I am wondering how to check the ES (electrostatic) convergence when the ES is used with the TRK (tracker) solver. I am currently running electron gun simulations with a matched B-field from a solenoid (imported from another project).

When the solver initiates the initial ES calculation a convergence criterion is set called 'desired accuracy', however I cannot find where this parameter is set/chosen.

I am worried because my TRK solver initiates at a point where there's no clear ES convergence, I am very confused because I cannot find a right solution for a relatively simple geometry.

I have attached a typical gun charge accuracy plot and the residual.

Thanks.