MICROCOMPUTERIZED MEASUREMENT AND ANALYSIS OF ELECTRON EMISSION PROPERTIES OF THERMIONIC CATHODES
热阴极发射特性的微机化测量和分析

A microcomputerized measuring system is developed. This system automatically acquires an I-V characteristic curve in 5 seconds with an accuracy of 0.05% (ful scale-range). The Schottky extrapolation field-free emission, the inflection point emission, the flection point emission, the average effective work, function, the Richardson .work function, the work function distribution at the operation temperature and other important informations that reflect properties of cathode are obtained by this system. The results after analysing four type of cathodes demonstrate that this system is very suitable for measuring the property changes of the cathode in the processes of activation, ageing, poisoning and life test. It is proved that this system can also be used to monitor the property of the cathode in the assembled tube by measuring a grid controlled travelling-wave tube.