Thermal field emission from a log-normal distribution: Impact on space charge and emittance

Emission from an array of dissimilar field emitters are known to produce non-uniform patterns that affect space charge forces within the electron beam produced, with consequences on emittance and transit time effects. To model variation, a semi-analytical Point Charge Model (PCM) gives rapid and analytical representations of tip current, variation, and emission statistics to be used in the MICHELLE Particle-In-Cell (PIC) code. A General Thermal-Field (GTF) emission model accounts for warm and hot field emission sources. The consequences of non-uniform space charge on emittance shall be investigated.