Deposit dose

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 define a
rectangular beam (especially the delta x and y parameters).

To get the deposit dose in the cell culture (inside a µ-dish), I use
USRBIN with the dose option. I have noticed that if I change the volume
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 region
should have an importance.

In the attached example (Si ions at 600 MeV/A, 24480 ions/cm2, 20x20cm2
for the beam size), the dose is about 0.8 cGy (the experimental dose 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.e.
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

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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
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