1 / 17

“new ” ideas

pile-up leveling versus luminosity leveling schemes r eminder - satellite bunches extremely flat collisions – flat beams?. “new ” ideas. Frank Zimmermann HL-LHC/LIU Joint Workshop 30 March 2012. example HL-LHC parameters. luminosity leveling at the HL-LHC. L ave [10 34 cm -2 s -1 ].

reece-lucas
Download Presentation

“new ” ideas

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. pile-up leveling versus luminosity leveling schemes • reminder - satellite bunches • extremely flat collisions – flat beams? “new” ideas Frank Zimmermann HL-LHC/LIU Joint Workshop 30 March 2012

  2. example HL-LHC parameters

  3. luminosity leveling at the HL-LHC Lave [1034 cm-2s-1] w/o leveling virtual peak luminosity leveling at 5x1034cm-2s-1 k=2, teff=15 h, Tta=5 h tlev tdec tta leveling at 2.5x1034cm-2s-1 k=8, teff=30 h, Tta=5 h t [h]

  4. key equations effective beam lifetime maximum leveling time for given luminosity teffscales with total beam current virtual peak luminosity (s=100 mb) optimum total luminosity optimum “decay time” after leveling

  5. average luminosity vs. tdec Lave [1034 cm-2s-1] pile up 95, turnaround time -= 5 h 2.72 25 ns leveling at 5x1034cm-2s-1 k=2, teff=13.5 h, Tta=5 h 1.89 leveling at 2.5x1034cm-2s-1 k=4, teff=27 h, Tta=5 h 50 ns same emittance, same pile up (95), same total beam current, same beta*, same crossing angle, tta=5 h tdec [h]

  6. average luminosity vs. tta Lave [1034 cm-2s-1] leveling at 5x1034cm-2s-1 k=2, teff=13.5 h, Tta=5 h 25 ns leveling at 2.5x1034cm-2s-1 k=8, teff=27 h, Tta=5 h 50 ns same emittance, same pile up (95), same total beam current, same beta*, same crossing angle, optimum decay time tta [h]

  7. average luminosity vs. pile up Lave [1034 cm-2s-1] 25 ns 50 ns same emittance, same (but possibly varying) total beam current, same (but varying) beta*, same crossing angle, optimum decay time pile up

  8. average vs. leveled luminosity Lave [1034 cm-2s-1] 50 ns 25 ns same emittance, same (but possibly varying) total beam current, same (but varying) beta*, same crossing angle, optimum decay time Llev [1034 cm-2s-1]

  9. performance with leveling for equal emittances & equal total beam current 25 ns gives 20-50% more integrated luminosity than 50 ns for equal pile up below ~150 25 ns and 50 ns yield equal integrated luminosity for the same pile up of ~175 50 ns delivers 20-50% more integrated luminosity than 25 ns at higher pile up

  10. controlled satellites for 50 ns mode e-cloud heat load almost unchanged by adding the satellites H. Maury constant luminosity 2x1033 cm-2s-1 at LHCb while luminosity changes in IPs 1 & 5 constant luminosity 2x1033cm-2s-1 at LHCb while luminosity changes in IPs 1 & 5

  11. LHC flat beams with b*x>>b*y LHC crab waist requires sx/sy≥10 (M. Zobov, D. Shatilov, 2010); → separate doublets & large Qc Jose Abelleira, Mikhail Zobov, Frank Zimmermann

  12. Mikhail Zobov, Dmitry Shatilov Angle = 2.0 mrad CW = 0 CW = 0.5

  13. “double half” quadrupole Stephan Russenschuck, Jose Abelleira,Frank Zimmermann

  14. a flat-beam optics sextupoles for local chromatic correction in y crab-waist sextupole Jose Abelleira

  15. even flatter beams, b*x>>b*y & ex>ey b*x ex/ey b*y ex/ey Jose Abelleira

  16. extremely flat beams, b*x>>b*y & ex>ey peak luminosity Nb=2x1011 25 ns spacing qc=3.9 mrad ex/ey Jose Abelleira

  17. conclusions 25-ns or 50-ns can deliver the same average luminosity or the same pile upat most 30-50% difference (for the same emittance and same total current); optimum choice depends on detectors and physics case generating controlled satellites in the injectors should be kept in mind for all 50-ns scenarios can the injectors deliver “flat” beams – and with which performance?

More Related