Re: FLUKA: Access to models ?
Hi all
as I already pointed out the ...RES variables are not always correct.
Their correct filling depends on
a) the input options, particularly those dealing with the level of
heavy transport
b) the physics processes occurred (fission and fragmentation lead to
meaningless ...RES variables, the fragments must be recovered somewhere
else).
For what concern energy/momentum and additive quantum number conservation,
there is NO NEED at all to check it. The code does it at each event and
prints warning messages if it is not fulfilled at the level of machine
accuracy. A check by the user can be misleading because there is a (mostly
historical) split between the "fast" part of the cascade, which conserve
energy based on NUCLEAR MASSES, and the evaporation part, which uses
ATOMIC MASSES. There subtle and somewhat questionable physics reasons for
this, however for doing a proper check one should take care of this
change which the code does correctly at the right point. However it is
impossible to do it correctly AFTER the interaction occurred unles one
knows which particles are coming from the fast rather than from the
evaporation stage. The differences are anyway small but can fake
the 1e-15 level of conservation.
Ciao
Alfredo
On Fri, 6 Apr 2001, Stefan Roesler wrote:
> Hi Laurent,
>
> Please find attached the mgdraw which I used to compute the damage to the
> NLC positron production target. It dumps recoil momenta of residual
> nuclei, heavy fragments and low-energy neutrons. I carefully compute the
> energy balance to make sure that PXRES,PYRES,PZRES,ERES,IBRES,ICRES,AMMRES
> are consistent with the present event.
>
> Please let me know if you find mistakes in this routine as compared to the
> one Alfredo is going to send you.
>
> Stefan
>
> ___________________________________
>
> Stefan Roesler
> SLAC
> P.O. Box 4349, MS 48
> Stanford, CA 94309
>
> Tel: 650-926-2048
> Fax: 650-926-3569
> E-mail: sroesler@slac.stanford.edu
> Stefan.Roesler@cern.ch
>
> On Fri, 6 Apr 2001, Laurent APHECETCHE wrote:
>
> > Alfredo Ferrari wrote:
> > >
> > > Hi all
> > >
> > > the excitation energy CANNOT be accessed at mgdraw level. TVCMS if
> > > everything is going correctly should come out =0 (no residual excitation
> > > energy). The excitation energy after PEANUT cannot be accessed and it
> > > would not be physically meaningful, since it depends a lot on the
> > > termination conditions and thresholds of the preequilibrium part (where
> > > the code assumes equilibrium is reached). The excitation energy after
>the
> > > cascade part which perhaps was the one Laurent was referring to, is also
> > > of course strongly dependent on the boundary between cascade and
> > > prequilibrium and does not bear any real physics meaning.
> > >
> > > Also Ekres,Px,y,zres are not necessarily updated correctly: their status
> > > depends on the physics input cards set by the user and if
>fission/fragmentation
> > > occurred etc. DON'T rely on any of these variables.
> > >
> > > Ciao
> > > Alfredo
> >
> > Hi Alfredo,
> >
> > Thanks for the reply, even if it seems discouraging...
> > What I would like to have is the distribution of nuclei recoil momenta,
> > in order to be able to compute damage energies. Is there a way to do
> > that, e.g. some combination of input cards insuring that Ekres,Px,y,zres
> > _are_ meaningful, or is it hopeless ?
> >
> > Best regards,
> >
> > --
> > Dr. Laurent APHECETCHE (mailto:aphecetc@in2p3.fr) (IN2P3-CNRS)
> > SUBATECH-EMN-4 rue Alfred Kastler-BP 20722-44307 NANTES cedex 03
> > TEL (+33/0) 2 51 85 84 17 - FAX (+33/0) 2 51 85 84 24 (France)
> > Collaborations PHENIX http://www.phenix.bnl.gov/~aphecetc et MEGAPIE.
> >
>
--
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