[VMC] Crash in g3track_

From: Laurent Aphecetche (aphecetc@in2p3.fr)
Date: Wed Jul 07 2004 - 19:01:08 MEST 

Hi (again ;-) )

I now have a sample VMC application (based for the moment on TGeant3, 
compiled with -DWITHROOT).
Geometry seems ok, but as soon as I try to throw particles (Geantinos) 
in there, I get a crash :

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread -1085118976 (LWP 29109)]
0x4017853d in g3track_ () at gtrak/gtrack.F:118
118                    CUTS(I) = Q(JTMN+I)
Current language:  auto; currently fortran
(gdb) print I
$1 = 1
(gdb) print JTMN
$2 = 16744448

As far as I understand, this is linked to the media/materials parameters.
So I assume my materials are ill-defined in some way.

Any hint on the possible cause ?

Thanks,

PS: Here's the way I define my materials/media (inspired from E01 ; I 
assume the negative parameters means Geant3 will compute them 
automatically, is that correct ?) :

   TGeoManager* gm = ...

   Double_t a2[2] = { 14.01, 16.00};
   Double_t z2[2] = {  7.0,   8.0};
   Double_t w2[2] = {  0.7,   0.3};
   Double_t density = 1.29e-03;
   int imatair = 15;

   gm->Mixture("Air", a2, z2, density, 2, w2, imatair);

   int isvol = 0; // not a sensitive volume
   Int_t ifield = 2;         // User defined magnetic field
   Double_t fieldm = 5.;     // Maximum field value (in kiloGauss)
   Double_t epsil  = .001;    // Tracking precision,
   Double_t stemax = -0.01;   // Maximum displacement for multiple scat
   Double_t tmaxfd = -20.;    // Maximum angle due to field deflection
   Double_t deemax = -.3;     // Maximum fractional energy loss, DLS
   Double_t stmin  = -.8;

   fImedAIRF = 19;
   fImedAIRLOWF = 18;

   // AIR, High Magnetic Field
   gm->Medium("AIRF",fImedAIRF,imatair,isvol,
	     ifield, fieldm, tmaxfd, stemax,
	     deemax, epsil, stmin);
				

   // AIR, Low Magnetic Field
   fieldm = 1.0;
   gm->Medium("AIRLOWF",fImedAIRLOWF,imatair,isvol,
	     ifield, fieldm, tmaxfd, stemax,
	     deemax, epsil, stmin);

-- 
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)
Collaboration PHENIX http://www.phenix.bnl.gov/~aphecetc

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