Dear Paola,
Many thanks again for the clear explanation.
It agrees my guess indeed. And thank you for the solutions for an asymmetrical issue. Luckily, my calculations are symmetric!
Thank you again!
Zhiyuan
> -----原始邮件-----
> 发件人: "Paola Sala" <paola.sala_at_mi.infn.it>
> 发送时间: 2020-10-13 16:35:47 (星期二)
> 收件人: "\"梅志远\"" <meizhiyuan_at_hust.edu.cn>
> 抄送: paola.sala_at_mi.infn.it, "fluka discuss" <fluka-discuss_at_fluka.org>
> 主题: Re: Re: [fluka-discuss]: Puzzles about the polar angle in USRYIELD card
>
> The polar angle defines a cone, not a point. For each and any polar angle,
> all the directions defining the surface of the cone share the same polar
> angle, and, yes, for the scoring it is assumed that there is symmetry in
> the azimutal angle. Again this is true not only at 90 degrees, but also at
> 10, 20 etc. In the 0,90 and 180 degrees cases the cone degenerates to a
> line/a plane.
> If your problem is not symmetric.. either you use the fluscw.f user
> routine to select intervals in the azimutal angle (from the paticle
> director cosines) ,
> or you score fluence with a r-z-phi USRBIN mesh.
> Hope this helps
>
> Paola
> > Dear Paola,
> > Thank you very much for your patient replies!
> > However, I have still a question about the naming convention of the polar
> > angle.
> >
> > It's clear about the meaning of zero polar angle and the 180 degrees polar
> > angle, namely the forward direction and the backward direction,
> > respectively.
> > However, for the perpendicular direction to the beam, there should be two
> > directions, 90 degrees and 270 degrees. So where is the 270 degrees?
> >
> > I guess FLUKA makes a symmetry treatment for the polar angle. The
> > particles emitted in the perpendicular direction to the beam, whatever 90
> > degrees and 270 degrees, are classified to a same polar angle. Is it true?
> >
> > Many thanks again and hope get your replies!
> >
> > Zhiyuan
> >
> >
> >> -----原始邮件-----
> >> 发件人: "Paola Sala" <paola.sala_at_mi.infn.it>
> >> 发送时间: 2020-10-13 14:49:38 (星期二)
> >> 收件人: "\"梅志远\"" <meizhiyuan_at_hust.edu.cn>
> >> 抄送: "fluka discuss" <fluka-discuss_at_fluka.org>
> >> 主题: Re: [fluka-discuss]: Puzzles about the polar angle in USRYIELD card
> >>
> >> Hello
> >> maybe there is a problem of naming convention.
> >> the polar angle is the angle between the direction of the particle and
> >> the
> >> direction of the beam. If the particle is emitted in the forward
> >> direction
> >> along the beam axis, it has zero polar angle. If emitted in a direction
> >> perprndicular to the beam, it has 90 degrees (pi) angle. Uf totally
> >> backward--> 180 degrees or 2pi.
> >> The 4pi is the total solid angle, where the additional 2pi comes from
> >> the
> >> integration on the azimuthal angle, the one measured in the plane
> >> perpendicular to the beam.
> >> Hope this helps
> >> Paola
> >> > Dear FLUKA experts,I want to obtain the photon yield around a Cu
> >> target
> >> > shot by an electron beam. I'd like to plot the yield with an angular
> >> > distribution. So I use the USRYIELD card.
> >> >
> >> >
> >> >
> >> >
> >> > I indeed get a plot as shown below. But I'm puzzled about the
> >> definition
> >> > of the polar angle, namely the X axis of the plot.
> >> >
> >> >
> >> >
> >> >
> >> > (1) Yes, I know the Upper limit of the polar angle is forced to π,
> >> why?
> >> > why not the natural upper limit of polar angle, 2π? In my opinion, the
> >> > maximal polar angle should be 2π to cover the full angular
> >> distribution.
> >> > For a polar angle of π, only half the angular distribution is
> >> obtained.
> >> > Maybe it works for usual Symmetric simulations. BUT for an
> >> asymmetrical
> >> > yield angular distribution, it cannot work. Did I get a wrong
> >> > understanding?
> >> >
> >> >
> >> >
> >> >
> >> > (2) How can I associate the X asis (namely the polar angle) to the
> >> solid
> >> > angle in sr?
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> > Any help is appreciate!
> >> >
> >> > Best regards!
> >> >
> >> > Zhiyuan
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >> > --
> >> >
> >> >
> >> > Zhiyuan Mei
> >> > meizhiyuan_at_hust.edu.cn
> >> >
> >> >
> >> > /---------------------------------------------------
> >> > Institute of Applied Electromagnetic Engineering(IAEE)
> >> > Huazhong University of Science and Technology(HUST)
> >> > Address: Luoyu Road 1037, Wuhan, China
> >> > Tel: +86-155-2701-7168
> >> > /---------------------------------------------------
> >> >
> >> >
> >> >
> >> >
> >> >
> >> >
> >>
> >>
> >> Paola Sala
> >> INFN Milano
> >> tel. Milano +39-0250317374
> >> tel. CERN +41-227679148
> >
> >
> > --
> > Zhiyuan Mei
> > meizhiyuan_at_hust.edu.cn
> >
> >
> > /---------------------------------------------------
> > Institute of Applied Electromagnetic Engineering(IAEE)
> > Huazhong University of Science and Technology(HUST)
> > Address: Luoyu Road 1037, Wuhan, China
> > Tel: +86-155-2701-7168
> > /---------------------------------------------------
> >
> >
> >
> >
> > __________________________________________________________________________
> > You can manage unsubscription from this mailing list at
> > https://www.fluka.org/fluka.php?id=acc_info
> >
> >
>
>
> Paola Sala
> INFN Milano
> tel. Milano +39-0250317374
> tel. CERN +41-227679148
--
Zhiyuan Mei
meizhiyuan_at_hust.edu.cn
/---------------------------------------------------
Institute of Applied Electromagnetic Engineering(IAEE)
Huazhong University of Science and Technology(HUST)
Address: Luoyu Road 1037, Wuhan, China
Tel: +86-155-2701-7168
/---------------------------------------------------
__________________________________________________________________________
You can manage unsubscription from this mailing list at https://www.fluka.org/fluka.php?id=acc_info
Received on Tue Oct 13 2020 - 12:36:50 CEST