Simulating Hypersonic Atmospheric Conditions in a Laboratory Setting using a 6-in-Diameter Helicon Source

Abstract

Summary form only given. While a spacecraft is reentering the atmosphere or a hypersonic vehicle is in flight, low-frequency electromagnetic radiation cannot penetrate the plasma layer that forms around the high speed vehicle. This interferes with real-time telemetry from hypersonic vehicles and interrupts spacecraft communications during atmospheric reentry. Hypersonic atmospheric plasmas are difficult to simulate in a laboratory setting because they are high density (~109 - 1011 cm-3 depending on altitude) and low temperature (~2 - 5 eV). A 6-cm-diameter helicon source capable of creating plasma with these requirements has been designed, fabricated and tested at the University of Michigan Plasmadynamics and Electric Propulsion Laboratory (PEPL). We present Langmuir probe, retarding potential analyzer and residual gas analyzer data from helicon source operation with argon, nitrogen and air.