Abstract: Systems and methods for cleaning an edge ring pocket are described herein. One of the methods includes providing one or more process gases to a plasma chamber, supplying a low frequency (LF) radio frequency (RF) power to an edge ring that is located adjacent to a chuck of the plasma chamber. The LF RF power is supplied while the one or more process gases are supplied to the plasma chamber to maintain plasma within the plasma chamber. The supply of the LF RF power increases energy of plasma ions near the edge ring pocket to remove residue in the edge ring pocket. The LF RF power is supplied during the time period in which a substrate is not being processed within the plasma chamber.

Abstract: A two stage fuel delivery system for an aircraft includes a first stage pump including an inlet connected to a source of fuel and an outlet connected to a combustor assembly, and a second stage pump including an inlet portion connected to the source of fuel and an outlet portion connected to the combustor assembly. A bypass valve is connected between the source of fuel, the inlet, and the inlet portion. The bypass valve selectively disconnects the second stage pump from the source of fuel. A metering valve is connected to the inlet and the inlet portion. The metering valve includes a metering valve inlet and a metering valve outlet. A pressure regulating valve is connected to the metering valve. A stage monitoring system is configured to detect a change in operation of the second stage and control the bypass valve.