The difference between USRBDX and USRYIELD?

[Newconcept_1979 (Siyuan1987)]

The USRBDX and USRYIELD card were used to tally triton current from one region to the other,
the results from the two card is different, it is showed below:

and the .inp file and results files are attached:
nLi6.inp (2.1 KB)
nLi6_31_tab.lis (119.3 KB)
nLi6_41_tab.lis (175.2 KB)

by the way, the probability of triton among polar angle 0 to 30 degree with all energy by one primary is 3.27E-3 for USRYIELD card;
and 2.76E-03 for USRBDX card;

and 3.24E-03 from Mcnp6 for the same case.

it seems the result from USRBDX card is less.

[Newconcept_1979 (Siyuan1987)]

Maybe, the result unit from Usrbdx card is probability/GeV not probability/GeV/sr.

[Newconcept_1979 (Siyuan1987)]

so, it is good giving the unit in the results file.

[sniang (Samuel Niang)]

Hello @Newconcept_1979

To see the difference between the USRBDX and the USRYIELD, here are some useful resources:

• Physical meaning of USRYIELD
• FLUKA manual USRBDX more specifically notes 2 and 3
• FLUKA manual USRYIELD

To come back to your plot, in the case of the USRBDX, it has been integrated integrated over the solid angle (as explicated by flair). Then is you divide by you solid angle 2pi * (1 - sqrt(3)/2) ~= 0.8417872144769, you obtain the same curves.

Let me know if you need more explanations.

[Newconcept_1979 (Siyuan1987)]

@sniang , thanks, i found the mistake.