From: Alberto Fasso' (Alberto.Fasso@cern.ch)
Date: Thu Feb 20 2003 - 11:39:39 CET
Dear Zhen Wu,
I have several remarks to make to your input file:
1) Have you prepared a PEMF file for tungsten?
2) Your geometry is not correct. A cylinder of radius 1.0 cannot be fully
contained inside a sphere of radius 1.0. The parts of the cylinder which
are not inside the sphere are defined as belonging both to region 1 and
to region 3. This is not allowed: just make the sphere a little bigger (for
instance with radius 2.0)
3) Option STEPSIZE should generally be avoided, unless there is a magnetic
field. FLUKA is very good at optimizing the step length, and STEPSIZE
would spoil the optimization.
4) Option SCORE, the way you use it, is asking to score "stars"
( = nuclear interactions) produced by electrons, positrons and photons.
Electrons and positrons cannot produce any star; photons can, but only if you
add option PHOTONUC (and with a 10 MeV electron beam it is unlikely that you
get any, anyway). If you want dose, use SCORE with particle number 211 or
208.
5) You have requested option USRBDX to score the number of photons going from
region 2 (vacuum) to region 3 (tungsten). Of course you don't get any!
You should either reverse the request (photons going from region 3 to region
2), or ask for "two-way" scoring by setting WHAT(1) = 11.
Regards,
Alberto Fassò
On Thu, 20 Feb 2003, wuzhen wrote:
> Fluka user,
>
> I'm a beginner of fluka. The following input file is the first input file i
> wrote. I want to get the fluence distribute of photon in the distance of 1 cm
> when the 10Mev election beam hits the tungsten target. But it seems not any
> photon is created! Who can tell me where does the error occur? Any help will
> be appreciated deeply!
>
> Best wishes to you!
>
> Zhen Wu
> 02/20/2003
>
> TITLE
> Testing fluka: Beam of electron through tungstEn target
> DEFAULTS NEW-DEFA
> *---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----*
> BEAM -1.0E-2 0.0 0.0 0.0 0.0 1.0ELECTRON
> BEAMPOS 0.0 0.0 -1.0
> GEOBEGIN 0.0 COMBINAT
> outer sphere and tungsten target
> *---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----*
> RPP 1 -10.0 10.0 -10.0 10.0 -10.0 10.0
> SPH 2 0.0 0.0 0.0 1.0
> RCC 3 0.0 0.0 -0.06 0.0 0.0 0.12
> 1.0
> END
> *---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----*
> BL1 4 +1 -2
> VA2 7 +2 -3
> TU3 7 +3
> END
> GEOEND
> *---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----*
> MATERIAL 74.0 184.0 19.3 23.0 0.0 0.0TUNGSTEN
> *---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----*
> ASSIGNMA 1.0 1.0
> ASSIGNMA 2.0 2.0
> ASSIGNMA 23.0 3.0
> STEPSIZE 0.001 0.01 1.0 3.0
> SCORE 3.0 4.0 7.0
> *---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----*
> OUTLEVEL 1.0 7.0
> *---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----*
> USRBDX 1.0 7.0 48.0 2.0 3.0 1.0Photons
> USRBDX 1.0E-2 1.0E-5 10.0 &
> RANDOMIZ 1.0
> START 100.0 9999999.
> STOP
>
-- Alberto Fassò CERN-EP/AIP, CH-1211 Geneve 23 (Switzerland) Phone: (41 22) 767 2398 Fax: (41 22) 767 9480 Alberto.Fasso@cern.ch
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