Hallo,
note that the spectrum integral is already available in the sum.lis file,
which is obtained by standard post-processing of the USRTRACK unformatted
output
Best regards
Francesco
**************************************************
Francesco Cerutti
CERN-EN/STI
CH-1211 Geneva 23
Switzerland
tel. +41 22 7678962
fax +41 22 7668854
On Mon, 21 Aug 2017, Santana, Mario wrote:
>
> Hi Alex,
>
>
>
> See comments inserted
>
>
>
> >>To update and specify the question:
>
>
>
> >>I made a setup where 50x50 cm beam made from source.f hits 50x50x1 RPP
> detector at 100 cm distance, see attached inp file and result pictures.
>
>
>
> >>My goal is to get photon/mm^2 equal to the spectrum source, see attached
> comparison picture.
>
> >>If I understand correct:
>
> >> USRTRACK gives me the number of photons entering the detector in such way
> : nr of photon multiplied by each energy bin expressed in GeV per cm-2. So I
> need to divide each bin (y) value by its energy >>and normalize to mm^2 in
> order to have photons/mm^2.
>
>
>
> No, you “must multiply the value of each energy bin by the width of the bin
> (even for logarithmic binning)”, see the FLUKA Manual.
>
>
>
> >>USRBDX gives me the number of photons leaving the surface area of the 2nd
> region in the card (?). I choose one way linear scoring and actually I am
> not sure what I am getting despite that I read the >>manual.Does it also
> show nr of photon in each energy range(bin) expressed in GeV per cm-2?
>
> Assuming there’s no angular dependence you can obtain the same result with
> USRBDX, but, additionally, you must multiply by 2*Pi, see from FLUKA Manual:
>
>
>
> “IMPORTANT! The results of a USRBDX boundary crossing estimator are
>
> always given as DOUBLE DIFFERENTIAL distributions of fluence (or
>
> current) in energy and solid angle, in units of cm-2 GeV-1 sr-1
> per
>
> incident primary, EVEN WHEN ONLY 1 INTERVAL (BIN) HAS BEEN
>
> REQUESTED, which is often the case for angular distributions.
>
> Thus, for example, when requesting a fluence or current energy
>
> spectrum, with no angular distribution, to obtain INTEGRAL
>
> BINNED results (fluence or current in cm-2 PER ENERGY BIN per
>
> primary) one must multiply the value of each energy bin by the
>
> width of the bin (even for logarithmic binning), AND BY 2 pi
>
> or 4 pi (depending on whether one-way or two-way scoring has
>
> been requested).”
>
>
>
> >>I am sorry if it's too obvious but for the first time with this scoring, I
> am lost. Could someone help me a little bit in this case?
>
>
>
> >>Regards
>
> >>Alex
>
>
>
> - Mario
>
>
>
>
>
>
>
>
> __________________________________________________________________________
>
>
> From: Ševčik Aleksandras
> Sent: Saturday, August 19, 2017 10:57:11 AM
> To: Santana, Mario; fluka-discuss_at_fluka.org
> Subject: Re: [fluka-discuss]: Normalization of results for x-ray tube output
> / source.f
>
>
>
> Hi, Mario,
>
>
>
> Thank you very much, I was thinking about integration of the curve but could
> you please tell how viable is the option to place the plane detector in the
> front of phantom and to score the number of photon crossing it, thus I can
> calculate average number of photons per mm^2 - just for double check. USRBDX
> would be suitable for this?
>
>
>
> Alex
>
>
> __________________________________________________________________________
>
>
> From: Santana, Mario <msantana_at_slac.stanford.edu>
> Sent: Saturday, August 19, 2017 1:10:43 AM
> To: Ševčik Aleksandras; fluka-discuss_at_fluka.org
> Subject: Re: [fluka-discuss]: Normalization of results for x-ray tube output
> / source.f
>
>
>
> Hi Alex,
>
>
>
> If you take the function photons(E) that you plot in “spektasjpg.jpg’ and
> you compute <photons> = INT_{Emin,Emax}(photons(E) x dE) / (Emax-Emin), this
> will tell you how many photons/mm^2 in average you will produce per mAs of
> current for your x-ray source.
>
> So, for a long enough simulation, you could just multiply the usual fluka
> normalization by that number:
>
> (pSv/primary) x (photons/mAs) -------> (pSv/mAs) because primary=photons
>
>
>
> of course this assumes that in your sampling ‘source.f’ routine you haven’t
> biased the weights of the starting photons.
>
>
>
> -Mario
>
>
>
> From: <owner-fluka-discuss_at_mi.infn.it> on behalf of Ševčik Aleksandras
> <aleksandras.sevcik_at_ktu.edu>
> Date: Friday, August 18, 2017 at 1:25 PM
> To: fluka-discuss <fluka-discuss_at_fluka.org>
> Subject: [fluka-discuss]: Normalization of results for x-ray tube output /
> source.f
>
>
>
> Dear experts,
>
>
>
> I have made a test simulation but now I am not sure about the correct way to
> normalize the results.
>
>
>
> I generated x-ray spectrum sample with SPEKTR 3.0 software, and using the
> help provided in this forum I was able to use modified source.f routine to
> re-create the beam and score the dose. I understand that that I get
> effective dose in pSv / primary. My question is what would be the correct
> approach to convert pSv/photon to pSv/mAs (x-ray Milliamp Seconds). Any
> comment / insight would be help,
>
>
>
> Regards
>
> Alex
>
>
>
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Received on Mon Aug 21 2017 - 09:44:56 CEST