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Title: Measurement of toroidal variation in conducted heat loads in locked mode induced disruptions on DIII-D

Abstract

Locked mode disruptions with controlled toroidal phase are produced in the DIII-­D tokamak by locking to large non-­axisymmetric applied magnetic perturbations with different toroidal phases. Additionally, the disruption conducted heat loads are found to go almost completely to the outer divertor region, possibly due to strong inner leg detachment, but possibly also due to plasma motion and limiting on the outer divertor leg shelf. The outer leg conducted heat loads are found to have a significant toroidal variation of order ±30%, with a dominantly n = 1 structure. The heat load phase is shifted from initial locked mode phase in a way that is approximately consistent with heat loss into the scrape-­off layer being enhanced at the mode island O-­point outer midplane crossing. These measurements suggest that pre-­existing locked modes can affect the conducted heat load structure during the thermal quench by affecting the thermal quench MHD phase. This is consistent with previous MHD simulations which indicated that pre-­disruption locked mode structures can persist and survive to some degree through the large thermal quench MHD. Finally, this work complements previous work [Shiraki2015] which showed that n = 1 structures in mitigated disruptions can create toroidal variation in the disruption radiatedmore » power.« less

Authors:
ORCiD logo [1];  [2];  [3];  [4]; ORCiD logo [1]; ORCiD logo [3];  [2];  [5]
  1. University of California–San Diego, La Jolla, CA (United States). Center for Energy Research
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  3. General Atomics, San Diego, CA (United States)
  4. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  5. 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:
1477435
Alternate Identifier(s):
OSTI ID: 1475239; OSTI ID: 1542734
Report Number(s):
LLNL-JRNL-777837
Journal ID: ISSN 1070-664X
Grant/Contract Number:  
FC02-04ER54698; FG02-07ER54917; AC52-07NA27344
Resource Type:
Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 25; Journal Issue: 10; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats

Hollmann, E. M., Commaux, N., Eidietis, N. W., Lasnier, C. J., Moyer, R. A., Paz-Soldan, C., Shiraki, D., and Watkins, J. G. Measurement of toroidal variation in conducted heat loads in locked mode induced disruptions on DIII-D. United States: N. p., 2018. Web. doi:10.1063/1.5052450.
Hollmann, E. M., Commaux, N., Eidietis, N. W., Lasnier, C. J., Moyer, R. A., Paz-Soldan, C., Shiraki, D., & Watkins, J. G. Measurement of toroidal variation in conducted heat loads in locked mode induced disruptions on DIII-D. United States. doi:10.1063/1.5052450.
Hollmann, E. M., Commaux, N., Eidietis, N. W., Lasnier, C. J., Moyer, R. A., Paz-Soldan, C., Shiraki, D., and Watkins, J. G. Tue . "Measurement of toroidal variation in conducted heat loads in locked mode induced disruptions on DIII-D". United States. doi:10.1063/1.5052450. https://www.osti.gov/servlets/purl/1477435.
@article{osti_1477435,
title = {Measurement of toroidal variation in conducted heat loads in locked mode induced disruptions on DIII-D},
author = {Hollmann, E. M. and Commaux, N. and Eidietis, N. W. and Lasnier, C. J. and Moyer, R. A. and Paz-Soldan, C. and Shiraki, D. and Watkins, J. G.},
abstractNote = {Locked mode disruptions with controlled toroidal phase are produced in the DIII-­D tokamak by locking to large non-­axisymmetric applied magnetic perturbations with different toroidal phases. Additionally, the disruption conducted heat loads are found to go almost completely to the outer divertor region, possibly due to strong inner leg detachment, but possibly also due to plasma motion and limiting on the outer divertor leg shelf. The outer leg conducted heat loads are found to have a significant toroidal variation of order ±30%, with a dominantly n = 1 structure. The heat load phase is shifted from initial locked mode phase in a way that is approximately consistent with heat loss into the scrape-­off layer being enhanced at the mode island O-­point outer midplane crossing. These measurements suggest that pre-­existing locked modes can affect the conducted heat load structure during the thermal quench by affecting the thermal quench MHD phase. This is consistent with previous MHD simulations which indicated that pre-­disruption locked mode structures can persist and survive to some degree through the large thermal quench MHD. Finally, this work complements previous work [Shiraki2015] which showed that n = 1 structures in mitigated disruptions can create toroidal variation in the disruption radiated power.},
doi = {10.1063/1.5052450},
journal = {Physics of Plasmas},
number = 10,
volume = 25,
place = {United States},
year = {2018},
month = {10}
}

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