PPPL-4536

First Observation Of ELM Pacing With Vertical Jogs In A Spherical Torus

Authors: S.P. Gerhardt, J-W. Ahn, J.M. Canik, R. Maingi, R. Bell, D. Gates, R. Goldston, R. Hawryluk, B.P. Le Blanc, J. Menard, A.C. Sontag, S. Sabbagh and K. Tritz

Abstract:
Experiments in a number of conventional aspect ratio tokamaks have been successful in pacing edge localized modes (ELMs) by rapid vertical jogging of the plasma. This paper demonstrates the first pacing of ELMs in a spherical torus plasma. Applied 30 Hz vertical jogs synchronized the ELMs with the upward motion of the plasma. 45 Hz jogs also lead to an increase in the ELM frequency, though the synchronization of the ELMs and jogs was unclear. A reduction in the ELM energy was observed at the higher driven ELM frequencies.
__________________________________________________

Accepted to: Nuclear Fusion (May, 2010)

__________________________________________________

Download PPPL-4536 (pdf 191 KB 8 pp)
__________________________________________________