A new tool for obtaining the frequency characteristics of the interaction of emission sites with adsorbates was developed. The technique is based on the use of a computerized field projector with online processing of patterns of the distribution of emission sites over the cathode surface. The resulting dependences reflect the frequency of fluctuations in the activity of individual sites. The influence of the choice of the threshold brightness parameter, the proximity of the sites to each other and the stability of the total emission current on the shape of these curves is considered. The coincidence of the shapes of curves constructed by various methods (in online mode, in post-processing mode and in the mode of random processes modeling) is analyzed. Keywords: field emission, emission current fluctuations, carbon nanotubes, registration of emission sites, adsorption processes on the surface.

The paper describes a technique for training multi-tip field cathodes with high voltage, which makes it possible to optimize the emission current on the basis of field projector data. The paper presents an algorithm for obtaining and analyzing experimental data, which allows for controlled training of the cathode surface, and also presents the results of the analysis of experimental data obtained for a promising nanocomposite structure of carbon nanotubes in polystyrene. Keywords: Field emission, test of the cold field emission mode, nanocomposite with carbon nanotubes, computerized field emission projector.