diff --git a/NPSimulation/Scorers/GaseousDetectorScorers.cc b/NPSimulation/Scorers/GaseousDetectorScorers.cc
index e57164f67bc9a56f13ea6421922818500ec03b0e..d47286f85e5bcc8a2f1a66735848f78b11167f7e 100644
--- a/NPSimulation/Scorers/GaseousDetectorScorers.cc
+++ b/NPSimulation/Scorers/GaseousDetectorScorers.cc
@@ -88,6 +88,8 @@ G4bool PS_GaseousDetector::ProcessHits(G4Step* aStep, G4TouchableHistory*) {
   cout << "t_ParticleName : " << particlename << endl;
   cout << "t_Energy       : " << t_Energy << endl;
   cout << "slice_posZ     : " << slice_posZ << endl; // it seems that step_size is not uniform
+  cout << "t_ParticleName.size()       = " << t_ParticleName.size() << endl;
+  cout << "t_SlicePosZ.size()          = " << t_SlicePosZ.size() << endl;
   cout << "t_EnergyLossPerSlice.size() = " << t_EnergyLossPerSlice.size() << endl;
   t_Level.clear();
   for (unsigned int i = 0; i < mysize; i++) {
@@ -122,6 +124,7 @@ void PS_GaseousDetector::EndOfEvent(G4HCofThisEvent*) {}
 void PS_GaseousDetector::clear() {
   m_Data.clear();
   t_Level.clear();
+  t_ParticleName.clear();
   //t_SliceNbr.clear();
   t_SlicePosZ.clear();
   t_EnergyLossPerSlice.clear();