RADMILOVÍC-RADJENOVÍC, M. ... et al, 2005. Particle-in-cell simulation of gas breakdown in micro-gaps. Journal of Physics D: Applied Physics, 38, pp.950–954.
Gas breakdown in large scale systems has been widely studied and is
reasonably well understood. Deviations from the well-known Paschen law,
however, have been reported in microgaps. One possible mechanism
responsible for these deviations is the increase of the secondary electron
emission yield due to the quantum tunnelling of electrons from the metal
electrodes to the gas phase. The high electric fields obtained in small gaps
combined with the lowering of the potential barrier seen by the electrons in
the cathode as an ion approaches lead to the onset of ion-enhanced field
emissions. Particle-in-cell/Monte Carlo simulations including ion-enhanced
field emission have been performed to evaluate the importance of these
mechanisms in the discharge breakdown. Deviations from the Paschen
curve in gaps smaller than 5μm can be explained based on this mechanism.