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Shah K, Ghosh J, Patel S, Chowdhuri MB, Jadeja KA, Shukla G, Macwan T, Kumar A, Dolui S, Singh K, Tanna RL, Patel KM, Dey R, Manchanda R, Ramaiya N, Kumar R, Aich S, Yadava N, Purohit S, Gupta MK, Nagora UC, Pathak SK, Atrey PK, Mayya KBK. Role of pinch in Argon impurity transport in ohmic discharges of Aditya-U Tokamak. Sci Rep 2023; 13:16087. [PMID: 37752170 PMCID: PMC10522584 DOI: 10.1038/s41598-023-42746-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Accepted: 09/14/2023] [Indexed: 09/28/2023] Open
Abstract
We present experimental results of the trace argon impurity puffing in the ohmic plasmas of Aditya-U tokamak performed to study the argon transport behaviour. Argon line emissions in visible and Vacuum Ultra Violet (VUV) spectral ranges arising from the plasma edge and core respectively are measured simultaneously. During the experiments, space resolved brightness profile of Ar1+ line emissions at 472.69 nm (3p44s 2P3/2-3p44p 2D3/2), 473.59 nm (3p44s 4P5/2-3p44p 4P3/2), 476.49 nm (3p44s 2P1/2-3p44p 2P3/2), 480.60 nm (3p44s 4P5/2-3p44p 4P5/2) are recorded using a high resolution visible spectrometer. Also, a VUV spectrometer has been used to simultaneously observe Ar13+ line emission at 18.79 nm (2s22p 2P3/2-2s2p2 2P3/2) and Ar14+ line emission at 22.11 nm (2s2 1S0-2s2p 1P1). The diffusivity and convective velocity of Ar are obtained by comparing the measured radial emissivity profile of Ar1+ emission and the line intensity ratio of Ar13+ and Ar14+ ions, with those simulated using the impurity transport code, STRAHL. Argon diffusivities ~ 12 m2/s and ~ 0.3 m2/s have been observed in the edge (ρ > 0.85) and core region of the Aditya-U, respectively. The diffusivity values both in the edge and core region are found to be higher than the neo-classical values suggesting that the argon impurity transport is mainly anomalous in the Aditya-U tokamak. Also, an inward pinch of ~ 10 m/s mainly driven by Ware pinch is required to match the measured and simulated data. The measured peaked profile of Ar density suggests impurity accumulation in these discharges.
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Affiliation(s)
- K Shah
- Department of Physics, Pandit Deendayal Energy University, Raisan, Gandhinagar, 382 007, India.
| | - J Ghosh
- Institute for Plasma Research, Bhat, Gandhinagar, 382 428, India.
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai, 400 094, India.
| | - S Patel
- Department of Physics, Pandit Deendayal Energy University, Raisan, Gandhinagar, 382 007, India
| | - M B Chowdhuri
- Institute for Plasma Research, Bhat, Gandhinagar, 382 428, India
| | - K A Jadeja
- Institute for Plasma Research, Bhat, Gandhinagar, 382 428, India
- Department of Nano Science and Advanced Materials, Saurashtra University, Rajkot, 360 005, India
| | - G Shukla
- ITER-India, Institute for Plasma Research, Koteshwar, Ahmedabad, 380 005, India
| | - T Macwan
- University of California, Los Angeles, CA, 90095, USA
| | - A Kumar
- Institute for Plasma Research, Bhat, Gandhinagar, 382 428, India
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai, 400 094, India
| | - S Dolui
- Institute for Plasma Research, Bhat, Gandhinagar, 382 428, India
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai, 400 094, India
| | - K Singh
- Institute for Plasma Research, Bhat, Gandhinagar, 382 428, India
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai, 400 094, India
| | - R L Tanna
- Institute for Plasma Research, Bhat, Gandhinagar, 382 428, India
- Institute of Science, Nirma University, Ahmedabad, 382 481, India
| | - K M Patel
- Institute for Plasma Research, Bhat, Gandhinagar, 382 428, India
| | - R Dey
- Institute for Plasma Research, Bhat, Gandhinagar, 382 428, India
| | - R Manchanda
- Institute for Plasma Research, Bhat, Gandhinagar, 382 428, India
| | - N Ramaiya
- Institute for Plasma Research, Bhat, Gandhinagar, 382 428, India
| | - R Kumar
- Institute for Plasma Research, Bhat, Gandhinagar, 382 428, India
| | - S Aich
- Institute for Plasma Research, Bhat, Gandhinagar, 382 428, India
| | - N Yadava
- Institute of Science, Nirma University, Ahmedabad, 382 481, India
| | - S Purohit
- Institute for Plasma Research, Bhat, Gandhinagar, 382 428, India
| | - M K Gupta
- Institute for Plasma Research, Bhat, Gandhinagar, 382 428, India
| | - U C Nagora
- Institute for Plasma Research, Bhat, Gandhinagar, 382 428, India
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai, 400 094, India
| | - S K Pathak
- Institute for Plasma Research, Bhat, Gandhinagar, 382 428, India
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai, 400 094, India
| | - P K Atrey
- Institute for Plasma Research, Bhat, Gandhinagar, 382 428, India
| | - K B K Mayya
- Department of Physics, Pandit Deendayal Energy University, Raisan, Gandhinagar, 382 007, India
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Shukla G, Chowdhuri MB, Shah K, Manchanda R, Ramaiya N, Tanna RL, Mayya KBK, Ghosh J. Impurity toroidal rotation profile measurement using upgraded high-resolution visible spectroscopic diagnostic on ADITYA-U tokamak. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:063517. [PMID: 34243548 DOI: 10.1063/5.0043789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 05/28/2021] [Indexed: 06/13/2023]
Abstract
A high-resolution spectroscopic diagnostic for the measurement of spatial profiles of impurity ion toroidal rotation velocities on the ADITYA-U tokamak has been upgraded to cover the complete plasma minor radius. Earlier, the coverage of diagnostics toward the plasma edge was restricted due to the placement of collection optics on the tangential port outside the vacuum vessel. The coverage of the full plasma minor radius, from 0 to 24 cm, has been achieved using the newly designed and developed collection optics that have seven lines of sight to view the tokamak plasma mounted inside a customized re-entrant view port which is installed in the shadow of the limiter inside the vacuum vessel. The upgraded diagnostic also includes a faster charged coupled device detector with a smaller pixel size for the detection of a small wavelength shift. The complete spatial profile has been measured using the Doppler shifted passive change exchange spectral line at 529.0 nm from the C5+ ion. In this article, we present the collection optics' design, installation, calibration, and results obtained using the upgraded diagnostic.
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Affiliation(s)
- G Shukla
- Department of Science, Pandit Deendayal Petroleum University, Gandhinagar 382 007, India
| | - M B Chowdhuri
- Institute for Plasma Research, Bhat, Gandhinagar 382 428, India
| | - K Shah
- Department of Science, Pandit Deendayal Petroleum University, Gandhinagar 382 007, India
| | - R Manchanda
- Institute for Plasma Research, Bhat, Gandhinagar 382 428, India
| | - N Ramaiya
- Institute for Plasma Research, Bhat, Gandhinagar 382 428, India
| | - R L Tanna
- Institute for Plasma Research, Bhat, Gandhinagar 382 428, India
| | - K B K Mayya
- Department of Science, Pandit Deendayal Petroleum University, Gandhinagar 382 007, India
| | - J Ghosh
- Institute for Plasma Research, Bhat, Gandhinagar 382 428, India
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