I am not sure I need such high max_particles, that is what I am trying to figure out. The thing is, I have a wall made of different materials, at the outer side of which I want to tally the neutron flux, for an activation study, therefore, with quite accurate values. I decided to split the geometry and use the developed branch of the code for afore mentioned feature. I managed to run calculation of the inner part collecting roughly 1e7 particles at half of the wall thickness more or less (the file generated was 913MB), so almost as much as the max_particle (setting 10 batches, 2 inactives, with 5e8 particles per batch). And yet, when I run the calculation for the outer region, the tallies are nulls (same batch configuration on this run as well).
Now I am trying with slightly higher max_particles, and particles per batch enough high to collect them. I do ask myself if there something else wrong in the model that affects the results, but I can’t come up with any different approach.