From: Giuseppe Battistoni (Giuseppe.Battistoni@mi.infn.it)
Date: Wed Dec 21 2005 - 09:22:51 CET
Hi Chris
the Eventv: ... messages are harmless. You get a lot in high energy
problems.
The Frmbrk is harmless as well.
The geometry error messages if frequent, are worrying.
Error -3 typically comes from mistaken assumptions, ie the code thinks
the particle is in region Y while it is in Z. Typically they point to
inaccuracies (rather than plain mistakes) in the geometry (ie not enough
digits for slanted bodies, big problems with the default precision setting
which is ok up to 100 m roughly etc, a user source where cosines are not
properly normalized). If they are rare (rare means one every 10^7-10^8
tracking) no problem. The tracking number is the Kloop variable.
Alfredo
On Tue, 20 Dec 2005, Chris Theis wrote:
> Dear Sirs,
>
> I'm currently performing FLUKA simulations where I start 7 TeV protons
> in a beam pipe for beam loss calculations. During the runs I encounter
> some interesting messages in the error file, which I do not understand
> and where you probably could shed some light on this. However, I have to
> mention that these messages do not crash the program I would very much
> like to understand them and their cause.
>
> During the whole run I receive quite an amount of messages like the
> following:
>
> Eventv: ekin+am < pla,ij,igreyt 5.53165567 5.54778857 14 1
> *** Kaon: P_min > 1.5 GeV/c: 15 1.52972114
>
> I recon the ekin+am is the sum of the kinetic energy and the rest mass
> but the rest of the message is rather unclear as I have no clue what
> pla, ij, igreyt and those numbers mean.
>
> Furthermore I get messages like the one below from the tracker:
>
> Geofar: Particle in region 95 (cell # 0) in position
> 9.493944493E-01 -8.027766844E+00 -3.509927151E+02
> is now causing trouble, requesting a step of 5.595938336E+00 cm
> to direction 2.293323168E-02 -1.062827117E-02 9.996805023E-01, error
> count: 0
> R2: 8.083711420E+00 R3: 3.510857907E+02 cm
> X*U (2D): 1.070939658E-01 X*U (3D): -3.507734798E+02 cm
> X*UOLD(2D): 1.070939658E-01 X*UOLD(3D): -3.507734798E+02 cm
> Kloop: 3653483, Irsave: 95, Irsav2: 202, error code: -3
> Nfrom: 21
> old direction 2.293323168E-02 -1.062827117E-02 9.996805023E-01,
> lagain, lstnew, lsense, lsnsct F T F F
> Particle index 14 total energy 4.066056530E+01 GeV Nsurf 0
> We succeeded in saving the particle: current region is n. 93 (cell
> # 0)
>
> Unfortunately I wasn't able to figure out what error code -3 really
> means and what could cause this problem. I debugged my geometry not only
> with FLUKA's grid debugger, but also with other means and found no
> problem like overlaps in that area.
>
> Finally there are also a couple of lines like this:
>
> *** Frmbrk: we are dealing with a bag of 8 388.916321
> identical nucleons, go on folks! ***
>
> Although that message seems to be quite encouraging I would be very
> interested what it actually means.
>
> Thank you very much for your assistance.
>
> Cheers
> Chris
>
> ------------------------------------------------------------------------
> --
> Chris Theis
> CERN/SC-RP - European Organization for Nuclear Research
> 1211 Geneva 23, Switzerland
> Phone: +41 22 767 8069 Office: 865-RC-030
> e-mail: Christian.Theis@cern.ch www: http://www.cern.ch/theis
> ------------------------------------------------------------------------
>
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