Features of evaluating properties of field emitters using effective parameters

The paper considers the features of evaluating the effective parameters of nanostructured field cathodes – the area of the field emission Seff and the field gain $\beta_{eff}$. A variety of approaches to parameter estimates is shown. The dependence of these estimates on the magnitude of the applied electric voltage is shown by the example of a three-dimensional model of a carbon nanotube. The possibility of the experimentally estimation of individual emission sites using a computerized field projector is considered. A method for analyzing the current-voltage characteristics in Fowler-Nordheim coordinates (IVC-FN) with an interval estimate of the effective parameters is proposed.