EMISSION PERFORMANCE OF FERROELECTRIC CATHODES

We observed the pulsed emissionbehaviours of our ferroelectric samples, when collector is grounded (FC), the maximum current density measured was 20A/cm² for ceramic PZT-95/5 and 38A/cm² for monocrystalline LiNbO₃. We also tested some recently trial-produced samples,the emitting current density was up tolloA/cm².Our experiment result shows that the breakdown threshold of sampleis a primal obstacle which makes the polarization difficult to fully reverse. In order to overcome negative effects of the grid electrode for ferroelectric emission,we put forwardanovelexcitingmode，E⊥P.