1 / 13

Dynamic Effects on Quadrupoles: Insights and Measurement Challenges

This study examines the dynamic effects on quadrupole magnets, particularly focusing on coupling current effects and resistive contact at cross-overs. It explores the complex interactions of current redistribution within superconducting cables and their impact on local fields and magnetization. The measurements utilized a 6-m twin rotating coil system, capturing integrated and local transverse fields over time and current conditions. Notably, the decay phenomena under constant current excitation were analyzed, revealing significant randomized behaviors, particularly in multipole parameters during different machine cycle scenarios. Conclusions highlight the need for further specialized measurements to understand these dynamic effects comprehensively.

clea
Download Presentation

Dynamic Effects on Quadrupoles: Insights and Measurement Challenges

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Dynamic effects on Quadrupoles S.Sanfilippo, N.Sammut, L.Bottura ,W.Venturini. AT-MTM

  2. Dynamic effects on quadrupoles_1 • Coupling current effects resistive contact at cross-overs Rc  dB/dt • Advance in field Db2dB/dt and 1/Rc • Allowed and non allowed multipole errors Dbrrn, Darrn. • No measurements in quadrupoles magnets for the moment.

  3. Dynamic effects on quadrupoles_2 • Decay • appears during constant current excitation. • associated with current redistribution in the superconducting cables. • result of a complex interaction: current redistribution  local field  magnetization  bore field • assume that the dynamics follows that of current diffusion: Powering history dependence

  4. Decay Measurement. Quantities measured :Integrated and local TF and harmonics as a function of time and current. System used :6-m twin rotating coil. Repeatability : 0.3 units (b2), 0.02 units (b6). • Parameters. I nominal I nominal I injection quench 50 A • Statistics : 9 MQs and 6 MQYs. Simulated Machine Cycle for MQ: decay at injection. Measurements performed after the training of the MQ,MQY up to ultimate.

  5. Decay results for MQs @760 A, 1000s

  6. Decay results for MQs (multipoles) @760 A, 1000s Feeble systematic. Significant random.

  7. Decay modelling for b2, b6. MQ

  8. Decay results for MQYs

  9. Decay results for MQYs (multipoles) @176 A, 1000s High value for a3 and a4 (systematic and random) enhanced by the behavior of SSS635!

  10. Example of SSS635. 6 units at 176 A! Decay @176 A, 1000s -2 units of decay.

  11. Decay modelling for b2, b6 MQY

  12. Decay results for TF of MQYs, MQM (block 4) average Statistic on 3 MQMs Statistic on 6 MQYs Still large random, smaller systematic than in SM18. Difficult to model (noise in the measurements).

  13. Conclusions and issues. • Decay of MQY, MQM, MQ quadrupole types: • Significant for b2 (-6 units,-4 units, -3 units), large random. • For b6 between 0.4 units and 0.6 units . • Strange behaviors in SM18 for non allowed multipoles (ex: SSS635). • Special measurements to be performed (2006, 2007). • Effect of the ramp rate (14 units foreseen for b2 for Rc~15mW, R. Wolf). • Influence of the pre-cycle on the decay (on spare magnets in 2007?). • flat-top current IFT • flat-top duration tFT • waiting time before injection tpre-injection • Injection duration.

More Related