USRBDX area mismatch

I have specifed a very simple geometry where the CR particles are generated from a certain radius using the GCR-SPE and SPECSOUR card. Next, I have defined a USRBDX card to score the fluence between two concentric sphere regions. I did not specify the area of the detector (so by default it should be 1cm^2). After simulation, when I looked into the sum.lis file for the detector, the area of detector is some large figure other than 1. To test further, I specified the area of the boundary crossing surface(i.e - the detector area). Again, the sum.lis file shows ’ the Area of the detector’ as a figure different from what I have specified. Is there any scenario when this happens or am I going about this in a misguided way?

Thanks a lot.

Best Wishes

Dear @amrit.p.nayak,

As always, please share your inputfile and in this case also the sum.lis files.
Thank you

Thanks for your quick response.
Please find attached the input file and the sum.lis file
Isotropic.inp (4.0 KB)
Isotropic_31_sum.lis (316.6 KB)

Dear @amrit.p.nayak ,

Please see my answer in the post below:

You would need to use the option NO-NORM to avoid FLUKA trying to apply the normalization factors for the Earth atmosphere’s model. What you see in the output is a pre-computed normalization factor. When using the NO-NORM option, your area will be equal to 1 (or whatever value you set in your *.inp file).



Thanks a lot for catering to the queries. This solution worked out perfectly.

Best Wishes