Re: AW: AW: Energy deposition

Dear Beatrice,

> Is it, then, correct if I activate the RADDECAY card, read my results as
> GeV/(cm3 s) for the specific time instant of the scoring detector associated
> to each USRBIN, then without rescaling them by the beam current, I have the
> energy deposition at that specific time?

yes (actually it is power density)

> In this case may I use the default settings for RADDECAY?

Normally lower transport thresholds (see WHAT(5)) are recommended for the
decay radiation, tipically down to 10 KeV for photons.

> My DCYTIMES are also negative, i.e. I want to score also during irradiation;
> is in this case the energy deposition due only to radioactive decay, too?

yes

> I guess that for negative DCYTIMES corresponding to the beginning of
> irradiation profile I get the results of an istantaneus analysis (that is
> without using IRRPROFI) because energy deposition is due to prompt radiation
> only.

no (see the answer just above), in order to get the prompt contribution -
which is the dominant one - you need a USRBIN scoring not linked to any
cooling time, regardless of the presence of RADDECAY, DCYTIMES, IRRPROFI.

Francesco

**************************************************
Francesco Cerutti
CERN-EN/STI
CH-1211 Geneva 23
Switzerland
tel. ++41 22 7678962
fax ++41 22 7668854

On Thu, 27 Jan 2011, beatrice pomaro wrote:

> Dear Dr. Cerutti,
> thank you for solving my problem; I would like to deepen the point
> on the use of RADDECAY, however.
> I understand that, by not using IRRPROFI and DCYTIMES (so no RADDECAY), I
> get GeV/(cm3 primary), while using USRBINs connected to IRRPROFI and
> DCYTIMES (and RADDECAY) I get GeV/(cm3 s). But I think this is what I need:
> I was interested in estimating the temperature field in concrete during and
> after many cycles of irradiation. I can get it by energy deposition results,
> but in this case I need not only immediate results (due only to prompt
> radiation), but also after long periods of irradiation (due to decay
> radiation).
> Is it, then, correct if I activate the RADDECAY card, read my results as
> GeV/(cm3 s) for the specific time instant of the scoring detector associated
> to each USRBIN, then without rescaling them by the beam current, I have the
> energy deposition at that specific time? In this case may I use the default
> settings for RADDECAY?
>
> My DCYTIMES are also negative, i.e. I want to score also during irradiation;
> is in this case the energy deposition due only to radioactive decay, too? I
> guess that for negative DCYTIMES corresponding to the beginning of
> irradiation profile I get the results of an istantaneus analysis (that is
> without using IRRPROFI) because energy deposition is due to prompt radiation
> only.
>
> Thank you very much
> Sincerely,
>
> Beatrice
>
>
>
>
>
> At 12.35 27/01/2011, Francesco Cerutti wrote:
>
> Dear Beatrice,
>
> meaningless negative energy deposition values and infinite
> statistical
> errors just come from the fact that your USRBIN energy detectors
> are
> associated to ... undefined cooling times: you input 8 cooling
> times and
> you ask over the range 13-22.
>
> But I would like to point out a more fundamental
> misunderstanding. You
> have to bear in mind the distinction between prompt and decay
> radiation,
> being the latter generated by the (late=not instantaneous) decay
> of the
> radioactive nuclei produced by the first.
> If you search - as usually - for prompt energy deposition values
> (indeed
> expressed in GeV/cm3 per beam proton), then irradiation profile
> and decay
> times are totally unrelevant. You do not need to ask FLUKA to
> perform the
> radioisotope decay (no need for RADDECAY) and you have to
> rescale the
> results by the beam current, getting instantaneous power density
> at
> any time during irradiation.
> On the other hand, by associating the USRBIN energy scoring to a
> given
> cooling time (referred to the input irradiation profile), you
> will
> directly get the power density at that time (in GeV/(cm3*s))
> *only due to
> the decay (electromagnetic) radiation*.
>
> Ciao
>
> Francesco
>
> **************************************************
> Francesco Cerutti
> CERN-EN/STI
> CH-1211 Geneva 23
> Switzerland
> tel. ++41 22 7678962
> fax ++41 22 7668854
>
> On Thu, 27 Jan 2011, beatrice pomaro wrote:
>
> > Dear Dr. Sommerer,
> > I disabled the Sternheimer and
> > Mat-prop card associated to Material UC2, however
> > I get the same negative energy deposition results
> > and INF values. The error messages you noticed
> > before (me too), are not anymore after disabling the cards,
> as you confirm.
> > But is there another problem in my input file,
> > then? I wonder if it is correct to activate RADDECAY with its
> default
> > values?
> > Sorry, to ask again
> >
> > Thank you,
> > Beatrice
> >
> >
> > At 18.29 26/01/2011, Sommerer, Florian wrote:
> >> Dear Beatrice,
> >>
> >> When rerunning your simulation I found the
> >> following lines written in the out and err file:
> >>
> >>
> >> *** dp/dx:d,imat,ztar,ij,po,eo -0.00179035082 31
> 34.6662384 1 0.572616202
> >> 1.09920164 ***
> >> *** x,xoster,ccster,d0ster -0.214465268 -0.2191
> -6.0247 0. ***
> >> *** dp/dx:d,imat,ztar,ij,po,eo -0.0134390424 31
> 34.6662384 1 0.618808585
> >> 1.12395685 ***
> >> *** x,xoster,ccster,d0ster -0.18077257 -0.2191
> -6.0247 0. ***
> >> *** dp/dx:d,imat,ztar,ij,po,eo -0.0225896654 31
> 34.6662384 1 0.668727261
> >> 1.15219403 ***
> >> ***
> >>
> >> Did you observe the same?
> >> I could be wrong but in my opinion these lines
> >> indicate a serious problem in the initialisation
> >> of the stopping power for Uranium dicarbide.
> >> That might be the reason for the negative values in the
> energy deposition.
> >>
> >> You are using Sternheimer parameters and you are
> >> assigning the ionization potential for Uranium
> >> dicarbide according to the values that are
> >> available in the flair data base. This is the recommended
> way to do it.
> >> However I think exactly there is the problem.
> >> When I omit Sternheimer values and ionization
> >> potential and run again, I don't get the error
> >> messages any more. I think the transport will
> >> still be reasonable without these parameters.
> >>
> >>
> >>
> >> Cheers, Florian
> >>
> >>
> >>
> >>
> >>
> >>
> >> --
> >> Dipl.-Ing. Dr. techn. Florian Sommerer
> >> Physiker
> >> Radiologische Klinik / Heidelberger
> Ionenstrahl-Therapiezentrum
> >> Florian.Sommerer_at_med.uni-heidelberg.de
> >> Im Neuenheimer Feld 450
> >> 69120 Heidelberg
> >> Germany
> >> -----Urspr=FCngliche Nachricht-----
> >> Von: beatrice pomaro [ mailto:pomaro_at_dic.unipd.it]
> >> Gesendet: Mittwoch, 26. Januar 2011 17:14
> >> An: Sommerer, Florian
> >> Betreff: Re: AW: Energy deposition
> >>
> >> Dear Dr. Sommerer,
> >> I had the same problem but I run
> >> flupix-2010 and, by reducing the number of
> >> binning, I had no more problems of stopping because of
> memory.
> >> I give in attachment the same input file, with
> >> less binning (I kept results requirement after
> >> 1hour, 1year, 10years and 50years from t0,
> >> suitably converted into seconds from the end of
> >> radiation profile), but I have the same problem
> >> of negative values and INF values for energ
> >> deposition (I put, in addition, just the USRBIN34 results).
> >> Many thanks for the support,
> >>
> >> Sincerely,
> >> Beatrice
> >>
> >>
> >> At 09.43 26/01/2011, you wrote:
> >> >Dear Beatrice,
> >> >
> >> > are you sure that you are using the input file you
> attached to the
> >> >previous mail?
> >> >I tried to rerun it (using FLUKA2008.3d.1) but it stops at
> >> >initialisation due to a lack of memory positions. Which is
> - I guess -
> >> >due to the big number of binnings you are using.
> >> >Can you please send the right file?
> >> >
> >> >Cheers, Florian
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >--
> >> >Dipl.-Ing. Dr. techn. Florian Sommerer
> >> >Physiker
> >> >Radiologische Klinik / Heidelberger
> Ionenstrahl-Therapiezentrum
> >> >Florian.Sommerer_at_med.uni-heidelberg.de
> >> >Im Neuenheimer Feld 450
> >> >69120 Heidelberg
> >> >Germany
> >> >-----Urspr=FCngliche Nachricht-----
> >> >Von: owner-fluka-discuss_at_mi.infn.it
> >> >[ mailto:owner-fluka-discuss_at_mi.infn.it] Im Auftrag von
> beatrice pomaro
> >> >Gesendet: Montag, 24. Januar 2011 18:26
> >> >An: fluka-discuss_at_fluka.org
> >> >Betreff: Energy deposition
> >> >
> >> >Dear Fluka users,
> >> > can you please have a look to the input file in
> attachment:
> >> >the problem is represented by a target made of
> >> >UC2 which is directly impinged by a proton beam (300microA,
> 70MeV),
> >> >within a concrete target bunker. I used IRRPROFI to model a
> beam
> >> >working 5000hours/year than stopping, for totally 9years.
> >> >I am interested in the results in terms of energy
> deposition
> >> >[Gev/(cm3 primary)] on the slice of shielding just in front
> of the
> >> >target source. However in the USRBIN files I have negative
> values of
> >> >energy deposition and 'INF' strings.
> >> >Can you address me where the problem is, please?
> >> >If I do not assign an IRRPROFI card for the beam
> irradiation profile
> >> >does, in this case, the energy deposition correspond to
> time=3D0?
> >> >
> >> >Many thanks for your help,
> >> >
> >> >Sincerely,
> >> >Beatrice Pomaro
> >
> > **************************************************
> > Ing. Beatrice Pomaro
> >
> > Universita' degli Studi di Padova
> > Dipartimento di Costruzioni e Trasporti
> > via Marzolo, 9 - 35131 Padova (Italy)
> > tel: +39 049 8275605
> > e-mail: pomaro_at_dic.unipd.it
> >
> >
> >
> >
>
> **************************************************
> Ing. Beatrice Pomaro
>
> Universita' degli Studi di Padova
> Dipartimento di Costruzioni e Trasporti
> via Marzolo, 9 - 35131 Padova (Italy)
> tel: +39 049 8275605
> e-mail: pomaro_at_dic.unipd.it
>
>
>
Received on Thu Jan 27 2011 - 21:58:31 CET