RE: How to calculate the emittance of beam using FLUKA

From: Markus Brugger <Markus.Brugger@cern.ch>
Date: Wed May 21 2008 - 10:18:12 CEST

Hi Yanjie,

sorry, I first misunderstood and thought you're only interested in the
particles and their energy (didn't see the 'emmitance'), thus yes USRBDX
and USRTRACK can't be used directly (see 2nd option below).

What you can use is 'USRDUMP' - this will produce what the FLUKA manual
calls a collision tape and chapter 11 describes in more detail which
information is contained. However, it might be that you want to modify
the existing code in MGDRAW.f selecting the quantities to be recorded.
This is the routine which is called when a USRDUMP card is present in
the input. Chapter 11 gives a detailed description of the available
variables and examples on how to dump the information. In addition there
is also an example on the web-course that can be found on the FLUKA
web-page. This way you can implement to dump only those particles that
are interesting for you.

Alternatively, you could use the user routine fluscw.f together with a
boundary crossing estimator (USRBDX). The routine is then called each
time a particle crosses that boundary (check flag ISCRNG = 1 inside
fluscw),
with all properties of that particle (coordinates, direction cosines,
weight, id) being passed on to fluscw as argument list.

hope that helps, cheers

Markus

> -----Original Message-----
> From: owner-fluka-discuss@mi.infn.it [mailto:owner-fluka-
> discuss@mi.infn.it] On Behalf Of Yuanjie BI
> Sent: 16 May 2008 04:04
> To: Markus Brugger; fluka-discuss@fluka.org
> Subject: RE: How to calculate the emittance of beam using FLUKA
>=20
> Hi,
>=20
> Thanks very much for the answer of Markus, but I still have trouble
> in estimate
> the emmitance of the beam.
> Generally, the incident beam is irregular. Assuming the direction of
> motion is z,
> I need the emmitance in x direction, so I need x coordinate and p_x
> distribution,
> that means for a given x, the p_x should be given, it seems that
> USRBDX or
> USRYIELD can't do this.
>=20
> Thank you very much!
>=20
>=20
> >> -----Original Message-----
> >From: Markus Brugger <Markus.Brugger@cern.ch>
> >Reply-To:
> >To: Yuanjie BI <biyuanjie@tsinghua.org.cn>, <fluka-
> discuss@fluka.org>
> >Subject: RE: How to calculate the emittance of beam using FLUKA
> >Date:Thu, 15 May 2008 14:34:06 +0200
> >
> >Hi,
> >
> >depending on what you would like to score in detail (particle energy
> =3D
> >spectra or other multi-differential yields, e.g., angular, etc..)
> you =3D
> >can use one of the following detectors:
> >
> >USRBDX
> > scoring average d2=3DD6/dEd=3DD9 (double-differential fluenceor
> current) =3D
> >of a given type or family of particles on a given surface (defined
> by =3D
> >the two 'touching' regions)
> >
> >USRYIELD
> > scoring double differential yield of particles escaping from a =3D
> >surface. The distribution can be with respect to energy and angle,
> but =3D
> >also other more "exotic" quantities=3D20
> >
> >-> see the manual for more details on each of the two cards
> >
> >hope this helps, cheers
> >
> >Markus
> >
> >> -----Original Message-----
> >> From: owner-fluka-discuss@mi.infn.it [mailto:owner-fluka-
> >> discuss@mi.infn.it] On Behalf Of Yuanjie BI
> >> Sent: Donnerstag, 15. Mai 2008 04:16
> >> To: fluka-discuss@fluka.org
> >> Subject: How to calculate the emittance of beam using FLUKA
> >>=3D20
> >> Dear fluka users,
> >>=3D20
> >> I want to calculate the change of emittance when proton beam
> passes
> >> through a thin
> >> foil. I can give the initial distribution of the beam using
> source.f,
> >> but I don't
> >> know which detector I can use to calculate the emittance after the
> >> foil. I hope
> >> someone can help me.
> >>=3D20
> >> Thank you very much!
> >> Best wishes
> >> BI Yuanjie
> >>=3D20
> >
> >
>=20
Received on Wed May 21 10:28:57 2008

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