Re: Use of Deq

From: Stefan Roesler <sroesler@mail.cern.ch>
Date: Mon Mar 31 2008 - 15:22:30 CEST

Hi Sunil,

I don't have NCRP 144 and IAEA 188; thus can only comment on your input:

- Photonuclear interaction are off by default. Therefore, you'll have to
uncomment PHOTONUC.

- deq99c.f does not apply to USRYIELD.

- Thus, the only card which folds with dose-equivalent factors in your
input is USRTRACK. Is this the dose output which you are refering to?

- You are correct, results are in pSv/primary.

- I'd recommend using EMFCUT (both for production and transport
thresholds) so that you are sure of your cutoffs.

- I guess that you have verified in the output file that deq99c folding
was indeed applied?

I take the liberty to cc fluka-discuss as the discussiuon might also be of
interest to others (or know a better answer).

Regards
Stefan

On Mon, 31 Mar 2008, Sunil C wrote:

> Hi Stefan
> I am having a normalization problem in a work of mine.
> Attached is a typical input where I use a cylindrical detector after a certain
> shield thickness to score photon dose using deq99.f routine.The primary beam
> is electron incident on 10 radiation lengths thickness of several targets. I
> vary the shield thickness and score the dose. On plotting the dose rate after
> shield against the shield thickness, the well known transmission curve can be
> obtained. I get a neat graph except of course at the higher thickness.
> Extrapolating the graph to zero thickness should give the unshielded dose
> rate. I am comparing this with the NCRP 144 (figure 3.5 page 45) and Swanson's
> IAEA tecdoc 188. I am getting results 100 times lesser unshielded dose rate
> with FLUKA calculations compared to the Swanson's rule of thumb given in IAEA
> 188 (page 53).
>
> Am I making a mistake while calculating the dose equivalent?
> I understand the units are in pSv/primary.
>
> Your comments will help me debug the problem.
>
> Thanks a lot
> Best Regards
> Sunil
>

-- 
___________________________________
Stefan Roesler
CERN, SC/RP
CH-1211 Geneva 23
Switzerland
Phone:  +41-22-7679891
Fax:    +41-22-7669639
E-mail: Stefan.Roesler@cern.ch
Received on Mon Mar 31 16:08:34 2008

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