Theoretical and experimental study of characteristics of the planar tetrode with field emission of diamond-like carbon film

The work is devoted to presenting the results of theoretical and experimental studies of the characteristics of a planar tetrode with field emission of diamond-like carbon film. Model representations of a field emission stimulation mechanism through existing in the film diamond-like carbon nanoclusters of two phases — diamond and graphite — have been developed. It is assumed that the presence of electrical conductive and dielectric nanoclusters makes film permeable under the applied external electrostatic field, provides field localization on nanoscale inhomogeneities and initiates a low-threshold field emission. The hypothesis is discussed that the structure arises ability to limit to some degree the emission current due to emergence and growth of space charge. The experimental tests of the described micro vacuum tetrode in the long pulse mode (quasi-static mode, pulse duration of 320 μs, pulse repetition frequency of 312.5 Hz) showed stable operation of device during the 8700 hours. If the initial average emission current density was 100 mA/cm
²
, then observed its reduction by 60% during the first 3700 hours and by 10% the next 5000 hours.