ELM mitigation with pellet ELM triggering and implications for PFCs and plasma performance in ITER
Abstract
The triggering of rapid small edge localized modes (ELMs) by high frequency pellet injection has been proposed as a method to prevent large naturally occurring ELMs that can erode the ITER plasma facing components. Deuterium pellet injection has been used to successfully demonstrate the on-demand triggering of edge localized modes (ELMs) at much higher rates and with much smaller intensity than natural ELMs. The proposed hypothesis for the triggering mechanism of ELMs by pellets is the local pressure perturbation resulting from reheating of the pellet cloud that can exceed the local high-n ballooning mode threshold where the pellet is injected. Nonlinear MHD simulations of the pellet ELM triggering show destabilization of high-n ballooning modes by such a local pressure perturbation. A review of the recent pellet ELM triggering results from ASDEX Upgrade (AUG), DIII-D, and JET reveals that a number of uncertainties about this ELM mitigation technique still remain. These include the heat flux impact pattern on the divertor and wall from pellet triggered and natural ELMs, the necessary pellet size and injection location to reliably trigger ELMs, and the level of fueling to be expected from ELM triggering pellets and synergy with larger fueling pellets. The implications of thesemore »
- Authors:
-
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Max Planck Inst. fur Plasmaphysik, Garching (Germany)
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- General Atomics, San Diego, CA (United States)
- ITER Organization, St. Paul Lez Durance (France)
- Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
- Univ. of California, San Diego, CA (United States)
- Publication Date:
- Research Org.:
- General Atomics, San Diego, CA (United States)
- Sponsoring Org.:
- USDOE
- OSTI Identifier:
- 1375959
- Alternate Identifier(s):
- OSTI ID: 1252293
- Grant/Contract Number:
- FC02-04ER54698; AC05-00OR22725; FG02-07ER54917; AC52-07NA27344
- Resource Type:
- Journal Article: Accepted Manuscript
- Journal Name:
- Journal of Nuclear Materials
- Additional Journal Information:
- Journal Volume: 463; Journal Issue: C; Journal ID: ISSN 0022-3115
- Publisher:
- Elsevier
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; Plasma properties; Gases; Gas injection & Fueling; Pellet; DIII-D; ELM
Citation Formats
Baylor, Larry R., Lang, P. T., Allen, Steve L., Combs, S. K., Commaux, N., Evans, Todd E., Fenstermacher, Max E., Huijsmans, G., Jernigan, T. C., Lasnier, Charles J., Leonard, Anthony W., Loarte, Alberto, Maingi, Rajesh, Maruyama, S., Meitner, S. J., Moyer, Richard A., and Osborne, Thomas H. ELM mitigation with pellet ELM triggering and implications for PFCs and plasma performance in ITER. United States: N. p., 2014.
Web. doi:10.1016/j.jnucmat.2014.09.070.
Baylor, Larry R., Lang, P. T., Allen, Steve L., Combs, S. K., Commaux, N., Evans, Todd E., Fenstermacher, Max E., Huijsmans, G., Jernigan, T. C., Lasnier, Charles J., Leonard, Anthony W., Loarte, Alberto, Maingi, Rajesh, Maruyama, S., Meitner, S. J., Moyer, Richard A., & Osborne, Thomas H. ELM mitigation with pellet ELM triggering and implications for PFCs and plasma performance in ITER. United States. https://doi.org/10.1016/j.jnucmat.2014.09.070
Baylor, Larry R., Lang, P. T., Allen, Steve L., Combs, S. K., Commaux, N., Evans, Todd E., Fenstermacher, Max E., Huijsmans, G., Jernigan, T. C., Lasnier, Charles J., Leonard, Anthony W., Loarte, Alberto, Maingi, Rajesh, Maruyama, S., Meitner, S. J., Moyer, Richard A., and Osborne, Thomas H. 2014.
"ELM mitigation with pellet ELM triggering and implications for PFCs and plasma performance in ITER". United States. https://doi.org/10.1016/j.jnucmat.2014.09.070. https://www.osti.gov/servlets/purl/1375959.
@article{osti_1375959,
title = {ELM mitigation with pellet ELM triggering and implications for PFCs and plasma performance in ITER},
author = {Baylor, Larry R. and Lang, P. T. and Allen, Steve L. and Combs, S. K. and Commaux, N. and Evans, Todd E. and Fenstermacher, Max E. and Huijsmans, G. and Jernigan, T. C. and Lasnier, Charles J. and Leonard, Anthony W. and Loarte, Alberto and Maingi, Rajesh and Maruyama, S. and Meitner, S. J. and Moyer, Richard A. and Osborne, Thomas H.},
abstractNote = {The triggering of rapid small edge localized modes (ELMs) by high frequency pellet injection has been proposed as a method to prevent large naturally occurring ELMs that can erode the ITER plasma facing components. Deuterium pellet injection has been used to successfully demonstrate the on-demand triggering of edge localized modes (ELMs) at much higher rates and with much smaller intensity than natural ELMs. The proposed hypothesis for the triggering mechanism of ELMs by pellets is the local pressure perturbation resulting from reheating of the pellet cloud that can exceed the local high-n ballooning mode threshold where the pellet is injected. Nonlinear MHD simulations of the pellet ELM triggering show destabilization of high-n ballooning modes by such a local pressure perturbation. A review of the recent pellet ELM triggering results from ASDEX Upgrade (AUG), DIII-D, and JET reveals that a number of uncertainties about this ELM mitigation technique still remain. These include the heat flux impact pattern on the divertor and wall from pellet triggered and natural ELMs, the necessary pellet size and injection location to reliably trigger ELMs, and the level of fueling to be expected from ELM triggering pellets and synergy with larger fueling pellets. The implications of these issues for pellet ELM mitigation in ITER and its impact on the PFCs are presented along with the design features of the pellet injection system for ITER.},
doi = {10.1016/j.jnucmat.2014.09.070},
url = {https://www.osti.gov/biblio/1375959},
journal = {Journal of Nuclear Materials},
issn = {0022-3115},
number = C,
volume = 463,
place = {United States},
year = {Sun Oct 05 00:00:00 EDT 2014},
month = {Sun Oct 05 00:00:00 EDT 2014}
}
Web of Science
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Works referencing / citing this record:
Numerical simulation of the effect of pellet injection on ELMs
journal, June 2019
- Chandra, D.; Sen, A.; Thyagaraja, A.
- Plasma Physics and Controlled Fusion, Vol. 61, Issue 8
Non-linear magnetohydrodynamic simulations of plasma instabilities from pellet injection in Large Helical Device plasma
journal, August 2019
- Futatani, Shimpei; Suzuki, Yasuhiro
- Plasma Physics and Controlled Fusion, Vol. 61, Issue 9
Pellet-Injector Technology—Brief History and Key Developments in the Last 25 Years
journal, December 2017
- Combs, S. K.; Baylor, L. R.
- Fusion Science and Technology, Vol. 73, Issue 4