# RE: Defining a beam along X axis with a rectangular spread in in Y and Z

From: Angelo Infantino <angeloinfa_at_hotmail.com>
Date: Sat, 25 May 2013 13:21:27 +0200

I in my experience, when I create beam along X axis, I always use the BEAMAXES card.
I define the beam in the Z direction (positive) and after that I rotate the "beam system" respect to the "geometry system".

cosxx=0 cosxy=0 cosxz=-1
coszx=1 coszy=0 coszz=0

Ciao

Angelo

> Date: Fri, 24 May 2013 16:22:49 -0700
> From: nozarm_at_triumf.ca
> To: fluka-discuss_at_fluka.org
> Subject: Re: Defining a beam along X axis with a rectangular spread in in Y and Z
>
> Hello again,
>
> I think I figured out how to do this. Used:
>
> BEAM -.075 4.0 4.0 1.0ELECTRON
> BEAMAXES 0.0 1. 0.0 1. 0.0 0.0
> BEAMPOS -260. 76.0 2941.5
>
>
> Looks like by definition, beam is always along z axis. Since I want to
> put the beam along the 'Frame' or 'Geometry' x axis, I need to define
> the direction cosines between the beam coordinate system and the 'Frame'
> or 'Geometry' coordinate system.
>
> Am I right?
>
> For some reason, I had to 'swap' the axis in flair to get the right plan
> view distribution. Don't know why this is... I thought plotting Z vs
> X, using 'Z-X' as axes should have worked but that is not the case.
>
> Best wishes,
> Mina
>
> On 13-05-24 03:44 PM, Mina Nozar wrote:
> > Hello everyone,
> >
> > This is the first time I have had to define a beam that is not along
> > the z axis and am having trouble figuring out how to define it.
> >
> >
> > The beam is an electron beam at 75 MeV. It is along the x axis and is
> > square in shape (in y and z) after the raster magnet.
> > I tried:
> >
> > BEAM -.075 4.0 4.0 1.0ELECTRON
> > BEAMPOS -260. 76.0 2941.5 1.
> >
> > And looked at the beam distribution but the distribution does not look
> > right.
> >
> > Do I need to use the BEAMAXES card? If so, what should the parameters
> > to it be? Reading the description on BEAMAXES card, it is not clear
> > to me what the WHAT(s) should be. After setting these parameters, how
> > does the BEAM card know that the 4x4 cm is the shape of the beam in
> > the Y and Z directions?
> >
> >
> > Thanks a lot,
> > Mina
> >
> >
>
Received on Sat May 25 2013 - 14:51:12 CEST

This archive was generated by hypermail 2.3.0 : Sat May 25 2013 - 14:51:13 CEST