Practical ferroelectric cathode

Summary form only given. Ferroelectric cathodes have the advantages of high luminance, high current density and low emittance. But the high current experiments show fast deterioration of the emission properties. We found that the emission current density is lower (<1 A/cm²) if we lower the driving voltage, but the lifetime of ferroelectric cathodes is extended extremely. So we propose a practical ferroelectric cathode electron gun which can operate under low vacuum (0.1 Pa) and low temperature (300K).