INVESTIGATION ON PULSE PROPERTIES OF IMPREGNATED BARIUM SCANDATE DISPENSER CATHODES

In this paper, an impregnated barium acandate dispenser cathode primarily for applicationin microwave tubes, especially in gyrotrons, is investigated in the following aspecta: （1） pulse emission abilityand work function distribution; （2） electron initial velocity distribution in pulse operation; （3） the effect ofpulse duration ratio; （4） the anomalous Schottky effect under intensive electric field. Some useful results areobtained: the pulse current density is higher than 20 A/cm（when T=850℃）; the anomalous Schottkyeffect is observed when the field intenaity is higher than 10V/cm; the cathode has flat Jft characteriaticwhen the pulse duration ratio is in the range of 5×10--4×10and an emission current density of 8.8A/cmis drawn. Finally, the experimental results are discussed in relation to papers of the cathode surfaceanalysis published at home and abroad.