ELM and inter-ELM heat and particle flux to a secondary divertor in the DIII-D tokamak
Abstract
DIII-D ELMing discharges with a secondary X-point (XPT) inside the vessel were used to evaluate the power distribution between the primary and secondary divertors. The magnetic balance, defined by the distance between the primary and secondary separatrices at the outer midplane (dRsep), was varied from -5 mm (lower-single-null, LSN) to +16 mm (upper-single-null, USN). In this work, we find that the secondary divertor receives up to 1/3 of the total heat flux (primary + secondary divertors), and it is dominated by the ELM-driven flux. Both the radially-integrated and the peak heat flux to the secondary divertor decay below ~50% of the maximum as dRsep is varied from -5 to +6mm, but the integrated heat flux decay flattens out and it would take dRsep above ~25mm to reduce the ELM heat flux to the secondary divertor below 10% of the one deposited to a well-defined SN. Both the secondary inner and outer strike points receive heat flux during ELMs. The peak heat flux is comparable in both strike points for dRsep < 10mm, but the inner strike point receives less than 15% of the total flux. Furthermore, this is experimental evidence that the secondary inner divertor region receives significant ELM fluxmore »
- Authors:
-
[1];
[1];
- Univ. of California, San Diego, La Jolla, CA (United States)
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- General Atomics, San Diego, CA (United States)
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
- Publication Date:
- Research Org.:
- General Atomics, San Diego, CA (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Org.:
- USDOE National Nuclear Security Administration (NNSA)
- OSTI Identifier:
- 1807533
- Alternate Identifier(s):
- OSTI ID: 1877320
- Report Number(s):
- LLNL-JRNL-836402
Journal ID: ISSN 0029-5515; TRN: US2212800
- Grant/Contract Number:
- FC02-04ER54698; FG02-07ER54917; AC52-07NA27344
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Nuclear Fusion
- Additional Journal Information:
- Journal Volume: 61; Journal Issue: 8; Journal ID: ISSN 0029-5515
- Publisher:
- IOP Science
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY
Citation Formats
Perillo, Renato, Boedo, Jose A., Lasnier, Charles, Rudakov, Dmitry L., Osborne, Tom H., and Watkins, Jonathan. ELM and inter-ELM heat and particle flux to a secondary divertor in the DIII-D tokamak. United States: N. p., 2021.
Web. doi:10.1088/1741-4326/ac0f38.
Perillo, Renato, Boedo, Jose A., Lasnier, Charles, Rudakov, Dmitry L., Osborne, Tom H., & Watkins, Jonathan. ELM and inter-ELM heat and particle flux to a secondary divertor in the DIII-D tokamak. United States. https://doi.org/10.1088/1741-4326/ac0f38
Perillo, Renato, Boedo, Jose A., Lasnier, Charles, Rudakov, Dmitry L., Osborne, Tom H., and Watkins, Jonathan. Fri .
"ELM and inter-ELM heat and particle flux to a secondary divertor in the DIII-D tokamak". United States. https://doi.org/10.1088/1741-4326/ac0f38. https://www.osti.gov/servlets/purl/1807533.
@article{osti_1807533,
title = {ELM and inter-ELM heat and particle flux to a secondary divertor in the DIII-D tokamak},
author = {Perillo, Renato and Boedo, Jose A. and Lasnier, Charles and Rudakov, Dmitry L. and Osborne, Tom H. and Watkins, Jonathan},
abstractNote = {DIII-D ELMing discharges with a secondary X-point (XPT) inside the vessel were used to evaluate the power distribution between the primary and secondary divertors. The magnetic balance, defined by the distance between the primary and secondary separatrices at the outer midplane (dRsep), was varied from -5 mm (lower-single-null, LSN) to +16 mm (upper-single-null, USN). In this work, we find that the secondary divertor receives up to 1/3 of the total heat flux (primary + secondary divertors), and it is dominated by the ELM-driven flux. Both the radially-integrated and the peak heat flux to the secondary divertor decay below ~50% of the maximum as dRsep is varied from -5 to +6mm, but the integrated heat flux decay flattens out and it would take dRsep above ~25mm to reduce the ELM heat flux to the secondary divertor below 10% of the one deposited to a well-defined SN. Both the secondary inner and outer strike points receive heat flux during ELMs. The peak heat flux is comparable in both strike points for dRsep < 10mm, but the inner strike point receives less than 15% of the total flux. Furthermore, this is experimental evidence that the secondary inner divertor region receives significant ELM flux which should be taken into account for the design of future generation tokamaks.},
doi = {10.1088/1741-4326/ac0f38},
journal = {Nuclear Fusion},
number = 8,
volume = 61,
place = {United States},
year = {Fri Jul 16 00:00:00 EDT 2021},
month = {Fri Jul 16 00:00:00 EDT 2021}
}
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