Molecular Dynamics Simulations of Field Emission From a Prolate   Spheroidal Tip
  High resolution molecular dynamics simulations with full Coulomb interactions of electrons are used to investigate field emission from a prolate spheroidal tip. The space charge limited current is several times lower than the current calculated with the Fowler-Nordheim formula. The image-charge is taken into account with a spherical approximation, which is good around the top of the tip, i.e. region where the current is generated. 
Kristinn Torfason and Agust Valfells and Andrei Manolescu
physics.plasm-ph