Alpha particle with GEANT4 and GARFIELD

Garfield++
1

Hello,
I would like to simulate ionization induced by an alpha particle of about 1 MeV in a gas volume and the avalanche of the ionization electrons. I see two options:

  1. Generate alpha track with Heeds, and then AvalacheMicroscopic, but it seems Heeds does not support alpha
  2. Combine GEANT4 and GARFIELD. I started from the example in
    Garfield/Examples/Geant4GarfieldInterface, but I have the following runtime error:
    -------- EEEE ------- G4Exception-START -------- EEEE -------
    *** G4Exception : Analysis_F001
    issued by : G4GenericAnalysisManager::OpenFileImpl
    Cannot open file “Garfield”.
    Please, use a file name with an extension or define the default file type
    via G4AnalysisManager::SetDefaultFileType()
    *** Fatal Exception *** core dump ***
    **** Track information is not available at this moment
    **** Step information is not available at this moment

-------- EEEE -------- G4Exception-END --------- EEEE -------

Any suggestion on which is the best way to go, and what’s the reason of the runtime error?
Thanks and best regards
Anna

2

Dear @acorsi ,

From a very rough looking at what you report, I see

Cannot open file “Garfield”.

So maybe there’s some file missing for the tutorial to work? Other than that, maybe @hschindl can help you better.

Cheers,
Vincenzo

3

Hi,
the runtime error should be have been fixed by this merge request (from yesterday):

Can you do a git pull and try again?

Heed is indeed not suitable for alphas. You could try the SRIM/TRIM interface:
https://garfieldpp.web.cern.ch/garfieldpp/examples/srim/

or indeed adapt the G4/Garfield++ example…

4

Indeed the runtime error disappeared, thanks! Now I can run up to the filling of the Garfield.root file. But just after I see a segfault, and the tree in garfield.root is empty.
Anna

### CAUGHT SIGNAL: 11 ### address: 0x0,  signal =  SIGSEGV, value =   11, description = segmentation violation. Unknown segmentation fault error: 0.

Backtrace:
[PID=90446, TID=-1][0/5]> 0   libdyld.dylib                       0x00007fff73260692 dyld_stub_binder + 282
[PID=90446, TID=-1][1/5]> 1   libG4analysis.dylib                 0x00000001098cb4d0 _ZN22G4ThreadLocalSingletonI24G4GenericAnalysisManagerED2Ev + 32
[PID=90446, TID=-1][2/5]> 2   libsystem_c.dylib                   0x00007fff7330b13c __cxa_finalize_ranges + 319
[PID=90446, TID=-1][3/5]> 3   libsystem_c.dylib                   0x00007fff7330b412 exit + 55
[PID=90446, TID=-1][4/5]> 4   libdyld.dylib                       0x00007fff73261cd0 start + 8
5

Hmm… no idea… Is this the G4/Garfield example out-of-the-box or did you make some changes?

6

Yes, out of the box…
For the precision, the tree is empty but the histogram are filled in the output root file.
Anna

7

Sorry for the delay in getting back to you. On which platform are you running?

8

Hello, it is MacOS Catalina.
Anna

9

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