REDUCTION OF CROSSED-FIELD DIODE TRANSMITTED CURRENT DUE TO ANODE SECONDARY-EMISSION

The limiting current theory for planar crossed-field diodes has long b een studied extensively for various emission energies and temperatures . However, experimental measurements of transmitted current have shown significant departure from theory. This paper attempts to explain the reduction in transmitted current from that expected in theory in term s of secondary electron emission created by electrons hitting the anod e. It is proposed that the presence of the secondary electrons increas es the charge density in the gap, thereby reducing the amount of curre nt transmitted. A detailed secondary emission model is implemented in a particle-in-cell code to study current reduction. The effect of seco ndary electrons on charge density, and on the resultant electric field and potential is also presented. (C) 1998 American Institute of Physi cs.