Plasma stream velocity measurement in pulsed plasma accelerator

A quasi-stationary type co-axial pulsed plasma accelerator (PPA) has been developed at CPP-IPR. The pulsed plasma device consist of a co-axial electrode assembly and it is powered by a 200 kJ Pulse Power System (PPS). The device produces high density and high velocity plasma stream and it is useful for studying plasma matter interaction (PMI) taking place due to ELMs events at Tokamak. Therefore the characterization of plasma stream such as the stream velocity is important to know the usefulness of the stream. The plasma stream velocity can be measured adopting a well-known time of flight technique. For this we have used a pair of PMTs and two pairs metallic plate-probe separated by a distance. In general, the plasma stream velocity of a PPA varies from few kilometers per second to few tens of kilometers per second depending on the discharge voltage as well as the driving pulse current. The plasma stream velocity, observed at the CPPIPR PPA, is found to be in the order of km/s and it is comparable to the velocity obtained in a similar device elsewhere in the world. The detail analysis of plasma stream velocity measurement with respect to discharge voltage and operating pressure condition along with the PPA facility existing at CPP-IPR has been reported in this presentation. (author)