LDM - D2

• • Taras and Daryl started measurements in the morning by connecting the laser tracker, measuring geometry, and beginning work on the first magnet. Two positions were completed, with the third expected to finish within an hour.
  • Measurements were conducted with ±20 A current, and the power supply behaved as expected. Laser tracker deviations were less than 50 microns, with points within tolerance.
  • The team is monitoring temperature variations that could affect the drift of the laser tracker.
  • The alignment system is available for local validation, and the team is working off a local copy before switching to the GSI network.
• Conclusion:
  • Measurements are stable and within tolerance. The process continues with the third position, and data will be shared at the end of the day.

• Air Pressure and Regulator Behavior
  • The inlet line pressure is 7.1 bar, below the desired 7.5–8 bar, while the output is around 5 bar, which is sufficient to keep the measurement head stable.
  • A key issue is that the pressure cannot be adjusted via the front dials; only the rear rack regulator is functional, and the front indicator shows red.
  • The current workaround is to set the regulator to achieve the current pressures and keep them constant during runs.
  • It was suggested to avoid remote or software changes mid-campaign to maintain validated settings. Using bottled dry air with a reducer was discussed as an option, but the current setup is deemed sufficient.
  • The lower pressure might be preferable given the G11 tube material and thickness, with no deformation observed.
  • The team will proceed with manual regulator control at current pressures and defer any software or hardware changes until after the campaign.

• On-call Support and Measurement Repeatability Plan
  •  
  • The proposed protocol is to measure the first magnet completely from both sides and then repeat the measurement the next day to assess repeatability and build confidence in the process. This will help detect stochastic effects.
  • The team agreed to invest extra time in repeatability checks to validate the full measurement process.

• System Precision, Documentation, and Sensitivity Factors
  • Questions were raised about the system's achievable precision and probe sensitivity for harmonics validation. A request was made for technical documentation on coil windings and sensitivity coefficients beyond what is in existing drawings.
  • It was stated that a user manual and drawings exist, and sensitivity factors are in a specific calculated file (not in FFFM). The typical precision is around 0.01 units for harmonics at room temperature. The device is intended for validating superconducting magnets at room temperature.
  • The complete Altium project for the LDM2 PCB, including the 26-layer board design, has been uploaded to this Indigo page. 

• Support Planning and Collaboration Agreement

  • Support: A week of training has been provided, and a user manual is being finalized. An external support visit is optional and contingent on local needs.

  • Collaboration Agreement: The agreement needs to be updated to include the LDM2 loan and upgrades to the GSI electronic rack done by CERN. A discussion is needed to clarify technical data and financial aspects.

  • LDM2 System Future: GSI will keep the LDM2 system for the remainder of 2026. A dedicated meeting will be scheduled to discuss long-term options, such as GSI producing new units for CERN.

  • Conclusion:

    • No immediate on-site support is required; remote data review will verify trustworthiness. A meeting will be scheduled to discuss the LDM2 system's future, and the collaboration agreement will be updated.

SSW :

• System Status and Project Timeline

  • Stretched Wire Status & Metrology Lab Timeline:

    • The stretched-wire system is at the metrology lab. A budget code will be requested at the end of the service.

    • The lab experienced a one-week delay due to a roof leak but targets finishing measurements by the end of June 2026.

    • After metrology, components will return to B311 for installation in early-to-mid July 2026. This will be followed by measurements on a magnet.

  • Cabling & PXI Crates:

    • Cabling is nearly complete, but there is an outstanding issue with the PXI crates that needs resolution.

  • Revised Timeline to Shipment:

    • The April plan to ship the stretched wire system by the end of July 2026 is now considered unrealistic due to the PXI crate issue and the need for thorough system validation.

    • A more realistic timeline suggests the system will not be ready before September or October 2026.

XI Crate and Computer Compatibility Issues

• • Description:
    • An issue was identified in which some PXI crate slots are not usable, with behavior dependent on the slot order and the computer used. Testing showed that CERN’s computer could recognize all cards, suggesting the problem lies with the current computer's configuration.
    • Replacing the computer is the proposed solution. However, there is a concern that PXI computers are outdated and difficult to procure, with previous lead times around six months.
    • A link to a purchased computer was shared (https://ekf.com/product/pc7/), but it is not the recommended model. The team will check for a spare FAIR-financed PXI computer in the lab as a potential mitigation.
  • Conclusion:
    • The team will pursue a new or spare compatible computer to resolve the PXI issue and continue troubleshooting while planning for a hardware replacement.

• Calibration Strategy for the Stretched Wire System

  • Description:

    • A concern was raised that performing a 2D calibration at GSI would cause the system to lose the 1D angular calibration previously done at CERN against a reference quadrupole. This is because 2D calibration compensates for stage misalignments, which alter the measurement plane.

    • It was proposed to postpone the 2D calibration and first use the system for measurements at cold temperatures to gather strength and field angle data.

    • After these initial measurements, a 2D calibration can be performed, and the system would then be recalibrated against the already measured magnet at GSI.

  • Conclusion:

    • PI should be booked for the 2D calibration only after the first successful cold measurements are completed, likely next year.