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Title: Lithium granule ablation and penetration during ELM pacing experiments at DIII-D

Journal Article · · Fusion Engineering and Design
ORCiD logo [1]; ORCiD logo [1];  [1];  [1];  [1];  [1];  [2];  [2];  [1];  [2]
  1. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  2. General Atomics, San Diego, CA (United States)
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At DIII-D, lithium granules were radially injected into the plasma at the outer midplane to trigger and pace edge localized modes (ELMs). Granules ranging in size from 300 – 1000 microns were horizontally launched into H-mode discharges with velocities near 100 m/sec, and granule to granule injection frequencies less than 500 Hz. While the smaller granules were only successful in triggering ELMs approximately 20% of the time, the larger granules regularly demonstrated ELM triggering efficiencies of greater than 80%. A fast visible camera looking along the axis of injection observed the ablation of the lithium granules. The duration of ablation was used as a benchmark for a neutral gas shielding calculation, and approximated the ablation rate and mass deposition location for the various size granules, using measured edge plasma profiles as inputs. This calculation suggests that the low triggering efficiency of the smaller granules is due to the inability of these granules to traverse the steep edge pressure gradient region and reach the top of the pedestal prior to full ablation

Research Organization:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); General Atomics, San Diego, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Fusion Energy Sciences (FES)
Contributing Organization:
Princeton Plasma Physics Laboratory, Princeton NJ 08543, USA
Grant/Contract Number:
AC02-09CH11466; FC02-04ER54698
OSTI ID:
1254685
Alternate ID(s):
OSTI ID: 1335172; OSTI ID: 1371726
Report Number(s):
PPPL-5219; PII: S0920379616303325; TRN: US1601725
Journal Information:
Fusion Engineering and Design, Vol. 112; ISSN 0920-3796
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 9 works
Citation information provided by
Web of Science

References (18)

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Cited By (2)

Numerical simulation of lithium granule injection in tokamak edge plasma journal January 2019
Modeling of Ablatant Deposition from Electromagnetically Driven Radiative Pellets for Disruption Mitigation Studies journal July 2019

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70 PLASMA PHYSICS AND FUSION TECHNOLOGY
Edge-localized Mode (ELM)
injection
pellets
lithium
particle dynamics