is based on fairly conservative criteria. For example, we have
adopted a space charge limited field of 250 kV/mm, which is at
the lower end of the statistical distribution shown in Figure 7.
Thus, the “deterministic” results shown in Figure 6 represent the
near worst-case failure criteria. In reality, one might often have
the situation shown in these figures without failure, as the local
space charge limited field may be appreciably larger than the
worst case assumed for the generation of these figures.