Use of a Helicon Source to Simulate Atmospheric Re - entry Plasma Densities IEPC - 2009 - 236

A 15-cm-diameter helicon source was used at the Plasmadynamics and Electric Propulsion Laboratory at the University of Michigan to simulate the density present in the plasma layer surrounding an atmospheric re-entry vehicle. In order to most closely simulate a re-entering vehicle, a “spacecraft surface” was created with a sheet of mica placed so that the bulk of the plasma would be above it. A 13.56 MHz RF-compensated single Langmuir probe was used to determine the plasma properties directly above the mica surface, and those results were compared with measured density data from re-entry vehicles on a ballistic trajectory. We found that near the mica surface (at 0.5 cm and 1.0 cm above the mica surface), the plasma densities were representative of those found at altitudes between 80 km and 85 km during atmospheric re-entry.