Dynamic measurement of impurity ion transport in runaway electron plateaus in DIII-D

Hollmann, E. M.; Bortolon, A.; Effenberg, F.; Eidietis, N.; Shiraki, D.; Bykov, I.; Chapman, B. E.; Chen, J.; Haskey, S.; Herfindal, J.; Lvovskiy, A.; Marini, C.; McLean, A.; O'Gorman, T.; Pandya, M. D.; Paz-Soldan, C.; Popović, Ž.

doi:10.1063/5.0080385

Title: Dynamic measurement of impurity ion transport in runaway electron plateaus in DIII-D

Journal Article · 01 February 2022 · Physics of Plasmas

DOI: https://doi.org/10.1063/5.0080385 · OSTI ID:1843186

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Univ. of California, San Diego, CA (United States); General Atomics
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
General Atomics, San Diego, CA (United States)
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Univ. of Wisconsin, Madison, WI (United States)
Univ. of California, Los Angeles, CA (United States)
Univ. of California, San Diego, CA (United States)
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Columbia Univ., New York, NY (United States)

In this work, the first dynamic (time-dependent) measurements of impurity ion radial (cross field) and parallel (along-field) diffusion coefficients for post-disruption runaway electron plateaus are presented. Small (~1 mm diameter) carbon or silicon pellets are fired into the edge of steady-state runaway electron (RE) plateaus, and the resulting radial and toroidal transport of singly charged impurity ions (C⁺ or Si⁺) is monitored with spatially distributed visible spectrometers. Consistent with previous steady-state particle balance estimates of Ar⁺ radial transport, radial (cross field) diffusion coefficients D_⟂ ≈ 2–5 m²/s are obtained, about 10× larger than expected from neo-classical theory. Parallel diffusion coefficients D_∥ ≈ 30–80 m²/s are estimated, also much (≈50×) larger than classical. It is speculated at present that these large diffusion coefficients may be due to turbulent transport. Indications of fairly significant (almost 2×) toroidal variation in electron density are seen in the RE plateaus, and this appears to cause some toroidal variation in impurity radial diffusion rates. Indications of slow (≈1 Hz) toroidal rotation in the impurity ions are observed, although the uncertainty in this measurement is large.

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Research Organization:: General Atomics, San Diego, CA (United States)

Sponsoring Organization:: USDOE

Grant/Contract Number:: FC02-04ER54698; FG02-07ER54917; AC02-09CH11466; AC05-00OR22725; AC52-07NA27344; FG02-04ER54744; AC05-06OR23100

OSTI ID:: 1843186

Journal Information:: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 2 Vol. 29; ISSN 1070-664X

Publisher:: American Institute of Physics (AIP)Copyright Statement

Country of Publication:: United States

Language:: English

References (29)

Drift wave theory for transport in tokamaks Weiland, Jan; Zagorodny, Anatoly Reviews of Modern Plasma Physics, Vol. 3, Issue 1 https://doi.org/10.1007/s41614-019-0029-x	journal	June 2019
Measurement of parallel transport of B+ and Al2+ impurities in a linear He+ plasma Hollmann, E. M.; Umstadter, K. R.; Doerner, R. P. Journal of Nuclear Materials, Vol. 415, Issue 1 https://doi.org/10.1016/j.jnucmat.2010.10.067	journal	August 2011
Pellet interaction with runaway electrons James, A. N.; Hollmann, E. M.; Yu, J. H. Journal of Nuclear Materials, Vol. 415, Issue 1 https://doi.org/10.1016/j.jnucmat.2011.01.135	journal	August 2011
Disruptions in ITER and strategies for their control and mitigation Lehnen, M.; Aleynikova, K.; Aleynikov, P. B. Journal of Nuclear Materials, Vol. 463 https://doi.org/10.1016/j.jnucmat.2014.10.075	journal	August 2015
Phase error correction method for a vibration compensated interferometer Van Zeeland, M. A.; Carlstrom, T. N. Review of Scientific Instruments, Vol. 75, Issue 10 https://doi.org/10.1063/1.1786641	journal	October 2004
Experimental investigation of opacity models for stellar interior, inertial fusion, and high energy density plasmas Bailey, J. E.; Rochau, G. A.; Mancini, R. C. Physics of Plasmas, Vol. 16, Issue 5 https://doi.org/10.1063/1.3089604	journal	May 2009
Status of research toward the ITER disruption mitigation system Hollmann, E. M.; Aleynikov, P. B.; Fülöp, T. Physics of Plasmas, Vol. 22, Issue 2 https://doi.org/10.1063/1.4901251	journal	November 2014
Thermal ion orbit loss and radial electric field in DIII-D deGrassie, J. S.; Boedo, J. A.; Grierson, B. A. Physics of Plasmas, Vol. 22, Issue 8 https://doi.org/10.1063/1.4928558	journal	August 2015
Faraday-effect polarimeter diagnostic for internal magnetic field fluctuation measurements in DIII-D Chen, J.; Ding, W. X.; Brower, D. L. Review of Scientific Instruments, Vol. 87, Issue 11 https://doi.org/10.1063/1.4960056	journal	August 2016
Study of Z scaling of runaway electron plateau final loss energy deposition into wall of DIII-D Hollmann, E. M.; Commaux, N.; Eidietis, N. W. Physics of Plasmas, Vol. 24, Issue 6 https://doi.org/10.1063/1.4985086	journal	June 2017
Model of vertical plasma motion during the current quench Kiramov, D. I.; Breizman, B. N. Physics of Plasmas, Vol. 24, Issue 10 https://doi.org/10.1063/1.4993071	journal	October 2017
Study of argon expulsion from the post-disruption runaway electron plateau following low-Z massive gas injection in DIII-D Hollmann, E. M.; Bykov, I.; Eidietis, N. W. Physics of Plasmas, Vol. 27, Issue 4 https://doi.org/10.1063/5.0003299	journal	April 2020
Dependence of the impurity transport on the dominant turbulent regime in ELM-y H-mode discharges on the DIII-D tokamak Odstrčil, T.; Howard, N. T.; Sciortino, F. Physics of Plasmas, Vol. 27, Issue 8 https://doi.org/10.1063/5.0010725	journal	August 2020
Recent Upgrades of the DIII-D Impurity Granule Injector Vorenkamp, M. S.; Nagy, A.; Bortolon, A. Fusion Science and Technology https://doi.org/10.1080/15361055.2017.1335144	journal	July 2017
A design retrospective of the DIII-D tokamak Luxon, J. L. Nuclear Fusion, Vol. 42, Issue 5 https://doi.org/10.1088/0029-5515/42/5/313	journal	May 2002
Measurements of injected impurity assimilation during massive gas injection experiments in DIII-D Hollmann, E. M.; Jernigan, T. C.; Parks, P. B. Nuclear Fusion, Vol. 48, Issue 11 https://doi.org/10.1088/0029-5515/48/11/115007	journal	September 2008
Effect of applied toroidal electric field on the growth/decay of plateau-phase runaway electron currents in DIII-D Hollmann, E. M.; Parks, P. B.; Humphreys, D. A. Nuclear Fusion, Vol. 51, Issue 10 https://doi.org/10.1088/0029-5515/51/10/103026	journal	September 2011
Transport studies using laser blow-off injection of low- Z trace impurities injected into the TJ-II stellarator Zurro, B.; Hollmann, E.; Baciero, A. Nuclear Fusion, Vol. 51, Issue 6 https://doi.org/10.1088/0029-5515/51/6/063015	journal	May 2011
Inter-machine comparison of the termination phase and energy conversion in tokamak disruptions with runaway current plateau formation and implications for ITER Martín-Solís, J. R.; Loarte, A.; Hollmann, E. M. Nuclear Fusion, Vol. 54, Issue 8 https://doi.org/10.1088/0029-5515/54/8/083027	journal	July 2014
Kink instabilities of the post-disruption runaway electron beam at low safety factor Paz-Soldan, C.; Eidietis, N. W.; Liu, Y. Q. Plasma Physics and Controlled Fusion, Vol. 61, Issue 5 https://doi.org/10.1088/1361-6587/aafd15	journal	March 2019
Magnetohydrodynamic simulations of runaway electron beam termination in JET Bandaru, V.; Hoelzl, M.; Reux, C. Plasma Physics and Controlled Fusion, Vol. 63, Issue 3 https://doi.org/10.1088/1361-6587/abdbcf	journal	January 2021
Dissipation of post-disruption runaway electron plateaus by shattered pellet injection in DIII-D Shiraki, D.; Commaux, N.; Baylor, L. R. Nuclear Fusion, Vol. 58, Issue 5 https://doi.org/10.1088/1741-4326/aab0d6	journal	March 2018
Physics of runaway electrons in tokamaks Breizman, Boris N.; Aleynikov, Pavel; Hollmann, Eric M. Nuclear Fusion, Vol. 59, Issue 8 https://doi.org/10.1088/1741-4326/ab1822	journal	June 2019
Study of argon assimilation into the post-disruption runaway electron plateau in DIII-D and comparison with a 1D diffusion model Hollmann, E. M.; Eidietis, N. W.; Herfindal, J. L. Nuclear Fusion, Vol. 59, Issue 10 https://doi.org/10.1088/1741-4326/ab32b2	journal	August 2019
MARS-F modeling of post-disruption runaway beam loss by magnetohydrodynamic instabilities in DIII-D Liu, Y. Q.; Parks, P. B.; Paz-Soldan, C. Nuclear Fusion, Vol. 59, Issue 12 https://doi.org/10.1088/1741-4326/ab3f87	journal	October 2019
Pellet sublimation and expansion under runaway electron flux Kiramov, Dmitrii I.; Breizman, Boris N. Nuclear Fusion, Vol. 60, Issue 8 https://doi.org/10.1088/1741-4326/ab966a	journal	July 2020
Characterization of cold background plasma during the runaway electron beam mitigation experiments in the JET tokamak Sridhar, S.; Reux, C.; Beyer, P. Nuclear Fusion, Vol. 60, Issue 9 https://doi.org/10.1088/1741-4326/ab9dd0	journal	August 2020
Recent progress in shattered pellet injection technology in support of the ITER disruption mitigation system ^* Gebhart, T. E.; Baylor, L. R.; Ericson, M. N. Nuclear Fusion, Vol. 61, Issue 10 https://doi.org/10.1088/1741-4326/ac1bc4	journal	September 2021
Scaling of plane-wave Born cross sections for electron-impact excitation of neutral atoms Kim, Yong-Ki Physical Review A, Vol. 64, Issue 3 https://doi.org/10.1103/PhysRevA.64.032713	journal	August 2001

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