Towards a RF/MW Instrumentation Suite Design for an Inductively Coupled Plasma Wind Tunnel*

Hypersonic flight is of significant relevance to the atmospheric entry stage of interplanetary missions and national defense, but the formation of a plasma around hypersonic vehicles presents numerous engineering challenges. One such challenge is communication blackout caused by the sheath of plasma attenuating radio signals. The Magnetoaerodynamics and Aerospace Plasma Laboratory at the University of Colorado Boulder (CU-MAPLAB) will house an inductively coupled plasma (ICP) wind tunnel facility that will allow for simulation of high enthalpy, continuous plasma flows. Measurement of radio signals emanating from and propagating through plasma is a standard non-invasive technique to measure signal propagation and plasma properties, but is underexplored for ICP torches. This research expands upon previous experimental work by utilizing a numerical simulation in COMSOL Multiphysics. Wave propagation physics are coupled with a simulated ICP torch for a comprehensive characterization of radio signal propagation through an ICP torch across multiple frequency ranges. Results from the numerical simulation will be used to inform radio instrumentation selection to enable experimental studies of signal propagation in the CU-MAPLAB plasma wind tunnel.