diff --git a/doc/musrSimAna.pdf b/doc/musrSimAna.pdf
index ca7e615..b38f357 100644
Binary files a/doc/musrSimAna.pdf and b/doc/musrSimAna.pdf differ
diff --git a/doc/musrSimAna.tex b/doc/musrSimAna.tex
index aaa4189..b6ca25b 100644
--- a/doc/musrSimAna.tex
+++ b/doc/musrSimAna.tex
@@ -435,6 +435,11 @@ All events should/have to be (?) saved in the Root tree
      This defines a group of detectors, where \emph{group} stands for ``B'' (backward), 
      ``F'' (forward), ``U'' (up), ``D'' (down), ``L'' (left) and ``R'' (right) detectors.
      This grouping is used in the definition of some conditions.
+   \item{\bf sampleID \emph{ID$_1$ ID$_2$ \ldots ID$_n$} } \\
+     Defines which volume (or volumes, if there are more) is the sample.  Typically, the
+     sample is just one volume, but sometimes there is a smaller volume inside of the sample,
+     to which a field is applied, so the small volume also has to be considered as the sample.
+     This information is needed for the condition ``muonDecayedInSample\_gen''.
    \item{\bf  setSpecialAnticoincidenceTimeWindow  \emph{detectorID}  \emph{timeMin}  \emph{timeMax} \emph{unit}} \\
      This command sets a special anti-coincidence time window for a detector \emph{detectorID}.
      Normally, the anti-coincidence time window is defined by {\tt VCOINCIDENCEW}, and is the same for all anti-coincidence
diff --git a/musrSimAna/musrAnalysis.cxx b/musrSimAna/musrAnalysis.cxx
index 42f7e15..4d25034 100644
--- a/musrSimAna/musrAnalysis.cxx
+++ b/musrSimAna/musrAnalysis.cxx
@@ -474,6 +474,23 @@ void musrAnalysis::ReadInInputParameters(char* charV1190FileName) {
 	  nscan = sscanf(pch,"%d",&N1);
 	} while (nscan==1);
       }
+      else if (strcmp(tmpString0,"sampleID")==0) {
+	int nscan; int N1; char NAME[100];
+	char *pch = line + strlen("sampleID");
+	do {
+	  nscan = sscanf(pch,"%d",&N1);
+	  SampleDetIDList.push_back(N1);
+	  nscan = sscanf(pch,"%s",NAME);
+	  char* pch2 = strstr(pch ,NAME)+strlen(NAME);
+	  pch=pch2;
+	  nscan = sscanf(pch,"%d",&N1);
+	} while (nscan==1);
+	std::cout<<"SampleID :";
+	for (std::list <Int_t>::const_iterator it=SampleDetIDList.begin(); it!=SampleDetIDList.end(); ++it) {
+	  std::cout<<" "<< *it;
+	}
+	std::cout<<std::endl;
+      }
       else if  (strcmp(tmpString0,"setSpecialAnticoincidenceTimeWindow")==0) {
 	int channelNumber;
 	double min, max;
@@ -823,10 +840,12 @@ void musrAnalysis::SaveHistograms(char* runChar, char* v1190FileName) {
 
   Long64_t numberOfMuonCandidates = mCounter->GetNumberOfMuonCandidates();
   Long64_t numberOfMuonCandidatesAfterVK = mCounter->GetNumberOfMuonCandidatesAfterVK();
+  Long64_t numberOfMuonCandidatesAfterVKandDoubleHitRemoval = mCounter->GetNumberOfMuonCandidatesAfterVKandDoubleHitRemoval();
   Double_t durationOfExperiment = (numberOfRewinds*rewindTimeBins*tdcresolution+currentTime)/1000000;
   hInfo->Fill(5,(Double_t) numberOfMuonCandidates);  // number of "triggers"
   hInfo->Fill(4,(Double_t) numberOfMuonCandidatesAfterVK);  // number of "triggers"
   hInfo->Fill(3,durationOfExperiment);
+  hInfo->Fill(8,(Double_t) numberOfMuonCandidatesAfterVKandDoubleHitRemoval);
   //==============================
   //  Write out the histograms
   std::cout<<"musrAnalysis::SaveHistograms()"<<std::endl;
@@ -1086,7 +1105,9 @@ void musrAnalysis::FillHistograms(Int_t iiiEntry) {
     
     // CALCULATE CONDITIONS
     alwaysTrue = true;
-    muonDecayedInSample_gen = muDecayDetID==201;
+    // Find whether the muon decayed in the sample;  the sample may consist of more than just one volume.  The ID
+    // of the sample volume (or volumes) is defined in the *.v1190 file after the keyword "sampleID":
+    muonDecayedInSample_gen = (find(SampleDetIDList.begin(), SampleDetIDList.end(), muDecayDetID)) != SampleDetIDList.end() ;
     muonTriggered_gen = muM0Time > -1000;
     muonTriggered_det = mCounterHitExistsForThisEventID;
     positronHit_det   = pCounterHitExistsForThisEventID;
diff --git a/musrSimAna/musrAnalysis.hh b/musrSimAna/musrAnalysis.hh
index b9cb4b2..fa3f6c5 100644
--- a/musrSimAna/musrAnalysis.hh
+++ b/musrSimAna/musrAnalysis.hh
@@ -409,6 +409,7 @@ private:
   std::list <Int_t> D_posCounterList;
   std::list <Int_t> L_posCounterList;
   std::list <Int_t> R_posCounterList;
+  std::list <Int_t> SampleDetIDList;
   //  std::list <Int_t>::iterator posCounterList_Iterator;
 };
 
diff --git a/musrSimAna/musrCounter.cxx b/musrSimAna/musrCounter.cxx
index 5013150..401abfc 100644
--- a/musrSimAna/musrCounter.cxx
+++ b/musrSimAna/musrCounter.cxx
@@ -32,6 +32,7 @@ musrCounter::musrCounter(int CHANNEL_NR, char CHANNEL_NAME[200], char CHANNEL_TY
   doubleHitN=0;
   numberOfMuonCandidates=0;
   numberOfMuonCandidatesAfterVK=0;
+  numberOfMuonCandidatesAfterVKandDoubleHitRemoval=0;
 }
 
 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
@@ -194,6 +195,8 @@ Bool_t musrCounter::GetNextGoodMuon(Int_t evtID, Long64_t timeBinMin, Long64_t&
       goto endOfThisHit;   
     }
 
+    numberOfMuonCandidatesAfterVKandDoubleHitRemoval++;
+  
     kEntry   = (it->second)->eventEntry;
     idet     = (it->second)->det_i;
     idetID   = (it->second)->det_id;
diff --git a/musrSimAna/musrCounter.hh b/musrSimAna/musrCounter.hh
index 058622f..b30f894 100644
--- a/musrSimAna/musrCounter.hh
+++ b/musrSimAna/musrCounter.hh
@@ -64,7 +64,7 @@ class musrCounter {
     void myPrintThisCounter(Int_t evtID,  Int_t detail=2);
     Long64_t GetNumberOfMuonCandidates(){return numberOfMuonCandidates;}
     Long64_t GetNumberOfMuonCandidatesAfterVK(){return numberOfMuonCandidatesAfterVK;}
-
+    Long64_t GetNumberOfMuonCandidatesAfterVKandDoubleHitRemoval(){return numberOfMuonCandidatesAfterVKandDoubleHitRemoval;}
 
   private:
   //    static musrCounter* pointerToAnalysis;
@@ -91,6 +91,7 @@ class musrCounter {
   Int_t doubleHitN;
   Long64_t numberOfMuonCandidates;
   Long64_t numberOfMuonCandidatesAfterVK;
+  Long64_t numberOfMuonCandidatesAfterVKandDoubleHitRemoval;
 };
 
 #endif
diff --git a/src/musrScintSD.cc b/src/musrScintSD.cc
index 63c8ccb..6ba7a38 100644
--- a/src/musrScintSD.cc
+++ b/src/musrScintSD.cc
@@ -269,18 +269,25 @@ void musrScintSD::ProcessOpticalPhoton(G4Step* aStep) {
     // whether a given cell already fired - if so, do not store the photon.
     G4bool APDcellAlreadyFired = false;
     G4int APDcellID = 0;
+    if (APDcellsTimeVariationRequested)  tmpTime += G4RandGauss::shoot(0,APDcellsTimeVariationSigma);
+
     if (APDcellsEffectRequested) {
       APDcellID = FindAPDcellID(aStep);
       //      G4cout<<"Cell ID="<<APDcellID<<G4endl;
-      for (optHitDetectorMapType::const_iterator it2 = optHitDetectorMap->begin(); it2 != optHitDetectorMap->end(); it2++ ) {
+      for (optHitDetectorMapType::iterator it2 = optHitDetectorMap->begin(); it2 != optHitDetectorMap->end(); it2++ ) {
 	if ((it2->second)==APDcellID) {
+	  //  G4cout<<"Already fired cell ="<<APDcellID<<G4endl;
 	  APDcellAlreadyFired = true;
-	  //	  G4cout<<"HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH already fired cell ="<<APDcellID<<G4endl;
+	  //  Now lets check whether the new photon came earlier than the already saved one.
+	  //  If so, delete the previous photon and store the time of the new one instead:
+	  if (tmpTime<(it2->first)) {
+	    optHitDetectorMap->erase(it2);
+	    optHitDetectorMap->insert(std::pair<G4double,G4int>(tmpTime,APDcellID));
+	  }
 	  break;
 	}
       }
     }
-    if (APDcellsTimeVariationRequested)  tmpTime += G4RandGauss::shoot(0,APDcellsTimeVariationSigma);
     if (!APDcellAlreadyFired) optHitDetectorMap->insert(std::pair<G4double,G4int>(tmpTime,APDcellID));
     //    G4cout<<"  tmpTime="<<tmpTime<<G4endl;
       //      G4cout<<"   Detection"<<G4endl;