Jan 2026-Mar 2026

USING ALTERNATE ZOOM LINK THIS WEEK

Attendees: MK, NT, SS, JI, BZ, SZ, ÉM,

Regrets: Many folks at APS in Denver this week

Announcements:

• RISQ 2026 Workshop at UW-Madison, 15-18 June 2026, with the first day the G4CMP day

Agenda:

• Logo competition!  
  • If you have an idea, please add it to the slide deck, which is currently empty?!?  Where are Selby's creations?
  • If you have comments about the submissions, please comment there as well
  • Since the slide deck is empty, let's give folks until end of March to contribute, then start the comment period
• Questions?  Discussion topics?  Impromptu presentations?
• AOB

USING ALTERNATE ZOOM LINK THIS WEEK

Attendees: MK, AC, PB, ÉM, PH, BZ, SQD, RR, JL, JI, BL, CS-W, EM, CL, TC, 

Regrets: RL – Travelling this week (seminar at A&M today at 9:30 Pacific, 11:30 Central, 12:30 Eastern), WL, 

Announcements:

• RISQ 2026 Workshop at UW-Madison, 15-18 June 2026, with the first day the G4CMP day
• Ryan Linehan: HEPEC Seminar at Texas A&M today, 11:30 am Central
• The G4CMP repository has been moved to the new G4CMP organization: https://github.com/G4CMP/G4CMP
  Details for current developers/users

  • Many thanks to Birgit and the SNOLAB/Laurentian group for setting this up!
  • If you have a current clone, you do not have to do anything.
    • GitHub will forward pushes and pulls automatically.
    • You will also get redirected in your browser if you access G4CMP through the old URL.
  • If you get tired of the message
    

    remote: This repository moved. Please use the new location:
    remote:   git@github.com:G4CMP/G4CMP.git
    To github.com:kelseymh/G4CMP.git

    when pushing to the remote repository you can update the link in your local clone with the following command:
    

    sed -i.bak '/url/s/kelseymh/G4CMP/' .git/config

  • If you make a new clone, please use the new URL moving forward
• New G4CMP V10-01-01 release, fixes memory leak.

Agenda:

• Some G4CMP-relevant talks at APS Global Summit (formerly March and April meetings)
  • CURIE (Colorado underground facility) is 30 min. from APS.  Please contact Caitlyn Stone-Whitehead if you're interested in a tour!
• AOB

USE ALTERNATE ZOOM  LINK : https://tamu.zoom.us/j/98334127553?pwd=XScBI5vpravn5CSgRANXbytKa0npoZ.1

Attendees: MK, EM, RR, BL, AC, JB, JL, BZ, JY, NT, SZ, SD, TC

Regrets: RL

Announcements: RISQ 2026 Workshop at UW-Madison, 15-18 June 2026, with the first day the G4CMP day

Agenda:

• Problems, problems, problems
  • Continuing to work on memory leak seen in V10-01-00 G4CMP-585 - Jira project doesn't exist or you don't have permission to view it. , culprit is in ParticleChangeForPhonon  G4CMP-547 - Jira project doesn't exist or you don't have permission to view it.
  • Complex identification of "actual" surface position at boundary steps has occasional failures  G4CMP-575 - Jira project doesn't exist or you don't have permission to view it.
  • G4CMP-576 - Jira project doesn't exist or you don't have permission to view it. Initial tiny (1 pm) step by hole gets treated like electron (looks like improperly cleared cache)
  • Want better energy scale for subdividing pure-phonon energy deposition
    • G4CMP-557 - Jira project doesn't exist or you don't have permission to view it.
    • G4CMP-578 - Jira project doesn't exist or you don't have permission to view it.
    • The uses of "Debye energy/temp/freq" should be clearly documented so people know what to put in when adding new materials.  Since we don't "really" use the parameter as a Debye-model upper limit (energy cutoff), we should explain what it is used for and why.
• Organizing Committee for G4CMP Session at RISQ 2026
  • Stefan Zatschler, Jesse Lutz, Jared Yamaoka, Ryan Linehan, Jake Inman
  • Similar tutorials as done at previous workshop, but bigger and better!  Beginner and advanced sessions.
    • Should we require everyone to conform to same G4 and G4CMP versions in advance?  Is anyone averse to upgrading for the tutorials?
    • Might be possible to provide a container with things set up for people to use?
    • Also planning a "check in" day a week or so before to help people get set up.
  • If your group has topics for the wider workshop, abstract submission is now open.
  • We'll be inviting people for "lightning talks" during the G4CMP day.
  • "This meeting is for us" – suggestions or requests from the community are welcome!
• Kelsey will get G4CMP repository moved over to the Organization (https://github.com/G4CMP/) by the end of this week.
• AOB

Attendees: RL, MK, RR, BL, SQD, ZC, JI, JY, IH, SZ, BZ, JB, ÉM, JG, WL, JL, JG

Announcements:

• V10-01-00 release with G4 v11 compatibility available 28 Jan 2026, continuing to work on bug fixes
  • Do not expect identical results with G4v10, but statistically consistent results okay
  • Do not expect identical results with G4CMPv09-09-02, but statistically should be consistent
  • In both cases, new processes or changed ordering in physics lists can change the random number sequence
• Reminder: Round robin next week. Put slides here: https://docs.google.com/presentation/d/11j5hdGHRS7d_eQukxLrHNqCFo_-jVcRps4B2qw3qgG4/edit?slide=id.p#slide=id.p
• Reminder: Logo "competition" ongoing
  • Ryan will make confluence page for submission link
• Reminder: whenisgood for potential new time: https://whenisgood.net/52ddbj7

Agenda:

• Unit Testing and CI/CD (PDF), Jake Inman, PNNL
  • Current code in tests directory give some initial intuition for things we want to test – ex. Make sure G4LatticeReader, or mesh electric field, etc., does what we want it to do
  • Something other projects do:  "Any time you create a class, you need to create a unit test for that class"
  • Unit test coverage in "dark corners," places that are crucial and aren't tested all that much
  • As releases are tags, would like to have "standard candles" to compare physics output (larger scale regression testing)
  • Whenever we have a bug, make a unit test based on how you tracked it down, and then add THAT test as a unit test to catch if bug happens again
  • Important to distinguish "validations" from "unit testing," but CI/CD can allow us to do both of these
• G4CMP Development Status – mostly to be punted to next time++
  • Notable bugs being worked on right now!
    • G4CMP-572 - Jira project doesn't exist or you don't have permission to view it. Fix for lattice orientation ( G4CMP-480 - Jira project doesn't exist or you don't have permission to view it. ) got lost with V10-00-00 release, now restored
    • G4CMP-575 - Jira project doesn't exist or you don't have permission to view it. , and related  G4CMP-580 - Jira project doesn't exist or you don't have permission to view it.
      
  • Notable bugs not being worked on just yet...
    • G4CMP-581 - Jira project doesn't exist or you don't have permission to view it. Annoying as heck, but may need a G4 debug build to track down
    • G4CMP-576 - Jira project doesn't exist or you don't have permission to view it. Not a big deal, as we (currently) force charges' first step to be 1 pm
  • Notable bugs which might have resolved on their own
    • G4CMP-560 - Jira project doesn't exist or you don't have permission to view it. This was already fixed on G4 v11 branch, should be good in V10-01-00.   Looks like Jake closed this Jira ticket just before this meeting!
  • UW-M replication note
• AOB

Attendees: RL, JY, Jeffrey Glasier, BZ, JB, JL, BL, ZC, SR, EM, ÉM, JI, SQD, IH, MK, ML

Announcements:

• Introductions: welcoming Ziyu Cai from Illinois Institute of Technology!
• Recent updates on branches: charge reflection bug fix on v10-00-00 harder than thought it would be, so for SCDMS, just rolling back to "no reflections = no reflections" –> will be v10-00-01 (later today!)
  • Jesse: Having a rule of thumb number here would be very helpful for spin qubit world
  • Emile: should be a Schottky barrier, and charge needs barrier energy to cross boundary, (but also small probability to cross based on tunneling), and this affects interface
    • Should suggest to Wade/other developers of this that we should consider adding this to G4CMP either in the code itself or as a guide parameter for a given material/material interface
• Then will likely push forward on G4v11
  • Will merge v10-00-01 onto G4v11 branch, check for conflicts, before putting it out as 10-01-01 – expect this to take a few days to do carefully.
  • Ryan will test 494 branch with validation scripts once it's ready
• Reminder of "Round Robin in 3 weeks" – ÉM, SR, JI, SQD, ZC, BZ, (WL?), RL, SZ

Agenda:

• Roll-over from last week: project planning for next year: spreadsheet of discussion: https://docs.google.com/spreadsheets/d/1fxSILYw-IVV5tdVRlLn-tUcfaElVIL9xjKmVdE6ZL2Q/edit?gid=0#gid=0
• Office hours
• AOB

Attendees: MK, RL, JY, WL, ÉM, BZ, SZ, JL, SD, EM, BL, TC

Announcements:

• Merged TFR → develop → V10-00-00 release
  • Two small bug-fixes needing fixing → version V10-00-01 (hopefully end of today, but may be tomorrow)
  • Merged latest develop onto G4v11 ( G4CMP-494 - Jira project doesn't exist or you don't have permission to view it. ) integration feature branch, version compatibility amendments to TFR code. Will go out as V10-01-00
    • Fully backward compatible, no physics changes
  • Once these are done, people doing development work may need to merge these things onto their branches – Mike will provide guidance
  • Jake's been seeing end-of-run cleanup segfault, which he's now fixed (double deletion somewhere)
• Stefan: knock-on effects of TFR on SCDMS framework ( G4CMP-567 - Jira project doesn't exist or you don't have permission to view it. )

Agenda:

• Should generally start looking at Jira tickets and planning for new features
  • Work plan: things we plan to develop for the next release, but may be useful to have confluence page of the work plan
• Validation
  • Want a fully-publicly-visible validation example with a few different geometries, so that we don't have to guess whether we've broken SCDMS physics
  • Add HVeV detector for NTL and charge dynamics validation
  • Have a version of a TFR-compatible geometry that also can be toggled to use KaplanQP
  • Leads into CI/CD as planned by BZ and SZ
• Existing projects:
  • WL: Going through G4CMP-515 - Jira project doesn't exist or you don't have permission to view it. , working on charge reflection – trying to support both specular and diffuse reflection
    • Once happy with G4CMP-514 - Jira project doesn't exist or you don't have permission to view it. , should bring 515 up to date with latest develop (but wait for fixes above)
    • Currently, 100% specular for holes, diffuse for driftElectrons
    • No surface phonon creation when you have electrons bouncing around at surfaces
    • May need a flag to enable recombination when charge falls below threshold energy for other processes so that charges don't bounce forever.
• AOB