Date: Tue, 20 Feb 2018 22:25:26 +0100
Dear Joachim,
Thank You a lot for help and explanation. Can You also advise how to read
the output of USRTRACK card while using RADDECAY? With RADDECAY card I am
obtaining results only in one bin:
[image: Obraz w treści 1]
and without it in all bins:
[image: Obraz w treści 2]
Can You please explain what is the reason behind it?
Best regards,
Agnieszka Witkowska
2018-02-09 9:48 GMT+01:00 Joachim Vollaire <joachim.vollaire_at_cern.ch>:
> Dear Agnieszka
>
> If I am not mistaken you are using a rectangular beam when generating
> photons at 662 keV while starting from the decay of Cs-137 you will have an
> isotropic generation of emitted radiations. So primary particle will not
> have the same probability to reach the detector in both cases. I guess this
> explain most of the discrepancy.
>
> Also as indicated in my previous email, the 662 keV photon is not coming
> from Cs-137 but by Ba-137m (populated at ~95 % from the decay of Cs-137),
> so for the sake of comparison of the two methods you may as well start with
> Ba-137m. To compare with a real life experiment you should of course start
> with Cs-137 (which will include both the contribution from Cs-137 and
> Ba-137m…)
>
> Hoping this help.
>
> Joachim
>
>
>
>
>
>
>
>
>
> *From:* Agnieszka Witkowska [mailto:witkowskaagnieszka07_at_gmail.com]
> *Sent:* 08 February 2018 22:38
> *To:* Joachim Vollaire <joachim.vollaire_at_cern.ch>
> *Cc:* FLUKA discussion <fluka-discuss_at_fluka.org>
> *Subject:* Re: [fluka-discuss]: RADDECAY - problem with card usage
>
>
>
> Dear Joachim,
>
>
>
> Thank You for reply and help. I have the same structure of the .inp file
> as in your example, the only difference is that I am scoring the electrons
> by USRTRACK card.
>
>
>
> I created two .inp files - one with RADDECAY card as a beam and another
> only with main energy line of Cs137 - 0.667MeV as a photon beam. In both
> cases I am interested in scoring the electrons in the ionization chamber
> volume.
>
>
>
> Simulations of those two files give me completely different results. With
> RADDECAY card I obtained 7.3796116E-05 cm/pr and with main energy
> line 4.2062059E-02 cm/pr (I am scoring electrons in two regions - those are
> results only from the first one).
>
>
>
> I do not understand where the differences in results come from, as I
> believe they shoud not differ as much.
>
>
>
> I attached both .inp files and obtained results of the simulations.
>
>
>
> Thank You for your support.
>
>
>
> Best regards,
>
> Agnieszka
>
>
>
> 2018-02-06 18:41 GMT+01:00 Joachim Vollaire <joachim.vollaire_at_cern.ch>:
>
> Dear Agnieszka
>
>
>
> It is not clear from your email (maybe you could send the input) what
> problem you are running. I assume you want to simulate the decay of Cs-137
> (you are not specifying which isotope decay of Cs you are interested in…).
>
> I have used an old input I have (it is not a point source in my case, but
> it is equivalent). Your input should have something like this :
>
>
>
> BEAM
> 1.0ISOTOPE
>
> BEAMPOS 0.0 0.15 0.0 0.24 0.0
> CYLI-VOL
>
> BEAMPOS 0.0 0.0 -0.125
>
>
> HI-PROPE 55. 137.
>
> *
>
>
>
>
>
> RADDECAY 2.0
>
>
>
>
>
> And you should adapt to what you want to score, but to see energy
> dependent spectra (maybe increase the energy upper limit) it could look
> like this:
>
>
>
> * Now scoring particles entering the scoring box
>
> *
>
> DCYSCORE -1. PHO-FL1 PHO-FL1
> USRBDX
>
> *
>
> USRBDX 1.0 PHOTON -55.0 CAPSIN CAPSUL1
> 1.0PHO-FL1
>
> USRBDX 0.001 0.0 300.0 &
>
> *
>
> DCYSCORE -1. ELE-FL1 ELE-FL1
> USRBDX
>
> *
>
> USRBDX 1.0 ELECTRON -55.0 CAPSIN CAPSUL1
> 1.0ELE-FL1
>
> USRBDX 0.001 0.0 300.0 &
>
>
>
>
>
> In my case it works fine (I have scored the energy spectra with the above
> cards), I checked with Cs-137 (which includes the decay of Ba-137m with
> FLUKA) or with Ba-137m itself and results are consistents (you see a
> continuous beta spectrum with end points at 514 and 1175 keV for Cs-137
> emitted radiations and the gamma line at 662 keV from Ba-137m with some
> discrete electrons at 624 and 655 keV).
>
>
>
> Greetings
>
> Joachim
>
>
>
> 55-Cs-137 ENDF=551370; A=137; Z=55; Iso=0; Level=0[MeV];
> Dmass=-86.55[MeV]; Hlife=9.49e+08[s]
>
> J/P=7/2+; Abund=0; Htox=6.7e-09; Itox=1.3e-08; Stat=0
>
> Decay modes:
>
> BetaMinus Diso: 0 BR: 5.400% Qval: 1.1756
>
> BetaMinus Diso: 1 BR: 94.600% Qval: 0.513596
>
> === Chain with 5.4 %
>
> 55-Cs-137 (5.4% BetaMinus) T1/2=9.49e+08
>
> 56-Ba-137
>
> === Chain with 94.6 %
>
> 55-Cs-137 (94.6% BetaMinus) T1/2=9.49e+08
>
> 56-Ba-137m
>
> === Chain with 94.6 %
>
> 55-Cs-137 (94.6% BetaMinus) T1/2=9.49e+08
>
> 56-Ba-137m (100% IsoTrans) T1/2=153
>
> 56-Ba-137
>
>
>
>
>
> *From:* owner-fluka-discuss_at_mi.infn.it [mailto:owner-fluka-discuss_at_
> mi.infn.it] *On Behalf Of *Agnieszka Witkowska
> *Sent:* 05 February 2018 22:02
> *To:* FLUKA discussion <fluka-discuss_at_fluka.org>
> *Subject:* [fluka-discuss]: RADDECAY - problem with card usage
>
>
>
> Dear Fluka Users,
>
>
>
> I have some uncertainties regarding usage of RADDECAY card. I have read
> the Fluka manual and I cannot understand how RADDECAY card works in terms
> of beam spectrum. For example I would like to set up a beam as a spectrum
> of caesium. By setting it by RADDECAY card I obtain strange results and the
> spectrum seems to be "flat" - my assumption is that RADDECAY does not take
> into consideration data about number of particles from each energy
> interval. Can You please advise if I am right and how to solve that
> problem? Is there any chance to correct it without usage of user routines?
>
>
>
> Thank You for your help in advance.
>
>
>
> Best regards,
>
> Agnieszka Witkowska
>
>
>
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