RE: USRBIN and geometry

Dear Alberto,

Thanks very much for your quick response. In your opinion which geometry
is more correct and closer to the reality?
I have also tried to do the same comparison but without beam line geometry
for aluminium (and some other materials of one element). The results of
USRBIN were exactely indentical but when I done it for water (and some
compounds) again I found a difference like a sharp cut after distal edge.
Again would you please give me a reason of this difference in case of
materails type? and tell me what is the best geometry to simulate the dose
by USRBIN. Is it one body target or a taget with subregions.

Best regards
Leena

________________________________________
From: Alberto Fasso' [fasso_at_mail.cern.ch]
Sent: 13 October 2010 23:33
To: fluka-discuss_at_fluka.org
Cc: Al-Sulaiti L Ms (PG/R - Physics)
Subject: Re: USRBIN and geometry

Dear Leena,

particle tracks are cut at boundaries, and your two inputs had a different
number of boundaries. For particles with energy larger than the cutoff,
the result should be the same: but a check that the energy is below the
cutoff is done at boundaries, and when you have less regions the checks
are less frequent. So, a small difference could arise due to particles
below threshold.
A similar, although not identical, effect was explained by Paola Sala
a few days ago (Oct. 7). See:
http://www.fluka.org/web_archive/earchive/new-fluka-discuss/3231.html

Alberto

On Wed, 13 Oct 2010, L.Al-Sulaiti_at_surrey.ac.uk wrote:

> Dear FLUKA experts,
>
> As I knowm, USRBIN is geometry independent. However, when I changed the
> target geometry and sliced it by XYP palts I have found some differences in
> all USRBINs ( for dose, protons fluence, primary proton fluence and all
> particles). I have attached two files 1- with one body ''water traget''
> 2- the target was divided into many subregion. The question is why USRBIN
> results are not the same in both files. Do I have any error in the geomety
> that caused this difference? Would you please help me find it.
>
> Best regards
> Leena
Received on Thu Oct 14 2010 - 17:08:46 CEST