From: wuzhen (wu_zhen01@mails.tsinghua.edu.cn)
Date: Thu Jun 12 2003 - 06:25:51 CEST
Dear fluka user,
As you know, there are two aspects in the induced radioactivity of the electron linear accelerators. One is direct process: photonulear reactions, such as (gamma,n),(gamma,p),(gamma,2n). The other process is indirect and consists in a neutron capture reaction after release of a neutron by a photoneutron reaction. The way in the Email of Victor Dushin seems for the second process. But i think the first process is more important. Using the RESNUCLE card, I think I can get the induced radioactivity originated from the two process. I think in case there is a neutron being produced in the photoneutron reaction, there should be a induced nucleus being produced. But in my case the neutron fluence can be got, but the number of induced nuclei is always zero. I want to know the reason. Whether is the number of the particle in my input file not enough, or are there some errors in the settings of my input file?
Thanks a lot
Zhen Wu,
Jun 12, 2003
TITLE
Electron beam hit tungsten target
DEFAULTS NEW-DEFA
*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----*
BEAM -15.0E-3 0.0 0.0 0.0 0.0 1.0ELECTRON
BEAMPOS 0.0 0.0 -1.0
*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----*
GEOBEGIN 0.0 COMBINAT
tungsten target/vacuum sphere/Blackhole Box
RPP 1 -10.0 10.0 -10.0 10.0 0.0 0.5
SPH 2 0.0 0.0 0.0 15.0
SPH 3 0.0 0.0 0.0 16.0
END
*-reg-----or-----or-----or-----or-----or-----or-----or-----or-----or-----
BL1 5 +3 -2
VA2 5 +2 -1
TU3 5 +1
END
*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----*
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
*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----*
PHOTONUC 1111. 23.0
*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----*
OUTLEVEL 1.0 7.0
*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----*
PHYSICS 2.0 EVAPORATION
*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----*
RESNUCLE 3.0 48.0 74.0 45.0 3.0 1.0TUNGSTEN
USRBDX 1.0 8.0 49.0 2.0 1.0 1.0Neutrons
USRBDX 2.0E-2 0.0 100.0 &
*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----*
RANDOMIZ 1.0
START 1.0E+5 9999999.
STOP
> ----- Original Message -----
> From: "VICTOR DUSHIN" <victor@atom.nw.ru>
> To: "wuzhen" <wu_zhen01@mails.tsinghua.edu.cn>
> Sent: Wednesday, June 11, 2003 4:46 PM
> Subject: Re: About Induced Radioactivity in electron linear accelerator
>
>
> > Dear Zhen Wu,
> > Please, take into account that you can get about
> > 1.E-5 neutrons per electron,
> > so, it's necessary about 10 -100 E+6 history for this task.
> > Two steps are more reasonable.
> > The first - to evaluate neutron flux, and second to calculate
> > nuclide productions (using any code).
> > Best wishes Victor Dushin
> >
> > * Dear fluka user,
> > * Recently, I'm researching the induced radioactivity in the electron linear accelerators which energy is about 10~20MeV.
> > * I want to use FLUKA to do some caculation about induced radioactivity. I have found some results caculated by FLUKA from some paper got from Internet. But I found these results are in very high energy(several hundred MeV or GeV). And It seems I can't get the accurate result in my example. My
> > result using the RESNUCLE is always zero. Would you mind provide some examples or some papers in this aspect? By the way, can you help me check my input file? Thanks a lot!
> > *
> > *
> > * Zhen Wu,
> > * Jun 10, 2003
> > *
> > * TITLE
> > * Electron beam hit tungsten target
> > * DEFAULTS NEW-DEFA
> > * *---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----*
> > * BEAM -15.0E-3 0.0 0.0 0.0 0.0 1.0ELECTRON
> > * BEAMPOS 0.0 0.0 -1.0
> > * *---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----*
> > * GEOBEGIN 0.0 COMBINAT
> > * tungsten target/vacuum sphere/Blackhole Box
> > * RPP 1 -10.0 10.0 -10.0 10.0 0.0 0.5
> > * SPH 2 0.0 0.0 0.0 15.0
> > * SPH 3 0.0 0.0 0.0 16.0
> > * END
> > * *-reg-----or-----or-----or-----or-----or-----or-----or-----or-----or-----
> > * BL1 5 +3 -2
> > * VA2 5 +2 -1
> > * TU3 5 +1
> > * END
> > * *---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----*
> > * 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
> > * *---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----*
> > * PHOTONUC 1111. 23.0
> > * *---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----*
> > * OUTLEVEL 1.0 7.0
> > * *---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----*
> > * PHYSICS 2.0 EVAPORATION
> > * *---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----*
> > * RESNUCLE 3.0 48.0 74.0 45.0 3.0 1.0TUNGSTEN
> > * USRBDX 1.0 8.0 49.0 2.0 1.0 1.0Neutrons
> > * USRBDX 2.0E-2 0.0 100.0 &
> > * *---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----*
> > * RANDOMIZ 1.0
> > * START 1.0E+5 9999999.
> > * STOP
> >
> > Best regards
> > Victor Dushin
> >
>
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