Advances in Low-Temperature Tungsten Spectroscopy Capability to Quantify DIII-D Divertor Erosion

doi:10.1109/TPS.2018.2797691

Title: Advances in Low-Temperature Tungsten Spectroscopy Capability to Quantify DIII-D Divertor Erosion

Abstract

Recent emphasis of tungsten (W) plasma–material interaction experiments on DIII-D has made it essential to enhance the W I and W II measurement capabilities of its spectroscopy diagnostic suite to acquire W sourcing measurements with high temporal, spatial, and wavelength resolution. To this end, four new viewing chords for the multichordal divertor spectrometer and divertor filterscope systems were installed, leading to a 7× increase in blue-light sensitivity. W I and low-Z impurity line identifications were performed in the 3995–4030 Å region, placing wavelengths within 0.1 Å of the National Institute of Standards and Technology values. A novel method was also developed for the DIII-D high-temporal resolution filterscopes to distinguish between W I light and background contamination, important due to the relatively weak intensity of this line, using two different bandpass filters with different widths but the same center wavelength. Finally, fast imaging of the W I 4008.75 Å spectral line with a PCO Pixelfly VGA 200/205 camera is allowed for discrimination between intra-edge-localized mode (ELM) and inter-ELM W I emission profiles with very high (~1 mm) spatial resolution.

Authors:

^[1]; Thomas, Daniel M. ^[1];

^[2]; Briesemeister, Alexis R. ^[2]

General Atomics, San Diego, CA (United States)
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Publication Date:: 2018-05-01

Research Org.:: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); General Atomics, San Diego, CA (United States)

Sponsoring Org.:: USDOE

OSTI Identifier:: 1436931

Alternate Identifier(s):: OSTI ID: 1435687

Grant/Contract Number:: [AC05-00OR22725; FC02-04ER54698]

Resource Type:: Accepted Manuscript

Journal Name:: IEEE Transactions on Plasma Science

Additional Journal Information:: [ Journal Volume: 46; Journal Issue: 5]; Journal ID: ISSN 0093-3813

Publisher:: IEEE

Country of Publication:: United States

Language:: English

Subject:: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; tungsten; lenses; plasma measurements; spectroscopy; spatial resolution; optical spectroscopy; plasma diagnostics; plasma-material interactions (PMIs); tokamaks

Citation Formats


                    Abrams, Tyler, Thomas, Daniel M., Unterberg, Ezekial A., and Briesemeister, Alexis R. Advances in Low-Temperature Tungsten Spectroscopy Capability to Quantify DIII-D Divertor Erosion.  United States: N. p., 2018. 
        Web.  doi:10.1109/TPS.2018.2797691.

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                    Abrams, Tyler, Thomas, Daniel M., Unterberg, Ezekial A., & Briesemeister, Alexis R. Advances in Low-Temperature Tungsten Spectroscopy Capability to Quantify DIII-D Divertor Erosion.  United States.  doi:10.1109/TPS.2018.2797691.

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                    Abrams, Tyler, Thomas, Daniel M., Unterberg, Ezekial A., and Briesemeister, Alexis R. Tue .  
        "Advances in Low-Temperature Tungsten Spectroscopy Capability to Quantify DIII-D Divertor Erosion".  United States.  doi:10.1109/TPS.2018.2797691.  https://www.osti.gov/servlets/purl/1436931.

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@article{osti_1436931,

  title        = {Advances in Low-Temperature Tungsten Spectroscopy Capability to Quantify DIII-D Divertor Erosion},

  author       = {Abrams, Tyler and Thomas, Daniel M. and Unterberg, Ezekial A. and Briesemeister, Alexis R.},

  abstractNote = {Recent emphasis of tungsten (W) plasma–material interaction experiments on DIII-D has made it essential to enhance the W I and W II measurement capabilities of its spectroscopy diagnostic suite to acquire W sourcing measurements with high temporal, spatial, and wavelength resolution. To this end, four new viewing chords for the multichordal divertor spectrometer and divertor filterscope systems were installed, leading to a 7× increase in blue-light sensitivity. W I and low-Z impurity line identifications were performed in the 3995–4030 Å region, placing wavelengths within 0.1 Å of the National Institute of Standards and Technology values. A novel method was also developed for the DIII-D high-temporal resolution filterscopes to distinguish between W I light and background contamination, important due to the relatively weak intensity of this line, using two different bandpass filters with different widths but the same center wavelength. Finally, fast imaging of the W I 4008.75 Å spectral line with a PCO Pixelfly VGA 200/205 camera is allowed for discrimination between intra-edge-localized mode (ELM) and inter-ELM W I emission profiles with very high (~1 mm) spatial resolution.},

  doi          = {10.1109/TPS.2018.2797691},

  journal      = {IEEE Transactions on Plasma Science},

  number       = [5],

  volume       = [46],

  place        = {United States},

  year         = {2018},

  month        = {5}

}

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DOI: 10.1109/TPS.2018.2797691

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Cited by: 5 works

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Figures / Tables:

Fig. 1.: Schematic of the collection lens, collimation optics, and pellicle beamsplitter system used to efficiently couple equal light intensity to the filterscope and MDS fiber optics.

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