Skyshine vs Direct Dose in MCNP5

[Will_007]

TL;DR

how to calculate skyshine dose with mcnp?

Hello - what is an accepted definition of the skyshinne dose in MCNP and how would you calculate this? If you have a source and a shield a few meters away between the dose point, the contribution that goes around the shield would be skyshine....but..what if you have a big source region (e.g., a building) and your dose point is a mile away - how would you separate skyshine component?

Thanks

 

[PSRB191921]

Hi, you can consider an importance (imp:p 0) 0, in the primary barrier

 

[Will_007]

Hi, you can consider an importance (imp:p 0) 0, in the primary barrier

Hey - yeah. This was my ultimate choice. Initially I put in a slab with really high fictitious density in the middle of my shield (to allow stuff to scatter back and around to the dose location), but ran a test case and imp=0 was way faster and almost identical results.

if there is no shield (other than air), and source is 50 yards away from the dose point, what does skyshine mean to you?

 

[PSRB191921]

"Skyshine" is a radiation scattered by sky air, outside the radiological
shielding.
In the first figure (geometry definition) in the second results with MCNP (reference Radiation Problems : From Analytical to Monte-Carlo Solutions ) :

 

[Will_007]

thanks