Mr. Chen Yuan,
I have already told you TWICE that FLUKA does not simulate wave effects.
What you call "a modulation phenomenon by the interface" is in fact what
is normally called refraction, and - as I have told you - is the result of
interference of wavelets. FLUKA does not handle wave interference.
Therefore, please don't insist anymore. There must certainly be specialized
programs that can deal with that sort of effect: look for one and don't
use FLUKA if you are interested only in that effect
Alberto
PS Discussions which have been initiated on the list should not be continued
by private e-mail
On Wed, 7 Jan 2015, shaogch_at_mail.ustc.edu.cn wrote:
>
>
>
> -----????-----
> ???:shaogch_at_mail.ustc.edu.cn
> ????:2015-01-05 08:59:14 (???)
> ???: fluka-discuss_at_fluka.org
> ??:
> ??: Re: [fluka-discuss]: RE: [fluka-discuss]: RE: [fluka-discuss]: Re: [fluka-discuss]: Transmittance do not agree with NIST???
>
>
>
> Dear Alberto?
>
> The attached one-page Figure pdf highlights the pdf paper for your
> consideration. Fig. 6 shows the radiography schematic diagram and Fig. 7 shows
> the photon signal at the detection plane. We agree that Rayleigh scattering in
> FLUKA is elastic scattering of photon particles?but for many photons the
> Rayleigh scattering at the interface should produce an accumulated signal as
> like Fig.7, i.e. the modulation phenomenon appears. In fact?if we use
> electrons or protons as incident particles, we can observe the similar
> modulation phenomenon by the interface. If the same phenomenon for photons, do
> we have to include some processes like Rayleigh scattering in the Fluka input
> file? If our input file is set correctly or the Rayleigh scattering is a
> default process, but still we cannot see the modulation phenomenon by the
> interface, can we say that Fluka can not accurately deal with photon
> scattering at the interface?
>
> Best regards
>
> Chen Yuan
>
>
>
>
> -----????-----
> ???:"Fasso, Alberto" <fasso_at_slac.stanford.edu>
> ????:2015-01-04 17:25:54 (???)
> ???: "shaogch_at_mail.ustc.edu.cn" <shaogch_at_mail.ustc.edu.cn>, "fluka-discuss_at_fluka.org" <fluka-discuss_at_fluka.org>
> ??:
> ??: [fluka-discuss]: RE: [fluka-discuss]: RE: [fluka-discuss]: Re: [fluka-discuss]: Transmittance do not agree with NIST???
>
>
>
> Refraction is a wave phenomenon (interference between Huygens wavelets at the surface of a medium). As I said,
>
> FLUKA does not simulate scattering of photons as waves, but as particles. Rayleigh scattering in FLUKA is just elastic scattering
>
> of photon particles
>
>
>
> Alberto
>
>
> ?
>
>
> From:owner-fluka-discuss_at_mi.infn.it <owner-fluka-discuss_at_mi.infn.it> on behalf of shaogch_at_mail.ustc.edu.cn <shaogch_at_mail.ustc.edu.cn>
> Sent: Saturday, January 3, 2015 6:51 PM
> To:fluka-discuss_at_fluka.org
> Subject: Re: [fluka-discuss]: RE: [fluka-discuss]: Re: [fluka-discuss]: Transmittance do not agree with NIST???
>
> Dear Alberto?
>
> According to you?FLUKA handles photons as particles?the Rayleigh or coherent scattering is included. So the refraction of photons at (steep) interfaces of different materials should be observed. Please see the paper attached, the phase contrast at the material interface are explained by refraction, which causes the intensity modulation phenomenon at the interface. Why can not we see the same phenomenon in the Fluka simulation? The attachments are my input file and the result.
>
> Best Regards
> Chen Yuan
>
>
>
> -----????-----
> ???:"Fasso, Alberto" <fasso_at_slac.stanford.edu>
> ????:2015-01-03 23:18:44 (???)
> ???: "shaogch_at_mail.ustc.edu.cn" <shaogch_at_mail.ustc.edu.cn>, "fluka-discuss_at_fluka.org" <fluka-discuss_at_fluka.org>
> ??:
> ??: [fluka-discuss]: RE: [fluka-discuss]: Re: [fluka-discuss]: Transmittance do not agree with NIST???
>
>
>
> ?Phase contrast imaging is based on wave behaviour of photons (interference and diffraction). FLUKA handles photons only as particles, so it cannot simulate x-ray phase contrast imaging?. For the same reason, FLUKA can simulate wigglers, but not undulators
>
>
>
>
> Alberto
>
>
>
>
>
> From:owner-fluka-discuss_at_mi.infn.it <owner-fluka-discuss_at_mi.infn.it> on behalf of shaogch_at_mail.ustc.edu.cn <shaogch_at_mail.ustc.edu.cn>
> Sent: Saturday, January 3, 2015 3:48 AM
> To:fluka-discuss_at_fluka.org
> Subject: Re: [fluka-discuss]: Re: [fluka-discuss]: Transmittance do not agree with NIST???
>
>
>
> Dear Mikhail?
>
> Thank you for your reply.Can Fluka simulate x-ray phase contrast imaging? If it can,How should I do?
>
> Best Regards
>
> Chen Yuan
>
>
> -----????-----
> ???:"\"Mikhail Polkovnikov <?????? ???????????>\"" <pmk_at_ihep.ru>
> ????:2014-12-31 00:47:12 (???)
> ???:shaogch_at_mail.ustc.edu.cn, fluka-discuss_at_fluka.org
> ??:
> ??: [fluka-discuss]: Re: [fluka-discuss]: Transmittance do not agree with NIST???
>
>
> On 30.12.2014 16:13, shaogch_at_mail.ustc.edu.cn wrote:
>
>
> Dear Fluka users?
>
> When I use X-ray to irradiate target,the transmittance F2/F1(F2 is the flux density from the target and F1 is the flux density from the vacuum) is smaller than the transmittance estimated from NIST website(http://physics.nist.gov/PhysRefData/XrayMassCoef/chap2.html) .Why does this happen? The primary X-ray energy is 10 keV.The production and transport cutoff I set for photon is 100 eV. TheproductionandtransportcutoffIsetfor electron is 1 keV. The attachments are my input file and output file.Please have a look at it.In a word,I don't know why the transmittance from fluka(about 50%) do not agree with NIST(about 97%).
>
> On the other hand,When I see my output file,it shows the following warning:
>
> **** Warning!!! Least square fit for blccra failed to keep max. rel. Blcc err. below 1% ****
> **** Max. error is 21.8 %, for beta2 = 0.03260 ****
>
>
> ZTILDE,AE1O3,BLCCRA= 1.20779E+01 2.08102E+00 1.52566E-02
>
> **** Warning!!! Least square fit for blccre failed to keep max. rel. Blcce err. below 1% ****
> **** Max. error is 5.3 %, for beta2 = 0.00358 ****
>
> What does this warning mean? Does it will affect the fluence scored by the usrbin detector? Any suggestions will be appreciated.
>
> Best Regards
>
> Chen Yuan
>
>
>
> Dear Chen Yuan,
>
> In your COMPOUND cards the "Mix" is set as atoms, but "f1" and "f3" are fractions of 1. like volume or mass.
> Are you sure that your mix is correct?
>
> If "Mix:" set as mass the result in attachment.
>
>
> Best regards,
> Mikhail
--
Alberto Fasso`
SLAC-RP, MS 48, 2575 Sand Hill Road, Menlo Park CA 94025
Phone: (1 650) 926 4762 Fax: (1 650) 926 3569
fasso_at_slac.stanford.edu
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Received on Wed Jan 07 2015 - 18:13:30 CET