Pulse thermionic emission performance of multi-crystal LaB6 cathode

A flat-plate diode cathode was produced using multi-crystal lanthanum hexaboride(LaB6) material. The anode was molybdenum, and the cathode was heated by thermal conduction and radiated with a graphite heater. The pulse emission properties and the emission stabilities were investigated at different cathode temperature and under different vacuum level. When the LaB6 cathode with an emission area of 0.012 1 cm2 was operated at 1 600 ℃, 1 650 ℃, 1 700 ℃, respectively, the corresponding maximum of pulse thermionic emission current densities were 34.0 A/cm2, 44.0 A/cm2, 53.8 A/cm2, under 2×10-4 Pa, the pulse width of 40 ms, and repetition frequency of 107 Hz. The pulse thermionic emission density of LaB6 cathode was also measured under 2×10-4 Pa, 5×10-4 Pa, 2×10-3 Pa, respectively, and it