In this arrangement, the impurity density is inferred from the electron density, measured BES and CXRS spectral radiances, and atomic emission rates.
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Affiliation(s)
- I O Bespamyatnov
- Fusion Research Center, The University of Texas at Austin, Austin, Texas 78712, USA.
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Rowan WL, Bespamyatnov IO, Granetz RS. Wide-view charge exchange recombination spectroscopy diagnostic for Alcator C-Mod. Rev Sci Instrum 2008; 79:10F529. [PMID: 19044672 DOI: 10.1063/1.2979865] [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
This diagnostic measures temperature, density, and rotation for the fully stripped boron ion between the pedestal top and the plasma core with resolution consistent with the profile gradients. The diagnostic neutral beam used for the measurements generates a 50 keV, 6 A hydrogen beam. The optical systems provide views in both poloidal and toroidal directions. The imaging spectrometer is optimized to simultaneously accept 45 views as input with minimum cross-talk. In situ calibration techniques are applied for spatial location, spectral intensity, and wavelength. In the analysis, measured spectra are fitted to a model constructed from a detailed description of the emission physics. Methods for removal of interfering spectra are included. Applications include impurity and thermal transport.
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Affiliation(s)
- W L Rowan
- Fusion Research Center, The University of Texas at Austin, Austin, Texas 78712, USA
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Sciamma EM, Bengtson RD, Rowan WL, Keesee A, Lee CA, Berisford D, Lee K, Gentle KW. Method to estimate the electron temperature and neutral density in a plasma from spectroscopic measurements using argon atom and ion collisional-radiative models. Rev Sci Instrum 2008; 79:10E324. [PMID: 19044486 DOI: 10.1063/1.2953577] [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
We present a method to infer the electron temperature in argon plasmas using a collisional-radiative model for argon ions and measurements of electron density to interpret absolutely calibrated spectroscopic measurements of argon ion (Ar II) line intensities. The neutral density, and hence the degree of ionization of this plasma, can then be estimated using argon atom (Ar I) line intensities and a collisional-radiative model for argon atoms. This method has been tested for plasmas generated on two different devices at the University of Texas at Austin: the helicon experiment and the helimak experiment. We present results that show good correlation with other measurements in the plasma.
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Affiliation(s)
- Ella M Sciamma
- The University of Texas at Austin, 1 University Station Austin, Texas 78712, USA
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19
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Gentle KW, Rowan WL, Bravenec RV, Cima G, Crowley TP, Gasquet H, Hallock GA, Heard J, Ouroua A, Phillips PE, Ross DW, Schoch PM, Watts C. Strong nonlocal effects in a tokamak perturbative transport experiment. Phys Rev Lett 1995; 74:3620-3623. [PMID: 10058251 DOI: 10.1103/physrevlett.74.3620] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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20
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Sugar J, Reader J, Rowan WL. Electric-quadrupole lines of Mo XVI. Phys Rev A 1995; 51:835-837. [PMID: 9911643 DOI: 10.1103/physreva.51.835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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21
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Gentle KW, Richards B, Austin ME, Bravenec RV, Brower DL, Gandy RF, Li WL, Phillips PE, Ross DW, Rowan WL, Schoch PM, Valanju PM, Wootton AJ. Equilibrium and perturbed fluxes and turbulence levels in a tokamak: Implications for models. Phys Rev Lett 1992; 68:2444-2447. [PMID: 10045399 DOI: 10.1103/physrevlett.68.2444] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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22
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Leboeuf J, Lee DK, Carreras BA, Dominguez N, Harris JH, Hedrick CL, Hidalgo C, Holmes JA, Ruiter J, Diamond PH, Ware AS, Ritz CP, Wootton AJ, Rowan WL, Bravenec RV. TEXT tokamak edge turbulence modeling. ACTA ACUST UNITED AC 1991. [DOI: 10.1063/1.859596] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [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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23
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Datla RU, Roberts JR, Woodward N, Lippman S, Rowan WL. Line identifications and radiative-branching ratios of magnetic dipole lines in Si-like Ni, Cu, Zn, Ge, and Se. Phys Rev A Gen Phys 1989; 40:1484-1487. [PMID: 9902284 DOI: 10.1103/physreva.40.1484] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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24
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Ritz CP, Bravenec RV, Schoch PM, Bengtson RD, Boedo JA, Forster JC, Gentle KW, He Y, Hickok RL, Kim YJ, Lin H, Phillips PE, Rhodes TL, Rowan WL, Valanju PM, Wootton AJ. Fluctuation-induced energy flux in the tokamak edge. Phys Rev Lett 1989; 62:1844-1847. [PMID: 10039785 DOI: 10.1103/physrevlett.62.1844] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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25
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Wang JS, Griem HR, Hess R, Rowan WL. Measurement of ionization and recombination rates for FeXVI-Fe XXII from time-resolved spectroscopy of tokamak plasmas. Phys Rev A Gen Phys 1988; 38:4761-4765. [PMID: 9900943 DOI: 10.1103/physreva.38.4761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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26
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Datla RU, Roberts JR, Durst RD, Hodge WL, Klepper CC, Rowan WL, Mann JB. Measurements of excitation rate coefficients for Al-like ions: Fe XIV, Ni XVI, and Cu XVII. Phys Rev A Gen Phys 1987; 36:5448-5450. [PMID: 9898821 DOI: 10.1103/physreva.36.5448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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27
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Wang JS, Griem HR, Rowan WL. Ionization and recombination rates for argon ions Ar XII-XVI from time-resolved spectroscopy of tokamak plasmas. Phys Rev A Gen Phys 1987; 36:951-954. [PMID: 9898945 DOI: 10.1103/physreva.36.951] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Huang LK, Lippmann S, Yu TL, Stratton BC, Moos HW, Finkenthal M, Hodge WL, Rowan WL, Richards B, Phillips PE, Bhatia AK. Experimental determination of line-intensity ratios of transitions within the n=2 complex of Be. Phys Rev A Gen Phys 1987; 35:2919-2927. [PMID: 9898492 DOI: 10.1103/physreva.35.2919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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29
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Roberts JR, Pittman TL, Sugar J, Kaufman V, Rowan WL. Magnetic-dipole wavelength measurements in the n=3 configurations of highly ionized Cu, Zn, Ga, As, Kr, and Y. Phys Rev A Gen Phys 1987; 35:2591-2595. [PMID: 9898449 DOI: 10.1103/physreva.35.2591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Wang JS, Griem HR, Hess R, Rowan WL, Kochanski TP. Ionization and recombination rates for highly ionized titanium ions from time-resolved spectroscopy of tokamak plasmas. Phys Rev A Gen Phys 1986; 33:4293-4306. [PMID: 9897171 DOI: 10.1103/physreva.33.4293] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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32
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Isler RC, Rowan WL, Hodge WL. Long-time impurity confinement as a precursor to disruptions in ohmically heated tokamaks. Phys Rev Lett 1985; 55:2413-2416. [PMID: 10032138 DOI: 10.1103/physrevlett.55.2413] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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