Hi,
I have encountered a segmentation fault whilst using the G4hLowEnergyIonisation
with generic ions. I am declaring primary particles in the
PrimaryGeneratorAction class with;

G4ParticleDefinition* particle = particleTable->GetIon(Z,A,0);

Then I am using the G4hLowEnergyIonisation process for generic ions. At run time
there is a segmentation fault. Using gdb I traced this back to the
GetMeanFreePath method of G4hLowEnergyIonisation class. It turns out that the
pointer "theIonEffChargeModel" is not initialised (well it is initialised to
NULL in the constructor). This initialisation is carried out in the
InitializeParametrisation method. In turn this is called by the
BuildPhysicsTable method. In this method there is an if statement like so:


  if(aParticleType.GetParticleType() == "nucleus" &&
     aParticleType.GetParticleName() != "GenericIon" &&
     aParticleType.GetParticleSubType() == "generic")
  {

     G4EnergyLossTables::Register(&aParticleType,
              theDEDXpTable,
              theRangepTable,
              theInverseRangepTable,
              theLabTimepTable,
              theProperTimepTable,
              LowestKineticEnergy, HighestKineticEnergy,
              proton_mass_c2/aParticleType.GetPDGMass(),
              TotBin);

     return;
  }

  if( !CutsWhereModified() && theLossTable) return;

  InitializeParametrisation() ;

It seems ions declared with the GetIon method are not considered GenericIons
(eg. type:nucleus name:C12[0.0] subtype:generic) and in this case (after
registering energy loss tables) the BuildPhysicsTable method returns (see
above). This occurs however BEFORE the call to the InitializeParametrisation
method. Consequently InitializeParametrisation is not called, hence the
theIonEffChargeModel pointer is never initialized and a segmentation fault
occurs when the GetMeanFreePath is called. I did work around this by declaring
the primary particle as a proton in the PrimaryGeneratorAction class, then using
the UI commands /gun/ion ..etc to declare the generic ion. It is possible that i
have misunderstood something here but i thought I'd submit a bug report anyway
just to be sure ;)
Best Regards,
Iwan Cornelius