Dear Alex,
In addition to the slides suggested by Nikhil, you may also find the slides from the most recent FLUKA course useful:
https://indico.cern.ch/event/540415/contributions/2194806/attachments/1285749/1912258/09_Statistics_and_sampling_2015.pdf
The discussion board archive is another place where you may find several relevant discussions. You may search it by matching text, or use a search engine like in this example:
https://www.google.com/search?q=%22enough+primaries%22+site%3Awww.fluka.org&ie=utf-8&oe=utf-8#q=%22statistical+error%22+site:www.fluka.org
Best regards,
George
----- Original Message -----
From: "nikhil shetty" <nikhil.nitk_at_gmail.com>
To: "Ševčik Aleksandras" <aleksandras.sevcik_at_ktu.edu>
Cc: "FLUKA Discussion List" <fluka-discuss_at_fluka.org>
Sent: Monday, February 20, 2017 7:50:21 AM
Subject: Re: [fluka-discuss]: uncertainty level in MC simulations
Hi Alex,
I am quoting a rule on page 19 from this presentation: www.*fluka*
.org/content/course/NEA/lectures/StatSampl.pdf
"*σ2 is converging like 1/N, while t is obviously proportional to N*"
So the variance is inversely proportional to the number of primaries.
Therefore to decrease the error (or one sigma standard deviation) by a
factor of 2, one has to run 4 times more primaries. Note the associated
cost of time.
The complete presentation might be worth the look to get an overview of
Monte Carlo statistics. It also gives you the number of batches to run,
which is in the range of 5 - 10 batches.
Cheers,
Nikhil
On Mon, Feb 20, 2017 at 12:23 PM, Ševčik Aleksandras <
aleksandras.sevcik_at_ktu.edu> wrote:
> Dear all,
>
>
> As I am learning mc on my own, I often lack some guidance even in the
> general subjects, so excuse me if the question is too basic.
>
>
> Is there any simple way /rule of thumb to determine how much histories I
> need to have/how much particles to run in order to get the desirable
> uncertainty level? Let's say I have a voxelised human phantom and measuring
> a dose distribution from the internal source. How many histories I need to
> run in order to have three sigma uncertainty level? Or does it vary and
> should be recalculated as errors averaging the different run files?
>
>
> Any advice/links to basic tutorials/other information regarding the topic
> will be much appreciated,
>
>
> Regards
>
> Alex
>
__________________________________________________________________________
You can manage unsubscription from this mailing list at
https://www.fluka.org/fluka.php?idc_info
Received on Mon Feb 20 2017 - 17:28:29 CET