Follow-Up from last meeting

MD data results & comparison plots.
- See https://its.cern.ch/jira/browse/BIPXL-120
Status of PS horizontal diagnostics or replacement decision.
- See https://its.cern.ch/jira/browse/BIPXL-61
- Seems to bo some thermal/radiation effects only visible in the PS
GBTX configuration reliability improvement.
- Solved with updates to the config in the internal driver
- 4.1.3-release
- 4.1.2-release
Telescope deployment progress & initial timing validation.
- See https://its.cern.ch/jira/browse/BIPXL-82 and https://its.cern.ch/jira/browse/BIPXL-62
Event rate investigation findings.
DMA / driver integration status.
- See https://its.cern.ch/jira/browse/BIPXL-161

Minutes

Date: 29/08/2025

Participants: James, Mark, Steen, Hampus, Juri, Lukas (Zoom), Gabriela (Zoom)

Timing & Synchronization: Current telescope timestamps limited to ±100 ns. TimeWalk correction demonstrated (~10 ns residual). SPS bunch-by-bunch requires <25 ns precision. Next step: SPS BGI calibration using single LHC bunch (1 x 5ns bucket filled) or in the future electron gun.
HL-LHC Beam Profile Review (23 Sept): BI contribution: 20-min BGI talk (James) on design, performance, and PS/SPS experience. Results needed before Lukas’ holiday.
Telescope: Detector correlations now clear; track χ² improving with ongoing software alignment. Next: reference crystal installation + multi-volume crystal tests.
DAQ/FESA Stability: Occasional crashes during MD runs (likely data-volume related). Stable in command-line mode; monitoring continues.
Hardware / Optics: Broken fibre in telescope channel traced to installation; procedure should be documented. GBTx configuration improved significantly and seems stable now in 4.1.3-release branch.
SPS BGI Vertical: Raw data path non-functional; likely SFP/module issue. Plan: retest in lab post-run with validated SD cards and spares.

PCIe/DMA Support: Ongoing difficulties with Edge + XDMA drivers. Options:
1. Investigate Edge 2.1 compatibility.
2. Fallback to commercial PCIe cards with supported DMA drivers.
  Decision required within 2 weeks to ensure 2026 PS/SPS BGI readiness.
PS Horizontal BGI: Persistent no ionization electron problem. Decision: build new instrument from existing spares; test and qualify before LS3.
PS BGI Front-Ends: Failing after minutes due to (probably) thermal problem. Hampus & Wilfried to implement solution with fan. Radiation damage to DC fans could be an issue.
SPS Shields: Horizontal now robust with RF shield. Vertical shield upgrade under study (diamond or smaller-hole variant). Decision point: end November. Possible MD to test shield options.

Farewell to Gabriela (final day). Team expressed gratitude for her 3 years of valuable contributions.