xiaopingguo165/wig

a companion for writing MCNP input decks

wig

wig is for use with MCNP provided by RSICC only. Any use of MCNP through wig is subject to the requirements and regulations imposed by RSICC.

wig has a couple parts. Click the links below or just read through if you're new here.

MCNP Compilation Help

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MCNP (Monte Carlo N Particle) software, from LLNL, is an incredible tool for simulation of neutrons, photons, and electrons. I use it extensively for my research, and it does a great job at a very complex task. Unfortunately, it's a nightmare to use. Basically uncompilable by real humans, finicky about input decks and spaces, and almost completely text only (even though Vis-Ed has gotten steadily better), there are lots of improvements that could be made.

I'll be honest here, I'm writing wig to scratch my own itch. I need a way to:

• create repeatable input decks
• automatically create publication worthy figures
• save geometry and materials as assets somewhere accessible and reusable
• add some sort of semantic meaning to the syntax of mcnp
• cite sources in input decks to remember where I got numbers and materials
• enable easy sending of input decks to be run on "clusters" through ssh

The name is a nod to Eugene Wigner, particularly his contributions to nuclear structure and quantum mechanics, where he made use of the random matrix to describe cross-section structure. MCNP makes use of random numbers to help us experimenters know what's physically going on, and I want wig to make use of the "random" syntax of MCNP for ease of use. So it's pronounced vig.

As of now, this package is in a really-really-really alpha stage. I think only I can use it because of it's finickiness. But, it allows for quick (and semantic) development of MCNP decks using a pipeline method. The pipeline method will be familiar to those that use MCNP a lot. The steps in the pipeline are:

1. Geometry (create geos)
2. Materials (create matls)
3. Cells (combine geos as needed and apply matls)
4. Physics (there's a pretty hands off way to define the common physics)
5. Sources (create source)
6. Tallies (there's pretty hands off way for some tally specs now)
7. Run

The pipeline method means that this package is very semantic, so instead of just typing in numbers separated by spaces, you actually assign variables and document things. You can also script MCNP because of python, for example if you wanted to move a source throughout a bunch of different simulations for time dependence. Finally, this code will, if you have the proper requirements, render pretty pictures of your simulation.