Public Minutes of 123rd Steering Board, 27th January 2021

1. Present: Susanna Guatelli, Marc Verderi, Alex Howard, Luciano Pandola, Koichi Murakami, Mihaly Novak, Ben Morgan, Gabriele Cosmo, Alberto Ribon, Dennis Wright, Gunter Folger, Vladimir Ivantchenko, Shogo Okada, Daren Sawkey, Witek Pokorski, Soon Yung Jun, Makoto Asai

Excused: John Allison (OB liaison), Sebastien Incerti, Ivana Hrivnacova\

2. Situation wrt to pandemic

No specific difficulties have to be reported.

3. Regular items

A round-table of working group activities was made, as well as a review of pending requirements and SB actions. Requirements from the Collaboration meeting will be added to JIRA.

Bug reports have been documented during the review. You are invited to update Bugzilla if you are in charge of some reports.

4. Status of WG census

The annual registration and census are ongoing. About 130 members registered so far, this number should be close to the final one. The census within the working groups is almost complete, and should be finalized within a few days.

5. Planning the 2021 11.0 major release

The 2021 release will be a major one, 11.0. To overcome the slow down of discussions due to lack of face to face meetings because of the pandemic, planning and content discussions are already starting.

Several items justify moving to a major release. The new tasking model is expected to become the default one soon, in replacement of the MT scheme, and feed-back on examples will be requested then. Some significant issues will need to be reviewed, like the thread local storage, or the stepping-verbose. C++17 will be adopted, this will be aided by documentation and internal seminar by video. VecGeom will become the default for the solids. An evaluation of a new scheme, and possibly its adoption, of offloading the stepping manager from the control of the conformance of the secondaries to threshold -transfering the full responsibility of this to processes- will be made. The expected benefits are performance gain and clearer responsibilities. The handling of data library will be improved, which will impact at least the global, materials and processes categories. The deprecated GNUmake build system will be retired. A solution will be provided to users not familiar with CMake.

6. Anticipated 2021 R&D activities

In addition to above developments, several R&D activities are identified.

Already started activities advertised to the R&D Task Force are fast simulation ones with classical parameterization but also Machine Learning- and GPU-based simulations. These last ones involve different institutions. The AdePT project aims at building a demonstrator of EM showers in a calorimeter, based on the physics part available in G4HepEm, and VecGeom for the geometry. Similar efforts are also made by the Celeritas project in the US.

A new effort regarding the assessment of the A64FX for the simulation is starting. The Geant4 KEK team has already performed tests of the ARM architecture for medical applications, with power-consumption as figure of merit. The KEK team has ordered one A64FX server to perform similar tests for the medical, and has offered to extend these tests to HEP cases. For these ones, the high memory bandwidth of the chip and related performance gain will be evaluated. The effort is mainly driven by KEK; some other Geant4 collaborators are joining.

A more theoretical approach to anticipate the possible gain we can get in Geant4 simulation with track parallelization was started. This is in general, without any specific platform in mind.

7. Events:

  • Past events
    • [Virtual] HSF-WLCG virtual workshop, 19-24 November 2020
      • The workshop, including the simulation session, has been constructive
    • [Virtual] IN2P3 & PHENIICS Geant4 School, Orsay (France), 23-27 November 2020
      • About 40 participants attended. The use of “break out rooms” with Zoom appeared as en convenient tool to handle hands on sessions.
    • [Virtual] 53rd Geant4 Technical Forum, 21 January 2021
      • The meeting was devoted to the 10.7 content for the Geant4 developers part. The users’ part, extended to two hours, offered enough time for discussion.
  • Near future events
    • [Virtual] COSPAR 2021, 28th Jan-4th Feb 2021
    • [Virtual] 54th Geant4 Technical Forum, first half of March anticipated
    • [Virtual] CHEP (17th-21st May 2021), abstract submission deadline Feb 28th 2021!

8. AOB

Ben Morgan has been appointed as co-convener of the HSF Simulation Working Group. Our congratulations to him ! Possible topics and meetings are under discussion, linked with the Task Force for R\&Ds to ensure link up and avoid duplication. Part of the remit is to identify link ups with other HSF groups, and items considered are training

  • could the large amount of Geant4 tutorial material be used and reshaped according to HSF training WG recommendations ?
  • and Python
    • how to improve Geant4 Python bindings ?
    • as to benefit from Python popularity in users communities, and also in HPC/CAD integration.

Meeting Date

Wednesday, January 27, 2021 - 12:00