7import g4py.Qmaterials, g4py.Qgeom
 
    8import g4py.ExN01pl, g4py.ParticleGun
 
   14g4py.Qmaterials.Construct()
 
   18g4py.ExN01pl.Construct()
 
   21g4py.ParticleGun.Construct()
 
   24gRunManager.Initialize()
 
   34print "\n*** write to a GDML file..." 
   35navigator= gTransportationManager.GetNavigatorForTracking()
 
   36world_volume= navigator.GetWorldVolume()
 
   39gdml_parser.Write(
"qgeom_out.gdml", world_volume)