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Kawachi Y, Ogawa K, Osakabe M, Kawamoto Y, Isobe M, Ida K. Fast-sampling fast-ion D-alpha measurement using multi-anode photomultiplier tube in large helical device. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2023; 94:103505. [PMID: 37819204 DOI: 10.1063/5.0159175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Accepted: 09/20/2023] [Indexed: 10/13/2023]
Abstract
A fast-sampling fast-ion D-alpha (F-FIDA) measurement has been developed in the large helical device in order to investigate fast ion dynamics associated with helically trapped fast-ion-driven Magnetohydrodynamic (MHD) bursts. F-FIDA consists of a multi-anode photomultiplier tube (PMT) and achieves a sampling rate of 10 kHz. During the deuterium experiment campaign in 2022, F-FIDA measured the spectrum of perpendicular fast ions, using perpendicular lines of sight. We compared F-FIDA with conventional FIDA, using an electron multiplying charge coupled device, and confirmed that the time-averaged images were generally consistent between the two. The statistical properties of the temporal evolution associated with MHD bursts were analyzed using a conditional sampling technique. The results showed that the PMT signal varied in different spatial and wavelength channels. Although the signal-to-noise ratio was poor and there was room for improvement, it could provide useful information for studies on the phase-space dynamics of fast ions.
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Affiliation(s)
- Y Kawachi
- Department of Electronics, Kyoto Institute of Technology, Matsugasaki, Sakyo Ward, Kyoto 606-8585, Japan
| | - K Ogawa
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki, Gifu 509-5292, Japan
- The Graduate University for Advanced Studies, SOKENDAI, Toki, Japan
| | - M Osakabe
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki, Gifu 509-5292, Japan
- The Graduate University for Advanced Studies, SOKENDAI, Toki, Japan
| | - Y Kawamoto
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki, Gifu 509-5292, Japan
- The Graduate University for Advanced Studies, SOKENDAI, Toki, Japan
| | - M Isobe
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki, Gifu 509-5292, Japan
- The Graduate University for Advanced Studies, SOKENDAI, Toki, Japan
| | - K Ida
- National Institute for Fusion Science, National Institutes of Natural Sciences, Toki, Gifu 509-5292, Japan
- The Graduate University for Advanced Studies, SOKENDAI, Toki, Japan
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Hou YM, Zhou HY, Chen W, Hao BL, Liu Y, Shi ZB, Zhang YP, Duan XR. Design and first measurements of the fast-ion D-alpha diagnostic at the HL-2A tokamak. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2023; 94:033508. [PMID: 37012805 DOI: 10.1063/5.0099281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 02/23/2023] [Indexed: 06/19/2023]
Abstract
The fast-ion D-alpha diagnostic (FIDA) is employed to detect Dα light emitted by neutralized fast ions during neutral beam injection. A tangentially viewing FIDA has been developed for the HuanLiuqi-2A (HL-2A) tokamak and typically achieves temporal and transverse spatial resolutions of ∼30 ms and ∼5 cm, respectively. A fast-ion tail on the red shifted wing of the FIDA spectrum is obtained and analyzed with the Monte Carlo code FIDASIM. Good agreement has been presented between the measured and simulated spectra. As the FIDA diagnostic's lines of sight intersect the central axis of neutral beam injection with small angles, the beam emission spectrum is observed with a large Doppler shift. Thus, tangentially viewing FIDA could detect only a small portion of fast ions with an energy of ≈ 20 ∼ 31 keV and a pitch angle of ≈ -1 ∼ -0.8. A second FIDA installation with oblique viewing is designed to minimize spectral contaminants.
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Affiliation(s)
- Y M Hou
- Southwestern Institute of Physics, Chengdu 610041, China
| | - H Y Zhou
- Southwestern Institute of Physics, Chengdu 610041, China
| | - W Chen
- Southwestern Institute of Physics, Chengdu 610041, China
| | - B L Hao
- Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China
| | - Y Liu
- Southwestern Institute of Physics, Chengdu 610041, China
| | - Z B Shi
- Southwestern Institute of Physics, Chengdu 610041, China
| | - Y P Zhang
- Southwestern Institute of Physics, Chengdu 610041, China
| | - X R Duan
- Southwestern Institute of Physics, Chengdu 610041, China
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Mencke JE, Moseev D, Salewski M, Larsen MR, Schmidt BS, Järleblad H, Lazerson S, Poloskei PZ, Ford O. Characterization of correlations of fast-ion H-alpha measurement volumes in Wendelstein 7-X by particle tracking. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:123503. [PMID: 36586887 DOI: 10.1063/5.0128594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 11/11/2022] [Indexed: 06/17/2023]
Abstract
This paper characterizes the correlation of simultaneous measurements with different fast-ion H-alpha (FIDA) spectroscopy sightlines on Wendelstein 7-X. Using a collisionless guiding-center code, it is shown that, for two investigated volumes in the bulk of the plasma, some regions of phase space are correlated and the magnetic configuration has little influence on this correlation. For the sightlines of the FIDA system, the correlation between these is explained well by the magnetic configuration. Sightlines with measurement volumes at the same spatial locations have the highest correlation, and sightlines with measurement volumes near the same flux surface but on different sides of the magnetic axis have a high correlation. The correlation between the blueshifted signal in the starting sightline and redshifted signal in the detection sightline is investigated, demonstrating that it is possible to investigate any finite interval of detection wavelengths. Due to the different shapes of the weight functions for the toroidal and oblique sightlines, the blue-redshift correlation is very different from the total-spectrum correlation. The correlation between the toroidal and oblique sightline fans is relatively much larger than the internal correlation in the oblique sightlines, which is however, much larger than the internal correlation in the toroidal sightlines. This is a result of the dependence of the weight functions on the angle between the sightline and magnetic field, illustrating how important it is for the FIDA sightlines to cover different angles with the magnetic field.
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Affiliation(s)
- Jacob Emil Mencke
- Department of Physics, Technical University of Denmark, Fysikvej, 2800 Kgs. Lyngby, Denmark
| | - Dmitry Moseev
- Max-Planck-Institut fuer Plasmaphysik, Wendelsteinstraße 1, 17491 Greifswald, Germany
| | - Mirko Salewski
- Department of Physics, Technical University of Denmark, Fysikvej, 2800 Kgs. Lyngby, Denmark
| | - Mads Rud Larsen
- Department of Physics, Technical University of Denmark, Fysikvej, 2800 Kgs. Lyngby, Denmark
| | | | - Henrik Järleblad
- Department of Physics, Technical University of Denmark, Fysikvej, 2800 Kgs. Lyngby, Denmark
| | - Samuel Lazerson
- Max-Planck-Institut fuer Plasmaphysik, Wendelsteinstraße 1, 17491 Greifswald, Germany
| | - Peter Zsolt Poloskei
- Max-Planck-Institut fuer Plasmaphysik, Wendelsteinstraße 1, 17491 Greifswald, Germany
| | - Oliver Ford
- Max-Planck-Institut fuer Plasmaphysik, Wendelsteinstraße 1, 17491 Greifswald, Germany
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Zhang J, Huang J, Chang JF, Wu CR, Heidbrink WW, Salewski M, Madsen B, Zhu YB, von Hellermann MG, Gao W, Xu Z, Wan B. Fast ion D-alpha measurements using a bandpass-filtered system on EAST. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:10D121. [PMID: 30399922 DOI: 10.1063/1.5038828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Accepted: 06/15/2018] [Indexed: 06/08/2023]
Abstract
Based on the charge exchange reaction between fast ions and a neutral beam, fast ion features can be inferred from the spectrum of Doppler-shifted Balmer-alpha light from energetic hydrogenic atoms. In order to study the interaction between instabilities and fast-ion transport, recently we extended the fast ion D-alpha (FIDA) measurements by using a combination of a bandpass filter and a photomultiplier tube (PMT) (f-FIDA). A bandpass filter selects the desired spectral band from 651 nm to 654 nm before detection by the PMT. Preliminary data from the EAST tokamak show that the active signals have been detected from reneutralized beam ions along the vertical and tangential viewing geometries. The details will be presented in this paper to primarily address the specifications and performance of f-FIDA hardware components and preliminary FIDA measurements.
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Affiliation(s)
- J Zhang
- Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031 Hefei, Anhui, China
| | - J Huang
- Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031 Hefei, Anhui, China
| | - J F Chang
- Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031 Hefei, Anhui, China
| | - C R Wu
- Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031 Hefei, Anhui, China
| | - W W Heidbrink
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
| | - M Salewski
- Department of Physics, Technical University of Denmark, Kongens Lyngby, Denmark
| | - B Madsen
- Department of Physics, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Y B Zhu
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
| | | | - W Gao
- Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031 Hefei, Anhui, China
| | - Z Xu
- Advanced Energy Research Center, Shenzhen University, Shenzhen 518060, People's Republic of China
| | - B Wan
- Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031 Hefei, Anhui, China
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