Hi Filimon,
The border surface is the surface between two touching volumes
and skin surface is a the surface of one volume which is entirely by
this surface. You can find more detailed explanation in Geant4 user
application guide:
http://geant4.web.cern.ch/geant4/UserDocumentation/UsersGuides/ForApplicationDeveloper/html/ch05s02.html#sect.PhysProc.Photo
--> see Boundary process
Regards,
Ivana
Filimon Roukoutakis wrote:
> Hi Ivana, thanks the output is indeed scintillation in my setup! All
> problems solved, just need to figure out the surface parameters for my
> fiber core and its enclosure in order to guide scintillation photons
> inside the fiber! Regarding this I have a probably newbie question. What
> is the difference between TVirtualMC::SetBorderSurface and
> TVirtualMC::SetSkinSurface? I assume that in any case I have to
> DefineOpSurface all my surfaces, correct? Regards,
> filimon
>
> On 09/22/2010 12:56 PM, Ivana Hrivnacova wrote:
>> Hi Filimon,
>>
>> I think, your previous problem was due to an incorrect build,
>> as the break happens at a place where we have never seen a problem
>> before.
>>
>> To see whether a photon comes from Cerenkov or scintillation, you can
>> access its creator process code (see TMCProcess.h), which is saved for
>> each particle in the stack as TParticle unique ID (this saving is done
>> in Ex03MCStack::PushTrack).
>> In the example E06, you can do following:
>> #include <TParticle.h>
>> #include <TMCProcess.h>
>> //_____________________________________________________________________________
>>
>> void Ex06MCApplication::PreTrack()
>> {
>> /// User actions at beginning of each track
>>
>> fVerbose.PreTrack();
>>
>> if (gMC->TrackPid() == 50000050 ) {
>> fGammaCounter++;
>> Int_t mech = gMC->GetStack()->GetCurrentTrack()->GetUniqueID();
>> cout << "Creator process: " << TMCProcessName[mech] << endl;
>> }
>> }
>>
>> If you then disable Cerenkov in g4config.in, you should see only
>> Creator process: Scintillation
>> Creator process: Scintillation
>> ...
>>
>> Best regards,
>>
>> Ivana
>>
>> Filimon Roukoutakis wrote:
>>> Hi Ivana,
>>> after reporting to you the versions (privately) I decided to update
>>> my geant4_vmc to r520. I do not know whether the problem could be
>>> related to the old version or to a mis-built (mixed root versions
>>> from previous build) of the vmc lib. In any case the problem now
>>> seems to have disappeared. I get the following for example. Question:
>>> Is Cerenkov really Cerenkov-produced or could it be scintillation
>>> photos? Is there going to be a difference in the label? I see some
>>> optical photons in the verbose output but do not know whether they
>>> come from scintillation or Cerenkov. I have also disabled Cerenkov in
>>> my g4config.in file but still get them. Thanks,
>>> filimon
>>>
>>> *********************************************************************************************************
>>>
>>> * G4Track Information: Particle = opticalphoton, Track ID = 4,
>>> Parent ID = 1
>>> *********************************************************************************************************
>>>
>>>
>>> Step# X(mm) Y(mm) Z(mm) KinE(MeV) dE(MeV) StepLeng
>>> TrackLeng NextVolume ProcName
>>> 0 -1.980e+02 9.062e-02 8.056e-04 3.140e-06 0.000e+00 0.000e+00
>>> 0.000e+00 Fibe initStep
>>> 1 -1.981e+02 6.756e-04 -2.530e-02 3.140e-06 0.000e+00 1.295e-01
>>> 1.295e-01 Cell Transportation
>>>
>>> *********************************************************************************************************
>>>
>>> * G4Track Information: Particle = e-, Track ID = 3, Parent ID = 1
>>> *********************************************************************************************************
>>>
>>>
>>> Step# X(mm) Y(mm) Z(mm) KinE(MeV) dE(MeV) StepLeng
>>> TrackLeng NextVolume ProcName
>>> 0 -2.029e+02 1.883e-02 1.015e-02 6.250e-01 0.000e+00 0.000e+00
>>> 0.000e+00 Shie initStep
>>> 1 -2.027e+02 -3.523e-01 -3.991e-01 5.192e-01 1.059e-01 6.266e-01
>>> 6.266e-01 Shie msc
>>> 2 -2.024e+02 -4.455e-01 -6.059e-01 4.583e-01 6.081e-02 3.948e-01
>>> 1.021e+00 Shie msc
>>> 3 -2.022e+02 -6.466e-01 -5.628e-01 3.895e-01 6.884e-02 3.065e-01
>>> 1.328e+00 Shie msc
>>> 4 -2.020e+02 -7.650e-01 -5.473e-01 3.518e-01 3.766e-02 2.420e-01
>>> 1.570e+00 Shie msc
>>> 5 -2.019e+02 -8.432e-01 -4.498e-01 2.978e-01 5.403e-02 2.046e-01
>>> 1.775e+00 Shie msc
>>> 6 -2.018e+02 -8.205e-01 -3.497e-01 2.325e-01 6.533e-02 1.617e-01
>>> 1.936e+00 Shie msc
>>> 7 -2.017e+02 -7.609e-01 -2.431e-01 1.769e-01 5.554e-02 1.434e-01
>>> 2.080e+00 Shie msc
>>> 8 -2.017e+02 -7.662e-01 -1.076e-01 0.000e+00 1.769e-01 3.740e-01
>>> 2.454e+00 Shie eIoni
>>> 9 -2.017e+02 -7.662e-01 -1.076e-01 0.000e+00 0.000e+00 0.000e+00
>>> 2.454e+00 Shie Scintillation
>>>
>>> *********************************************************************************************************
>>>
>>> * G4Track Information: Particle = gamma, Track ID = 2, Parent
>>> ID = 1
>>> *********************************************************************************************************
>>>
>>>
>>> Step# X(mm) Y(mm) Z(mm) KinE(MeV) dE(MeV) StepLeng
>>> TrackLeng NextVolume ProcName
>>> 0 -2.045e+02 2.579e-03 -2.126e-03 3.628e-02 0.000e+00 0.000e+00
>>> 0.000e+00 Shie initStep
>>> 1 -2.018e+02 1.243e-02 -2.453e-02 0.000e+00 8.701e-04 2.647e+00
>>> 2.647e+00 Shie phot
>>>
>>> *********************************************************************************************************
>>>
>>> * G4Track Information: Particle = e-, Track ID = 516, Parent ID
>>> = 2
>>> *********************************************************************************************************
>>>
>>>
>>> Step# X(mm) Y(mm) Z(mm) KinE(MeV) dE(MeV) StepLeng
>>> TrackLeng NextVolume ProcName
>>> 0 -2.018e+02 1.243e-02 -2.453e-02 3.541e-02 0.000e+00 0.000e+00
>>> 0.000e+00 Shie initStep
>>> 1 -2.018e+02 2.109e-02 -2.345e-02 0.000e+00 3.541e-02 2.450e-02
>>> 2.450e-02 Shie eIoni
>>> 2 -2.018e+02 2.109e-02 -2.345e-02 0.000e+00 0.000e+00 0.000e+00
>>> 2.450e-02 Shie Scintillation
>>> --- Finish event
>>> Stack Info
>>> Total number of particles: 516
>>> Number of primary particles: 1
>>> TParticle: e- p: 0.080000 0.000000 0.000000 Vertex:
>>> -3.000000e+02 0.000000e+00 0.000000e+00 -1 0
>>> TParticle: e- p: 0.000636 -0.000393 -0.000722 Vertex:
>>> 2.023844e+01 1.380119e+00 -9.969215e-01 0 1
>>> TParticle: gamma p: 0.000220 0.000013 -0.000016 Vertex:
>>> 2.010258e+01 1.367762e+00 -9.843252e-01 0 2
>>> TParticle: gamma p: 0.000054 0.000004 -0.000003 Vertex:
>>> 2.003232e+01 1.362088e+00 -9.787132e-01 0 3
>>> TParticle: Cherenkov p: -0.000000 -0.000000 -0.000000 Vertex:
>>> 1.956514e+01 1.336273e+00 -9.358289e-01 0 4
>>> TParticle: Cherenkov p: -0.000000 0.000000 -0.000000 Vertex:
>>> 1.956895e+01 1.336443e+00 -9.361586e-01 0 5
>>> TParticle: Cherenkov p: 0.000000 -0.000000 0.000000 Vertex:
>>> 1.924589e+01 1.321851e+00 -9.082567e-01 0 6
>>> TParticle: Cherenkov p: -0.000000 -0.000000 0.000000 Vertex:
>>> 1.881176e+01 1.300382e+00 -8.703480e-01 0 7
>>> TParticle: Cherenkov p: -0.000000 -0.000000 -0.000000 Vertex:
>>> 1.875277e+01 1.297413e+00 -8.649779e-01 0 8
>>> TParticle: Cherenkov p: -0.000000 0.000000 -0.000000 Vertex:
>>> 1.873954e+01 1.296666e+00 -8.637950e-01 0 9
>>> TParticle: Cherenkov p: -0.000000 -0.000000 0.000000 Vertex:
>>> 1.871651e+01 1.295366e+00 -8.617343e-01 0 10
>>> TParticle: Cherenkov p: -0.000000 0.000000 0.000000 Vertex:
>>> 1.873194e+01 1.296237e+00 -8.631147e-01 0 11
>>> TParticle: Cherenkov p: 0.000000 0.000000 0.000000 Vertex:
>>> 1.871305e+01 1.295171e+00 -8.614247e-01 0 12
>>> TParticle: Cherenkov p: 0.000000 0.000000 -0.000000 Vertex:
>>> 1.873276e+01 1.296283e+00 -8.631885e-01 0 13
>>> TParticle: Cherenkov p: 0.000000 -0.000000 -0.000000 Vertex:
>>> 1.823852e+01 1.270792e+00 -8.154165e-01 0 14
>>> TParticle: Cherenkov p: -0.000000 -0.000000 -0.000000 Vertex:
>>> 1.826841e+01 1.272338e+00 -8.185104e-01 0 15
>>> TParticle: Cherenkov p: -0.000000 0.000000 -0.000000 Vertex:
>>> 1.820691e+01 1.268963e+00 -8.122148e-01 0 16
>>> TParticle: Cherenkov p: -0.000000 0.000000 -0.000000 Vertex:
>>> 1.818631e+01 1.267756e+00 -8.101328e-01 0 17
>>> TParticle: Cherenkov p: -0.000000 -0.000000 0.000000 Vertex:
>>> 1.821648e+01 1.269523e+00 -8.131813e-01 0 18
>>> TParticle: Cherenkov p: 0.000000 -0.000000 0.000000 Vertex:
>>> 1.812218e+01 1.263938e+00 -8.033476e-01 0 19
>>> TParticle: Cherenkov p: -0.000000 -0.000000 -0.000000 Vertex:
>>> 1.785667e+01 1.247947e+00 -7.732789e-01 0 20
>>> TParticle: Cherenkov p: 0.000000 0.000000 -0.000000 Vertex:
>>> 1.775054e+01 1.242225e+00 -7.610460e-01 0 21
>>>
>>>
>>>
>>> On 09/21/2010 09:03 PM, Ivana Hrivnacova wrote:
>>>>
>>>> Dear Filimon,
>>>>
>>>> It is difficult to see what gets wrong just from the back trace;
>>>> could you run with /tracking/verbose 1 and send me the end of file
>>>> with a few tracks?
>>>> Also, what are the versions of everything (root, geant4, geant4_vmc)
>>>> and what is your physics list selection?
>>>>
>>>> Best regards,
>>>>
>>>> Ivana
>>>>
>>>> Filimon Roukoutakis wrote:
>>>>> Dear Ivana, thanks for all this information. I have started my
>>>>> implementation and at the moment I get the following output.
>>>>> I assume this happens right when starting to track optical photons
>>>>> because by enabling more G4-native verbosity I can see that I have
>>>>> some optical photons created (and presumably put in the stack, so
>>>>> the scintillation mechanism part seems to work...). Any hint on
>>>>> where to look for the problem? The problem occurs in my case even
>>>>> if I comment out all my optical geometry code, the thing that
>>>>> triggers it is the addition of "+optical" to my
>>>>> TG4Runconfiguration... The N06 example runs properly even after
>>>>> enabling scintillation, so I guess I miss something from the
>>>>> example in my code.
>>>>> filimon
>>>>>
>>>>> *** Break *** floating point exception
>>>>>
>>>>>
>>>>>
>>>>> ===========================================================
>>>>> There was a crash (#7 0x00a7136d in SigHandler(ESignals) () from
>>>>> /opt/root/v5-27-04/lib/libCore.so.5.27).
>>>>> This is the entire stack trace of all threads:
>>>>> ===========================================================
>>>>> #0 0x006cd422 in __kernel_vsyscall ()
>>>>> #1 0x05e997d3 in __waitpid_nocancel () at
>>>>> ../sysdeps/unix/syscall-template.S:82
>>>>> #2 0x05e3ade3 in do_system (line=<value optimized out>) at
>>>>> ../sysdeps/posix/system.c:149
>>>>> #3 0x0039327d in system (line=0xbce79c0
>>>>> "/opt/root/v5-27-04/etc/gdb-backtrace.sh 16138 1>&2") at
>>>>> pt-system.c:29
>>>>> #4 0x00a6981d in TUnixSystem::Exec(char const*) () from
>>>>> /opt/root/v5-27-04/lib/libCore.so.5.27
>>>>> #5 0x00a6fed5 in TUnixSystem::StackTrace() () from
>>>>> /opt/root/v5-27-04/lib/libCore.so.5.27
>>>>> #6 0x00a71265 in TUnixSystem::DispatchSignals(ESignals) () from
>>>>> /opt/root/v5-27-04/lib/libCore.so.5.27
>>>>> #7 0x00a7136d in SigHandler(ESignals) () from
>>>>> /opt/root/v5-27-04/lib/libCore.so.5.27
>>>>> #8 0x00a66a32 in sighandler(int) () from
>>>>> /opt/root/v5-27-04/lib/libCore.so.5.27
>>>>> #9 <signal handler called>
>>>>> #10 0x0595718a in G4VProcess::AtRestGPIL (this=0xba37360,
>>>>> track=..., condition=0xa394118) at
>>>>> /home/filimon/geant4.9.3/source/processes/management/include/G4VProcess.hh:456
>>>>>
>>>>> #11 0x05955cd2 in G4SteppingManager::InvokeAtRestDoItProcs
>>>>> (this=0xa394010) at src/G4SteppingManager2.cc:298
>>>>> #12 0x05952d5b in G4SteppingManager::Stepping (this=0xa394010) at
>>>>> src/G4SteppingManager.cc:160
>>>>> #13 0x0595eff3 in G4TrackingManager::ProcessOneTrack
>>>>> (this=0xa393fe8, apValueG4Track=0xbce69c8) at
>>>>> src/G4TrackingManager.cc:126
>>>>> #14 0x028695f0 in G4EventManager::DoProcessing (this=0xa393fa0,
>>>>> anEvent=0xb7bcf00) at src/G4EventManager.cc:185
>>>>> #15 0x02869d18 in G4EventManager::ProcessOneEvent (this=0xa393fa0,
>>>>> anEvent=0xb7bcf00) at src/G4EventManager.cc:335
>>>>> #16 0x052349c0 in G4RunManager::DoEventLoop (this=0xa393e68,
>>>>> n_event=10, macroFile=0x0, n_select=-1) at src/G4RunManager.cc:235
>>>>> #17 0x052343a8 in G4RunManager::BeamOn (this=0xa393e68, n_event=10,
>>>>> macroFile=0x0, n_select=-1) at src/G4RunManager.cc:140
>>>>> #18 0x05d96677 in TG4RunManager::ProcessRun (this=0xa3d2ad8,
>>>>> nofEvents=10) at run/src/TG4RunManager.cxx:397
>>>>> #19 0x05d9af17 in TGeant4::ProcessRun (this=0xa3ca390,
>>>>> nofEvents=10) at run/src/TGeant4.cxx:1179
>>>>> #20 0x058d7f46 in TMCApplication::RunMC (this=0xa35cca0,
>>>>> nEvents=10) at TMCApplication.cpp:126
>>>>>
>>>>>
>>>>> On 09/20/2010 11:05 AM, Ivana Hrivnacova wrote:
>>>>>>
>>>>>> Dear Filimon,
>>>>>>
>>>>>> The examples in VMC implement the same setting (the same as it was
>>>>>> at the time when we did this work) as the novice examples in Geant4.
>>>>>>
>>>>>> The parameters which are in geant4_vmc preceded with the comment:
>>>>>> // Added (for Geant3)
>>>>>> are not needed in Geant4 (and they are not present in Geant4
>>>>>> native example N06) and were added in order to get the example
>>>>>> working with Geant3, where all three sets of parameters for
>>>>>> Cerenkov process are always requested (see
>>>>>> TVirtualMC::SetCerenkov(...)). Note, that they have special values
>>>>>> (DBL_MAX for absorption and 0. for efficiency).
>>>>>>
>>>>>> The scintillation is inactivated in the macro as it is also
>>>>>> inactivated in Geant4 native example in the default macro.
>>>>>>
>>>>>> The Birks correction is implemented in G4Scintillation.cc since
>>>>>> G4.9.2
>>>>>> (see:
>>>>>> http://hypernews.slac.stanford.edu/HyperNews/geant4/get/opticalphotons/311/1.html)
>>>>>>
>>>>>> what was after the implementation of the examples in VMC,
>>>>>> that's why the setting of the Birk constant to the material, which
>>>>>> you can find in Geant4 native example is missing in the VMC example.
>>>>>> As this setting is done in a different way than the setting of
>>>>>> other material properties, it will need a special support in the
>>>>>> VMC interface. I will have a look at it and let you know when this
>>>>>> is available.
>>>>>>
>>>>>> Geant3 does not include scintillation process at all.
>>>>>>
>>>>>> Best regards,
>>>>>>
>>>>>> Ivana
>>>>>>
>>>>>>
>>>>>>
>>>>>> Filimon Roukoutakis wrote:
>>>>>>> Dear all,
>>>>>>> I am going through example E06 of geant4_vmc tarball. Trying to
>>>>>>> simulate a lead/scint fiber calorimeter (now moving to the
>>>>>>> optical part as the energy deposition seems correct according to
>>>>>>> data comparison) I have an initial question.
>>>>>>> In the Ex06DetectorConstruction.cxx file in the
>>>>>>> ConstructOpProperties method there are some comments like "Added
>>>>>>> (for Geant3)". Since I do not know to which set of properties
>>>>>>> they apply (only for efficiency?), my question is, are these only
>>>>>>> used by G3 back-end, in the sense that G4 handles them
>>>>>>> differently? If yes, by which mechanism? I see that in the
>>>>>>> provided g4config.in file the scintillation is deactivated. In my
>>>>>>> use-case should I then enable this (or simply delete the lines)
>>>>>>> and provide all the G3 information that is in the
>>>>>>> ConstructOpProperties in a G4 format in the g4config file or are
>>>>>>> the fields under "Added (for Geant3)" also applicable for G4 (I
>>>>>>> am obviously interested for the yield/MeV and the slow/fast
>>>>>>> component arrays and ratio/settings). To summarize, if I just
>>>>>>> remove the line about disabling scintillation in the g4.in file,
>>>>>>> will scintillation work correctly for both G3 _and G4 with
>>>>>>> something similar to the example code (provided ofcourse that I
>>>>>>> use the proper values for my scintillating material where
>>>>>>> applicable...)?
>>>>>>> A more advanced but related question is whether there is some
>>>>>>> provision for birk's law under G3 or G4. Any provision/experience
>>>>>>> on this?
>>>>>>> Thanks,
>>>>>>> filimon
>>>>>>
>>>>>
>>>>
>>>
>>
>
--
==============================================================
e-mail: Ivana.Hrivnacova_at_cern.ch
address: Institut de Physique Nucléaire, 91406 Orsay, France
phone: +33 169156594
==============================================================
Received on Wed Sep 22 2010 - 13:46:59 CEST