Intense gyrotron-based quasi-optical microwave beams for material processing

Summary form only given. Microwave processing of materials has traditionally utilized frequencies in the 0.915 and 2.45 GHz regions. Microwave power sources are readily available at these frequencies but the relatively long wavelengths can present challenges in uniformly heating materials. An additional difficulty is the poor coupling of many ceramic based materials to the microwave energy. Los Alamos National Laboratory scientists, working in conjunction with the National Center for Manufacturing Sciences (NCMS), have established a high-frequency demonstration processing facility utilizing gyrotron based RF sources. The facility is primarily intended to demonstrate the unique features available at frequencies as high as 84 GHz. We can readily provide well defined 37 GHz beams at continuous wave (CW) power levels in the 10 kW range. We have also provided beams at 84 GHz at 10 kW CW power levels. We are presently preparing a facility to demonstrate the sintering of ceramics at 28 GHz. This paper presents an overview of our present demonstration processing facility and describes some of the features we have available now and will have available in the near future.