Dear Beatrice
Maybe a first suggestion (as already mentioned by Francesco) is to use the decay of Co-60 in the source definition (it is more elegant than averaging the two gamma rays) and would allow you to use your source activity for the normalization. Consider the following cards:
BEAM 0.0 ISOTOPE
HI-PROPE 27. 60.
RADDECAY 1.
And don’t forget DCYSCORE otherwise you will not get any contribution associated to the decay of Co-60….
DCYSCORE -1.0 0. 0. ***** ***** USRBIN
*
Concerning the transport threshold I would use something lower for electrons (1 MeV is high), what about using 100 keV as for photons….
Could you please reformulate your question on the normalization, not sure I understand properly. You source is calibrated and you know it gives 53 Gy/h _at_ 20 cm ? If this is the case, you should use this value to derive the corresponding Co-60 activity (1 Bq leading to two photons in 99.88 % branching ratio) and use this for normalization all quantities scored with FLUKA.
Looking at analytical codes based on gamma conversion factor, your source strength should be of the order of 6.5 TBq, does it make sense ?
Greetings
Joachim
From: owner-fluka-discuss_at_mi.infn.it [mailto:owner-fluka-discuss_at_mi.infn.it] On Behalf Of Beatrice Pomaro
Sent: 13 October 2016 10:56
To: Francesco Cerutti <Francesco.Cerutti_at_cern.ch>
Cc: FLUKA discussion <fluka-discuss_at_fluka.org>
Subject: RE: [fluka-discuss]: Fwd: Gamma-ray experiment
Dear Dr. Cerutti,
sorry but I'd have another question about the photon flux rate of the experiment with gamma-ray source that I submitted to the forum's attention: since 53 Gy/h is the declared dose at 20cm from the source (in contact with the irradiated concrete sample) shall I use 53Gy/h for the computation below (which leads to 7.668E10 photons/(s kg_concrete) ) or shall I use the dose exactly at the source?
And should I multiply the photon flux obtained from Fluka (particle/(cm2 primary)) by the same quantity: photons/(s kg_concrete) to get the flux rate: photons/(cm2 s kg_concrete) ?
In the input file I used NEW-DEFA and card EMFCUT with sdum: PROD-CUT for electron kinetic energy threshold 0.001: GeV and photon production threshold: 0.0001 GeV . Hope it is fine.
Many thanks for your kind attention,
Best regards,
Beatrice
---
**************************************************
Ing. Beatrice Pomaro
Universita' degli Studi di Padova
Dipartimento di Ingegneria Civile, Edile e Ambientale
Via F. Marzolo, 9 - 35131 Padova (Italy)
tel.: +39 049 8275592
e-mail: beatrice.pomaro_at_dicea.unipd.it<mailto:beatrice.pomaro_at_dicea.unipd.it>
Il 09-10-2016 23:07 Francesco Cerutti ha scritto:
actually the average gamma energy is 1.25 MeV, giving 7.36E10 photons/(s kg)
On Sun, 9 Oct 2016, Francesco Cerutti wrote:
Dear Beatrice,
fine with the first point. Then, when one divides by 1.2 MeV transformed into J [assuming the all energy is absorbed in the sample], the result is 7.668E10 photons/(s kg), to be multiplied by the sample mass [assuming an uniform irradiation].
I understand that you already multiplied by the concrete density and are left with the volume normalization, that's correct.
Kind regards
Francesco
**************************************************
Francesco Cerutti
CERN-EN/STI
CH-1211 Geneva 23
Switzerland
tel. ++41 22 7678962
fax ++41 22 7668854
On Sun, 9 Oct 2016, Beatrice Pomaro wrote:
Dear Dr. Cerutti,
thank you very much for your explanation. I agree with you in the
definition of the
energy deposition in a volume. Also I am using PHOTONs as primary
particle, yes.
If I want to compute the photon rate, the 60Co source working at
53Gy/h=0.01472
Gy/s and 1.2MeV, shall I transform 0.01472 Gy/s into 0.01472 W/kg where
this
quantity is per kg of the concrete sample placed around the source (to be
tested),
is it correct?
Then I need to divide it for the electronic charge (1.6*10-19 C) and the
energy of
the gamma rays (1.2*10+6 eV) so to obtain: 1.92*10+8 photons/(cm3 s) where
cm3 is
the volume of the concrete sample?
Is it correct?
Thank you in advance,
Best regards,
Beatrice
---
**************************************************
Ing. Beatrice Pomaro
Universita' degli Studi di Padova
Dipartimento di Ingegneria Civile, Edile e Ambientale
Via F. Marzolo, 9 - 35131 Padova (Italy)
tel.: +39 049 8275592
e-mail: beatrice.pomaro_at_dicea.unipd.it<mailto:beatrice.pomaro_at_dicea.unipd.it>
Il 07-10-2016 19:17 Francesco Cerutti ha scritto:
Dear Beatrice,
I miss the expected meaning of GeV/(cm2 s). Energy is deposited in a
volume and with a cartesian or cylindrical USRBIN [*not* with a
USRBIN
per region] you get GeV/(cm3 primary) as you wrote. Multiplying by
the
photon rate (I assume you decided to use PHOTONs as primary
particles
instead of directly simulating the 60Co decay through ISOTOPE), you
will get power deposition density (that can be expressed in W/cm3)
and
I would be pretty happy with that, with no need for a further
manipulation by an ill-defined quantity.
Do not hesitate to come back with your thoughts if in fact you turn
out
not to be happy.
Cheers
Francesco
**************************************************
Francesco Cerutti
CERN-EN/STI
CH-1211 Geneva 23
Switzerland
tel. ++41 22 7678962
fax ++41 22 7668854
On Thu, 6 Oct 2016, Beatrice Pomaro wrote:
Dear Anton,
thank you very much for your advice, may I ask you also about the output
results of a USRBIN score? We read in fact from the manual: "The results
from USRBIN are normalised per unit volume and per unit primary weight,"
does it mean that for energy deposition in order to get GeV/(cm2 s) out of
GeV/(cm3 primary) one needs to multiply Fluka result by the particle flux
(particle/s) and the length in direction orthogonal to the flux of the
region of interest for the scoring?
Thank you in advance for your explanation,
Best regards,
Beatrice
Il 27-09-2016 15:49 Anton Lechner ha scritto:
Dear Beatrice,
Running your input file, one gets following error message:
*** Too many terms in parenthesis expansion ***
*** Execution terminated ***
I think the message is quite self-explaining. The issue lies in
the definition of the second zone of the rAir region. As a good
practice, I would try not to use too many parenthesis (you can
equally define the geometry without using any parenthesis at
all). Also note that if you have too many bodies in a zone
definition this can also slow down the simulation. It is better
to have more zones with fewer bodies than to have one zone with
many bodies.
Besides, on the EMFCUT card you set the production cuts for
e-/e+ and photons to 0. Note that physics models are no longer
applicable at very low energies and one should respect the
minimum values recommended in the manual. I quote:
"The minimum threshold energy for transport and production of
photons is 100 eV. For electrons and positrons, it is 1 keV."
Cheers, Anton
____________________________________________________________________________
From: owner-fluka-discuss_at_mi.infn.it<mailto:owner-fluka-discuss_at_mi.infn.it>
[owner-fluka-discuss_at_mi.infn.it<mailto:owner-fluka-discuss_at_mi.infn.it>] on behalf of Beatrice Pomaro
[beatrice.pomaro_at_dicea.unipd.it<mailto:beatrice.pomaro_at_dicea.unipd.it>]
Sent: 27 September 2016 15:00
To: fluka-discuss
Subject: [fluka-discuss]: Fwd: Gamma-ray experiment
Dear Fluka experts,
I am trying to reproduce an irradiation experiment due to gamma-rays
from a Cobalt60 source.
I am using Flair. I can not run the input file because the 001.out
file stops before reading regions, while the file .out gives a
generic error message (that I am reporting here below):
Dir: /home/flupix/Desktop/Prova
Cmd: /usr/bin/nohup /usr/local/fluka/flutil/rfluka -e
/home/flupix/Desktop/Prova/Prova.flair -M 2 Prova
$TARGET_MACHINE = Linux
$FLUPRO = /usr/local/fluka
Initial seed copied from /usr/local/fluka
Running fluka in /home/flupix/Desktop/Prova/fluka_2030
======================= Running FLUKA for cycle # 1
=======================
/usr/local/fluka/flutil/rfluka: line 359: 2058
Aborted (core dumped) "${EXE}" < "$INPN" 2> "$LOGF" >
"$LOGF"
No .err files are produced yet, since the analysis stops before.
I am attaching here my input file. Would you tell me what I am doing
wrong, please?
Thank you in advance,
Best regards,
Beatrice Pomaro
--
**************************************************
Ing. Beatrice Pomaro
Universita' degli Studi di Padova
Dipartimento di Ingegneria Civile, Edile e Ambientale
Via F. Marzolo, 9 - 35131 Padova (Italy)
tel.: +39 049 8275592
e-mail: beatrice.pomaro_at_dicea.unipd.it<mailto:beatrice.pomaro_at_dicea.unipd.it>
--
**************************************************
Ing. Beatrice Pomaro
Universita' degli Studi di Padova
Dipartimento di Ingegneria Civile, Edile e Ambientale
Via F. Marzolo, 9 - 35131 Padova (Italy)
tel.: +39 049 8275592
e-mail: beatrice.pomaro_at_dicea.unipd.it<mailto:beatrice.pomaro_at_dicea.unipd.it>
--
**************************************************
Ing. Beatrice Pomaro
Universita' degli Studi di Padova
Dipartimento di Ingegneria Civile, Edile e Ambientale
Via F. Marzolo, 9 - 35131 Padova (Italy)
tel.: +39 049 8275592
e-mail: beatrice.pomaro_at_dicea.unipd.it<mailto:beatrice.pomaro_at_dicea.unipd.it>
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Received on Tue Oct 18 2016 - 19:28:25 CEST