Confused by output of AuNP example

[afish58]

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Geant4 Version: 11.2.1

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Hi all, Happy New Year!

Perhaps a silly question but I was playing around with the extended/medical/dna/AuNP example and was a bit confused by one of the outputs. One of the plots produced is the location of secondary particles created outside of the nanoparticle (r=50nm). However this histogram has bins down to r=36nm, which I don’t believe should be shown.

I believe it’s filled in TrackingAction so I added this print statement:

 if(RNP<R && track->GetTrackID() != 1 ){
  // my check -------------------------------------------
  if ((RNP<50)||(R<50)){
    G4cout<<"Position: "<<R<<'\n'<<"RNP: "<<RNP<<G4endl;
  }
  // ----------------------------------------------------
  
  if(track->GetDefinition()->GetPDGCharge() != 0){
     analysisManager->FillH1(6,R);  //<-- this line
     analysisManager->FillH2(1,R,trackE);
   }else {
     analysisManager->FillH1(7,R); //<-- and this line
     analysisManager->FillH2(2,R,trackE);
   }

 }

and nothing prints. I’ve checked in the root TBrowser and its the bins <50nm are filled before running the plot.C macro so I assume that means it’s being filled during the simulation, but a debug print statement shows it shouldn’t be. From my understanding, these bins shouldn’t be filled, I’m curious if I’m misinterpreting something.

My question is a bit broad, but what is causing this to be filled? If anyone has any input it would be appreciated, thank you in advance!

[ngoc]

let’s ping the example author @dsakata

[dsakata]

Sorry for the delay.

The 1D histogram was defended with the range from 10nm to Rmax (1000 um in the default macro) of the water absorber.

However, in the plot.C, fixed range has beed applied for the histogram definition.

The most practical approach could be changing the maximum range of the histogram in plot.C

Before:
TH1D *h1sec_tot = new TH1D(“h1Sec_tot”,“h1Sec_tot”,NR,1,5);

Correction:
TH1D *h1sec_tot = new TH1D(“h1Sec_tot”,“h1Sec_tot”,NR,1,6); // upto1000 um

We may changed the vmaxR_log value (Rmax) in the HistManager.cc to fixed value, in the next Geant4 release.

[afish58]

That fixed it! And fixing vmaxR_log to 1e6 in the HistoManager.cc fixed the same issue on the energy deposition distribution histogram.

Thank you!