Noise diagnostics has been performed on the cold field-emission cathode in high-vacuum. The tested cold field-emission cathode, based on tungsten wire with ultra-sharp tip coated by epoxy was designed to meet the requirements of transmission electron microscopy, which uses a small and stable source of electrons. Current fluctuations are reduced by improving the structure and fabrication technology. Noise was measured both in time and frequency domains, which gives information about current fluctuations and also about charge transport. Mutual correlation between the noise spectral density, extractor voltage and beam brightness was analyzed.

The aim of the research was to determine the effect of sonochemical treatments on homogenization of powders as well as phase composition and thermal stability of sinters. The compounds were prepared from Eu2O3 and ZrO2 powders, weighed in the mass ratio 1:1. Initially ultrasound treatment was applied. 750-Watt ultrasonic processor VCX-750 equipped with sealed converter VC-334 and horn 630-0219 with the diameter of 13 mm (Sonics & Materials, Inc.) was used as a source of ultrasound. Applied ultrasound frequency was 20 kHz, power density was controlled in the range from 75 W/cm2 to 340 W/cm2. Investigated compounds were synthesized via solid-state reaction (SSR). The Differential Scanning Calorimetry (DSC) was used in order to investigate the effect of sonochemical treatment on the synthesis of prepared mixtures the powders particle size distribution was analyzed. Ultrasound treatment what wasn’t never been reported before.