Dear Karol,
in your example you sample photons on a surface isotropically,
therefore current (= number of photons) and fluence (= tracklength
density) do not coincide.
You should rather normalize to current: current and fluence are
different and only coincide for perpendicular impact (which is
not your case).
Best regards,
Andrea and Francesco
Il 09/02/2017 22:50, Szymczyk Karol ha scritto:
> Dear Andrea
> Thank you very much for your response.
> It confirmed me, that simulations and the source.f works correctly, -now I can continue my work.
>
> Referring to the concerns that you noticed:
> I got energy spectrum distribution from my colleagues, wherein the amount of the particles was expressed in N / cm ^ 3 / s.
> (detector like a sheet of thickness 1 cm)
>
> I tried to calculate the Energy spectrum using the voxels (1cm^3) using URSTRACK.
> In the USRTRACK manual
> http://www.fluka.org/fluka.php?id=man_onl&sub=89
> there is an information that:
> -the volume of the detector in cm**3,
> -the results of the energy spectrum are normalized to cm**2.
>
> There is a comparison between the USRBDX and USRTRACK in the Lectures about Scoring:
> http://www.fluka.org/content/course/NEA/lectures/Scoring.pdf
> (slajd 15)
> "remember: USRBDX scores on a surface, while USRBIN scores Fluence in volumes and gives no differential information"
>
> The results in my simulations are quite the same :USRTRACK (detector like a sheet of thickness 1 cm) , and USRBDX (surface)
>
> Based on this information I realized that I could simplify the reasoning, and use the surface as a source spectrum (instead of the voxels).
> Am I right?
>
> This is exactly one more question, but I understand (from the lactures and tests), that my simplification is correct.
>
> Thank you for any comments.
>
> Best regards, and thank you one more time for help.
>
> Karol Szymczyk
>
> ________________________________________
> From: Andrea Fontana [andrea.fontana_at_pv.infn.it]
> Sent: Wednesday, February 08, 2017 10:11 PM
> To: Szymczyk Karol; fluka-discuss_at_fluka.org
> Subject: Re: [fluka-discuss]: DOSE-EQ normalization, isotropic source, energy spectrum on the geometry
>
> Dear Karol,
> I have tested your sourcetest.f routine and I was able to reproduce
> your results regarding the initial position sampling (looking at
> the screenshots) and also the generated spectrum seems to follow well
> the spectrum.dat file. Also regarding the angular distribution your
> algorithm
> seems to work well and reproduces a isotropic source on the +z half sphere.
>
> So your source.f routine is ok in my opinion.
>
> Regarding the normalization, since in your source you sample one photon
> per time, the result is normalized per photon: therefore you should
> multiply by the surface and by your fluence rate.
>
> However I do not understand your units particle/cm^3/s: why cm^3,
> shouldn't be cm^2? In this case the normalization that you suggest
> is correct.
>
> I hope this helps and I look forward to your reply.
> Kind regards,
> Andrea
>
>
>
> Il 08/02/2017 15:51, Szymczyk Karol ha scritto:
>> Dear Fluka experts
>>
>> My issue is to implement the isotropic source with energy spectrum on
>> the geometry-flat surface (like ROCA function, but for the flat
>> surface, not sphere)
>>
>>
>> My input is the energy spectrum from the front of the chamber(the unit
>> in column 2 are particle/cm^3/s)
>>
>>
>> -I use part of the 'well known', user routine source.f ,(course in
>> Athens) to implement the Energy spectrum.
>>
>> http://www.fluka.org/fluka.php?id=course&sub=program&navig=2&which=demokritos2009
>> <http://www.fluka.org/fluka.php?id=course&sub=program&navig=2&which=demokritos2009>
>>
>>
>> -I used a isotropic source, with z ditribution Z+
>>
>>
>> https://pcfluka.mi.infn.it/FLUKA/web_archive/earchive/new-fluka-discuss/9628.html
>>
>>
>> -I randomizesd the position of a particle on a designed area
>>
>>
>> It is working well (in my opinion)!
>>
>>
>> Firstly I would like to kindly ask you, if this kind of source.f
>> routine is ok, in your opinion?
>>
>>
>> Secondly ,the main problem is to well normalize the results.
>>
>> Main main issiu is to calculate the Dose EQ in the area around the target.
>>
>> To calculate the DOSE-EQ, I need the real number of preliminary
>> particles/s.
>>
>> -My input has totaly 603 particle/cm^3/s (just an example)
>>
>> -source surface is 60cm*60cm
>>
>>
>> Should I multiply the DOSE-EQ results by the source surface area, and
>> totaly nymer of particle/cm^3/s (603 particles)?, or should I do
>> somethig else.
>>
>>
>> You are more then welcome to open my attached files.
>>
>> I am looking forward for any suggestions.
>>
>>
>> Best regards.
>> Karol Szymczyk
> --
> ========================================================================
> Dr. Andrea Fontana tel: +39 0382 987991
> Istituto Nazionale fax: +39 0382 423241
> di Fisica Nucleare
> Sezione di Pavia e-mail: andrea.fontana_at_pv.infn.it
> Via Bassi 6 web : www.pv.infn.it/~fontana
> 27100 PAVIA, Italy
> ========================================================================
>
--
========================================================================
Dr. Andrea Fontana tel: +39 0382 987991
Istituto Nazionale fax: +39 0382 423241
di Fisica Nucleare
Sezione di Pavia e-mail: andrea.fontana_at_pv.infn.it
Via Bassi 6 web : www.pv.infn.it/~fontana
27100 PAVIA, Italy
========================================================================
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Received on Fri Feb 10 2017 - 16:20:04 CET