LARP Role in Plans for HL-LHC Upgrades Giorgio Apollinari - US LARP Director USLUO, UW Madison – November 6th- 8th, 2013

Three Strong Reasons for LHC Upgrade hypothetical luminosity evolution By continuous performance improvement and consolidation By implementing HL-LHC Almost a factor 3 J. Strait - 2003 1) after few years, statistical error hardly decreases 2) radiation damage limit of IR quadrupoles (~700 fb-1) reached by ~2020 =→ time for an upgrade! 3) extending physics potential!

Triplets Radiation Damage L. Bottura – RLIUP, Oct ’13 LTSW – FSU, November 2013

Context: Baseline LHC Upgrade Path Time Line: LS1*: “Nominal” (2013-2014) Complete repairs of the superconducting joint and pressure relief problems which caused “the incident” in 2008 and currently limit the energy to 4+4 TeV. “Lost memory” and retraining issues may limit the beam energy to somewhere between 6.5 and 7 TeV per beam. At least 1x1034 cm-2s-1 peak luminosity LS2: “Ultimate” (2017) injector and collimation upgrades At least 2x1034 cm-2s-1 peak luminosity LS3: “HL-LHC” (~2022-2023) Lower b* and compensate for crossing angle to maximize luminosity 5x1034 cm-2s-1 leveled luminosity LARP lives in the context of LS3, with some “test deliverables” needed by LS2

LTSW – FSU, November 2013

HL-LHC Working Packages Significant LARP and other US Involvement LTSW – FSU, November 2013

LARP History & Evolution The US LHC Accelerator Research Program (LARP) was formed in 2003 to coordinate US R&D related to the LHC accelerator and injector chain at Fermilab, Brookhaven, and Berkeley SLAC joined shortly thereafter Has also had some involvement with Jefferson Lab, Old Dominion University and UT Austin LARP has contributed to the initial operation of the LHC, but much of the program is focused on future upgrades The program is currently funded at a level of about $12-13M/year, divided among. Magnet research (~half of program) Accelerator research (Crab cavities, WBFS, Collimators, e-hollow lens,..) Programmatic activities, including support for personnel at CERN FY13-FY14 Evolution Initial convergences on deliverables for HL-LHC Program handled like a “project”

HL-LHC (main) magnet Needs Type Material Field/Gradient (T)/(T/m) Aperture (mm) Length (m) Q1,Q3 Q2 Single aperture Nb3Sn (12.1) 140 150 8 6.7 D1 Nb-Ti 5.2 D2 Twin aperture 3.5…5.0 95…105 7…10 Q4 (5.9) 90 120 4.2 DS 11T 10.8 60 11 Correctors and other (resistive) magnets not listed

A matter of conductors ! HTS 20+ T 16T 10 T

US in-kind Contribution to HL-LHC: a preliminary look Various Candidates: 150 mm aperture Nb3Sn quadrupoles Crab Cavities High Bandwidth Feedback System Collimation and hallow e-beams 11 T Nb3Sn dipoles Large Aperture NbTi D2 separator magnets Process of convergence among CERN-DOE-U.S. Labs-LARP initiated in Dec ‘2012 Initial consensus on core Priorities: Committed to a major stake in Nb3Sn quads Crab cavities up to the SPS test and possibly beyond to production High bandwidth feedback was seen as a high impact contribution for modest resources. Back up options: 11 T dipoles Proper “hand-off” if not continued in US Hollow electron beams for halo removal Support R&D into this effort in the event it’s chosen as a primary technology and circumstances allow its funding. Low priority There was not much interest in pursuing the D2 separators. More than 75% of possible US Contribution to HL-LHC

HL-LHC Nb3Sn Magnets IR Magnet 4 Q1 and 4 Q3 (2 per IR) plus 1 spare each from US Q1 and Q3 will probably contain 2 ~4.5 m long magnets each, for a total of ~20 qudrupoles 4 Q2a and 4 Q2b from CERN Option still open on the lenght of Q2. E. Todesco

Ten years of intense R&D Subscale Quad. SQ 0.3 m long 110 mm bore 2004-2006 SQ02 TQS01 LRS01 Technology Quadrupole TQS - TQC 1 m long 90 mm bore 2006-2010 Long Racetrack LRS 3.6 m long No bore 2006-2008 LQS01 LQS03 Long Quadrupole LQS 3.7 m long 90 mm bore 2007-2012 G > 170 T/m Very Preliminary ! HQ01b-c HQ01d-e HQ02 High Field Quadrupole HQ 1 m long 120 mm bore 2008-2014 Summary graphics by courtesy of G. Sabbi and H. Felice (LBNL)

Long Magnets: LQS of LARP 3.3 m coils, 90 mm aperture Goal: 200 T/m at 1.9 K LQS01a: 202 T/m at 1.9 K LQS01b: 222 T/m at 4.6 K 227 T/m at 1.9 K LQS02: 198 T/m at 4.6 K 150 A/s 208 T/m at 1.9 K 150 A/s limited by one coil LQS03: 208 T/m at 4.6 K 210 T/m at 1.9 K 1st quench: 86% s.s. limit

S(L)QXF Models & QXF Production 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 Coil tooling Model Coil fabrication (SQXF) Support structure Model Magnet Construction Prototype tooling Prototype construction (LQXF) Series production Installation S(L)QXF Models Short and Long QXF Models will require approximately 1.0 metric Ton of Nb3Sn in US ordered by FY15 (more at CERN) Series Production US scope: 20 4.5 m long quads, i.e. 80 coils (UL=450m) Unit Weigth ~ 100Kg/coil: total 8-8.5 metric Tons of Nb3Sn. Considerable faction (~30-40%) needs to be available in cable format by early 2018 Assuming 18 months for strand delivery and ~few months for QC and cabling, a large order from US HL-LHC needs to be placed by late 2015/early 2016.

11 T Development This Ain’t LARP At this time not a US in-kind contribution. Intellectually relevant as R&D program toward high field, accelerator quality, dipoles and a possible 100 km machine

Collimators and 11T Dipoles This Ain’t LARP Create space for additional collimators by replacing 8.33 T MB with 11 T Nb3Sn dipoles compatible with LHC lattice and main systems. 119 Tm @ 11.85 kA (in series with MB) MB.B8R/L 11 T Nb3Sn MB.B11R/L 15,66 m LS2 : IR-2 4 MB => 8 x 5.5 m CM + spares LS3 : IR-1,5 and Point-3,7 4 x 4 MB => 32 x 5.5 m CM + spares 5.5 m Nb3Sn 3 m Collim 5.5 m Nb3Sn 3 m Collim Focus of joint R&D program aimed at Accelerator Quality Magnets between CERN and US. R&D program to be completed in US with conclusion of Short (1m) Models.

11T Dipole R&D This Ain’t LARP Success ! Single aperture model Twin aperture model Second Nb3Sn Accelerator Quality Dipole (1m long) – Dec ‘12 Success !

Crab Cavities UK LARP Additional benefit Currently aiming for: Without some compensation for crossing angle, Reducing the b* will only increase luminosity by ~75% ! “Piwinski Angle” Technical Challenges Crab cavities have only barely been shown to work. Never in hadron machines LHC bunch length requires low frequency (400 MHz) 19.4 cm beam separation needs “compact” (exotic) design Additional benefit Crab cavities are an easy way to level luminosity! Currently aiming for: Down-select ~next year SPS test in 2015 UK LARP

First test of CC (ODU-SLAC at J-LAB)

RF-Dipole Nb prototype “Crab Kissing” Scheme RF-Dipole Nb prototype DQWR prototype 17-Jan-2013 New crossing strategy under study to soften the pile-up density: some new schemas have interesting potential as “crab-kissing”, to be discussed with all experiments “Pile-up at HL-LHC and possible mitigation” Stephane Fartoukh on Wed. 2nd Oct. USLUO, November 2013

CC Cryomodules UK Concept BNL Concept D2 Q4 IP 11 meters

SPS Test (2016-2017) Cryo layout

High Bandwidth Feedback System The high bandwidth feedback system is a proposed feedback system for the SPS, which leverages LARP experience with the LHC LLRF system, to address intra-bunch instabilities Proposal LARP will continue R&D related to the system. The deliverable would be a functional feedback system the SPS, for which The US contribution would be the complete, full-function, instability control system hardware, firmware and software necessary to operate at the SPS (and potentially LHC, PS). The CERN contribution will include the vacuum structures (pickup(s) and kicker(s)) and all tunnel related cable plant.

Conclusion Strong domestic program and collaboration with CERN for HL-LHC upgrade First proposal for down-selection of deliverables IR quads Crab cavities High Bandwidth Feedback System LARP tasked with risk reduction in 2014-2017 in preparation for Project era (‘18-’22). LTSW – FSU, November 2013