External irradiation: which type of thermostat to use ?

I just found out what was wrong with thermostat 2. A simple typo in the fix langevin for the inner thermostat.

Instead of

fix thermostatin central_atoms_in langevin 300.0 300.0 0.03 ${seed2}
it must be

fix thermostatin thermal_atoms_in langevin 300.0 300.0 0.03 ${seed2}

A simple mistake that changes everything ! I was removing the energy from the region where the cascade takes place, instead of the thermostat.

Now results are much more consistent.