From: Santana, Mario <msantana_at_SLAC.Stanford.EDU>

Date: Sun, 16 Jan 2011 23:57:47 -0800

Date: Sun, 16 Jan 2011 23:57:47 -0800

I agree with Anna, don't use UBEAM.

just define the maximum radius (R) inside source.f or in one of the parameters

of the SOURCE card, and then sample the radius with R*SQRT(FLRNDM(dummy))

On Jan 16, 2011, at 11:26 PM, Hamideh Jalali wrote:

*> Hi
*

*>
*

*> Thanks for your reply. As I mentioned I want to define an uniform
*

*> beam which travels in a ring of aluminum in x-y plane.
*

*>
*

*> Mario,
*

*> I realized the necessity of using SQRT but what is 3D and 3D 2 that
*

*> you have added to the commands?
*

*>
*

*> Best Regards
*

*> Hamideh
*

*>
*

*> On 1/16/11, Santana, Mario<msantana_at_slac.stanford.edu> wrote:
*

*>> Hamideh,
*

*>>
*

*>> Actually, if you want uniform sampling in 2-D cylindrical coordinates
*

*>> you need to do the following:
*

*>>
*

*>> r = UBEAM * SQRT(FLRNDM(dummy))
*

*>>
*

*>> without the SQRT you would be giving more weight to the positions closer
*

*>> to the beam axis.
*

*>>
*

*>> Mario
*

*>>
*

*>>
*

*>> On Jan 16, 2011, at 1:28 AM, Hamideh Jalali wrote:
*

*>>
*

*>>> Dear FLUKA experts
*

*>>>
*

*>>> I'm going to define a circular beam in x-y plane ( a beam which
*

*>>> travels around a circle of radius r and center (0,0,0)). Is it correct
*

*>>> if I follow these steps:
*

*>>>
*

*>>> In BEAMPOS card:
*

*>>> WHAT(1)-WHAT(3):x,y,z coordinates of the center of the
*

*>>> circle(XBEAM-YBEAM-ZBEAM)
*

*>>> WHAT(4): radius of the circle (UBEAM)
*

*>>>
*

*>>> Then I modify source.f by adding these command:
*

*>>>
*

*>>> r = UBEAM * (FLRNDM(dummy)
*

*>>> alpha = 2 * PI* (FLRNDM(dummy))
*

*>>>
*

*>>>
*

*>>> XFLK (NPFLKA) =3D3D XBEAM + r * COS(alpha)
*

*>>> YFLK (NPFLKA) =3D3D YBEAM + r * SIN(alpha)
*

*>>> ZFLK (NPFLKA) =3D3D ZBEAM
*

*>>>
*

*>>> I would be grateful for your help.
*

*>>> Hamideh
*

*>>>
*

*>>
*

*>>
*

Received on Mon Jan 17 2011 - 16:49:39 CET

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