DD4hep Meeting December 5th, 2024

Present:  A.Sailer, M.Frank, A.Tolosa Delgado

Apologies:

Link to minutes of previous meeting

Merged PRs

• PR1357   : Bug fix in Segmentation's CylindricalGridPhiZ: phi range
• PR1358   : New functions for Drift Chamber data extension DCH_info_struct
• PR1359   : Increase the max number of particles allowed for hepevt input 
  ISSUE1356: Limitation on the number of event for hepevt
• PR1362   : Geant4AssemblyVolume: use the same copy ID for the
               Geant4 Volume as was set in DD4hep geometry construction

Pending Problems

• ISSUE1199: Persist hepmc vertex status code into output
                        ==> Should we eliminate Geant4EventReaderHepMC
                        ==> Decision: Geant4EventReaderHepMC will be removed
• ISSUE1285:  Memory Consumption of Sensitive Detectors
                        ==> Should be handled as illustrated in PR1288. Intrinsic problem of the Geant4VolumeManager;
• ISSUE1296:  DetectorImp::endDocument() called twice for some geometries?
                        ==> Unsure if it is a problem wrongly configuring multiple xml inputs.
• ISSUE1297:  Possible to dump all available readout elements?
                       ==> Possibly a copy of unsolved ISSUE580 from Valentin about enumerating all sensitive cells.
• ISSUE1319: Problem with regexSensitiveDetector and volume IDs
                       ==> Interesting use case for reg-ex sensitive detectors
                               having a VolumeMgr equivalent.
• ISSUE1320:  Replacing a Handle<Segmentation> which contains a MultiSegmentation with the underlying Segmentation
                       ===> Unclear what he really means. Questions after re-reading, calls like:
  

  Handle<SomeSegmentation> seg = multisegmentation->subSegmentation(cellID);
  or
  Segmentation* seg = multisegmentation->subSegmentation(cellID);
  

        Pending (no changes since last meeting):

• PR1240:     Add multithreading support to ddsim
• PR1304:     SurfaceManager: lazily construct surface maps on demand (Leonhard Reichenbach)
• PR1314:     Cylinder segment surface (Armin Ilg)
  
  

        "New" issues:

• ISSUE 1335: Uniform random picking of points on detector surfaces for noise studies
              This problem is linked to #1297 and #580.
  
  
• ISSUE 1360:   Issue with Assembly volume and g4-copynumbers
• ISSUE1361: Controlling Geant4 smart voxelization from the detector constructor
               ====> CPU speed-up issue from Alvaro
               ====> Markus shall provide a flag in the dd4hep::Volume class to propagate this feature to G4.
• ISSUE1363: Rotated coordinate system on a measurement surface
               ===> Frank ?
• ISSUE1364: Potential Inclusion of Geant4 Kernel Initialization in Per-Event Timing
               Complaint that the event execution time of ddsim includes G4 kernel initialization.
                Description will be changed by Andre.

Closed issues and fixed problems

• ISSUE 1343: want to get a parameter into ddsim SDAction at run time.
  
  

Round Table

Andre:    NTR
Markus: Playing with web-eve. 
Alvaro:    NTR

AOB

-----

Next meeting:   January 9th, 2024