IPP 2025-10-11

Status on Hysteresis Compensation


Contents


Recap - Hysteresis Compensation

  • Hysteresis compensation by compensating fields directly

Recap - Hysteresis Compensation in SPS

Benefits in current operation


Eddy current decay on main magnet circuits

Show plots on B-Train vs orbit decays measured on beam Show plots on lab QF vs tune decays measured on beam


Chromaticity change due to dipole precycle

  • Removing (flattening) the dipole precycle changes 3rd order multipole
    • Chromaticity measured with and without MD1
    • Chromatic sextupoles would be needed to compensate
    • Dipole compensation might need also sextupoles
  • Removing precycle (in cycle time) needs characterization and compensation on main quadrupoles
    • TBD, but might not be possible from magnetic measurements

Challenges

Blocking points


Future & outlook

  • Anton’s DOCT contract finishes in January 2026 - before SPS beam commissioning
  • Additional Parallel MDs for determining the impact of SPS quadrupole precycle effect
  • Additional Dedicated MD for flat bottom compensation.

Conclusion