Fast warm dispenser cathodes - modified standard designs

Summary form only given. Several current and future mini TWT applications require fast (2.5 - 6 second) turn on of the TWT and hence the cathode-heater assembly it contains. This work was intended to develop low cost modified standard cathode/heater designs to achieve these requirements. Traditional dedicated designs (bombarders, metal potting, multiple heaters), with their associated high costs, are available, but a low cost alternative is also desired for many applications. Standard cathode-heater designs currently in use in mini TWT´s have been modified to enhance the warm up performance. Flexible designs have been produced with minor heater modifications, mass reductions, and configuration changes. Semicon Associates has assembled a dedicated set of equipment to evaluate the fast warm up performance of dispenser cathode heater assemblies. A programmable power supply that can simulate the end user´s power supply and a fully capable data acquisition system are included. Assemblies can be exercised and evaluated as required. Temperature is monitored using single or two color pyrometers.