Biasing with zero importance region

Physics, Transport and Magnetic Fields
1

Version

FLUKA: 4-4.1
Flair: 3.3-1

Description

Dear FLUKA Experts,

I ran a simulation of a simple point source of Co-60 and Cs-137 inside a building and evaluated the dose to air spheres at various locations outside, coming from skyshine. I therefore thought the easiest way to get a very quick result was to set the importance of the walls and floor to zero to eliminate particles coming from them. I also used different regions around the building to set different particles importances in order to increase the number of particles reaching the dose points.

Reading the manual, I’m not entirely sure whether zero importance is allowed for a region. So I doubt my results account for all contributions.

WHAT(3)

Region importance (allowed values range from 0.0001 to 100000.)

Input files

41i_tot.flair (7.0 KB)

source.f (9.1 KB)

41i_tot.inp (6.8 KB)

Thank you for your help.

Corrado

2

Dear Corrado,

If you put a region’s importance to zero, then FLUKA will reset it to 1.0. You can verify this in the .out file by searching for “Particle importances”.

If you want to get rid of the backscattering from the walls and floor, you can set their material to BLCKLHOLE to stop all particles there.

Cheers,

David

3

Thank you David.

Cheers,

Corrado