Pitfalls and troubleshooting
Things to check in case of suspicious results
Unresolved resonance probability table sampling
Unresolved resonance probability table sampling is not used by default. This method is needed to account for self-shielding effects in the unresolved resonance region. The effect is usually not significant in thermal systems, but can lead to noticeable discrepancies in fast-spectrum systems.
Probability table sampling is switched on using the set ures option.
Mass vs. atomic densities
The densities and compositions of materials can be entered in atomic (positive values) or mass units (negative values). Using incorrect units can lead to unexpected results. The difference may not be clearly noticeable if the material consists nuclides with similar atomic weight, but