diff --git a/src/musrDetectorConstruction.cc b/src/musrDetectorConstruction.cc
index 309404a..c00f70a 100644
--- a/src/musrDetectorConstruction.cc
+++ b/src/musrDetectorConstruction.cc
@@ -1609,6 +1609,11 @@ void musrDetectorConstruction::DefineMaterials()
   SiO2->AddElement(O,  natoms=2);
   SiO2->AddElement(Si, natoms=1);
 
+  G4Material* Si3N4 = new G4Material("Si3N4", 3.2*CLHEP::g/CLHEP::cm3, ncomponents=2);
+  Si3N4->AddElement(Si, natoms=3);
+  Si3N4->AddElement(N,  natoms=4);
+  
+
   G4Material* Al2O3 = new G4Material("Al2O3", 3.985*CLHEP::g/CLHEP::cm3, ncomponents=2); // saphire
   Al2O3->AddElement (Al, natoms=2);
   Al2O3->AddElement (O,  natoms=3);
diff --git a/src/musrPhysicsList.cc b/src/musrPhysicsList.cc
index d5d71a3..7cb93aa 100644
--- a/src/musrPhysicsList.cc
+++ b/src/musrPhysicsList.cc
@@ -381,7 +381,8 @@ void musrPhysicsList::ConstructEM()
 	  else if (stringProcessName=="G4StepLimiter")                pManager->AddProcess(new G4StepLimiter,nr1,nr2,nr3);
 	  else if (stringProcessName=="G4UserSpecialCuts")            pManager->AddProcess(new G4UserSpecialCuts,nr1,nr2,nr3);
 //	  else if (stringProcessName=="G4DecayWithSpin")      pManager->AddProcess(new G4DecayWithSpin,nr1,nr2,nr3);
-          //  else if (stringProcessName=="G4hIonisation")        pManager->AddProcess(new G4hIonisation,nr1,nr2,nr3);
+          else if (stringProcessName=="G4hIonisation")        pManager->AddProcess(new G4hIonisation,nr1,nr2,nr3);
+          else if (stringProcessName=="G4hMultipleScattering")        pManager->AddProcess(new G4hMultipleScattering,nr1,nr2,nr3);
 	//  else if (stringProcessName=="G4hLowEnergyIonisation")      pManager->AddProcess(new G4hLowEnergyIonisation,nr1,nr2,nr3);
 	  else if (stringProcessName=="musrMuFormation")              pManager->AddProcess(new musrMuFormation,nr1,nr2,nr3);
 	  else if (stringProcessName=="musrMuEnergyLossLandau")       pManager->AddProcess(new musrMuEnergyLossLandau,nr1,nr2,nr3);