Knowledge of the impurity concentration and temperature in the core plasma
gradient region as well as the SOL is a vital element on the road to docume
nting and understanding the physics of L- and H-mode transport and the tran
sport barrier itself To this end, the Li-beam diagnostic capabilities on W7
-AS and ASDEX-Upgrade have been expanded to include the measurement of radi
al profiles of impurity ion density and temperature via charge-exchange-spe
ctroscopy (Li-CXS). After presenting the method of Li-CXS this paper descri
bes the experimental setup on W7-AS as well as ASDEX-Upgrade and presents f
irst results on both experiments. Measurements of C6+ and Ne10+ spectral li
nes prove the viability of Li-CXS. In the plasma edge region of W7-AS (r(ef
f) > 8 cm) a C6+ concentration of about 0.5% could be measured. Temperature
values found for C6+ are similar to proton/deuteron temperatures. The inte
nsities of several LiI spectral lines (2p-->2s, 3d-->2p, 4s-->2p, 4d-->2p)
have been measured and are used to critically check the underlying cross se
ction database employed within the collisional-excitation Li-beam model, es
pecially for collision processes involving higher Li-states (n greater than
or equal to 3). It was found that the ratio of the spectral Lines correspo
nding to 3d-->2p and 2p-->2s transitions is overestimated by the model. The
se deviations could be eliminated by using improved cross sections in the d
atabase. (C) 1999 Elsevier science B.V. All rights reserved.