Take worst case
This presentation is the property of its rightful owner.
Sponsored Links
1 / 11

Take worst case PowerPoint PPT Presentation


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

Take worst case. MKI.D5R8.B2:TEMP_MAGNET_DOWN. Analysis of heating. Took all fills (to end September) where in stable beams for longer than 10 h Considered only time from top of ramp onwards Used number of bunches, average bunch current and bunch length as inputs

Download Presentation

Take worst case

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


Take worst case

Take worst case

MKI.D5R8.B2:TEMP_MAGNET_DOWN


Analysis of heating

Analysis of heating

  • Took all fills (to end September) where in stable beams for longer than 10 h

  • Considered only time from top of ramp onwards

  • Used number of bunches, average bunch current and bunch length as inputs

  • Fitted initial heating rate (~linear) over first 2 hours as measure of power in

  • Used cooling after beam off for measure of power out


Analysis to end september

Analysis (to end September)


Model including cooling

Model including cooling

  • Semi-empirical model makes reasonable predictions

    • Replicates cooling after about 12 h

    • Assuming heating from beam power ( Nb, Ib^2, 1/Lb^2), cooling from radiation ( DT^4) and from conduction ( DT)


Cooling coefficients

Cooling coefficients

  • Used cooldowns at technical stops or MDs


Outlook for 2012

Outlook for 2012

2600 bunches


Longer term behaviour

Longer-term behaviour

  • Saturation of temperature after a few fills

    • Assumed 15 h coast, 4h turnaround (to 3.5 TeV)

50 ns, 1.6e11 per bunch


Temperature at injection

Temperature at injection

  • Cooling at about 3 deg per hour

    • Cool to ‘interlock’ level after less than 1 h after dump

    • Cool to 334 K (61 C) after 2 h

50 ns, 1.6e11 per bunch


Temperature at injection1

Temperature at injection

  • With 2e11 in 50 ns might be in trouble

    • 2 h to cool to interlock limit

    • 4 h to reach 334 K (61 C)

50 ns, 2.0e11 per bunch


Looks better for 25 ns

Looks better for 25 ns

  • Cooling at about 3 deg per hour

    • Cool to ‘interlock’ level after less than 1 h after dump

    • Cool to 334 K (61 C) after 2 h

50 ns, 1.6e11 per bunch


Conclusions

Conclusions

  • Worse for 2012 if push 50 ns intensity

    • Might affect operation at 2e11 per bunch

  • 25 ns seems to have more margin – looks OK for 1.1e11 per bunch and 2600 b


  • Login