Application of the 263Â GHz/1Â kW gyrotron setup to produce a metal oxide nanopowder by the evaporation-condensation technique

The use of a subterahertz gyrotron setup with output frequency of 263 GHz and a nominal power of 1 kW as a radiation source to obtain nanoscale particles of metal oxides by the evaporation-condensation technique is demonstrated. Zinc oxide ZnO and tungsten trioxide WO3 were the test substances. The substance evaporation was provided by a focused beam of electromagnetic radiation with an estimated microwave-energy flux density of about 20 kW/cm2 and was followed by deposition of the particles on the water-cooled surface. The sizes of the obtained particles ranged from 20 to 500 nm. A threefold increase in the substance evaporation rate compared with the previous experiments, in which a technological gyrotron setup with a frequency of 24 GHz and a nominal power of 7 kW was used, has been shown.