GSI-CERN Collaboration for MM systems

Wednesday 26 Aug 2026, 16:00 → 17:40 Europe/Zurich

ZOOM

Carlo Petrone (CERN)

SSW Progress Updates 24082026.pdf

SSW Progress Updates 24082026.pptx

Meeting Notes

• Stretch Wire System Status and Calibration Findings

  • Summary of ~2.5 weeks of testing on Ref Quad 2: the system returned to the measurement hall but will go back to Ref Quad 2 due to space constraints.

  • The original rack-mounted FDI could not be calibrated; it was replaced with the repaired GSI FDI, which operates correctly and provides valid data.

  • Found low integrated gradient (~4–4.5 T vs expected ~13.3) caused by the wire touching the holder due to pulley position; a temporary plastic tape fix restored expected values.

  • The issue appears on both A and B stages; indicates the pulley sits too low relative to the design.

  • Conclusion: Mechanical contact between wire and holder produced erroneous readings; a robust mechanical fix is required.

 

• Mechanical Remediation Options for Pulley/Wire Interference

  • Tape is a proof-of-principle only; unacceptable for delivery and long-term stability.

  • Preferred approach: redesign/adjust the pulley holder so the wire never contacts the structure; avoid epoxy or added contact surfaces that would alter dynamics.

  • Proposed options:

    • Keep the existing hole; redesign the pulley holder to move the pulley higher/sideways while maintaining stiffness/stability.

    • Consider an intermediate plate to reposition the pulley; possibly reduce pulley diameter after careful analysis. 

      • Next steps discussed:

        • Unscrew the pulley to measure hole location (from plate edges) and the intended wire path.

        • Collaborate with the draftsman to propose adjusted holder/plate solutions.

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      • Conclusion: Engineer a stable, long-term mechanical solution that preserves calibration integrity.

       

       

• Measurement Quality, Noise, and Repeatability

  • Integrated gradients and roll-angle results are comparable to those of CERN stretch-wire systems.

  • Repeatability (relative standard deviation × 10,000) ~1.0 (X) and 0.8 (Y), about 2 times worse than reference systems.

  • Suspected noise source: the motor controller (different from CERN units) generating electromagnetic interference.

  • Mitigation underway: motor controller moved to the top of the rack; re-measure to assess impact; consider shielding if confirmed.

  • Conclusion: The noise is likely linked to the motor controller; further tests will confirm this and guide mitigation.

 

• Resonance Frequency (Sag) Measurements and Dynamic Response

  • Using the resonance method at the same tension vs SSW10: similar resonance frequency, but the GSI system shows higher noise and a much lower/less distinct oscillation amplitude.

  • Two contributors:

    • Electrical noise (as above).

    • Non-equivalent dynamic excitation: controller/software acceleration/speed limits and the shake position relative to flux lines affect the response. 

       

      • Actions taken: varied speed/acceleration limits; continued investigation of software limits and shake position inside the magnet.

      • FFT shows higher-frequency components (likely noise) outside the algorithm’s search band; it does not bias frequency detection but indicates room for improvement.

      • Conclusion: Tune motion profiles and excitation geometry; continue noise mitigation.

       

       

• Power Supply Testing (AC Mode)

  • Plan to test the magnet power supply in AC mode as a stress test and for future room-temperature superconducting magnet measurements.

  • Conclusion: AC-mode testing is scheduled and important for final project needs.

 

• Hardware and PC/Storage Updates

  • Replacement of old PCs with new PXI (Compact) systems: offers received; order to be placed; estimated delivery ~8 weeks.

  • MTPC122 failure traced to the hard drive; replaced with a CERN Samsung SSD and Windows image; FFMM installed and functioning.

  • Additional Samsung SSDs ordered; compatibility will be checked.

  • Conclusion: Computing hardware refresh is in progress; the failed PC has been recovered with a new SSD.

 

• Rotating Coil Scanner Measurements Status

  • All required magnets measured (8 total); results include multipoles and field at each position.

  • Internal review scheduled; a link will be shared with participants.

  • Conclusion: Rotating coil campaign completed successfully; summary to follow.

 

• Potential Funding and Collaboration for Stretched Wire Development

  • Proposal to seek funding to open hardware to scientific users or transfer to industry, subject to partner agreement.

  • CERN notes that any industry-involved funding must go through Knowledge Transfer; broader multi-institute academic collaboration is also an option.

  • A dedicated meeting will be scheduled after the program link is shared.

  • Conclusion: Explore funding/collaboration options; coordinate with Legal/KT as needed.

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16:00 → 16:20 General infomations

Speakers: Alexander Bleile, Anna Mierau, Carlo Petrone (CERN), Christian-Eric Roux, Daryl Bao Wen Teo (GSI - Helmholtzzentrum fur Schwerionenforschung GmbH (DE)), Kei SUGITA, Matthias Bonora-Tam (CERN), Mr Taras Parfylo (GSI), Dr Vasily Marusov

16:20 → 16:40 SSW advancement and challenges

Speakers: Daryl Bao Wen Teo (GSI - Helmholtzzentrum fur Schwerionenforschung GmbH (DE)), Matthias Bonora-Tam (CERN), Mr Taras Parfylo (GSI)

16:40 → 17:00 Conclusions and action plan

ALL