The quantum tunneling is a phenomenon that provides numerous technological applications through direct application of the concepts of quantum mechanics. According to this phenomenon, electrons can be extracted from metal surfaces under which there is a huge potential gradient, ie, an intense local electric field. Through a system known as microhollow cathode two metal layers interspersed by a thin mica layer (with thickness d = 3 μm), perforated with holes of diameter D = 200 μm at a pressure of 20 Torr, led the extraction of cold electrons at a local electric microfield of approximately 15 V/nm. The voltage of about 390 V applied at these metals allowed the passage of electrons through the potential barrier at the cathode hole region. The Fowler-Nordheim curve confirmed the effectiveness of the phenomenon in the generation of microplasma inside the hole, visible to the naked eyes.
quantum tunneling; microhollow cathode; Fowler-Nordheim
