The ESL parameter of the input panel sets the Equivalent Series Inductance of the specific type of capacitors. Enter the value in nano Henry (nH or 1E-9 Henry). Each capacitor type is described by the 3 parameters CAP, ESR and ESL in the same row.
The circuit simulated will have NUM capacitors of this type in parallel.
Notice that ESL values from datasheets are often too optimistic as the mounting inductance is not (fully) accounted for. Physical size of the capacitor, placement of vias and the lengths of the vias to reach into the power planes are the primary factors determining the total ESL.
Measuring the ESL is fairly simple, and a good routine to do as part of new board designs.
Typical ESL values can be found in the literature – here are some examples from measurements presented in “Right the First Time” by Lee Ritchey and John Zasio.
Notice that footprint and placement of vias is often more significant that the values found in the datasheet. On top of this value, the effect of the via length needs to be added.