RE: [fluka-discuss]: RADDECAY - problem with card usage

From: Joachim Vollaire <joachim.vollaire_at_cern.ch>
Date: Tue, 6 Feb 2018 17:41:33 +0000

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



__________________________________________________________________________
You can manage unsubscription from this mailing list at https://www.fluka.org/fluka.php?id=acc_info

Flux.png
(image/png attachment: Flux.png)

Received on Tue Feb 06 2018 - 20:03:18 CET

This archive was generated by hypermail 2.3.0 : Tue Feb 06 2018 - 22:28:50 CET