2005 47th Annual Meeting of the Division of Plasma Physics
Monday–Friday, October 24–28, 2005;
Denver, Colorado
Session CI1b: Transport Barrier Physics
3:00 PM–5:00 PM,
Monday, October 24, 2005
Adam's Mark Hotel
Room: Plaza Ballroom ABC
Chair: Charles Bush, Oak Ridge National Laboratory
Abstract ID: BAPS.2005.DPP.CI1b.1
Abstract: CI1b.00001 : Structure and Motion of Edge Turbulence in NSTX and Alcator C-Mod
3:00 PM–3:30 PM
Preview Abstract
Abstract
Author:
Stewart Zweben
(PPPL)
This talk will describe recent 2-D imaging measurements of edge
turbulence
in NSTX and present some comparisons with Alcator C-Mod and with
theory and
simulation. The measurements were made using the visible line
emission from
localized neutral deuterium or helium gas puffs [1-3]. Ultra-high
speed
movies of the turbulent structure and motion of this light
emission were
made in both NSTX and C-Mod with a spatial resolution of 64 pixels
(poloidally) x 64 pixels (radially), with 300 time frames at 250,000
frames/sec. In Ohmic and L-mode plasmas the edge is always highly
turbulent
and often contains localized structures (``blobs'') which move at
about 1
km/sec both radially and poloidally. A model has been developed
to convert
the local light emission to density and temperature for
comparisons of the
observed blob motion in NSTX with analytic scalings [4] and 2D
simulations.
Movies of the L-H transition in NSTX will be presented and
analyzed; the
transition evolves from a turbulent state to a more quiescent
state without
much apparent change in the local turbulence flows. Additional NSTX
phenomena will be shown if time allows (e.g. ELMs, MHD, etc.).
The imaging
results in NSTX will be compared with those in C-Mod and with
turbulence
simulations where possible. Opportunities for additional
comparisons between
experiment and theory will be discussed.\newline
[1] S.J. Zweben et al, Nucl. Fus. 44, 134, 2004
\newline
[2] R.J. Maqueda et al, Rev. Sci. Inst. 74, 2020, 2003
\newline
[3] J.L. Terry et al, Phys. Plasmas 10, 1739, 2003
\newline
[4] J.R. Myra and D.A. D'Ippolito, Lodestar Report {\#}LRC-05-105
(2005).
\newline
\newline
In collaboration with: R.J. Maqueda, J.L. Terry, D. D'Ippolito,
O. Grulke,
J.A. Krommes, T. Munsat, J. Myra, D. Russell, D. Stotler, T.
Stoltzfus-Dueck, M. Umansky, A.E. White, K.M. Williams, X. Xu and
the NSTX
and Alcator C-Mod Teams
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2005.DPP.CI1b.1