Date: Wed, 8 Jul 2015 11:54:51 +0000
Dear Sunil,
Thank you so much, now I understand my output. Can you please comment on my second
question either USRBIN can be used to score spatial activity from residuals like I am scoring
residual dose? Paola Sala in a post written that it cannot be used to score a particular isotope but I am interested in spatial distribution of total activity.
Best regards,
Zafar
________________________________
From: Sunil C [csunil11_at_gmail.com]
Sent: 08 July 2015 09:56
To: Zafar Yasin
Cc: Vittorio Boccone; fluka-discuss_at_fluka.org
Subject: Re: [fluka-discuss]: Residual dose and activity
Dear Zafar
The neutrons produced in a reaction will simply escape from the system, once the beam has stopped.
For example, a neutron of 0.025 eV (very slow in the neutron world) has a velocity of 2.2 km/s. Indeed, they will cover a lot of distance in a very short time span and thus wont be there to contribute to the dose anywhere near the origin.
So, unless you have ultra cold neutrons, you will not see any beta decay, which is what you get even if they did hang around long enough.
The photons are still being produced because the material under irradiation has become radioactive and is decaying with its characteristic decay constant.
Best Regards
Sunil
On Wed, Jul 8, 2015 at 12:11 PM, Zafar Yasin <Zafar.Yasin_at_cern.ch<mailto:Zafar.Yasin_at_cern.ch>> wrote:
Dear Vittorio and Fluka experts,
Thank you very much for replying. You mean after one minute of cooling time there will be no contribution to residual dose from neutrons? I really not understanding this as neutrons have mean life
of 15 minutes and half life of 10 minutes, and where these neutrons go for this period? If there is clearly large contribution from photons after 1 minute of cooling time, there should be
some contribution from neutrons or not?
Secondly, can you please also comment on my question how can I use ACTIVITY option in USRBIN to see spatial distribution of activity as the way we normally use FLUKA is not accepting.
Thank you.
Best regards,
Zafar
________________________________
From: Vittorio Boccone [dr.vittorio.boccone_at_ieee.org<mailto:dr.vittorio.boccone_at_ieee.org>]
Sent: 07 July 2015 22:13
To: Zafar Yasin
Cc: Ferreira De Almeida Lourenco, Ana; Eleftherios Skordis; Joachim Vollaire; fluka-discuss_at_fluka.org<mailto:fluka-discuss_at_fluka.org>
Subject: Re: [fluka-discuss]: RE: Understanding USRBDX output files
Dear Zafar,
it would be nice (next time) to start a new thread for your question as it's not completely related to Ana's.
I see you have for those cases a very low statistics.
Your "neut-dose" USRBIN is eventually queued though the DCYSCORE card as well, which means - toghether with RADDECAY WHAT(1)=1 - that the particle will be scored at the specified cooling time. In your case the effects dose caused by neutrons will be negligible. Remove the DCYSCORE card for the neut-dose and you will actually have a clear sign of the neutron effects coming from the prompt radiation. For scoring both radiation, you should switch to semi-analogue mode.
Best
Vittorio
On Tue, Jul 7, 2015 at 11:58 AM, Zafar Yasin <Zafar.Yasin_at_cern.ch<mailto:Zafar.Yasin_at_cern.ch>> wrote:
Dear Joachim, Lefteris, and Fluka experts,
Thanks a lot for giving time, I was doing the same mistake as Ana was doing. Actually, I have another problem and I have
stuck at that point. I am doing MC simulations for beam dumps and related shielding using FLUKA and everything is ok for prompt beam.
But when I start after irradiation of 200 days and for a few cooling times , I am not satisfied with the results I get.
To prepare my input I exactly followed the lecture of the FLUKA course , 2012, and even run the input file that is available on the web.
But when I run my input file, I have a few issues:
Firstly, I am not seeing anything from neutron contribution, the USERBIN residual dose rate plot from neutrons is empty and contribution
from all particles and photons seems not so good, please see attached plots. Plot from residual nuclei is not complete too.
Secondly, LAM-BAS card seems not here or in prompt case, but I was able to get good contribution from neutrons by using this card.
Thirdly, I want to see spatial distribution of activity , I want to use USRBIN card for this as in the comment in my input file attached, but
flair seems not happy with this and reply you can't do this way.
I have attached my input file, is there any problem in the input file or else?
Thank you!
Best regards,
Zafar
________________________________
From: Ferreira De Almeida Lourenco, Ana [am.lourenco_at_ucl.ac.uk<mailto:am.lourenco_at_ucl.ac.uk>]
Sent: 07 July 2015 10:55
To: Eleftherios Skordis; Joachim Vollaire; Zafar Yasin; fluka-discuss_at_fluka.org<mailto:fluka-discuss_at_fluka.org>
Subject: Re: Understanding USRBDX output files
Dear Joachim, Lefteris and All,
Thank you very much for your reply.
That was my problem! I was running several runs with different seed numbers but the RANDOMIZ card was set has a comment - well picked up [😊]
I have another question:
In the output file, sum.lis, from USRBDX card, results are give in units of steredians and degrees. How are the quantities related?
Many thanks,
Ana
________________________________
De: Eleftherios Skordis <eleftherios.skordis_at_cern.ch<mailto:eleftherios.skordis_at_cern.ch>>
Enviado: 7 de julho de 2015 08:30
Para: Joachim Vollaire; Zafar Yasin; Ferreira De Almeida Lourenco, Ana; fluka-discuss_at_fluka.org<mailto:fluka-discuss_at_fluka.org>
Assunto: RE: Understanding USRBDX output files
Hi both,
It is most likely that you have no RANDOMIZ card active in your input.
For Ana, looking at your input file, you have comment the card out and thus getting only the same history over and over again.
Kind regards
Lefteris
-----------------------
Eleftherios Skordis
Dep. EN/STI, CERN
CH-1211 GENEVA 23
SWITZERLAND
OFFICE: +41-22-7679541<tel:%2B41-22-7675461>
________________________________
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 Joachim Vollaire [joachim.vollaire_at_cern.ch<mailto:joachim.vollaire_at_cern.ch>]
Sent: 07 July 2015 09:37
To: Zafar Yasin; Ferreira De Almeida Lourenco, Ana; fluka-discuss_at_fluka.org<mailto:fluka-discuss_at_fluka.org>
Subject: [fluka-discuss]: RE: Understanding USRBDX output files
Hi
The most likely cause is that you are not differentiating your runs and starting with the same random seeds. You are thus computing the error based on the same exact histories and averaged means so the variance is zero in that case. You can check it is the case by converting two of your data files to ascii and check if they are identical.
As instructed in the manual you should have a minimum of five independent runs (different random seeds) to compute representative errors
Hoping this help
Greetings
Joachim
From: owner-fluka-discuss_at_mi.infn.it<mailto:owner-fluka-discuss_at_mi.infn.it> [mailto:owner-fluka-discuss_at_mi.infn.it<mailto:owner-fluka-discuss_at_mi.infn.it>] On Behalf Of Zafar Yasin
Sent: 06 July 2015 22:54
To: Ferreira De Almeida Lourenco, Ana; fluka-discuss_at_fluka.org<mailto:fluka-discuss_at_fluka.org>
Subject: [fluka-discuss]: RE: Understanding USRBDX output files
Dear Fluka users and Ana,
I am also facing the same problem but with USRTRACK card, I am not using the URBDX, while I do activation
analysis for prompt beam it is ok.
Best regards,
Zafar
________________________________
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 Ferreira De Almeida Lourenco, Ana [am.lourenco_at_ucl.ac.uk<mailto:am.lourenco_at_ucl.ac.uk>]
Sent: 06 July 2015 11:51
To: fluka-discuss_at_fluka.org<mailto:fluka-discuss_at_fluka.org>
Subject: [fluka-discuss]: Understanding USRBDX output files
Dear FLUKA experts,
I am simulating a proton beam in a target cylinder and scoring fluence differential in energy and angle in a ring detector using a USRBDX card.
For a non zero fluence I'm getting a error of zero. Why is the error zero? Example of sum.lis file:
...
Tot. resp. (Part/cmq/pr) 0.8798609 +/- 0.000000 %
( --> (Part/pr) 0.8798609 +/- 0.000000 % )
...
Also, in the sum.lis files the angular distribution and respective fluence are given in units of steradians and degrees. How are these two quantities related?
Please find attached my input file.
Many thanks,
Ana
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