Skip navigation
Please use this identifier to cite or link to this item:
Title: ELM frequency enhancement and discharge modification through lithium granule injection into EAST H-modes
Contributors: Lunsford
Hsu, J.S.
Sun, Z.
Maingi, R.
Mansfield, D.K.
Xu, W.
Zuo, G.Z.
Huang, M.
Diallo, A.
Osborne, T.
Tritz, K.
Canik, J.
Meng, X.C.
Gong, X.Z.
Wan, B.N.
Li, J.G.
U. S. Department of Energy contract number DE-AC02-09CH11466
Keywords: ELM
Issue Date: Oct-2018
Publisher: Princeton Plasma Physics Laboratory, Princeton University
Related Publication: Nuclear Fusion
Abstract: The injection of impurity granules into fusion research discharges can serve as a catalyst for ELM events. For sufficiently low ELM frequencies, and granule sizes above a threshold, this can result in full control of the ELM cycle, referred to as ELM pacing. For this research, we extend the investigation to conditions where the natural ELM frequency is too high for ELM pacing to be realized. Utilizing multiple sizes of lithium granules and classifying their effects by granule size, we demonstrate that ELM mitigation through frequency multiplication can be used at ELM triggering rates that nominally make ELM pacing unrealizable. We find that above a size threshold, injected granules promptly trigger ELMs and commensurately enhance the ELM frequency . Below this threshold size, injection of an individual granule does not always lead to the prompt triggering of an ELM; however, collective ablation in the edge pedestal region does enhance the ELM frequency. Specifically, Li granules too small to individually trigger ELMs were injected into EAST H-mode discharges at frequencies up to 2.3 kHz; collectively the granules were observed to enhance the natural ELM frequency up to 620 Hz, resulting in a ~2.4x multiplication of the natural ELM frequency and a 50% decrease of the ELM size.
Appears in Collections:NSTX-U

Files in This Item:
File Description SizeFormat 
ARK_DATA.zip4.7 MBUnknownView/Download

Items in Dataspace are protected by copyright, with all rights reserved, unless otherwise indicated.