addphsp error

[ChillError404]

I am currently working on Monte Carlo simulations using BEAMnrc and DOSXYZnrc for surface dose calculations.

I generated multiple phase-space files from BEAMnrc (parallel runs) and attempted to combine them using addphsp. However, I encountered the following error:

***WARNING***
Total no. of particles in combined file will exceed 2^32-1.
This number cannot be stored in the header.
Exiting now.

My goal is to create a large phase-space file (~80–150 GiB) to reduce latent variance for shallow depth dose calculations (~0.007 cm), where statistical uncertainty is very sensitive.

Is there any recommended workaround to handle phase-space files exceeding the 2^32-1 particle limit?

Thank you very much for your help.

[rtownson]

My suggestion is to use smaller phase-spaces, and then combine your simulation results manually. Or, use variance reduction techniques so that you don't need such a large phase-space. Alternatively, use BEAMnrc as a shared library source (compile with make library), so that you can always ask for more particles and don't need to write a phase-space at all.