RE: [fluka-discuss]: how to include the divergence in the source.f / photons

From: Ševčik Aleksandras <aleksandras.sevcik_at_ktu.edu>
Date: Tue, 23 Jul 2019 07:27:38 +0000

Dear Sougata Rakshit,

Wonderful, it works indeed!
But may I ask two more moments here:

1) I need to set up the certain values ( 0.2 ) for BEAMPOS WHAT(4) & (5) - direction cosine of the beam with respect to the x & y-axis. It does not take values from the card now when I use this modified routine. What additional line should be included for this?
2) also this code works for angular flat beam only, but not for rectangular flat beam - does the code differs much in such case?

If you or anybody else could find an opportunity to help with this, I will greatly appreciate such help,

Regards
Alex

-----Original Message-----
From: Sougata <sougata_at_barc.gov.in>
Sent: Tuesday, July 23, 2019 07:47
To: Ševčik Aleksandras <aleksandras.sevcik_at_ktu.edu>
Cc: fluka-discuss_at_fluka.org; owner-fluka-discuss_at_mi.infn.it
Subject: Re: [fluka-discuss]: how to include the divergence in the source.f / photons


Dear Alex,

Please note following if it can help you.

cos 200 mrad=0.98007
So we have to randomize direction cosine along beam axis from 0.98007 to 1 (i.e. cos (0 degree) to cos (200 mrad))

you can try following code as

* Cosines (tx,ty,tz)
         COSTH = ONEONE-(1-0.98007)*FLRNDM(TTT)
         IF(COSTH.GT.ONEONE) COSTH=ONEONE
         IF(COSTH.LT.-ONEONE) COSTH=-ONEONE
         PHI = TWOPIP*FLRNDM(SSS)
         UBEAM=SQRT(ONEONE-COSTH*COSTH)*COS(PHI)
         VBEAM=SQRT(ONEONE-COSTH*COSTH)*SIN(PHI)
         WBEAM=COSTH
       TXFLK (NPFLKA) = UBEAM
       TYFLK (NPFLKA) = VBEAM
* TZFLK (NPFLKA) = WBEAM
       TZFLK (NPFLKA) = SQRT ( ONEONE - TXFLK (NPFLKA)**2
     & - TYFLK (NPFLKA)**2 )

I think it will work.

Regards,

--
SOUGATA RAKSHIT / सौगत रक्षित
Scientific Officer(D) / वैज्ञानिक आधिकारीक(D) RSSD / आर एस एस डि Bhabha Atomic Research Centre / भाभा परमानु अनुसंधान केंद्र
Mumbai-400 085 / मुंबई-400 085
Tel: +91-022-2559 2214/ दूरभाष: +91-022-2559 2214
On 2019-07-23 00:21, Ševčik Aleksandras wrote:
> Dear experts,
> 
> I am using the attached source.f to sample the designed photon
> spectrum, however, I noticed that BEAM WHAT(3) does not respond to the
> values if source routine is activated - just as stated in the manual.
> 
> Is there any "simple" way to make my source beam with divergence 200
> mrad, or only additional piece of code must be included in the
> source.f?
> 
> Looking through old forum archives I found similar code for that
> purpose:
> 
>  Divbm_Sigma = Divbm*0.2
> 
>  CALL FLNRR2 (RGAUSSDIVX,RGAUSSDIVY)
> 
>  DIV_VECTORX = RGAUSSDIVX*Divbm_Sigma
> 
>  DIV_VECTORY = RGAUSSDIVY*Divbm_Sigma
> 
>  TXHLP = TAN( DIV_VECTORX )
> 
>  TYHLP = TAN( DIV_VECTORY )
> 
>  THELP = SQRT( TXHLP*TXHLP + TYHLP*TYHLP + ONEONE )
> 
>  TXFLK (NPFLKA) = TXHLP / THELP
> 
>  TYFLK (NPFLKA) = TYHLP / THELP
> 
>  TZFLK (NPFLKA) = SQRT ( ONEONE - LTXFLK (NPFLKA)**2 - TYFLK
> (NPFLKA)**2 )
> 
>  TXFLK (NPFLKA) = UBEAM
> 
>  TYFLK (NPFLKA) = VBEAM
> 
>  TZFLK (NPFLKA) = WBEAM
> 
>  TZFLK (NPFLKA) = SQRT ( ONEONE - TXFLK (NPFLKA)**2
> 
>  & - TYFLK (NPFLKA)**2 )
> 
> But simply applying it the code is not compiled, and my lack of
> experience with user routines is a big obstacle to move forward from
> this point. In addition, my BEAMPOS is defined with WHAT(1)-(WHAT(3)
> and also rotation value for WHAT(5) is used. Also the beam is directed
> to positive Z direction.
> 
> Could anyone share a similar working source.f file which would
> directly use BEAM WhHAT(3) value, or maybe guide me through this
> coding problem?
> 
> Both source.f routines - the original and the one I tried to modify -
> are attached.
> 
> Thank you very much,
> 
> Rgds
> 
> Alex
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Received on Tue Jul 23 2019 - 10:42:50 CEST