Re: USRBIN scoring by Region and volume normalization

From: Francesco Collamati <francesco.collamati_at_roma1.infn.it>
Date: Wed, 05 Jun 2013 11:57:25 +0200

Thanks for the clarifying reply, but I still have some troubles in
making it work.
I have written a simulation in order to test this volume normalisation.
I attach it: it is a simple lead block with an electron source (in
order to have all the energy detected).
With a variable, I've tried to change one dimension of the block to se
if the dose eq in the output changes with it. Anyway, for all the three
configuration I obtain the same exact value, suggesting the division per
the volume is automatically executed.
What am I missing?
Thanks again

Francesco

Il 2013-06-01 20:59 Anna Ferrari ha scritto:
> 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 Landstraße 400
> D - 01328 Dresden (Germany)
> Tel. +49 351 260 2872



Received on Wed Jun 05 2013 - 12:58:38 CEST

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