Re: USRBIN scoring by Region and volume normalization

From: Anna Ferrari <a.ferrari_at_hzdr.de>
Date: Sat, 01 Jun 2013 20:59:41 +0200

Hello Francesco,
There is no contradiction! The "truth" is both what is written in the manual
AND what is written in the answer you found on the FLUKA discussion list.

FLUKA calculates dose equivalent multiplying fluence (in part/cm^2) by
fluence-to-dose-equivalent conversion coefficients (in pSv/(part/cm^2)).
As written in the manual, binning by region does not give you a result
normalized by volume: this means it does not give you a fluence but a particle
tracklength. To get the fluence you need to divide yourself the tracklength by
the region volume. For other kinds of binning this is not needed, because the
division by the bin volume, which is calculated analytically, is done by the
program.
The multiplication by the the fluence-to-dose-equivalent conversion
coefficient is done by the program via the AUXSCORE command, in the same way
as for other kinds of binning.

Summarizing:
- Cartesian or cylindrical binning:
dose equiv. in pSv = tracklength in cm / volume in cm3 (DIVISION MADE BY THE
PROGRAM) * fluence-to-dose-equivalent conversion coefficient in
pSv/(part/cm^2)
- Region binning:
dose equiv. in pSv = tracklength in cm / volume in cm3 (DIVISION DONE BY YOU)
  * fluence-to-dose-equivalent conversion coefficient in pSv/(part/cm^2)

Hope it helps to clarify,
regards,
Anna

Am Sat, 1 Jun 2013 14:44:32 +0200 schrieb Francesco Collamati
<francesco.collamati_at_roma1.infn.it>:
> Hello Fluka Users
> I'm writing (again!) because in the understanding of the meaning of my
>simulation output I came across a doubt I was not able to resolve.
>
> I am using a USRBIN scoring (of DOSE-EQ) with Region binning. According to
>the manual, this should give a result which is not normalized per volume, but
>only per primary particle.
> However, i found my result quite different from the one expected, and
>googling a bit I found this fluka discussion
>(http://www.fluka.org/FLUKA/web_archive/earchive/new-fluka-discuss/4590.html)
> in which it is reported:
> This means that with the region binning option you will not get the average
> fluence in the volume (in part/cm^2), but the total tracklength in the
> selected region. To get the fluence and finally the correct average dose
> equivalent (always in pSv/primary) you have to divide offline by the volume.
>
> so, which is the truth!?
> how can i get the total eq-dose in a certain region!?
> thanks again
>Francesco

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Anna Ferrari
Institute of Radiation Physics
Helmholtz-Zentrum Dresden-Rossendorf e.V.
Bautzner Landstra├če 400
D - 01328 Dresden (Germany)
Tel. +49 351 260 2872
Received on Sat Jun 01 2013 - 22:23:21 CEST

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