Why Does Changing the Splitting Mesh in MCNP5 Affect Histories and File Outputs?

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SUMMARY

Changing the splitting mesh in MCNP5 can significantly impact the simulation's ability to generate histories and output files. Initially, using an excessive number of fine intervals (15 in a 10cm region) resulted in billions of collisions without producing any histories. Reducing the number of splits allowed for successful history generation, but warnings about particles escaping the weight window mesh persisted. The underlying issue was identified as a conflict between the OpenMPI and MPICH2 libraries.

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gurps409
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HIya, I am not actually sure why this is happening so was wondering if anyone can help.

im running in photon mode and I am trying to generate a weight window. initially i think my splitting mesh was over done a little bit (ok too much say about 15 fine intervals in a 10cm region) and i wouldn't go past one history. just billions of collisions were occurring. I reduced the number of splitting and now I am getting histories but why did this happen? my geometry is fine but is very complicated.

now that I am getting histories, and scoring in some of the regions i want but I am not getting a wwgout file. i do, however, get a warning saying some of my particles have escaped the wwg mesh.

thanks in advanced. i am relatively new to mcnp but I am on a mission to learn this!
 
Engineering news on Phys.org
The problem is Solved.
It was because of the conflict of libraries (openmpi and mpich2).
 

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