Hi Roman
Be careful, FLUKA calculates value per primary particle. A primary particle is for example, once single particle from a beam (for most cases) or one single decay if you use the more specific case of a radioactive source....
Thus if you want an integrated quantity (Gy deposited in a target during one year for example), you would need to multiply the calculated dose (averaged behaviour normalized to a single primary) by the time of your experiment x the beam intensity (total number of beam particles delivered to the target).
Now let's say you are looking at a shielding case and that you want to calculate a prompt dose equivalent rate value to check you are below a given limit of xx uSv/h applicable for your shielding design around your accelerator. FLUKA would score (using DOSE-EQ in a USRBIN for example) the dose equivalent per primary beam particle -> pSv/primary. You would multiply by the beam intensity (protons / s for example) to obtain pSv/s and by 3600 / 1e6 to go to uSv/h which would be the relevant unit for this application....
One exception to what I describe above is the definition of an irradiation profile and decay time associated to the scoring cards of interest (RADDECAY, IRRPROFI, DCYTIMES, DCYSCORE...). In that case, the beam intensity is provided in the irradiation profile and the quantities after a given cooling time accounts for the irradiation condition (it is used to solve the Bateman equations -> in the build-up term)...
For the second part of your question, no the WHAT(6) has nothing to do with this (and I believe is rarely use). It might be linked to the possibility for the user to stop (nicely) the run before the total number of primary requested is reached -> creating a (r)source.stop file in the fluka_*** directory created by the rfluka script for the run. It might be that every xx s defined in WHAT(6) the code is looking for the existence of the file in question.....
To conclude, what should direct the number of primary particles you run or the CPU time is the statistical uncertainty of the scored quantities.
Hoping this help
Joachim
From: Roman Savinov [mailto:rsavinov_at_calpoly.edu]
Sent: 19 April 2016 08:43
To: Joachim Vollaire <joachim.vollaire_at_cern.ch>; fluka-discuss_at_fluka.org
Subject: Re: duration of an experiment
Joachim,
thank you for your explanation.
Do I understand it right that FLUKA always outputs basically the rate value (dose rate, flux rate) so I multiply the output by the time of the experiment to get the total dose or flux?
Anyway, what is the "time reserved for an interactive run" (what(6) of the START card)?
Does is have anything to do with the time of experiment? I can't find any good explanation of what this is.
thank you,
Roman
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Received on Tue Apr 19 2016 - 17:17:28 CEST