Existing MCNP inp files

[UCano]

Is it possible to calculate WWs with already existing MCNP input files or is it just limited to hardcoded models?

Thanks in advanced,
Unai

[SAnsell]

The answer to this is yes and no.

CombLayer has some old function that allow an existing MCNP geometry to be read in. It was actually used to place a traditionally coded MCNP model into a larger CombLayer model, for example a moderator was coded in MCNP and placed into a full target station model. There is/was a system for agreeing the outer boundary surfaces etc.

I haven't used them for a very long time -- nor do I know of anyone using it, and I am not sure that they currently work. The main reason for that is that I removed the boost/regex and replaced it with std/regex (which avoided the problem of regex changing every 10 minutes!). However, I coded but didn't test those areas.

So the way you should do it is remove your outer void, build the default world CombLayer model [this is just a sphere with a huge radius [20000cm is the default]. Then read your model into that. If that works, then you are free to do all the other things that CombLayer does, e.g. weight window generation, wext calcs, adding tallies, rotation of the model, validity checking, writing out to other codes e.g. fluka/phits etc.

I will leave the issue open -- the plan is that if I get some time this weekend etc I will try a test case, but if anyone else manages, (or fails) please post a comment about it.