Development and calibration of a multi-delay coherence imaging diagnostic on the MAST-U tokamak.

Doyle, R S; Lonigro, N; Allcock, J S; Silburn, S A; Turner, M M; Feng, X; Leggate, H

Abstract

The MAST-U Super-X divertor provides the opportunity to study fusion plasma exhaust under novel conditions. However, in order to study these conditions, advanced diagnostics are required. Following the development of the MAST-U Multi-Wavelength Imaging (MWI) diagnostic, we present the installation of a multi-delay coherence imaging spectroscopy (CIS) system within the MAST-U MWI, along with modifications made to the MWI for effective operation. This diagnostic will measure either carbon ion flow velocities and temperatures or electron densities through Dγ emission. We have extended previously developed techniques for wavelength calibration to account for errors due to the misalignment of interferometer components. In addition, we have developed a comprehensive calibration procedure to account for the temperature dependence of the instrument's delays by fitting to a linearly modified version of the delay equation presented by Veiras et al. [Appl. Opt. 49(15), 2769 (2010)]. Together, these procedures reduce the cost and hardware complexity of implementing CIS instruments when compared to those that use in situ or tunable laser calibration systems, as calibrations can be generated to good accuracy using previously measured data. [Abstract copyright: © 2024 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC) license (https://creativecommons.org/licenses/by-nc/4.0/).]

Citation

Doyle, R. S., Lonigro, N., Allcock, J. S., Silburn, S. A., Turner, M. M., Feng, X., & Leggate, H. (2024). Development and calibration of a multi-delay coherence imaging diagnostic on the MAST-U tokamak. Review of Scientific Instruments, 95(5), Article 053505. https://doi.org/10.1063/5.0205584

• Journal Article Type: Article
• Acceptance Date: Apr 25, 2024
• Online Publication Date: May 1, 2024
• Publication Date: May 1, 2024
• Deposit Date: Jun 12, 2024
• Publicly Available Date: Jun 12, 2024
• Journal: Review of Scientific Instruments
• Print ISSN: 0034-6748
• Electronic ISSN: 1089-7623
• Publisher: American Institute of Physics
• Peer Reviewed: Peer Reviewed
• Volume: 95
• Issue: 5
• Article Number: 053505
• DOI: https://doi.org/10.1063/5.0205584
• Public URL: https://durham-repository.worktribe.com/output/2471696