1
|
Chen M, Zhu Y, Luo C, Shi L, Tobias BJ, Luhmann NC. Synthetic diagnostic for electron cyclotron emission imaging. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:10H117. [PMID: 30399739 DOI: 10.1063/1.5035426] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Accepted: 06/20/2018] [Indexed: 06/08/2023]
Abstract
Synthetic diagnostics are aimed at simulating the response of diagnostic systems under actual experimental scenarios and are the key to drawing quantitative inferences from experimental data. The synthetic Electron Cyclotron Emission Imaging (ECEI) diagnostic is suitable for evaluation of the improvement arising from the application of Field Curvature Adjustment (FCA) lenses in the design of the upgraded Experimental Advanced Superconducting Tokamak (EAST) tokamak ECEI system. In previous ECEI systems, a curved image plane is inevitable in optics systems comprising only convex lenses, which leads to significant crosstalk between vertically adjacent channels and strongly limits the vertical channel resolution of the imaging system. The synthetic ECEI diagnostic results show that, with FCA lenses applied, the upgraded ECEI system has significant advantages to focus on high poloidal wavenumber structures with the aberrations from the spherical surfaces corrected and the various artifacts related to the field curvature suppressed. Also, the synthetic ECEI diagnostic is used for some quantitative calculations to partially decouple the effect of density fluctuations and temperature fluctuations for a given plasma.
Collapse
Affiliation(s)
- M Chen
- Department of Electrical and Computer Engineering, University of California, Davis, California 95616, USA
| | - Y Zhu
- Department of Electrical and Computer Engineering, University of California, Davis, California 95616, USA
| | - C Luo
- Department of Electrical and Computer Engineering, University of California, Davis, California 95616, USA
| | - L Shi
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
| | - B J Tobias
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - N C Luhmann
- Department of Electrical and Computer Engineering, University of California, Davis, California 95616, USA
| |
Collapse
|
2
|
Li JX, Zhu YL, Chen M, Cao JH, Dannenberg J, Domier C, Luhmann NC. A new method of out-of-focus millimeter wave imaging in fusion plasma diagnostics using Bessel beams. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:093506. [PMID: 30278691 DOI: 10.1063/1.5012778] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 08/26/2018] [Indexed: 06/08/2023]
Abstract
Electron cyclotron emission imaging (ECEI) and microwave imaging reflectometry diagnostics have been employed on a number of magnetic fusion plasma confinement devices. The common approach is based on a Gaussian beam assumption, which generates good spatial resolution (centimeter level). However, the radial focal depth is limited by the poloidal resolution, which is comparable with the Rayleigh length (∼150 mm). By contrast, a new Bessel beam approach has been developed and demonstrated to generate much longer focal depth with the property of propagation stability. To test the new approach, the DIII-D tokamak LCP ECEI optics have been re-designed to support a Bessel beam approach based on an axicon lens. The achievable radial coverage can exceed that of the current Gaussian approach by 3×. The imaging result is discussed in this paper based on the simulation analysis and laboratory testing result.
Collapse
Affiliation(s)
- J X Li
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Y L Zhu
- University of California at Davis, Davis, California 95616, USA
| | - M Chen
- University of California at Davis, Davis, California 95616, USA
| | - J H Cao
- University of California at Davis, Davis, California 95616, USA
| | - J Dannenberg
- University of California at Davis, Davis, California 95616, USA
| | - C Domier
- University of California at Davis, Davis, California 95616, USA
| | - N C Luhmann
- University of California at Davis, Davis, California 95616, USA
| |
Collapse
|
3
|
Zhou T, Liu Y, Ti A, Figini L, Zhao H, Zhu Z, Ling B. Synthetic Diagnostic for Interpreting the ECE Spectrum on EAST. FUSION SCIENCE AND TECHNOLOGY 2018. [DOI: 10.1080/15361055.2017.1396165] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Tianfu Zhou
- Chinese Academy of Sciences, Institute of Plasma Physics, Hefei 230031, China
| | - Yong Liu
- Chinese Academy of Sciences, Institute of Plasma Physics, Hefei 230031, China
| | - Ang Ti
- Chinese Academy of Sciences, Institute of Plasma Physics, Hefei 230031, China
| | | | - Hailin Zhao
- Chinese Academy of Sciences, Institute of Plasma Physics, Hefei 230031, China
| | - Zeying Zhu
- Chinese Academy of Sciences, Institute of Plasma Physics, Hefei 230031, China
| | - Bili Ling
- Chinese Academy of Sciences, Institute of Plasma Physics, Hefei 230031, China
| |
Collapse
|
4
|
Zhu YL, Xie JL, Yu CX, Zhao ZL, Gao BX, Chen DX, Liu WD, Liao W, Qu CM, Luo C, Hu X, Spear AG, Luhmann NC, Domier CW, Chen M, Ren X, Tobias BJ. Millimeter-wave imaging diagnostics systems on the EAST tokamak (invited). THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:11D901. [PMID: 27910310 DOI: 10.1063/1.4959162] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Millimeter-wave imaging diagnostics, with large poloidal span and wide radial range, have been developed on the EAST tokamak for visualization of 2D electron temperature and density fluctuations. A 384 channel (24 poloidal × 16 radial) Electron Cyclotron Emission Imaging (ECEI) system in F-band (90-140 GHz) was installed on the EAST tokamak in 2012 to provide 2D electron temperature fluctuation images with high spatial and temporal resolution. A co-located Microwave Imaging Reflectometry (MIR) will be installed for imaging of density fluctuations by December 2016. This "4th generation" MIR system has eight independent frequency illumination beams in W-band (75-110 GHz) driven by fast tuning synthesizers and active multipliers. Both of these advanced millimeter-wave imaging diagnostic systems have applied the latest techniques. A novel design philosophy "general optics structure" has been employed for the design of the ECEI and MIR receiver optics with large aperture. The extended radial and poloidal coverage of ECEI on EAST is made possible by innovations in the design of front-end optics. The front-end optical structures of the two imaging diagnostics, ECEI and MIR, have been integrated into a compact system, including the ECEI receiver and MIR transmitter and receiver. Two imaging systems share the same mid-plane port for simultaneous, co-located 2D fluctuation measurements of electron density and temperature. An intelligent remote-control is utilized in the MIR electronics systems to maintain focusing at the desired radial region even with density variations by remotely tuning the probe frequencies in about 200 μs. A similar intelligent technique has also been applied on the ECEI IF system, with remote configuration of the attenuations for each channel.
Collapse
Affiliation(s)
- Y L Zhu
- School of Physics, University of Science and Technology of China, Anhui 230026, China
| | - J L Xie
- School of Physics, University of Science and Technology of China, Anhui 230026, China
| | - C X Yu
- School of Physics, University of Science and Technology of China, Anhui 230026, China
| | - Z L Zhao
- School of Physics, University of Science and Technology of China, Anhui 230026, China
| | - B X Gao
- School of Physics, University of Science and Technology of China, Anhui 230026, China
| | - D X Chen
- School of Physics, University of Science and Technology of China, Anhui 230026, China
| | - W D Liu
- School of Physics, University of Science and Technology of China, Anhui 230026, China
| | - W Liao
- School of Physics, University of Science and Technology of China, Anhui 230026, China
| | - C M Qu
- School of Physics, University of Science and Technology of China, Anhui 230026, China
| | - C Luo
- School of Physics, University of Science and Technology of China, Anhui 230026, China
| | - X Hu
- University of California, Davis, California 95616, USA
| | - A G Spear
- University of California, Davis, California 95616, USA
| | - N C Luhmann
- University of California, Davis, California 95616, USA
| | - C W Domier
- University of California, Davis, California 95616, USA
| | - M Chen
- University of California, Davis, California 95616, USA
| | - X Ren
- University of California, Davis, California 95616, USA
| | - B J Tobias
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| |
Collapse
|
5
|
Shi L, Valeo EJ, Tobias BJ, Kramer GJ, Hausammann L, Tang WM, Chen M. Synthetic diagnostics platform for fusion plasmas (invited). THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:11D303. [PMID: 27910444 DOI: 10.1063/1.4961553] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A Synthetic Diagnostics Platform (SDP) for fusion plasmas has been developed which provides state of the art synthetic reflectometry, beam emission spectroscopy, and Electron Cyclotron Emission (ECE) diagnostics. Interfaces to the plasma simulation codes GTC, XGC-1, GTS, and M3D-C1 are provided, enabling detailed validation of these codes. In this paper, we give an overview of SDP's capabilities, and introduce the synthetic diagnostic modules. A recently developed synthetic ECE Imaging module which self-consistently includes refraction, diffraction, emission, and absorption effects is discussed in detail. Its capabilities are demonstrated on two model plasmas. The importance of synthetic diagnostics in validation is shown by applying the SDP to M3D-C1 output and comparing it with measurements from an edge harmonic oscillation mode on DIII-D.
Collapse
Affiliation(s)
- L Shi
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA
| | - E J Valeo
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA
| | - B J Tobias
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA
| | - G J Kramer
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA
| | - L Hausammann
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA
| | - W M Tang
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA
| | - M Chen
- Department of Mechanical and Aerospace Engineering, University of California, Davis, California 95616, USA
| |
Collapse
|