[Zurück]

F. Laggner, E. Wolfrum, M. Willensdorfer, G. Birkenmeier, T. Kobayashi, F. Aumayr, . ASDEX Upgrade Team:
"Reconstruction of electron density perturbations using lithium beam emission spectroscopy";
Poster: Deutsche Physikalische Gesellschaft (DPG) Frühjahrstagung 2013, Jena/Germany; 27.02.2013.

The lithium beam diagnostic at ASDEX Upgrade is routinely used to
measure plasma edge electron density (
n
e
) profiles. With a recently
installed diagnostics upgrade (better light sensitivity and faster data
acquisition) one can resolve turbulent structures at the plasma edge.
A sensitivity study is performed to quantify the capabilities of the
diagnostic. The response of the emission profile to a
n
e
perturbation
depends on the radial position of the perturbation. It is possible to
resolve
n
e
perturbations in the scrape off layer (SOL) with a high
accuracy in perturbation height and width.
First experimental results from a 800 kA, ECRH heated, L-mode
discharge are interpreted. The SOL
n
e
perturbations reach 100% of
the average
n
e
value which is consistent with the SOL
n
e
being dom-
inated by intermittent bursts.