Introduction:

Inside the high vacuum chambers of the plasma heater of the future nuclear fusion reactors, such as ITER or DEMO, so-called “dark currents” are produced which, with time, cause damages to different components. Although this typical emission has an explanation on the basis of field emission theory, there are still many questions to be described. The objective was to use a model based on Density Functional Theory to describe some aspects of the field emission due to contaminated surfaces or nanometric irregularities.

Methods:

Studies were conducted on tungsten and tungsten carbide surfaces contaminated with carbon, as well as on clean tungsten corrugated surfaces.

Results:

Knowledge of the origin of “dark currents” was advanced, as well as its relation with different irregularities on the cathode surfaces.

        · resumo em Espanhol     · texto em Espanhol     · Espanhol ( pdf )