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Su P, Zhong H, Tan Y, Gao Z, Zai Y, Liu H, Zeng L, Zhu X, Ling B, Cheng Z, Liu W, Wang S, Wang B. Implementation and data processing of a five-channel microwave interferometer with high temporal resolution and low noise on Sino-UNIted Spherical Tokamak. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:043538. [PMID: 34243439 DOI: 10.1063/5.0043667] [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: 03/18/2021] [Indexed: 06/13/2023]
Abstract
A five-channel microwave interferometer with high temporal resolution and high phase resolution has been developed for measuring electron density profiles and fluctuations on the Sino-UNIted Spherical Tokamak. A correction algorithm, based on the low signal amplitude detection, is proposed to eliminate the fringe jump errors. The correction algorithm achieves an accuracy of 92%. The density profile is reconstructed through the Park-matrix method, with the geometry of magnetic surfaces calculated by the equilibrium fitting. The reconstructed density profiles for discharges with supersonic molecular beam injection are in good agreement with the results of another 94 GHz single-channel horizontal interferometer and the Langmuir probes. The temporal resolution of the system is 0.5 µs and the line-integrated electron density resolution is 1 × 1015 m-2, which benefits from the single sideband modulation technique. Therefore, the multichannel interferometer system is capable of studying the details of the high-frequency (up to 200 kHz) density fluctuation such as that in the minor disruption event.
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Affiliation(s)
- Pengjuan Su
- Department of Engineering Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Heng Zhong
- Department of Engineering Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Yi Tan
- Department of Engineering Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Zhe Gao
- Department of Engineering Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Yingqi Zai
- Department of Engineering Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Haiqing Liu
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, People's Republic of China
| | - Long Zeng
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, People's Republic of China
| | - Xiang Zhu
- Advanced Energy Research Center, Shenzhen University, Shenzhen 518060, People's Republic of China
| | - Bili Ling
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031, People's Republic of China
| | - Zhengbo Cheng
- Department of Engineering Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Wenbin Liu
- Department of Engineering Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Shouzhi Wang
- Department of Engineering Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Binbin Wang
- Department of Engineering Physics, Tsinghua University, Beijing 100084, People's Republic of China
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Boboc A, Gil C, Pastor P, Spuig P, Edlington T, Dorling S. Upgrade of the JET far infrared interferometer diagnostic. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:10E341. [PMID: 23130803 DOI: 10.1063/1.4737420] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In recent years there has been a major upgrade of the JET far infrared diagnostic system consisting of a new laser system with the wavelength at 118.8 μm at and more advanced processing electronics for phase counting. This provides a second colour measurement of the electron plasma density on the vertical system. Due to the shorter wavelength, the plasma induced laser beam refraction is reduced by a factor of three alleviating density errors caused by loss of signal (so-called "fringe jumps" [A. Murari et al., Rev. Sci. Instrum. 77, 073505 (2006)]), in particular during high performance plasmas experiments in JET.
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Affiliation(s)
- A Boboc
- EURATOM/CCFE Association, Culham Science Centre, Abingdon, United Kingdom.
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