High brightness electron beam produced by a ferroelectric cathode

Abstract

We report experimental measurements of a high brightness electron beam produced by a ferroelectric cathode. Up to 36 A of current (10 A/cm2) were obtained at a voltage of 22.5 kV. Electron beam emission was obtained with a dc voltage held between the cathode and anode, and a gate pulse of 1–2 kV applied across the sample. The beam normalized emittance was measured at 10 kV to be 5 mm mrad with a normalized beam brightness of 1.2×1011 A/m2 rad2. This value of beam brightness exceeds that of thermionic cathodes. The ferroelectric cathode emission is found to exceed that of a thermionic cathode using the same geometry.