Experimental Study on a Weakly-Ionized Rarefied Arc-Jet Flowing Supersonically along a Mirror and Cusp Magnetic Field
K. Tajima1, A. Nezu2, H. Matsuura2, and H. Akatsuka1, 2
1Department of Energy Sciences, Tokyo Institute of Technology, Japan
2Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Japan
Abstract- We experimentally study the characteristics of supersonically flowing helium plasma along a mirror and cusp magnetic field, including the flow direction along open field lines. The plasma is initially generated by arc discharge under atmospheric pressure, followed by a supersonic expansion into a weak uniform longitudinal magnetic channel in a rarefied gas wind tunnel as a plasma expansion chamber, and finally, expanded along the mirror or cusp magnetic field. Along the mirror type magnetic field, the plasma forms a high potential region around the plasma boundary and a low potential region around the axis of the plasma. For the cusp type, we observed a dark region, which is considered to be a shock wave.
Keywords-Acceleration, arc-jet flow, mirror magnetic fields, cusp magnetic field, plasma measurements