Page 29 - Study of Neutral Gas Pressure Dynamics in C-2W Using Inverted Magnetron Ionization Gauges

Imaging used to identify arcs on biased electrodes
• Harsh conditions promote electrode arcing:
• gas and/or plasma accumulation in the electrode gaps
• heating from ion bombardment
• high voltage differences between neighboring electrodes
• Analysis of supply I-V traces is insufficient to identify all arcing events.
• Not all arcs lead to power supply overcurrent.
• Arcing can occur to a floated electrode.
• Imaging can identify bright regions on electrode surfaces.
• Thoughtful spectral filtering is necessary to distinguish arcing from plasma outflow and ionization.
• Potential arcs are identified by via an image processing algorithm run after each shot.
Presenter: Erik Granstedt 29