References for the Particle Field Interaction, Nonrelativistic Interface
1. C. D. Child, “Discharge from hot CaO.” Physical Review (Series I), vol. 32, no. 5, pp. 492–511, 1911.
2. S. Humphries, “Numerical modeling of space-charge-limited charged-particle emission on a conformal triangular mesh.” Journal of Computational Physics, vol. 25, no. 2, pp. 488–497, 1996.