Investigation of fringe plasma parameters on a high power rf driven ion source.
It has been observed that there are differences between the uncompensated Langmuir probes installed in the upper and lower areas of the rf driven H(-) sources at IPP Garching. The two probes often had substantially different floating potentials or ion saturation currents. In an effort to understand the reasons for these differences a Langmuir probe analysis system was used on the probes to collect the full current voltage characteristic. The results show what is likely the formation of an ion-ion plasma. The paper shows the effect of beam extraction and the presence of caesium on the probe characteristics.
McNeely
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Max Planck Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstrasse 2, 85748 Garching, Germany. p.mcneely@ipp.mpg.de
Schiesko
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