In the present paper, we report a procedure to calculate tunnel currents
as a function of the applied voltage,
by an optimization of the master equation, for a highly disordered tunnel
junction array. We take a very large scatter of the tunnel resistances of
the individual junctions.
In order to reduce
the number of equations, several approaches have still been considered
in the past. Here, we propose a procedure without any decoupling:
we show that relevant results can be obtained inside and outside
the Coulomb gap once the charge state range is automatically centered,
already from a ±2 truncation of the equation set, for small offset charges
or low applied voltage.
This last step is achieved in a straightforward way, through the calculation of the
total tunneling rate leaving a given configuration.
This has been
assessed there for the first time on a highly disordered array of five junctions.