Effect of Heat and Mass Transfer of Alloying Elements on the Parameters of Thermoemission Cathodes

The regularities of cathode processes for activated thermionic cathodes, operating in three typical modes found experimentally, are theoretically studied. An evolutionary physical–mathematical model is used considering the processes occurring in the bulk and on the surface of a solid body and in the cathode plasma with reference to each other. The agreement between the theoretical results and the experimental data confirms the accuracy of the developed model. It is shown that the unsteadiness of the cathode and near-cathode processes is caused by the change of the emission characteristics of the cathode material during its operation.