skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

This content will become publicly available on August 5, 2020

Title: Advances in neutral tungsten ultraviolet spectroscopy for the potential benefit to gross erosion diagnosis

Abstract

A spectral survey of tungsten emission in the ultraviolet region has been completed in the DIII-D tokamak and the CTH torsatron to assess the potential benefit of UV emission for the diagnosis of gross W erosion. Here, a total of 29 W I spectral lines are observed from the two experiments using survey spectrometers between 200 and 400 nm with level identifications provided based on a structure calculation for many of the excited states that produce strong emission lines. Of the 29 observed lines, 20 have not previously been reported in fusion relevant plasmas, including an intense line at 265.65 nm which could be important for benchmarking the frequently exploited line at 400.88 nm. Nearly all of the observed spectral lines decay down to one of the six lowest energy levels for neutral W, which are likely to be long-lived metastable states. The impact of metastable level populations on the W I emission spectrum and any erosion measurement utilizing a spectroscopic technique is potentially significant. Yet, the high density of W I emission in the UV region allows for the possibly of determining the relative metastable fractions and plasma parameters local to the erosion region. Additionally, the lines observed inmore » this work could be used to perform multiple independent gross erosion measurements, leading to more accurate diagnosis of gross tungsten erosion.« less

Authors:
ORCiD logo [1];  [1];  [1];  [1];  [1];  [2];  [2];  [2];  [3]; ORCiD logo [4];  [5]
  1. Auburn Univ., AL (United States)
  2. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  3. General Atomics, San Diego, CA (United States)
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  5. Queen's Univ., Belfast, Northern Ireland (United Kingdom)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)
OSTI Identifier:
1561607
Alternate Identifier(s):
OSTI ID: 1569476
Grant/Contract Number:  
AC05-00OR22725; SC0015877; FC02-04ER54698; FG02-00ER54610; AC52-07NA27344
Resource Type:
Accepted Manuscript
Journal Name:
Plasma Physics and Controlled Fusion
Additional Journal Information:
Journal Volume: 61; Journal Issue: 9; Journal ID: ISSN 0741-3335
Publisher:
IOP Science
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; erosion, tungsten, plasma facing components, ultraviolet, spectroscopy, S/XB, metastable states

Citation Formats

Johnson, C. A., Ennis, D. A., Loch, S. D., Hartwell, G. J., Maurer, D. A., Allen, S. L., Victor, B. S., Samuell, C. M., Abrams, Tyer, Unterberg, Ezekial A., and Smyth, R. T. Advances in neutral tungsten ultraviolet spectroscopy for the potential benefit to gross erosion diagnosis. United States: N. p., 2019. Web. doi:10.1088/1361-6587/ab2b25.
Johnson, C. A., Ennis, D. A., Loch, S. D., Hartwell, G. J., Maurer, D. A., Allen, S. L., Victor, B. S., Samuell, C. M., Abrams, Tyer, Unterberg, Ezekial A., & Smyth, R. T. Advances in neutral tungsten ultraviolet spectroscopy for the potential benefit to gross erosion diagnosis. United States. doi:10.1088/1361-6587/ab2b25.
Johnson, C. A., Ennis, D. A., Loch, S. D., Hartwell, G. J., Maurer, D. A., Allen, S. L., Victor, B. S., Samuell, C. M., Abrams, Tyer, Unterberg, Ezekial A., and Smyth, R. T. Mon . "Advances in neutral tungsten ultraviolet spectroscopy for the potential benefit to gross erosion diagnosis". United States. doi:10.1088/1361-6587/ab2b25.
@article{osti_1561607,
title = {Advances in neutral tungsten ultraviolet spectroscopy for the potential benefit to gross erosion diagnosis},
author = {Johnson, C. A. and Ennis, D. A. and Loch, S. D. and Hartwell, G. J. and Maurer, D. A. and Allen, S. L. and Victor, B. S. and Samuell, C. M. and Abrams, Tyer and Unterberg, Ezekial A. and Smyth, R. T.},
abstractNote = {A spectral survey of tungsten emission in the ultraviolet region has been completed in the DIII-D tokamak and the CTH torsatron to assess the potential benefit of UV emission for the diagnosis of gross W erosion. Here, a total of 29 W I spectral lines are observed from the two experiments using survey spectrometers between 200 and 400 nm with level identifications provided based on a structure calculation for many of the excited states that produce strong emission lines. Of the 29 observed lines, 20 have not previously been reported in fusion relevant plasmas, including an intense line at 265.65 nm which could be important for benchmarking the frequently exploited line at 400.88 nm. Nearly all of the observed spectral lines decay down to one of the six lowest energy levels for neutral W, which are likely to be long-lived metastable states. The impact of metastable level populations on the W I emission spectrum and any erosion measurement utilizing a spectroscopic technique is potentially significant. Yet, the high density of W I emission in the UV region allows for the possibly of determining the relative metastable fractions and plasma parameters local to the erosion region. Additionally, the lines observed in this work could be used to perform multiple independent gross erosion measurements, leading to more accurate diagnosis of gross tungsten erosion.},
doi = {10.1088/1361-6587/ab2b25},
journal = {Plasma Physics and Controlled Fusion},
number = 9,
volume = 61,
place = {United States},
year = {2019},
month = {8}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on August 5, 2020
Publisher's Version of Record

Save / Share:

Works referenced in this record:

Determination of the tungsten divertor retention at ASDEX Upgrade using a sublimation probe
journal, September 2002


Ionization state, excited populations and emission of impurities in dynamic finite density plasmas: I. The generalized collisional–radiative model for light elements
journal, January 2006

  • Summers, H. P.; Dickson, W. J.; O'Mullane, M. G.
  • Plasma Physics and Controlled Fusion, Vol. 48, Issue 2
  • DOI: 10.1088/0741-3335/48/2/007

Calculation and experimental test of the cooling factor of tungsten
journal, January 2010


Modeling and Analysis of Erosion and Redeposition For Limiter and Divertor Impurity Control Systems
journal, July 1983


High heat flux Langmuir probe array for the DIII-D divertor plates
journal, October 2008

  • Watkins, J. G.; Taussig, D.; Boivin, R. L.
  • Review of Scientific Instruments, Vol. 79, Issue 10
  • DOI: 10.1063/1.2982423

The inter-ELM tungsten erosion profile in DIII-D H-mode discharges and benchmarking with ERO+OEDGE modeling
journal, April 2017


Experimental determination of S/XB values of W I visible lines
journal, December 2009

  • Nishijima, D.; Doerner, R. P.; Baldwin, M. J.
  • Physics of Plasmas, Vol. 16, Issue 12
  • DOI: 10.1063/1.3270108

Relativistic R -matrix calculations for the electron-impact excitation of neutral molybdenum
journal, October 2017


Tungsten divertor erosion in all metal devices: Lessons from the ITER like wall of JET
journal, July 2013


A design retrospective of the DIII-D tokamak
journal, May 2002


Quantification of tungsten sputtering at W/C twin limiters in TEXTOR with the aid of local WF 6 injection
journal, December 2011


The Design and Use of Tungsten Coated TZM Molybdenum Tile Inserts in the DIII-D Tokamak Divertor
journal, August 2017


Experiments with tungsten limiters in TEXTOR-94
journal, October 1998


Excitation cross sections of low-lying levels of the tungsten atom
journal, June 2008


Multichord spectroscopy of the DIII‐D divertor region
journal, October 1992

  • Brooks, N. H.; Howald, A.; Klepper, K.
  • Review of Scientific Instruments, Vol. 63, Issue 10
  • DOI: 10.1063/1.1143469

Tungsten spectroscopy for the measurement of W-fluxes from plasma facing components
journal, October 2007

  • Beigman, I.; Pospieszczyk, A.; Sergienko, G.
  • Plasma Physics and Controlled Fusion, Vol. 49, Issue 11
  • DOI: 10.1088/0741-3335/49/11/006

Design, Construction, and Operation of the Compact Toroidal Hybrid
journal, May 2017


Modelling of Be transport in PSI experiments at PISCES-B
journal, June 2009


Erratum: “Experimental determination of S/XB values of W I visible lines” [Phys. Plasmas 16, 122503 (2009)]
journal, January 2011

  • Nishijima, D.; Doerner, R. P.; Baldwin, M. J.
  • Physics of Plasmas, Vol. 18, Issue 1
  • DOI: 10.1063/1.3532971

Erosion of a tungsten limiter under high heat flux in TEXTOR
journal, June 2007


Spectroscopic determination of impurity influx from localized surfaces
journal, December 1989


Compilation of Wavelengths, Energy Levels, and Transition Probabilities for W I and W II
journal, March 2006

  • Kramida, A. E.; Shirai, T.
  • Journal of Physical and Chemical Reference Data, Vol. 35, Issue 1
  • DOI: 10.1063/1.1836763

The Filterscope
journal, March 2003

  • Colchin, R. J.; Hillis, D. L.; Maingi, R.
  • Review of Scientific Instruments, Vol. 74, Issue 3
  • DOI: 10.1063/1.1537038

ELM-resolved divertor erosion in the JET ITER-Like Wall
journal, January 2016


Assessing material migration through 13C injection experiments
journal, August 2011


Solid tungsten Divertor-III for ASDEX Upgrade and contributions to ITER
journal, May 2015


Operation of TEXTOR-94 with tungsten poloidal main limiters
journal, March 2001


Advances in Low-Temperature Tungsten Spectroscopy Capability to Quantify DIII-D Divertor Erosion
journal, May 2018

  • Abrams, Tyler; Thomas, Daniel M.; Unterberg, Ezekial A.
  • IEEE Transactions on Plasma Science, Vol. 46, Issue 5
  • DOI: 10.1109/TPS.2018.2797691