'Institute of Electrical and Electronics Engineers (IEEE)'
Abstract
This work presents the design, development and
experimental results obtained from an RF plasma cathode
Electron Beam (EB) gun for material processing applications. EB
currents of up to 38 mA at –60 kV were extracted and correlated
to Optical Emission Spectroscopy (OES) measurements. OES
measurements and Argon II ratios were used to compare hollow
and flat electrode designs as well as to examine changes in other
key plasma parameters (i.e. plasma pressure and excitation
power). The spectroscopic measurements and Argon II ratios
indicated a higher ionization rate for the hollow electrode
geometries and plasma parameters that generated larger EB
currents (i.e. higher excitation power and lower pressure). The
RF plasma cathode gun was compared to a DC plasma cathode
gun. The DC plasma cathode produced larger currents than the
RF plasma chamber. This result agreed with the OES
measurements, which showed a higher ionisation in the DC
plasma