Negatively Charged Conical Electrostatic Probes in a Supersonic Flow

width of waveguide (interferometer) electron charge current to probe dimensionless probe current I/neu^n^ sin# ion mobility Knudsen number based on probe length path length between horns (microwave interferometer) or probe length Mach number particle mass particle density Reynolds number based on probe length dimensionless mobility ion Schmidt number fluid to probe temperature ratio freestream velocity angle of attack phase difference in radians (microwave interferometer) dielectric constant conical probe half-angle Debye length over probe length free space wavelength (microwave interferometer)