Delta-ray production threshold

Users and experts,

With FLUKA, I have calculated the dose deposited by iron ions at 1 GeV
and secondaries (electrons, photons, protons...) in a cell culture with
1 micron thick (between a cover slip and water).
I used the HADROTHErapy option, with a transport cutoff at 1 keV for all
particles and 150 eV for electrons (as Alfredo Ferrari suggested in a
paper PMB 56 - 2011).
When I modified the delta-ray production threshold (only in the cell
culture) from 1 keV to 10 and 100 keV, the dose deposited by heavy ions
increased and the dose from electrons decreased, as expected. But if I
consider the total dose in the cell culture, it is not constant, ranging
from 0.18 cGy to 0.2 cGy (the experimental dose was about 0.2 cGy).
Total doses in cover slip (1 mm thick) and in water (1.9 cm) remain
constant.

I am wondering what could be the reason of such results in the cell
culture.

Thank you in advance for your help and suggestions.

Jean-Emmanuel

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Jean-Emmanuel Groetz
Laboratoire Chrono-Environnement UMR CNRS 6249
Chimie-Physique & Rayonnements
Université de Franche-Comté
16 route de Gray
25030 Besançon Cedex
France
mailto : jegroetz_at_univ-fcomte.fr
tel : +33 (0) 3 81 66 65 07
fax : +33 (0) 3 81 66 65 22
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