Rapid Feasibility Tests Using A TE_10nVariable Aperture Resonant Applictor

A variable-aperture, variable-plunger microwave resonant cavity has been characterized using slotted line techniques for processing a wide range of different materials at 2,450 MHz. Data for the voltage standing wave ratio, S, as a function of the cavity length and frequency, as well as heating rates using a 1.5 kW test source, are presented. Initial heating rates in particulates in the range 0.4°Cls to 20°Cls were observed. Temperatures close to 650°C have been reached in ceramic compounds within a few minutes. The limiting factor of reaching 1000°C, a requirement for the ceramic compounds to attain the superconducting phases, is thermal radiation loss from the heated samples. Plasmas at subatmospheric pressures were readily obtained with this applicator.