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Usage of Dirc in concord with certain detectors [message #9083] Tue, 28 July 2009 17:33 Go to next message
donghee is currently offline  donghee
Messages: 385
Registered: January 2009
Location: Germnay
first-grade participant
From: *kph.uni-mainz.de
Dear Dirc experts,

The Dirc module must carefully be used in the MC simulation, if you really want to put dirc detector into full chain MC simulation e.g, any kind of physics analysis with all detectors.

When you introduce Dirc in your simulation, take care calling the Dirc class.
You have to put PndDrc at the end of your script in runsimulation.C

If you can do for example like this, then should be filled all info.
Quote:


FairDetector *Gem = new PndGemDetector("GEM", kTRUE);
FairDetector *Dch = new PndDchDetector("DCH", kTRUE);
FairDetector *Lumi = new PndLumi("Lumi", kTRUE);
PndDrc *Drc = new PndDrc("DIRC", kTRUE);



But if you ignore the postion of Drc, like following, then losing your task for GEM, Dch and Lumi.
Quote:



PndDrc *Drc = new PndDrc("DIRC", kTRUE);
FairDetector *Gem = new PndGemDetector("GEM", kTRUE);
FairDetector *Dch = new PndDchDetector("DCH", kTRUE);
FairDetector *Lumi = new PndLumi("Lumi", kTRUE);





I think that Dirc experts have to clean up this mess.
If you make the digitization procedure from differently produced simulation files,
you can simply check what happen.
But I'm not sure whether it depends on the event topology.
I'm just guessing that some tracking is abandoned due to the Dirc part, then cannot goes to next detectors.

Quote:


*** GTRACK *** More than 10000 steps, tracking abandoned!



Maybe this should be some potential problem in the future.

Best wishes,
Donghee Kang
Re: Usage of Dirc in concord with certain detectors [message #9084 is a reply to message #9083] Tue, 28 July 2009 17:41 Go to previous messageGo to next message
StefanoSpataro is currently offline  StefanoSpataro
Messages: 2736
Registered: June 2005
Location: Torino
first-grade participant

From: *to.infn.it
I have not understood why the simulation should be affected by the order of detectors.

Could you please show some sample, some plots, where you can see this effect?

In general the killed particles are just cherenkov photons reflected thousand of times inside the rods. And dch/gem/lumi are outside the dirc acceptance, then particles hitting the dirc will never enter inside those detectors.

Could you please give further informations?
Re: Usage of Dirc in concord with certain detectors [message #9085 is a reply to message #9083] Tue, 28 July 2009 18:11 Go to previous messageGo to next message
donghee is currently offline  donghee
Messages: 385
Registered: January 2009
Location: Germnay
first-grade participant
From: *kph.uni-mainz.de
Dear Dirc expert and Stefano,

I have tested to understand what is happening in the Dirc part.

I prepared two codes, one is including Dirc and
other one is excluding Dirc during the simulation using runSim.C
and runDigi.C

After digitization or hit producing, the final statistics in every part of any detectors are clearly different in two cases.
But in principle, the hit in MVD or TPC detector must be same, regardless of using Dirc.

The reason is following.
If the Dirc task failed in the running MC, all information are thrown away even though other detectors are correctly worked.

I can give you some number

without Dirc -> Entries of PndTpcDigi.fBits is 24577
with Dirc -> Entries of PndTpcDigi.fBits is 8844

These two numbers must be 24577 in any case.
That means, despite Dirc is incompetent to judge,
the statistics are greatly influenced by this wrong decision in the Dirc session.
This is apparently misconcept!!!


Best wishes,
Donghee Kang

[Updated on: Tue, 28 July 2009 18:14]

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Re: Usage of Dirc in concord with certain detectors [message #9086 is a reply to message #9085] Tue, 28 July 2009 18:18 Go to previous messageGo to next message
StefanoSpataro is currently offline  StefanoSpataro
Messages: 2736
Registered: June 2005
Location: Torino
first-grade participant

From: *to.infn.it
Could you please send your macros, so that we can test them exactly?
Re: Usage of Dirc in concord with certain detectors [message #9087 is a reply to message #9086] Tue, 28 July 2009 20:23 Go to previous messageGo to next message
Carsten Schwarz is currently offline  Carsten Schwarz
Messages: 288
Registered: March 2004
first-grade participant
From: *dip0.t-ipconnect.de
Dear debuggers,

I'm listening carefully your discussion in order to fix the problem. I thought the exiting of GTRACKS refers only to photons. I'm grateful for every information.

Best regards
Carsten (barrel-DIRC)
Re: Usage of Dirc in concord with certain detectors [message #9088 is a reply to message #9086] Wed, 29 July 2009 10:39 Go to previous messageGo to next message
donghee is currently offline  donghee
Messages: 385
Registered: January 2009
Location: Germnay
first-grade participant
From: *kph.uni-mainz.de
Dear PANDA colleague,

find attached the MC scripts and small mount of data produced by pseudo-DVCS events generator with exclusive electron + gamma + anti-proton particle.
Anti-proton goes to very forward direction, responding detector should be dch or lumi and partly gem. electron has mostly an opposite direction, i.e, backward direction.
Gamma is distributed in the forward and central part of spectrometer.

There are 2 main scripts as you can expect: runMC.C and runDigi.C
Quote:


pandaroot/macro>tar -xvzf dvcs.tar.gz
pandaroot/macro>root runMC.C
pandaroot/macro>root runDigi.C



I would like to confirm two things.

At First:
In the runMC.C, the Dirc part is located at the end in order to store all detector infomation.
If you move dirc part into the middle part of the runMC script, then the MC info. of detectors, which are calling below the dirc part, could not record anymore when you go to digitization. The output can produce but content should be empty!
Therefore I suggested that you have to put Dirc part at the end of script.

Second :
As I already mentioned.
If you try to run simulation and digitization without Dirc and with Dirc,
you can find the different result in both output.
Please open your digi output, and have a look any detector info.
Both statistics should be different.

Best wishes,
Donghee Kang









  • Attachment: dvcs.tar.gz
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Re: Usage of Dirc in concord with certain detectors [message #9144 is a reply to message #9088] Thu, 06 August 2009 14:58 Go to previous messageGo to next message
StefanoSpataro is currently offline  StefanoSpataro
Messages: 2736
Registered: June 2005
Location: Torino
first-grade participant

From: *15-87-r.retail.telecomitalia.it
Hello,
I have tried to study this behaviour.
First I have run tutorials/lhetrack/run_sim_tpccombi_pgun.C"(100,13,1)" with the standard macro, where Drc is at the end, and everything was running fine.
Than I have moved the Drc part just before Tpc, almost at the beginning, and after 10 events I have a crash in geometry (TGeoNode::Safety).
This is the backtrace:

Toggle Spoiler


Then I have tried to move it between TPC and MVD, and now the error is in TGeoNavigator::FindNextDaughterBoundary :

Toggle Spoiler


I have removed the pipe, thinking about some overlap between it and the DIRC, but without improvements. I have removed all the detectors, and then the simulation runs. Once I put inside all the detectors one by one (keeping dirc at the top after cave), at emc I have again the crash.

Then, we have some problems with geometry, maybe some conflict between dirc and emc, but I am not sure. What is strange is that the crash depends on the order of detectors.
Expert should maybe take a look, trying to understand what is going wrong.

I have done all my tests with geant3 and old external packages. I will try tpo see what will happen with the new ones.


Re: Usage of Dirc in concord with certain detectors [message #9145 is a reply to message #9144] Thu, 06 August 2009 16:27 Go to previous messageGo to next message
asanchez is currently offline  asanchez
Messages: 350
Registered: March 2006
first-grade participant
From: *kph.uni-mainz.de
Hi stephano,
so far i remember, the Dirc geometry is a full cylinder
without gap to place the pellet pipe.
Maybe the problem is due to this fact.

regards
Alicia.
Re: Usage of Dirc in concord with certain detectors [message #9148 is a reply to message #9145] Thu, 06 August 2009 17:02 Go to previous messageGo to next message
StefanoSpataro is currently offline  StefanoSpataro
Messages: 2736
Registered: June 2005
Location: Torino
first-grade participant

From: *15-87-r.retail.telecomitalia.it
If I remember well, Carsten has modified the geometry to avoid the overlap with the pipe.
It should not be the case.
Re: Usage of Dirc in concord with certain detectors [message #9154 is a reply to message #9144] Thu, 06 August 2009 19:52 Go to previous message
StefanoSpataro is currently offline  StefanoSpataro
Messages: 2736
Registered: June 2005
Location: Torino
first-grade participant

From: *15-87-r.retail.telecomitalia.it
I have tried also with july09 external packages, the same problem in geometry appears.
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