Re: Dose and dose rate estimation, some general questions

From: <>
Date: Wed, 08 Sep 2010 17:00:24 +0200

Le 08/09/2010 11:13, Andrey Smolyakov wrote :

Hello Andrey,
> Dear Fluka experts, I ask for your help and some clarification on how to
> estimate dose and dose rate in Fluka.
> The scope of my problem:
> I need to calculate peak radiation level after one proton beam shot. In
> order to do this I define a radiation profile by IRRPROFI, request
> radiative decay simulation by RADDECAY, define decay time for scoring by
> DCYTIMES and associate my estimator with this decay time by DCYSCORE.
> This part of the code looks this way:
> IRRPROFI 1.0E-6 1.0E+18
> DCYSCORE 1.0 1.0
> Here I define a beam with duration of 10mks and total number of
> particles 1E12. And I request scoring right after the beam has passed.
In addition you should put these two cards as well :
PHYSICS with what(1) = 1.0 and SDUM = COALESCE
PHYSICS with what(1) = 3.0 and SDUM = EVAPORAT
> And now I have some questions as to what data I will obtain in this way:
> 1. In my regular simulation WITHOUT the four lines mentioned above my
> USRBIN estimator will produce data on dose deposited in it's binning by
> all primary and secondary particles (for which the transport has been
> requested, of course). I suppose it will not include dose deposited by
> decay products. Is this true?
I did not find the accurate answer to this in the manual, I wonder if a
FLUKA author could clarify this one.
I would say both but I am not sure.
> 2. Now WITH these four lines, will the estimator produce data for dose
> rate deposited by primary/secondary particles AND decay products (A)? Or
> will it be dose rate due to ONLY decay products (B)?
This is related to your DCYTIMES values, if it is after irradiation
(positive value) the answer is B, if it is during irradiation (negative
value) the answer is probably the same as for question n°1.
> 3. Since the dose rate is defined as a dose over some period of time,
> what (how long) period of time is taken in FLUKA to estimate dose rate?
> Or if is not strictly defined, what are the guidelines to asses it?
I did not understand this one : if you want to know the dose rate during
irradiation, any time (negative value) should be OK.
On the other hand, if you want to know the dose rate after irradiation,
the value is probably strongly related to your cooling times, related to
the half lifes of your products.
> 4. In case of 1 and 2B are true, how to calculate total dose and dose
> rate?
With your four lines as you named them you will get results per unit
time (dose rated) and without you will get results per primary (dose).
Knowing alternatively the exposure time and the number of particles per
unit time you can get dose and dose rate in any case.
> 5. Extra question. If I want to score dose not in GeV but in Sv then in
> case of difficult geometry it is better to use USERWEIG card and
> corresponding user routine. According to the manual, I need to prepare
> FLUSCW routine, compile and link to the Fluka library.
Did you see that you can calculate dose and dose equivalent directly
without the proprer code and link within FLUKA the latter with a routine
which converts fluence into effective dose equivalent or ambiant dose
equivalent with AUXSCORE card ?
> But how can I
> link multiple user routines, say, if apart from FLUSCW I need to define
> my own MAGFLD routine? What is the correct syntax for command to do it?
You should do like this : $FLUPRO/flutil/lfluka -o myfluka -m fluka
routine1.o routine2.o routine3.o => it will create a FLUKA executable
named myfluka (this is for standard compilation only not with heavy
ions) linked with the 3 routines.
> Thanks in advance,
Hope it helps a little bit waiting for some expert advice.
> Andrey Smolyakov
> Engineer
> Institute for Theoretical and Experimental Physics
> B.Cheremushkinskaya 25, Moscow, Russia

Sébastien Wurth
Institut de Physique Nucléaire
Service compétent en radioprotection
Bât. 104, 1er étage, pièce E128
91406 ORSAY Cedex
tel. : +33 1 69 15 67 26
mail :
Received on Thu Sep 09 2010 - 09:22:19 CEST

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