1 / 41

R&D Topics for the Phase II Upgrade of the LHC

R&D Topics for the Phase II Upgrade of the LHC. Eric Prebys, Fermilab Director, US LHC Accelerator Research Program (LARP). Outline. Limits to LHC Luminosity LHC Upgrade Plans and Schedule LARP-affiliated Upgrade Projects Nb 3 Sn Magnet Program PS2 Project Crab Cavities. LHC Luminosity.

kirkpatrickr
Download Presentation

R&D Topics for the Phase II Upgrade of the LHC

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. R&D Topics for the Phase II Upgrade of the LHC Eric Prebys, Fermilab Director, US LHC Accelerator Research Program (LARP)

  2. Outline • Limits to LHC Luminosity • LHC Upgrade Plans and Schedule • LARP-affiliated Upgrade Projects • Nb3Sn Magnet Program • PS2 Project • Crab Cavities E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  3. LHC Luminosity • Because the LHC is a p-p machine, high luminosity is needed to extend the physics reach to reasonable fraction of the beam energy for the physics processes of most interest: Higgs, SUSY, etc… • Current plan: • come up “fairly quickly” to 1034 cm-2s-1 • Increase luminosity over the next decade to as high as 1035 cm-2s-1, assuming the detectors show they can handle it. E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  4. Limits to LHC Luminosity* • Brightness, limited by • PSB injection energy • PS • Max tune-shift Beam current, limited by e-cloud and other instabilities • b*, limited by • magnet technology • chromatic effects Geometric factor, related to crossing angle… *see, eg, F. Zimmermann, “CERN Upgrade Plans”, EPS-HEP 09, Krakow, for a thorough discussion of luminosity factors. E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  5. Current LHC Acceleration Sequenceand Brightness Issues Space Charge Limitations at Booster and PS injection Transition crossing in PS and SPS Schematic ONLY. Scale and orientation not correct E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  6. IR Layout • Nominal Bunch spacing: 7.5 m • Collision spacing: 3.75 m • ~2x15 parasitic collisions per IR Separation Dipole Final Triplet IP ~59 m Implement Crossing Angle E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  7. Crossing Angles Luminosity effects E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  8. Crossing Angle Considerations • Crossing angle reduces luminosity • However, crossing angle also reduces tune-shift • In principle, the two effects should cancel “Piwinski Angle” “Large Piwinksi Angle” (LPA) Solution E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  9. Other Option: Crab Cavities • Possibilities • 2 or 4 cavities in “global” scheme • Implications for apertures/collimation • 8 for full “local” • Main Technical question • Space constraints -> 800 MHz elliptical (simple) versus 400 MHz “exotic”. • Critical review at CERN in September E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  10. Without Compensation Separation of first parasitic interaction Nominal crossing angle with no compensation (9.5s) G. Sterbini E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  11. LHC Upgrade path • Initial operation • Ramp up to 1x1034 cm-2s-1 • Phase I upgrade • After ~2 years of operation (~2013) • Replace 70 mm triplet quads with 120 mm quads • b* goes from 50->30 cm • Linac4 to increase PSB injection energy to reduce space charge effects • Luminosity goes to 2.5x1034 cm-2s-1 • Phase II upgrade • Second half of next decade (nominally 2020) • Luminosity goal: 1x1035 • Details still under study • New technology for larger aperture quads (Nb3Sn) • crab cavities? • Improved injector chain (PS2 + SPL) No major changes to optics or IR’s Possible Significant Changes E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  12. LHC Parameters and Options excerpted from F. Zimmermann, “LHC Upgrades”, EPS-HEP 09, Krakow, July 2009 E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  13. Common Upgrade Elements • All require a magnet technology beyond NbTi for the final focusing triplets • Almost certainly Nb3Sn • All require Increased brightness, currently limited by • Space charge + painting effects of 50 MeV proton injection at injection into PSB. • Will be addressed by Linac4 upgrade for Phase I • Space charge and transition crossing effects in (50 year old!) PS Replace PS with new PS2 E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  14. PS2 Goal: Double brightness to LHC *Chosen based in tune-shift limit at injection ** Chosen to be well above SPS transition M. Benedikt, PS2 Internal Review, May 2008 E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  15. PS2 vs Fermilab Main Injector Clearly significant synergy between PS2 and MI in Project X era *see talk by S. Nagaitsev, this conference E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  16. New CERN machines E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  17. Injector Upgrade Initial Phase I Proton flux / Beam power Linac4 Linac2 50 MeV 160 MeV Phase II PSB SPL’ RCPSB SPL 1.4 GeV ~ 5 GeV PS Linac4: PSB injector (160 MeV) SPL: Superconducting Proton Linac (~ 5 GeV) SPL’: RCPSB injector (0.16 to 0.4-1 GeV) RCPSB: Rapid Cycling PSB (0.4-1 to ~ 5 GeV) PS2: High Energy PS (~ 5 to 50 GeV – 0.3 Hz) PS2+:Superconducting PS (~ 5 to 50 GeV – 0.3 Hz) SPS+: Superconducting SPS (50 to1000 GeV) DLHC: “Double energy” LHC (1 to ~14 TeV) 26 GeV PS2 (PS2+) 40 – 60 GeV Output energy SPS SPS+ 450 GeV 1 TeV LHC DLHC 7 TeV ~ 14 TeV M. Benedikt, R. Garoby, CERN DG E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  18. US LHC Accelerator Research Program (LARP) • Proposed in 2003 to coordinate efforts at US labs related to the LHC accelerator (as opposed to CMS or ATLAS) • Originally FNAL, BNL, and LBNL • SLAC joined shortly thereafter • Some work (AC Dipole) supported at UT Austin • LARP Goals • Advance International Cooperation in High Energy Accelerators • Advance High Energy Physics • By helping the LHC integrate luminosity as quickly as possible • Advance U.S. Accelerator Science and Technology • LARP includes projects related to initial operation, but a significant part of the program concerns the LHC upgrades E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  19. LARP Contributions to initial LHC Operation • Schottky detector • Used for non-perturbative tune measurements (+chromaticities, momentum spread and transverse emmitances) • Tune tracking • Implement a PLL with pick-ups and quads to lock LHC tune • Investigating generalization to chromaticity tracking • AC dipole • US AC dipole to drive beam • Measure both linear and non-linear beam optics • Luminosity monitor • High radiation ionization detector integrated with the LHC neutral beam absorber (TAN) at IP 1 and 5. • Personnel • Toohig Fellowship Postdoc program • Long Term Visitors E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  20. Significant LARP Contributions to LHC Upgrades • Rotatable Secondary Collimators • Required to meet Phase I luminosity goals • Electron Cloud Feedback for SPS • Will be needed to handle increased intensity after PS2 • Nb3Sn Magnet Program • Goal: demonstrate Nb3Sn as a viable magnet technology on a time scale that will allow accelerator quality magnets to be built for Phase II • PS2 Activities, primarily • Space charge effects • Electron cloud effects • LARP will contribute for 2012 “white paper”, and then take part in further design R&D • Crab Cavities? • LARP currently steering R&D • Future depends on CERN’s decisions I will focus on these E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  21. LARP Magnet program • Magnet groups at FNAL, BNL, and LBNL working to demonstrate that Nb3Sn is a viable technology for use in the LHC Phase II upgrade. • Currently pushing all parameters • Long Quad (LQ): 4m quad with 90 mm aperture • High field Quad (HQ): 1m quad with 120 mm aperture • “Deliverables” will be • “accelerator quality” magnets (HQ-2) matched to LHC Phase I aperture • Length: 2 m • Aperture: 120 mm • Gradient: >200 T/m • Long magnet with detailed field quality studies • Length: 6 m • Aperture: 90 mm • Gradient: > 220 T/m • Accelerator physics questions: • Optical design • Field quality requirements • Beam loss/heat loading issues • Radiation damage. E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  22. Motivation for Nb3Sn • Nb3Sn can be used to increase aperture/gradient and/or increase heat load margin, relative to NbTi • Very attractive, but no one has ever built an accelerator quality magnet out of Nb3Sn Phase I magnets 120 mm aperture E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  23. Competing Magnet Designs • Collar: • Traditional magnet design • Pre-load provided by a series of collars which hold coils in place. • Shell: • New concept • Pre-load produced by inflatable bladder, and secured by insertable keys. E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  24. LARP Technology Quadrupole (TQ) Program • Double-layer, shell-type coil • 90 mm aperture, 1 m length • Two support structures: • - TQS (shell based) • - TQC (collar based) • Target gradient200 T/m TQC TQS Winding & curing (FNAL - all coils) Reaction & potting (LBNL - all coils) G. Sabbi, LARP Review, July 2009 E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  25. Initial TQ (90 mm x 1m) Results • Two coil/model series using different wire design • 30 coils fabricated, distributed production line • 11 tests performed (FNAL, LBNL and CERN) • Surpassed 200 T/m with 10% margin (TQS02a/c) • All training quenches >200 T/m in TQS02c/d TQ01 OST-MJR 54/61 TQ02 OST-RRP 54/61 61 Results of TQS02c test (CERN) SSL 1.9K SSL 4.4K Stability issues at 1.9K (LHC operating point) E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  26. Conductor Tests at Fermilab Mirror Magnet Facility (TQM) • Hypothesis: smaller filament increases conductor stability • Conclusion: switch to new 108/127 conductor for future magnets Smaller filament conductor (RRP 108/127) Traditional conductor (RRP 54/61) E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  27. Comparing Technologies • Collar: • Good: • Established technique with NbTi magnets • Straightforward to scale from short prototypes to long magnets • Alignment and heat distribution problems solved • Bad: • As yet no design to reach the highest gradients/apertures (excessive stress). • Difficult to replace damaged coils • Shell: • Good: • Can achieve higher gradients/apertures than collar design • Much easier to disassemble and replace damaged coil • Bad: • New • Differential contraction problems when scaling to longer magnets • Some alignment and heat distribution problems must be solved. • Tentative conclusion Pursue shell design E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  28. HQ (120 mm x 1 m) Status • Based entirely on shell concept • Design and modeling ~complete • Structure being procured • Coil fabrication in process • Complete two prototypes in 2010 E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  29. Long Quad (90 mm x 4m) Status • 4 coils ~ready for (LQS01) assembly • Shell-structure is ready • Pre-assembly practice in progress • Readiness review: ~July 27 • Test prep ~completed • Readiness review TBD • Ready to test in October 2009 G. Ambrosio, LARP Review, July 2009 E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  30. Schedule of Magnet Program • Work to finalize the magnet plan and demonstrate the technology in the context of the Phase II upgrades • Assume ~5 year production schedule for triplets based on Nb3Sn • Even if Phase-II is in 2020, there will have to be overlap between production and R&D Existing Magnet Program Future Construction Project E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  31. PS2 Design Outline* • Coordination and basic lattice design • Linear correction systems • Non-linear dynamics and correction systems • Collective effects and feedback systems • Space charge studies • Impedance estimates and instabilities • e- cloud effects and vacuum system requirements • Damping system specifications • Collimation aspects • Machine protection • Instrumentation specifications and commissioning strategy Our Involvement *M. Benedikt and Y. Papaphilippou E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  32. PS2 Space Charge Simulations J. Qiang E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  33. PS2 Electron Cloud Simulations • Goal: develop mitigation techniques, particularly RF feedback • LARP will contribute sections to 2012 white paper, then participate in design R&D MI PS2 M. Furman E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  34. Crab Cavities • LARP steering international effort to propose a viable crab cavity design • Includes collaborators from CERN, US, UK, and Japan • Working toward major technology down selection • 800 MHz elliptical vs. 400 MHz “exotic” • Damping scheme • Critical review at CERN in September E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  35. Recent success at KEKB • Crab Cavities enabled a peak luminosity of • 20+ years after crab cavities initially proposed • Hopefully a bit faster next time > 2x design 1x1034 cm-2 s-1 Z. Doležal, EPS-HEP 09, Krakow, July 2009 E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  36. R. Calaga, LARP DOE Review, July 2009 E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  37. R. Calaga, LARP DOE Review, July 2009 E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  38. Cavity and Cryomodule Design Status • 2 cell SRF cavity @800 MHz • 3 aggressive damping schemes • LARP, KEK, UK • Down selection • Multipacting, thermal, mechanical etc... • Cryostat development underway (FNAL) • interfaces, • RF-cryogenic-mechanical constraints E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  39. 5-6 Year Plan CERN Review E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  40. Things I didn’t have time to talk about • A great deal of work at CERN • NbTi program for Phase I • Details of accelerator physics for Phase II • Additional injector projects for Phase I and Phase II • Linac 4 • SPL • Additional PS2 topics • US Tasks outside of LARP • Superconducting separators and feedboxes for Phase I (“APUL” project) • Important LARP tasks • Beam-beam simulation and compensation, particularly electron lens • Crystal Collimation • LLRF projects • Additional instrumentation projects E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

  41. Acknowledgements • This talk represents the work of many people, in particular • Within LARP • Peter Wanderer, Tom Markiewicz, GianLucca Sabbi, Giorgio Ambrosio, Sasha Zlobin, Wolfram Fischer, Rama Calaga, Arup Ghosh, Uli Wienands • Too many to mention from CERN, but I’ve borrowed material directly from • Frank Zimmermann, Michael Benedikt • Thanks to the conference organizers and the audience E. Prebys, LHC Upgrades - VIII International Workshop in Memory of V.P. Sarantsev, Alushta, Ukraine

More Related