Dear Mitja,
some time ago I asked the same question, just open this link and read the
whole thread (" Next in thread" button :-)
http://www.fluka.org/FLUKA/web_archive/earchive/new-fluka-discuss/8299.html
Regards
Yuri
2017-01-05 19:58 GMT+01:00 Mitja Majerle <majerle_at_ujf.cas.cz>:
> Dear experts,
>
> I would like to program to source.f the sampling of the beam divergence,
> gaussian with FWHM (as can be defined with BEAM card). How do I do this
> properly ?
>
> I start with sampling of the isotropic distribution, where I sample
> vectors as u=cos(theta), v=sqrt(1-u^2)sin(phi), w=sqrt(1-u^2)cos(phi),
> where cos(theta) is sampled uniformly in the interval [-1,1] and phi in the
> interval [0,2Pi]. My idea for beam divergence was to sample theta, and
> since dOmega=sin(theta)*dtheta*dphi and dN/dOmega is gaussian, this gives
> that I need to sample theta from sin(theta)*gauss(FWHM). If I tabulate the
> values and then sample I get oscillations near theta=0. How is this
> (sampling with DIVBM) implemented in the fluka source code ?
>
> Thank you,
>
> Mitja
>
> __________________________________________________________________________
> You can manage unsubscription from this mailing list at
> https://www.fluka.org/fluka.php?id=acc_info
>
>
__________________________________________________________________________
You can manage unsubscription from this mailing list at
https://www.fluka.org/fluka.php?id=acc_info
Received on Fri Jan 06 2017 - 19:10:21 CET