Re: DOSE and DOSE-EQ

From: Alberto Fasso' <fasso_at_SLAC.Stanford.EDU>
Date: Mon, 30 Jul 2012 12:05:56 -0700 (PDT)

Dear Oleg,

DOSE-EQ is not dose multiplied by a quality factor or by a radiation weighting
factor! It is fluence folded with an energy dependent conversion coefficient,
which has been calculated as an organ-weighted sum of doses inside a human
phantom. (The doses calculated in each organ are weighted with Radiation
Weighting Factors, but in the case of photons and electrons these factors are
equal to 1). The result is affected by geometrical effects, self-absorption,
build up factors etc.
If you scored it in a 1 cm3 elementary volume, the result will be averaged over
that volume. DOSE-EQ, like DOSE, is a point quantity but can be averaged over
regions of any size.
If you have difficulties understanding how a quantity calculated in a
phantom can be applied to a point, you should consider the concepts
of "expanded" and "aligned" field introduced by the ICRU (International
Committee for Radiation Quantities and Units"):

     Aligned and Expanded Field: the fluence and its energy distribution
     at the reference point are assumed to be constant over the whole volume of
     the detector, but its angular distribution is unidirectional

I take this opportunity to remind you that with FLUKA you can calculate
DOSE and DOSE-EQ due only to the gamma of Am-243. Alpha decay and spontaneous
fission are not simulated yet by FLUKA.

Alberto

On Sun, 29 Jul 2012, Oleg Tkach wrote:

>
> Dear FLUKA authors,
>
>
> I calculated DOSE and DOSE-EQ in the 1 sm3 elementary volume of A150 from
> the Am-243 isotope source (geometry is very simple). But the results are
> different. We think that Gy has to be equal to Sv in this case.
>
>
> Could you explain the reason of this difference?
>
> Input file is attached.
>
>
> Thank in advance,
>
> Oleg
Received on Mon Jul 30 2012 - 22:57:00 CEST

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