High frequency pacing of edge localized modes by injection of lithium granules in DIII-D H-mode discharges

Bortolon, A.; Maingi, R.; Mansfield, D. K.; Nagy, A.; Roquemore, A. L.; Baylor, L. R.; Commaux, N.; Jackson, G. L.; Gilson, E. P.; Lunsford, R.; Parks, P. B.; Chrystal, C.; Grierson, B. A.; Groebner, R.; Haskey, S. R.; Makowski, M. J.; Lasnier, C. J.; Nazikian, R.; Osborne, T.; Shiraki, D.; Van Zeeland, M. A.

doi:10.1088/0029-5515/56/5/056008

Title: High frequency pacing of edge localized modes by injection of lithium granules in DIII-D H-mode discharges

Abstract

A newly installed Lithium Granule Injector (LGI) was used to pace edge localized modes (ELM) in DIII-D. ELM pacing efficiency was studied injecting lithium granules of nominal diameter 0.3-0.9 mm, speed of 50-120 m/s and average injection rates up to 100 Hz for 0.9 mm granules and up to 700 Hz for 0.3 mm granules. The efficiency of ELM triggering was found to depend strongly on size of the injected granules, with triggering efficiency close to 100% obtained with 0.9 mm diameter granules, lower with smaller sizes, and weakly depending on granule velocity. Robust ELM pacing was demonstrated in ITER-like plasmas for the entire shot length, at ELM frequencies 3-5 times larger than the \natural" ELM frequency observed in reference discharges. Within the range of ELM frequencies obtained, the peak ELM heat flux at the outer strike point was reduced with increasing pacing frequency. The peak heat flux reduction at the inner strike point appears to saturate at high pacing frequency. Lithium wasfound in the plasma core, with a concurrent reduction of metallic impurities and carbon. Overall, high frequency ELM pacing using the lithium granule injection appears to be compatible with both H-mode energy con nement and attractive H-mode pedestalmore »« less

Authors:

^[1]; Maingi, R. ^[1]; Mansfield, D. K. ^[1]; Nagy, A. ^[1]; Roquemore, A. L. ^[1]; Baylor, L. R. ^[2]; Commaux, N. ^[2]; Jackson, G. L. ^[3]; Gilson, E. P. ^[1];

^[1]; Parks, P. B. ^[3]; Chrystal, C. ^[4]; Grierson, B. A. ^[1]; Groebner, R. ^[3];

^[1]; Makowski, M. J. ^[5]; Lasnier, C. J. ^[5]; Nazikian, R. ^[1]; Osborne, T. ^[3]; Shiraki, D. ^[2] more »

Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
General Atomics, San Diego, CA (United States)
Oak Ridge Associated Univ., Oak Ridge, TN (United States)
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Publication Date:: Fri Apr 08 00:00:00 EDT 2016

Research Org.:: Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); General Atomics, San Diego, CA (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Sponsoring Org.:: USDOE National Nuclear Security Administration (NNSA)

Contributing Org.:: Princeton Plasma Physics Laboratory, Princeton, NJ; Oak Ridge National Laboratory, Oak Ridge, TN; General Atomics, San Diego, CA; Oak Ridge Associated Universities, Oak Ridge, TN; Lawrence Livermore National Laboratory, CA

OSTI Identifier:: 1254013

Alternate Identifier(s):: OSTI ID: 1246536; OSTI ID: 1459511; OSTI ID: 1542718

Report Number(s):: PPPL-5251; LLNL-JRNL-752101
Journal ID: ISSN 0029-5515

Grant/Contract Number:: AC02-09CH11466; FC02-04ER54698; AC52-07NA27344; AC05-00OR22725

Resource Type:: Accepted Manuscript

Journal Name:: Nuclear Fusion

Additional Journal Information:: Journal Volume: 56; Journal Issue: 5; Journal ID: ISSN 0029-5515

Publisher:: IOP Science

Country of Publication:: United States

Language:: English

Subject:: 42 ENGINEERING; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; tokamak; ELM; pacing; pellet; mitigation; head load; control; Physics - Plasma physics

Citation Formats


                    Bortolon, A., Maingi, R., Mansfield, D. K., Nagy, A., Roquemore, A. L., Baylor, L. R., Commaux, N., Jackson, G. L., Gilson, E. P., Lunsford, R., Parks, P. B., Chrystal, C., Grierson, B. A., Groebner, R., Haskey, S. R., Makowski, M. J., Lasnier, C. J., Nazikian, R., Osborne, T., Shiraki, D., and Van Zeeland, M. A. High frequency pacing of edge localized modes by injection of lithium granules in DIII-D H-mode discharges.  United States: N. p., 2016. 
Web.  doi:10.1088/0029-5515/56/5/056008.

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                    Bortolon, A., Maingi, R., Mansfield, D. K., Nagy, A., Roquemore, A. L., Baylor, L. R., Commaux, N., Jackson, G. L., Gilson, E. P., Lunsford, R., Parks, P. B., Chrystal, C., Grierson, B. A., Groebner, R., Haskey, S. R., Makowski, M. J., Lasnier, C. J., Nazikian, R., Osborne, T., Shiraki, D., & Van Zeeland, M. A. High frequency pacing of edge localized modes by injection of lithium granules in DIII-D H-mode discharges.  United States.  https://doi.org/10.1088/0029-5515/56/5/056008

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                    Bortolon, A., Maingi, R., Mansfield, D. K., Nagy, A., Roquemore, A. L., Baylor, L. R., Commaux, N., Jackson, G. L., Gilson, E. P., Lunsford, R., Parks, P. B., Chrystal, C., Grierson, B. A., Groebner, R., Haskey, S. R., Makowski, M. J., Lasnier, C. J., Nazikian, R., Osborne, T., Shiraki, D., and Van Zeeland, M. A. Fri .  
"High frequency pacing of edge localized modes by injection of lithium granules in DIII-D H-mode discharges".  United States.  https://doi.org/10.1088/0029-5515/56/5/056008.  https://www.osti.gov/servlets/purl/1254013.

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@article{osti_1254013,

  title        = {High frequency pacing of edge localized modes by injection of lithium granules in DIII-D H-mode discharges},

  author       = {Bortolon, A. and Maingi, R. and Mansfield, D. K. and Nagy, A. and Roquemore, A. L. and Baylor, L. R. and Commaux, N. and Jackson, G. L. and Gilson, E. P. and Lunsford, R. and Parks, P. B. and Chrystal, C. and Grierson, B. A. and Groebner, R. and Haskey, S. R. and Makowski, M. J. and Lasnier, C. J. and Nazikian, R. and Osborne, T. and Shiraki, D. and Van Zeeland, M. A.},

  abstractNote = {A newly installed Lithium Granule Injector (LGI) was used to pace edge localized modes (ELM) in DIII-D. ELM pacing efficiency was studied injecting lithium granules of nominal diameter 0.3-0.9 mm, speed of 50-120 m/s and average injection rates up to 100 Hz for 0.9 mm granules and up to 700 Hz for 0.3 mm granules. The efficiency of ELM triggering was found to depend strongly on size of the injected granules, with triggering efficiency close to 100% obtained with 0.9 mm diameter granules, lower with smaller sizes, and weakly depending on granule velocity. Robust ELM pacing was demonstrated in ITER-like plasmas for the entire shot length, at ELM frequencies 3-5 times larger than the \natural" ELM frequency observed in reference discharges. Within the range of ELM frequencies obtained, the peak ELM heat flux at the outer strike point was reduced with increasing pacing frequency. The peak heat flux reduction at the inner strike point appears to saturate at high pacing frequency. Lithium wasfound in the plasma core, with a concurrent reduction of metallic impurities and carbon. Overall, high frequency ELM pacing using the lithium granule injection appears to be compatible with both H-mode energy con nement and attractive H-mode pedestal characteristics, but further assessment is needed to determine whether the projected heat flux reduction required for ITER can be met.},

  doi          = {10.1088/0029-5515/56/5/056008},

  journal      = {Nuclear Fusion},

  number       = 5,

  volume       = 56,

  place        = {United States},

  year         = {Fri Apr 08 00:00:00 EDT 2016},

  month        = {Fri Apr 08 00:00:00 EDT 2016}

}

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Works referencing / citing this record:

Fusion applications for lithium: wall conditioning in magnetic confinement devices
journal, October 2019

Kaita, Robert
Plasma Physics and Controlled Fusion, Vol. 61, Issue 11
DOI: 10.1088/1361-6587/ab4156

ELM frequency enhancement and discharge modification through lithium granule injection into EAST H-modes
journal, October 2018

Lunsford, R.; Hu, J. S.; Sun, Z.
Nuclear Fusion, Vol. 58, Issue 12
DOI: 10.1088/1741-4326/aae2c1

Results from an improved flowing liquid lithium limiter with increased flow uniformity in high power plasmas in EAST
journal, November 2018

Zuo, G. Z.; Hu, J. S.; Maingi, R.
Nuclear Fusion, Vol. 59, Issue 1
DOI: 10.1088/1741-4326/aaedcb

Ablation of solid pellets induced by supra-thermal ions in the far scrape-off layer of DIII-D plasmas
journal, June 2019

Bortolon, A.; Kramer, G. J.; Maingi, R.
Nuclear Fusion, Vol. 59, Issue 8
DOI: 10.1088/1741-4326/ab267f

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Title: High frequency pacing of edge localized modes by injection of lithium granules in DIII-D H-mode discharges

Abstract

Citation Formats

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