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Title: Injected mass deposition thresholds for lithium granule instigated triggering of edge localized modes on EAST

Abstract

The ability of an injected lithium granule to promptly trigger an edge localized mode (ELM) has been established in multiple experiments. By horizontally injecting granules ranging in diameter from 200 microns to 1mm in diameter into the low field side of EAST H-mode discharges we have determined that granules with diameter > 600 microns are successful in triggering ELMs more than 95% of the time. Granules were radially injected from the outer midplane with velocities ~ 80 m/s into EAST upper-single null discharges with an ITER like tungsten monoblock divertor. ELM triggering was a prompt response to granule injection, and for granules of a sufficient size there was no evidence of a "trigger lag" phenomenon as observed in full metal machines. We also demonstrated that the triggering efficiency decreased with granule size during dynamic size scans. These granules were individually tracked throughout their injection cycle in order to determine their efficacy at triggering an ELM. Furthermore, by simulating the granule injection with an experimentally benchmarked neutral gas shielding (NGS) model, the ablatant mass deposition required to promptly trigger an ELM is calculated and the fractional mass deposition is determined. Simulated 900 micron granules capable of triggering an ELM show amore » peaked mass deposition of 3.9 x 1017 atoms per mm of penetration at a depth of approximately 5 cm past the separatrix.« less

Authors:
 [1];  [2];  [1];  [2];  [1];  [2];  [2];  [1];  [3];  [4];  [5];  [2];  [6];  [2];  [2];  [2]
  1. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  2. Chinese Academy of Sciences (CAS), Beijing (China). Inst. of Plasma Physics
  3. General Atomics, San Diego, CA (United States)
  4. Johns Hopkins Univ., Baltimore, MD (United States)
  5. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  6. Hunan Univ., Changsha (China). Dept. of Applied Physics
Publication Date:
Research Org.:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1414904
Grant/Contract Number:  
No.11321092; No.11405210; No.11605246; No.11625524; AC02-09CH11466; FC02-04ER54698; FG02-09ER55
Resource Type:
Accepted Manuscript
Journal Name:
Nuclear Fusion
Additional Journal Information:
Journal Volume: 58; Journal Issue: 3; Journal ID: ISSN 0029-5515
Publisher:
IOP Science
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats

Lunsford, R., Sun, Zhen, Maingi, Rajesh, Hu, Jiansheng, Mansfield, D. K., Xu, Wei, Zuo, Guizhong, Diallo, Ahmed, Osborne, Tom H., Tritz, Kevin, Canik, John M., Huang, Ming, Meng, Xiancai, Gong, Xianzu, Wan, Baonian, and Li, Jiangang. Injected mass deposition thresholds for lithium granule instigated triggering of edge localized modes on EAST. United States: N. p., 2017. Web. https://doi.org/10.1088/1741-4326/aaa2ac.
Lunsford, R., Sun, Zhen, Maingi, Rajesh, Hu, Jiansheng, Mansfield, D. K., Xu, Wei, Zuo, Guizhong, Diallo, Ahmed, Osborne, Tom H., Tritz, Kevin, Canik, John M., Huang, Ming, Meng, Xiancai, Gong, Xianzu, Wan, Baonian, & Li, Jiangang. Injected mass deposition thresholds for lithium granule instigated triggering of edge localized modes on EAST. United States. https://doi.org/10.1088/1741-4326/aaa2ac
Lunsford, R., Sun, Zhen, Maingi, Rajesh, Hu, Jiansheng, Mansfield, D. K., Xu, Wei, Zuo, Guizhong, Diallo, Ahmed, Osborne, Tom H., Tritz, Kevin, Canik, John M., Huang, Ming, Meng, Xiancai, Gong, Xianzu, Wan, Baonian, and Li, Jiangang. Tue . "Injected mass deposition thresholds for lithium granule instigated triggering of edge localized modes on EAST". United States. https://doi.org/10.1088/1741-4326/aaa2ac. https://www.osti.gov/servlets/purl/1414904.
@article{osti_1414904,
title = {Injected mass deposition thresholds for lithium granule instigated triggering of edge localized modes on EAST},
author = {Lunsford, R. and Sun, Zhen and Maingi, Rajesh and Hu, Jiansheng and Mansfield, D. K. and Xu, Wei and Zuo, Guizhong and Diallo, Ahmed and Osborne, Tom H. and Tritz, Kevin and Canik, John M. and Huang, Ming and Meng, Xiancai and Gong, Xianzu and Wan, Baonian and Li, Jiangang},
abstractNote = {The ability of an injected lithium granule to promptly trigger an edge localized mode (ELM) has been established in multiple experiments. By horizontally injecting granules ranging in diameter from 200 microns to 1mm in diameter into the low field side of EAST H-mode discharges we have determined that granules with diameter > 600 microns are successful in triggering ELMs more than 95% of the time. Granules were radially injected from the outer midplane with velocities ~ 80 m/s into EAST upper-single null discharges with an ITER like tungsten monoblock divertor. ELM triggering was a prompt response to granule injection, and for granules of a sufficient size there was no evidence of a "trigger lag" phenomenon as observed in full metal machines. We also demonstrated that the triggering efficiency decreased with granule size during dynamic size scans. These granules were individually tracked throughout their injection cycle in order to determine their efficacy at triggering an ELM. Furthermore, by simulating the granule injection with an experimentally benchmarked neutral gas shielding (NGS) model, the ablatant mass deposition required to promptly trigger an ELM is calculated and the fractional mass deposition is determined. Simulated 900 micron granules capable of triggering an ELM show a peaked mass deposition of 3.9 x 1017 atoms per mm of penetration at a depth of approximately 5 cm past the separatrix.},
doi = {10.1088/1741-4326/aaa2ac},
journal = {Nuclear Fusion},
number = 3,
volume = 58,
place = {United States},
year = {2017},
month = {12}
}

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Figures / Tables:

Table 1 Table 1: Injection parameters for high power granule discharges. aDischarge #70605 was undertaken immediately after switching granule sizes without clearing the crystal surface. As such the average granule size at the beginning of the discharge is larger than the sizes at the end. bFor the smallest granule sizes injected inmore » discharge #70607 the impeller was driving in multiple granules per pass, thus the actual frequency is capped by the 300 Hz impeller frequency. The uncertainty indicated in row 2 of column 3 is indicative of the uncertainty in all velocity estimates.« less

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Works referenced in this record:

A quarter-century of H-mode studies
journal, November 2007


Edge-localized-modes in tokamaks
journal, September 2014


Secondary ELM filaments in NSTX
journal, June 2009


Chapter 4: Power and particle control
journal, June 2007


ELM divertor peak energy fluence scaling to ITER with data from JET, MAST and ASDEX upgrade
journal, August 2017


Effects of ELMs on ITER divertor armour materials
journal, June 2007


New Steady-State Quiescent High-Confinement Plasma in an Experimental Advanced Superconducting Tokamak
journal, February 2015


New Edge Coherent Mode Providing Continuous Transport in Long-Pulse H-mode Plasmas
journal, May 2014


Multi-device studies of pedestal physics and confinement in the I-mode regime
journal, July 2016


First observation of ELM pacing with vertical jogs in a spherical torus
journal, May 2010


ELM mitigation by means of supersonic molecular beam and pellet injection on the EAST superconducting tokamak
journal, August 2015


Pellet Injection Technology and Its Applications on ITER
journal, September 2016

  • Baylor, L. R.; Combs, S. K.; Duckworth, R. C.
  • IEEE Transactions on Plasma Science, Vol. 44, Issue 9
  • DOI: 10.1109/TPS.2016.2550419

ELM mitigation with pellet ELM triggering and implications for PFCs and plasma performance in ITER
journal, August 2015


High frequency pacing of edge localized modes by injection of lithium granules in DIII-D H-mode discharges
journal, April 2016


ELM pace making and mitigation by pellet injection in ASDEX Upgrade
journal, April 2004


First Results of ELM Triggering With a Multichamber Lithium Granule Injector Into EAST Discharges
journal, May 2018


Characterization of peeling–ballooning stability limits on the pedestal
journal, April 2004

  • Snyder, P. B.; Wilson, H. R.; Osborne, T. H.
  • Plasma Physics and Controlled Fusion, Vol. 46, Issue 5A
  • DOI: 10.1088/0741-3335/46/5A/014

Concept Design of CFETR Tokamak Machine
journal, March 2014

  • Song, Yun Tao; Wu, Song Tao; Li, Jian Gang
  • IEEE Transactions on Plasma Science, Vol. 42, Issue 3
  • DOI: 10.1109/TPS.2014.2299277

Techniques for injection of pre-characterized dust into the scrape-off layer of fusion plasma
journal, October 2011


First observations of ELM triggering by injected lithium granules in EAST
journal, September 2013


Anomalous Behavior of the Coefficient of Normal Restitution in Oblique Impact
journal, October 2004


Multi-species impurity granule injection and mass deposition projections in NSTX-U discharges
journal, May 2017


Review: Pellet injection experiments and modelling
journal, July 2007


Analysis of low Z a impurity pellet ablation for fusion diagnostic studies
journal, March 1988


Model of ablation flow near light-atom pellets with surface boundary conditions
journal, March 1994


On the fluctuation of line radiation emitted during aluminum micro-pellet ablation in magnetized plasmas
journal, January 1999


Lithium granule ablation and penetration during ELM pacing experiments at DIII-D
journal, November 2016


Non-linear MHD modelling of ELM triggering by pellet injection in DIII-D and implications for ITER
journal, April 2014


Non-linear MHD simulations of edge localized modes (ELMs)
journal, November 2009


Mitigation of divertor heat flux by high-frequency ELM pacing with non-fuel pellet injection in DIII-D
journal, August 2017


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    Modeling of Ablatant Deposition from Electromagnetically Driven Radiative Pellets for Disruption Mitigation Studies
    journal, July 2019


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


    EMC3-EIRENE modelling of edge plasma and impurity emissions compared with the liquid lithium limiter experiment on EAST
    journal, August 2018