Secondary electron emission from insulators and negative electron affinity semiconductors

Based on expression of primary range R and the R at E-po >= 10.0 keV and L at E-po >= 1.0 keV calculated by ESTAR program [1], the method of obtaining formula for R at E-po >= 1.0 keV is presented; where E-po is incident energy of primary electron, and L is the energy loss of primary electron per unit path length at the incident surface of the materials. Based on the obtained formula for R, experimental delta, relationships among parameters of delta and the processes and characteristics of secondary electron emission SEE, the universal formula for delta is deduced and the method of calculating delta at E-po > 1.0 keV of insulators and negative electron affinity NEA semiconductors is presented and experimentally proved, where delta is secondary electron yield. The methods of calculating mean escape depth of secondary electrons 1/alpha and B of insulators and NEA semiconductors are presented, respectively; where B is the probability that an internal secondary electron escapes into vacuum upon reaching the surface of emitter. From the relationships among parameters of SEE and the comparison between the values of 1/alpha and B obtained in this study and those obtained in former work, it concludes that the methods of calculating 1/alpha and B are correct.