133     if ( aMaterialPropertyTable ) {
 
  134        AttenuationLengthVector = aMaterialPropertyTable->
 
  135                                                 GetProperty(
"ABSLENGTH");
 
  136            if ( AttenuationLengthVector ){
 
  137              AttenuationLength = AttenuationLengthVector->
 
  138                                          Value(thePhotonMomentum);
 
  148         return AttenuationLength;