Dual-pass upgrade to the Thomson scattering diagnostic on the Prototype-Material Plasma Exposure eXperiment (Proto-MPEX)

Kafle, N.; Biewer, T. M.; Donovan, D. C.

doi:10.1063/1.5039370

Dual-pass upgrade to the Thomson scattering diagnostic on the Prototype-Material Plasma Exposure eXperiment (Proto-MPEX)

Journal Article · Thu Aug 16 04:00:00 EDT 2018 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.5039370· OSTI ID:1464859

; ;

The Thomson scattering (TS) diagnostic on the Prototype-Material Plasma Exposure eXperiment has been upgraded to measure electron temperature (Te) and density (ne) simultaneously at two axial locations. After the first pass through the vacuum vessel, the exiting laser beamline is re-collimated in the atmosphere and rerouted into the vacuum vessel for the second pass. The upgrade will help diagnose axial Te and ne gradients between the “central chamber” and the target region which are located 1 m and 2.5 m, respectively, downstream from the Helicon radio-frequency source. The TS measurements have given Te ≈ 4–15 eV and ne ≈ 2–4 × 1019 m−3 at the central chamber and Te ≈ 1–2 eV and ne ≈ 1–2 × 1019 m−3 at the target region. The upgrade also increases the number of sampling points at the target region from 3 fibers to 5 fibers, measuring 3 cm radially across the plasma column, and 25 fibers in the central chamber, radially spanning 8 cm. The intensified CCD camera is double triggered for each laser pulse in order to measure (1) the TS and laser stray light and (2) the plasma background light that contains nuisance emission lines and bremsstrahlung. Subtracting the background light from the TS photons improves the temperature and density measurements. Details of the diagnostic setup, axial and radial measurements, and areas for further optimization are discussed.

Sponsoring Organization:: USDOE

Grant/Contract Number:: AC05-00OR22725

OSTI ID:: 1464859

Alternate ID(s):: OSTI ID: 1607299

Journal Information:: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 10 Vol. 89; ISSN 0034-6748

Publisher:: American Institute of PhysicsCopyright Statement

Country of Publication:: United States

Language:: English

References (10)

Thomson scattering of plasma turbulence on PSI-2 Hubeny, M.; Schweer, B.; Luggenhölscher, D. Nuclear Materials and Energy, Vol. 12 https://doi.org/10.1016/j.nme.2016.12.006	journal	August 2017
Laser Thomson scattering system applicable to low-temperature plasma in the divertor simulator MAP-II Okamoto, A.; Kado, S.; Kajita, S. Review of Scientific Instruments, Vol. 76, Issue 11 https://doi.org/10.1063/1.2135281	journal	November 2005
Advanced Thomson scattering system for high-flux linear plasma generator van der Meiden, H. J.; Lof, A. R.; van den Berg, M. A. Review of Scientific Instruments, Vol. 83, Issue 12 https://doi.org/10.1063/1.4768527	journal	December 2012
Preface: Proceedings of the 20th Topical Conference on High-Temperature Plasma Diagnostics, Atlanta, Georgia, USA, 1–5 June 2014 Biewer, T. M.; Hillis, D. L. Review of Scientific Instruments, Vol. 85, Issue 11 https://doi.org/10.1063/1.4890410	journal	November 2014
First results from the Thomson scattering diagnostic on proto-MPEX Biewer, T. M.; Meitner, S.; Rapp, J. Review of Scientific Instruments, Vol. 87, Issue 11 https://doi.org/10.1063/1.4959163	journal	August 2016
High resolution Thomson scattering system for steady-state linear plasma sources Lee, K. Y.; Lee, K. I.; Kim, J. H. Review of Scientific Instruments, Vol. 89, Issue 1 https://doi.org/10.1063/1.5003723	journal	January 2018
Plasma flow measurements in the Prototype-Material Plasma Exposure eXperiment (Proto-MPEX) and comparison with B2.5-Eirene modeling Kafle, N.; Owen, L. W.; Caneses, J. F. Physics of Plasmas, Vol. 25, Issue 5 https://doi.org/10.1063/1.5019266	journal	May 2018
The Challenges of Plasma Material Interactions in Nuclear Fusion Devices and Potential Solutions Rapp, J. Fusion Science and Technology https://doi.org/10.1080/15361055.2017.1333859	journal	June 2017
Laser light scattering in laboratory plasmas Evans, D. E.; Katzenstein, J. Reports on Progress in Physics, Vol. 32, Issue 1 https://doi.org/10.1088/0034-4885/32/1/305	journal	January 1969
Developing the science and technology for the Material Plasma Exposure eXperiment Rapp, J.; Biewer, T. M.; Bigelow, T. S. Nuclear Fusion, Vol. 57, Issue 11 https://doi.org/10.1088/1741-4326/aa7b1c	journal	July 2017

Similar Records

Dual-pass upgrade to the Thomson scattering diagnostic on the Prototype-Material Plasma Exposure eXperiment (Proto-MPEX)

Conference · Mon Oct 01 00:00:00 EDT 2018 · OSTI ID:1607299

Observations of electron heating during 28 GHz microwave power application in proto-MPEX

Journal Article · Mon Feb 19 23:00:00 EST 2018 · Physics of Plasmas · OSTI ID:1429196

First results from the Thomson scattering diagnostic on Proto-MPEX

Conference · Thu Dec 31 23:00:00 EST 2015 · OSTI ID:1295137

Dual-pass upgrade to the Thomson scattering diagnostic on the Prototype-Material Plasma Exposure eXperiment (Proto-MPEX)

Citation Formats

References (10)

Similar Records

Related Subjects