Clarification of the mechanism of the break-down at the multi-aperture grids

Akashi, Keisuke; Kojima, Atsushi; Yoshida, Masafumi; Hanada, Masaya; Yamano, Yasushi*

To improve the voltage holding capability of the large-size multi-aperture grid, the clarification of the mechanism of the break-down should be understood. However, the relation between the locally electric field and the break-down is still unclear. This time, this relation was investigated by direct measurement of the dark current density as the initiation of the break-down may be caused by the field-emitted electrons. As a result, the break-down probability increases with the current density, and current density of 0.1 mA/m cause the break-down at 50% in 10 s pulse.