Limits of operation of conventional RF windows for electron cyclotron waves launchers in a reactor

The main thermomechanical problems of conventional ceramic RF windows for electron cyclotron wave launchers at 140GH/sub z/, in a reactor, and a design approach based on a simplified analytical procedure and more detailed finite element analyses are presented. The RF power which can be transmitted per disk window depends among others on the assumed power flux distribution, the cooling conditions, the geometry and the disk support conditions. A limit of about 250 KW has been evaluated on the basic of material integrity considerations in terms of maximum bending tensile, compressive and buckling stresses. These preliminary estimates do not account for irradiation effects nor for probabilistic fracture mechanics behavior of the ceramic disks. Improvements (use of higher strength materials and advanced window concepts) are suggested