Transition from electron- to ion-interaction of LH-waves in ASDEX

In our experiments up to 1 MW LH-power at 2.45 GHz was launched into deuterium plasmas for 1s. Wave spectra with a refractive index anti Nparallel up to 4.4 were applied. The line-averaged electron density anti ne was scanned from 1.3 to 5.4 x 1019 m-3 at a plasma current of 420 kA. A neutral particle analyzer was used to measure the perpendicular charge-exchange neutral hydrogen and deuterium flux up to 10 and 20 keV, respectively. In addition to the passive method active CX was applied with a diagnostic neutral hydrogen beam. The main advantage of the passive analysis is its continuous applicability during the discharge. The active method in principle allows space-resolved measurements, but normally in the pulsed beam mode only. Comparing the results of both methods can help to localize phenomena detected with the passive method. (orig.)