A flat-plate diode cathode was produced by using multi-crystal lanthanum hexaboride 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 levels. When a cathode with an emission area of 0.0121cm2 was operated at 1600C, 1650C and 1700C, the corresponding maxima of pulse thermionic emission current densities were 34.0, 44.0 and 53.8A/cm2, respectively, under 2 x 10-4Pa, pulse width of 40μs and repetition frequency of 107Hz. The pulse thermionic emission density of the cathode was also measured under 2 x 10-4, 5 x 10-4 and 2 x 10-3Pa and it was found that the pressure had little effect upon the pulse thermionic emission density. Furthermore, it was found that the emission current density was not affected by the pulse width.

Pulse Thermionic Emission Performance of Multi-Crystal LaB6 Cathode. Lin, Z.L., Cao, G.C., Qi, K.C., Wang, X.J.: High Power Laser and Particle Beams, 2007, 19[5], 873-6