Study of Complex Cathode Emission Characters

Abstract

Based on the study of explosive emission, the dielectric enhanced electric-field emission model is brought forward, and the metal-dielectric complex cathode material is manufactured. Based on the investigation of surface-flashover explosive emission, the graphite-carbon fiber complex cathode is manufactured, too. Then the experiments are developed respectively, and the results show the electron emission density of these two complex cathode materials is also more than 17 kA/cm 2 , and their lifetime is exceeding 10 5 pulses.

Investigating emission characteristics and plasma properties in a long-pulse magnetically insulated coaxial diode with different cathode materials

“…Thirdly, with the merits of the long-term electrical stability, the shortest current rise onset time, the lowest emission electric field threshold, the strongest emission capability, the best emission uniformity, and the lowest expansion velocity, metal-dielectric is the preferred material for cathode other than aluminum, bronze, graphite, silicon-aluminum alloy and stainlesssteel. The reason for these superior characteristics of the metal-dielectric cathode maybe related to the combination of surface flashover and explosive emission plasma at the interface [12,16]. Apart from its a bit larger cathode expansion velocity, the graphite performs well.…”

“…The perveance of the edged aluminum cathode with different diode voltage in the MICD is listed in table 3. Generally, the perveance in macroscopic is just correlated to the dimensions of diode [12]. However, the perveance of the same edged aluminum cathode slightly aggravates with the increasing diode voltage.…”

“…The current rise onset time of the six types of cathodes is specified in figure 3(c), while the correlated turn on voltage can be observed in figure 3(a). Based on its definition, the perveance represents the ability of the electron gun to emit electrons excluding the impact of diode voltage [12]. Therefore, we can relate the perveance to the 'emission capability' of this cathode in the MICD.…”