Public minutes of 117th SB meeting on December 13th, 2019

Present:Susanna Guatelli, Makoto Asai, Alberto Ribon, Dennis Wright, Koichi Murakami,Daren Sawkey, Alex Howard, Mihaly Novak, Ben Morgan, Soon Yung Jun, Vladimir Ivanchenko, Sebastien Incerti, Gabriele Cosmo, Marc Verderi, Gunter Folger, John Allison (OB Liaison), Hisaya Kurashige, Witek Pokorski, Luciano Pandola


1. Regular items

  • The open requirements, pending actions, status of long open bug reports, as well as physics and computing performance monitoring were reviewed.
  • Requirements expressed during the 2019 Collaboration meeting and associated Technical Forum were reviewed, and will be integrated into next development plans.
  • Hadronic physics performance:
    • Some changes (increased energy response and narrower lateral showers) driven mostly by the change in the transition region between string and intranuclear cascade models (the new transition is [3, 6] GeV, consistently for all particles, whereas before it had different values according to the particle types, in particular [3, 12] GeV for the most important ones (pions, kaons and nucleons). This new transition region, suggested by thin-target data, implies to use more Fritiof and less Bertini than before.
    • Regarding the increased energy response in hadronic showers, we recommend to tune the Birks quenching parameter from e/h data (instead of using a constant value taken from an old paper under the assumption of non delta-ray emission, which is clearly inconsistent with the simulation).
  • Computing performance:
    • CPU performances of 10.6 is similar to 10.5, but a couple of issues are under investigation.
      • In Shielding, there is a ~18% slow down which is not understood.
      • In other NeutronHP-based physics lists (like FTFP_BERT_HP, QGSP_BERT_HP, FTFP_INCLXX and QGSP_INCLXX) besides the above ~18% slow-down (to be understood), there is a further ~12% slow-down which is due to the now default activation of radioactive decay.

2. 2020 Collaboration processes

  • Membership to be renewed in January through the web page registration.
  • Each WG should make census to be concluded by January 31st, 2020.
  • 2020 is an election year. Elections of WG coordinator and representatives will be discussed at the first SB meeting in 2020.

3. Shaping version 11.0

  • The Steering Board is Identifying and reviewing status and planning of major development items in the coming year(s) that should motivate the decision for going for a major release.
    • Note: Not only major API changes but also major improvements in physics, etc., would justify a major release.
  • During the January census, each working group will survey:
    • Changes that may break user’s code
    • Big changes w.r.t. the way G4 is used/run
    • Or big features being added or significantly improved

4. Publication board

  • The Publication Board is now composed by :
    • Soon Yung Jun - Chair (term: ~Sep.2020)
    • Susanna Guatelli (term: ~Sep.2021)
    • Alex Howard (term: ~Sep.2022)

5. 2020 Collaboration meeting

  • As announced at the 2019 Collaboration meeting, the 2020 Collaboration meeting will be hosted at the IRISA Laboratory in Rennes, France
  • Date is confirmed to be September 21-25th, 2020

6. AOB

6.1 Recent events

4.2 Near future events

Meeting Date

Friday, December 13, 2019 - 12:00