Implementation of low temperature spectrometers for the JET high resolution Thomson scattering diagnostic for disruption plasma measurements

Journal Article · 21 July 2024 · Review of Scientific Instruments

DOI: https://doi.org/10.1063/5.0220344 · OSTI ID:2432524

Huang, Zhouji  ^[1]; Kos, D.  ^[1]; Maslov, M.  ^[1]; Scannell, R.  ^[1]; Clark, J.  ^[2]; Ficker, O.  ^[3]; Jachmich, S. ^[4]; Lehnen, M.  ^[4]; Reux, C. ^[5]; Sheikh, U.  ^[6]

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1. UK Atomic Energy Authority Research Group, Abingdon (United Kingdom). Culham Laboratory
2. Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
3. Czech Academy of Sciences (CAS), Prague (Czech Republic). Institute of Plasma Physics
4. ITER Organization, St. Paul Lez Durance (France)
5. CEA, IRFM, Saint Paul Lez Durance (France)
6. Ecole Polytechnique Federale Lausanne (EPFL) (Switzerland)

This work presents a system upgrade of the High Resolution Thomson Scattering (HRTS) diagnostic on JET that allows it to measure low temperature (1–500 eV) plasma pre- and post-Thermal quench (TQ), which would help us further understand the Shattered Pellet Injection (SPI) physics. The upgrade was done by connecting optic fibers from the original HRTS system to four spectrometers specialized in measuring low temperature plasmas. The upgraded system allows for the measurement of low temperature plasma at up to 12 spatial points, which can be flexibly distributed throughout the JET outer midplane profile during the dedicated SPI experiments. In other JET experiments, four previously unused groups of fibers were used to measure the central plasma to provide disruption data without changing the standard HRTS system. The low temperature Thomson scattering system was installed, commissioned, and cross-calibrated against the standard HRTS diagnostic in a calibration pulse. The system worked reliably during the JET experiments and provided electron density and temperature profiles for pre- and post-TQ low temperature plasmas in the SPI campaign.

• Research Organization: Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
• Sponsoring Organization: UK Research and Innovation (UKRI); USDOE
• Contributing Organization: The JET Contributors
• Grant/Contract Number: AC02-09CH11466
• OSTI ID: 2432524
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 7 Vol. 95; ISSN 0034-6748
• Publisher: American Institute of Physics (AIP)Copyright Statement
• Country of Publication: United States
• Language: English