How to get the scattered dose from concrete using MCNP5?

[DF19]

Hello fellow nuclear engineers and physicists,

Does anyone know how to just get the scattered dose from a surface like concrete using MCNP5? I'm doing a project for a shielding class and I need to compare scattered dose and direct (uncollided) dose for a point detector. The photons are coming from a point source.

I've experimented with tallies associated with energy bins, but it's getting real complicated and I can't find a clever way to filter just the photons scattered from concrete.

My only theory is finding the dose with just air, then finding the dose with the concrete and air and subtracting the two to find the scattered dose from the concrete.

 

[DF19]

Here is my input file, it has the geometry in it.

 

[raining Pete]

Hi there,

I'm not an expert in MCNP5, but have you tried using the "surface current" tally? This tally is specifically designed for calculating the currents on surfaces, so it might be useful for your project. You can specify the material of the surface (in this case, concrete) and the energy range you're interested in, and it should give you the scattered dose in that specific energy range.

Another option could be to use the "track length estimator" tally, which calculates the total path length of particles in a specific material. You could specify concrete as the material and get the total path length of scattered photons in that material, which you could then use to calculate the scattered dose.

I hope this helps and good luck with your project!