Re: Deposit dose

From: Jean-Emmanuel Groetz <jegroetz_at_univ-fcomte.fr>
Date: Mon, 31 Jan 2011 11:07:32 +0100

Francesco,

Thank you very much for your details.
Indeed, dividing by the region volume, the absorbed dose given by FLUKA
is very close to experimental value, and also is better than the result
from MCNPX. Same conclusion for iron ions at 1 GeV/A.
In my original input file, several AUXSCORE cards were used to see the
different contributions from primaries and secondaries. So I deleted the
AUXSCORE for electrons, photons to simplify the attached file for
testing.

Jean-Emmanuel

> I missed one remark
>
> > actually just running your Si beam input one gets 0.2 cGy as measur=
ed.
>
> limiting the dose scoring to HEAVYION as you did (why?) by AUXSCORE, o=
ne
> indeed gets 10% less
>
> Francesco
>
> On Sat, 29 Jan 2011, Francesco Cerutti wrote:
>
> >
> > Hi,
> >
> > actually just running your Si beam input one gets 0.2 cGy as measur=
ed.
> >
> > DOSE values scored by USRBIN *per region* represent in fact the rat=
io between
> > the energy deposited over the whole region and the material density=
 (i.e.
> > GeV*cm3/g) and need to be divided by the region volume in order to =
get dose.
> > Despite the fact that you input the region volumes, which are used =
only for
> > renormalizing the quantities scored by the SCORE card, as pointed o=
ut in the
> > manual (SCORE card). So applying the GeV/g->Gy conversion and multi=
plying by
> > the integrated beam intensity (24480*20*20 ions) you end up finding=
 the
> > expected number.
> >
> > By the way, energy deposition density (GeV/cm3) and dose (GeV/g) ar=
e
> > intensive quantities and, as such, in an uniform radiation field do=
 not
> > depend on the volume/mass extent.
> >
> > All the best
> >
> > Francesco
> >
> > **************************************************
> > Francesco Cerutti
> > CERN-EN/STI
> > CH-1211 Geneva 23
> > Switzerland
> > tel. ++41 22 7678962
> > fax ++41 22 7668854
> >
> > On Wed, 26 Jan 2011, Jean-Emmanuel Groetz wrote:
> >
> >> Dear Fluka users,
> >>
> >> Further to my previous message last week, I have still problems to=

> >> assess the dose deposited by heavy ions in a cell culture.
> >> Anna and Francesco (thanks to them) show me the right way to defin=
e a
> >> rectangular beam (especially the delta x and y parameters).
> >>
> >> To get the deposit dose in the cell culture (inside a =C2=B5-dish)=
, I use
> >> USRBIN with the dose option. I have noticed that if I change the v=
olume
> >> of the region corresponding to the cell culture, it has no effect =
on the
> >> dose result.
> >>
> >> I would like to know if I misunderstand something :
> >> - dose result is given in GeV/g/primary
> >> - energy deposition is given in GeV/cm3/primary
> >> - since the dose is in J/kg, the mass (or the volume) of the regio=
n
> >> should have an importance.
> >>
> >>
> >> In the attached example (Si ions at 600 MeV/A, 24480 ions/cm2, 20x=
20cm2
> >> for the beam size), the dose is about 0.8 cGy (the experimental do=
se is
> >> ~0.2 cGy and my MCNPX calculations give 0.27 cGy). For Fe ions (1 =
GeV/A,
> >> 8323 ions/cm2, same beam size), the dose from Fluka is the same, i=
=2Ee.
> >> 0.8 cGy (good news!!), but it's still not the expected result, i.e=
 0.2
> >> cGy.
> >>
> >> What I am doing wrong or what I have forgotten ?
> >>
> >> Thanks in advance.
> >> Jean-Emmanuel
> >>
> >>
> >> --=20
> >> _____________________________________________
> >>
> >> Jean-Emmanuel Groetz
> >> Laboratory of Physical Chemistry and Radiation
> >> University of Franche-Comte
> >> 16, route de Gray
> >> 25030 Besancon Cedex
> >> France
> >>
> >> mailto: jegroetz_at_univ-fcomte.fr
> >> phone: +33 3 81 66 65 07
> >> fax : +33 3 81 66 65 22
> >> ______________________________________________
> >

--=20
________________________________________________________________
Jean-Emmanuel Groetz
Universit=C3=A9 de Franche-Comt=C3=A9
Laboratoire de Chimie Physique et Rayonnements Alain Chambaudet
UMR CEA E4
16, route de Gray
25030 Besan=C3=A7on Cedex
France

mailto : jegroetz_at_univ-fcomte.fr
tel : +33 (0) 3 81 66 65 07
fax : +33 (0) 3 81 66 65 22
________________________________________________________________
Received on Mon Jan 31 2011 - 12:25:23 CET

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