Dynamic field effects in main LHC dipoles
Sponsored Links
This presentation is the property of its rightful owner.
1 / 4

Dynamic field effects in main LHC dipoles PowerPoint PPT Presentation


  • 55 Views
  • Uploaded on
  • Presentation posted in: General

Dynamic field effects in main LHC dipoles. During ramps, boundary-induced coupling currents (BICCs) are induced in the LHC cable creating a field ripple with period  twist pitch length

Download Presentation

Dynamic field effects in main LHC dipoles

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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Dynamic field effects in main LHC dipoles

  • During ramps, boundary-induced coupling currents (BICCs) are induced in the LHC cable creating a field ripple with period  twist pitch length

  • BICCs diffuse along the cable during stationary excitation with time constants  1000 s, leading to demagnetization of allowed harmonics of the order of a few units (decay)

  • As soon as current ramping is resumed, the field snaps back to (almost) the previous hysteresis curve with an exponential law vs. magnet current

  • Decay and snapback amplitudes depend to some extent upon all cycle parameters, mostly: - increase (~linearly) with pre-cycle flat-top current- increase with pre-cycle flat-top duration- decrease with pre-injection duration


Decay and snapback in model LHC dipoles vs. injection current

Parametric study carried out on 1 m long model magnet shows no clear evidence of the dependence of absolute harmonic effects vs Iinj


Decay and snapback in main LHC dipoles vs. injection current

Absolute B3 decay: reduction of 15% from 0.45 TeV to 1 TeV injection(influence of longer ramp to injection not taken into account)


Decay and snapback in main LHC dipoles vs. injection current

Normalized B3 decay: reduction of a factor 2.6 from 0.45 TeV to 1 TeV injection


  • Login