Output of USRBIN Dose Eq

Source Definition
1

I have checked the neutron dose after a 30 cm thick Portland cement shield. To determine the dose equivalent at 1 cm, I used the USRBIN scoring card in FLUKA. After obtaining the results, I have a couple of questions:

  1. How do I convert the results into sieverts (Sv)?
  2. How do I normalize the results to a practical scenario?

if you need to check the files you can see here
source_newgen.f (20.8 KB)
SOURCE IN AIR.inp (2.2 KB)
SOURCE IN AIR.flair (2.8 KB)
Am-Be.txt (1.1 KB)

2

Dear Brijesh,

please have a look at the following lecture:

Cheers,
David

1 Like
3

Thanks David I understand what is the process to score the USRBIN Dose eq but still i am not getting dose at 1 cm of the shielding
Can you please guide me where i am doing wrong
source_newgen.f (20.8 KB)
SOURCE IN AIR.inp (2.1 KB)
SOURCE IN AIR.flair (2.0 KB)
Am-Be.txt (1.1 KB)

5

Dear Brijesh,
I would split the answer in two steps.
(1) The USRBIN output for the DOSE-EQ scoring is given in pSv units, so you need to multiply it by factor 1e12 to get Sv. You can use Y axis normalization filed in the Flair Plot tab to do this.

(2) For the normalization for the practical scenario you should set/control 3 things
(2.1) Dose is calculated “per source particle”, so you have to multiply the USRBIN output by the number of source particles in your real life applications to get “real life” values, same as point (1).
(2.2) As Sv are biologic equivalent units, it is necessary to set relevant conversion factor table. It can be Fluka default or, defined using AUXSCORE card, depends on applications

(2.3) Depending on the applications, it may be relevant to check if slow neutrons libraries are installed in your Fluka, for the energy defined in your project.

Kind regards,
Illia

1 Like