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Title: Localized divertor leakage measurements using isotopic tungsten sources during edge-localized mode-y H-mode discharges on DIII-D

Abstract

Experiments carried out on DIII-D using a novel setup of isotopic tungsten (W) sources in the outer divertor have characterized how the W leakage from this region depends on both the exact source location and edge-localized mode (ELM) behavior. The sources are toroidally-symmetric and poloidally-localized to two regions: (1) the outer strike point (OSP) with natural abundance of W isotopes; and (2) the far-target with highly-enriched 182W isotopes. With the use of a dual-faced collector probe (CP) in the main scrape-off layer (SOL) near the outside midplane and source-rate spectroscopy, a proxy for divertor impurity leakage is developed herein. Using this proxy, it is found that for the OSP W location, there is a nearly linear increase of leakage with the power across the separatrix (), which is consistent with the effect of an increased upstream ion temperature parallel gradient force in the near-SOL; trends in the pedestal density and collisionality are also seen. Conversely, it is found that for the far-target W location leakage falls off rapidly as increases and ELM size decreases, which is suggestive that ELM size plays a role in the leakage from this location. Indications for main SOL W contamination is evidenced by the measurementmore » of large deposition asymmetries on the two opposite CP faces. These measurements are coupled with interpretive modeling showing SOL W accumulation near the separatrix furthest from both targets driven by forces parallel to the magnetic field. This experimental setup, together with the target and upstream W measurements, provides information on the transport from different divertor W source locations and leakage. These studies help to elucidate the physics driving divertor impurity source rates and leakage, with and without ELMs, and provide better insight on the link in the chain connecting wall impurity sources to core impurity levels in magnetic fusion devices.« less

Authors:
ORCiD logo [1];  [2];  [3];  [4];  [4];  [5];  [2];  [3];  [6]; ORCiD logo [2];  [2];  [7];  [8]; ORCiD logo [4]; ORCiD logo [5];  [2];  [6];  [8]; ORCiD logo [8];  [1] more »;  [6];  [8];  [1];  [3]; ORCiD logo [1];  [8];  [9]; ORCiD logo [2];  [10];  [11];  [12];  [13];  [11];  [6];  [2];  [13];  [1];  [2];  [1];  [4] « less
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  2. General Atomics, San Diego, CA (United States)
  3. Univ. of California, San Diego, CA (United States)
  4. Univ. of Tennessee, Knoxville, TN (United States)
  5. Univ. of Toronto, ON (Canada)
  6. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  7. Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge Inst. for Science and Education (ORISE), Oak Ridge, TN (United States)
  8. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
  9. North Carolina State Univ., Raleigh, NC (United States)
  10. Oak Ridge Associated Univ., Oak Ridge, TN (United States)
  11. Auburn Univ., AL (United States)
  12. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  13. Univ. of Wisconsin, Madison, WI (United States)
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24); USDOE National Nuclear Security Administration (NNSA); Fusion Energy Sciences Postdoctoral Fellowship Program
OSTI Identifier:
1601269
Alternate Identifier(s):
OSTI ID: 1606906
Report Number(s):
[SAND-2020-1019J]
[Journal ID: ISSN 0029-5515; 683258]
Grant/Contract Number:  
[AC04-94AL85000; FC02-04ER54698; NA0003525; AC05-00OR22725]
Resource Type:
Accepted Manuscript
Journal Name:
Nuclear Fusion
Additional Journal Information:
[ Journal Volume: 60; Journal Issue: 1]; Journal ID: ISSN 0029-5515
Publisher:
IOP Science
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; impurity transport; divertor; tungsten; DIII-D

Citation Formats

Unterberg, E. A., Abrams, T., Bykov, I., Donovan, D. C., Duran, J. D., Elder, J. D., Guo, H. Y., Hollmann, E. M., Lasnier, C. J., Leonard, A. W., Moser, A. L., Nichols, J. H., Nygren, R. E., Rudakov, D. L., Stangeby, P. C., Thomas, D. M., Victor, B. S., Watkins, J. G., Wampler, William R., Zach, M. P., Allen, S. L., Barton, J. L., Baylor, L. R., Boedo, J. A., Briesemeister, A. R., Buchenauer, D. A., Coburn, J. D., Chrobak, C. P., Ding, R., Ennis, D. A., Grierson, B. A., Hinson, E. T., Johnson, C. A., McLean, A. G., Petrie, T. W., Schmitz, O., Shiraki, D., Wang, H. Q., Wilcox, R. S., and Zamperini, S. Localized divertor leakage measurements using isotopic tungsten sources during edge-localized mode-y H-mode discharges on DIII-D. United States: N. p., 2019. Web. doi:10.1088/1741-4326/ab537b.
Unterberg, E. A., Abrams, T., Bykov, I., Donovan, D. C., Duran, J. D., Elder, J. D., Guo, H. Y., Hollmann, E. M., Lasnier, C. J., Leonard, A. W., Moser, A. L., Nichols, J. H., Nygren, R. E., Rudakov, D. L., Stangeby, P. C., Thomas, D. M., Victor, B. S., Watkins, J. G., Wampler, William R., Zach, M. P., Allen, S. L., Barton, J. L., Baylor, L. R., Boedo, J. A., Briesemeister, A. R., Buchenauer, D. A., Coburn, J. D., Chrobak, C. P., Ding, R., Ennis, D. A., Grierson, B. A., Hinson, E. T., Johnson, C. A., McLean, A. G., Petrie, T. W., Schmitz, O., Shiraki, D., Wang, H. Q., Wilcox, R. S., & Zamperini, S. Localized divertor leakage measurements using isotopic tungsten sources during edge-localized mode-y H-mode discharges on DIII-D. United States. doi:10.1088/1741-4326/ab537b.
Unterberg, E. A., Abrams, T., Bykov, I., Donovan, D. C., Duran, J. D., Elder, J. D., Guo, H. Y., Hollmann, E. M., Lasnier, C. J., Leonard, A. W., Moser, A. L., Nichols, J. H., Nygren, R. E., Rudakov, D. L., Stangeby, P. C., Thomas, D. M., Victor, B. S., Watkins, J. G., Wampler, William R., Zach, M. P., Allen, S. L., Barton, J. L., Baylor, L. R., Boedo, J. A., Briesemeister, A. R., Buchenauer, D. A., Coburn, J. D., Chrobak, C. P., Ding, R., Ennis, D. A., Grierson, B. A., Hinson, E. T., Johnson, C. A., McLean, A. G., Petrie, T. W., Schmitz, O., Shiraki, D., Wang, H. Q., Wilcox, R. S., and Zamperini, S. Wed . "Localized divertor leakage measurements using isotopic tungsten sources during edge-localized mode-y H-mode discharges on DIII-D". United States. doi:10.1088/1741-4326/ab537b.
@article{osti_1601269,
title = {Localized divertor leakage measurements using isotopic tungsten sources during edge-localized mode-y H-mode discharges on DIII-D},
author = {Unterberg, E. A. and Abrams, T. and Bykov, I. and Donovan, D. C. and Duran, J. D. and Elder, J. D. and Guo, H. Y. and Hollmann, E. M. and Lasnier, C. J. and Leonard, A. W. and Moser, A. L. and Nichols, J. H. and Nygren, R. E. and Rudakov, D. L. and Stangeby, P. C. and Thomas, D. M. and Victor, B. S. and Watkins, J. G. and Wampler, William R. and Zach, M. P. and Allen, S. L. and Barton, J. L. and Baylor, L. R. and Boedo, J. A. and Briesemeister, A. R. and Buchenauer, D. A. and Coburn, J. D. and Chrobak, C. P. and Ding, R. and Ennis, D. A. and Grierson, B. A. and Hinson, E. T. and Johnson, C. A. and McLean, A. G. and Petrie, T. W. and Schmitz, O. and Shiraki, D. and Wang, H. Q. and Wilcox, R. S. and Zamperini, S.},
abstractNote = {Experiments carried out on DIII-D using a novel setup of isotopic tungsten (W) sources in the outer divertor have characterized how the W leakage from this region depends on both the exact source location and edge-localized mode (ELM) behavior. The sources are toroidally-symmetric and poloidally-localized to two regions: (1) the outer strike point (OSP) with natural abundance of W isotopes; and (2) the far-target with highly-enriched 182W isotopes. With the use of a dual-faced collector probe (CP) in the main scrape-off layer (SOL) near the outside midplane and source-rate spectroscopy, a proxy for divertor impurity leakage is developed herein. Using this proxy, it is found that for the OSP W location, there is a nearly linear increase of leakage with the power across the separatrix (), which is consistent with the effect of an increased upstream ion temperature parallel gradient force in the near-SOL; trends in the pedestal density and collisionality are also seen. Conversely, it is found that for the far-target W location leakage falls off rapidly as increases and ELM size decreases, which is suggestive that ELM size plays a role in the leakage from this location. Indications for main SOL W contamination is evidenced by the measurement of large deposition asymmetries on the two opposite CP faces. These measurements are coupled with interpretive modeling showing SOL W accumulation near the separatrix furthest from both targets driven by forces parallel to the magnetic field. This experimental setup, together with the target and upstream W measurements, provides information on the transport from different divertor W source locations and leakage. These studies help to elucidate the physics driving divertor impurity source rates and leakage, with and without ELMs, and provide better insight on the link in the chain connecting wall impurity sources to core impurity levels in magnetic fusion devices.},
doi = {10.1088/1741-4326/ab537b},
journal = {Nuclear Fusion},
number = [1],
volume = [60],
place = {United States},
year = {2019},
month = {11}
}

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Works referenced in this record:

Divertor retention for recycling impurities
journal, October 1992


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


Measurement and verification of z eff radial profiles using charge exchange recombination spectroscopy on DIII-D
journal, March 1998


Plasma-surface interaction in the Be/W environment: Conclusions drawn from the JET-ILW for ITER
journal, August 2015


Interpretation of plasma impurity deposition probes. Analytic approximation
journal, January 1987


Edge-localized-modes in tokamaks
journal, September 2014


Basic physical processes and reduced models for plasma detachment
journal, March 2018


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


Materials migration in JET with ITER-like wall traced with a 10 Be isotopic marker
journal, August 2015


Atomic Data and Modelling for Fusion: the ADAS Project
conference, January 2011

  • Summers, H. P.; O’Mullane, M. G.
  • 7TH INTERNATIONAL CONFERENCE ON ATOMIC AND MOLECULAR DATA AND THEIR APPLICATIONS - ICAMDATA-2010, AIP Conference Proceedings
  • DOI: 10.1063/1.3585817

Helium transport in the edge plasma of a tokamak reactor
journal, August 1991


Neoclassical conductivity and bootstrap current formulas for general axisymmetric equilibria and arbitrary collisionality regime
journal, July 1999

  • Sauter, O.; Angioni, C.; Lin-Liu, Y. R.
  • Physics of Plasmas, Vol. 6, Issue 7
  • DOI: 10.1063/1.873240

Overview and status of ITER internal components
journal, October 2014


Tungsten transport and sources control in JET ITER-like wall H-mode plasmas
journal, August 2015


DiMES PMI research at DIII-D in support of ITER and beyond
journal, November 2017


Impurity production and transport in the divertor tokamak ASDEX
journal, June 1989


Particle Exhaust from Plasma Discharges with an Expanded-Boundary Divertor
journal, November 1981


Modelling of impurity flow in the tokamak scrape-off layer
journal, January 1984


Tungsten: an option for divertor and main chamber plasma facing components in future fusion devices
journal, March 2005


Utilization of outer-midplane collector probes with isotopically enriched tungsten tracer particles for impurity transport studies in the scrape-off layer of DIII-D (invited)
journal, October 2018

  • Donovan, D. C.; Unterberg, E. A.; Stangeby, P. C.
  • Review of Scientific Instruments, Vol. 89, Issue 10
  • DOI: 10.1063/1.5039347

Evidence of near-SOL tungsten accumulation using a far-SOL collector probe array and OEDGE modelling in the DIII-D metal rings L-mode discharges
journal, May 2019


Experimental validation of a model for particle recycling and tungsten erosion during ELMs in the DIII-D divertor
journal, December 2018


Indications of an inward pinch in the inner SOL of DIII-D from 13C deposition experiments
journal, June 2009


Impurity transport at the plasma edge
journal, December 1990


Overview on plasma operation with a full tungsten wall in ASDEX Upgrade
journal, July 2013


Overview of the EAST in-vessel components upgrade
journal, October 2015


Erosion, screening, and migration of tungsten in the JET divertor
journal, August 2019


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


The tungsten divertor experiment at ASDEX Upgrade
journal, December 1996


Use of isotopic tungsten tracers and a stable-isotope-mixing model to characterize divertor source location in the DIII-D metal rings campaign
journal, May 2019


Experimental divertor physics
journal, June 1997


The WEST project: Testing ITER divertor high heat flux component technology in a steady state tokamak environment
journal, October 2014


Interpretive modeling of simple-as-possible-plasma discharges on DIII-D using the OEDGE code
journal, March 2003


EMC3-Eirene simulations of the spatial dependence of the tungsten divertor retention in ASDEX Upgrade
journal, November 2011


DIVIMP modeling of the toroidally symmetrical injection of 13CH4 into the upper SOL of DIII-D
journal, March 2005


Modelling of carbon migration during JET 13 C injection experiments
journal, August 2008


Experimental results on boundary plasmas, resulting surface interactions and extrapolation to large fusion devices
journal, October 1980


Discharge resolved impurity flux measurements in the edge plasma of ASDEX Upgrade by exposure of collector probes
journal, June 2007


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


Monte Carlo simulations of tungsten redeposition at the divertor target
journal, January 2014


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

Transport of tungsten to collector probes in DIII-D
journal, January 2019


Tungsten as plasma-facing material in ASDEX Upgrade
journal, April 2003