Characterisation of a thermionic plasma source apparatus for high-density gaseous plasma antenna applications

A thermionic plasma source apparatus has been developed and characterised for high-density gaseous plasma antenna (GPA) applications. The system produces a cylindrical plasma column which is 100 mm long with a diameter of 8 mm and operates with a total plasma power consumption of 70 to 200 W, depending mainly on the DC discharge current. The plasma column electron density and temperature is measured via microwave interferometry and optical emission spectroscopy. The plasma properties are investigated for Ar, Kr and Xe at pressures from 1 to 4 mbar. The system has demonstrated higher electron densities (>1019 m-3) at low pressures (