Plans for a Superconducting Proton Linac at CERN Part 2 R. Garoby – 10/06/2010

OUTLINE Introduction (SC linac) Low Power SPL in a new LHC injector complex High power SPL as a proton driver R & D plans

High Power SPL as a proton driver * Detailed during Workshop on “European Strategy for Future Neutrino Physics” CERN, 1-3 October 2009

SC-linac [160 MeV ® 5 GeV] with ejection at intermediate energy HP-SPL: Block diagram Compared to the LP-SPL, it requires: Upgrade of infrastructure (cooling water, electricity, cryogenics etc.) Replacement of klystron power supplies, Addition of 5 high b cryomodules to accelerate up to 5 GeV SC-linac [160 MeV ® 5 GeV] with ejection at intermediate energy 0 m 0.16 GeV 110 m 0.73 GeV 291 m 2.5 GeV 500 m 5 GeV High Power SPL as a proton driver Medium b cryomodule High b cryomodules High b cryomodules Debunchers From Linac4 Ejection To PS2 and Accumulator 9 x 6 b=0.65 cavities 11 x 8 b=1 cavities 13 x 8 b=1 cavities EURISOL to Length: ~500 m

HP-SPL: main characteristics & options Beam characteristics of the main options Option 1 Option 2 Energy (GeV) 2.5 or 5 2.5 and 5 Beam power (MW) 2.25 MW (2.5 GeV) or 4.5 MW (5 GeV) 5 MW (2.5 GeV) and 4 MW (5 GeV) Rep. frequency (Hz) 50 Protons/pulse (x 1014) 1.1 2 (2.5 GeV) + 1 (5 GeV) Av. Pulse current (mA) 20 40 Pulse duration (ms) 0.9 1 (2.5 GeV) + 0.4 (5 GeV) Faster rep. rate Þ new power supplies, more cooling etc. High Power SPL as a proton driver 2 ´ beam current Þ 2 ´ nb. of klystrons etc .

SPL-based proton driver: principle [1/8] Parameter Basic value Range Beam energy [GeV] 10 5 - 15 Burst repetition rate [Hz] 50 ? Number of bunches per burst (n) 4 1 – 6 ? Total duration of the burst [ms] ~ 50 40 - 60 Time interval between bunches [ms] (tint) 16 ~ 50/(n-1) Bunch length [ns] 2 1 - 3 Specifications (from ISS report) SPL – based Proton Driver SPL-based 5 GeV – 4 MW proton drivers have been designed [SPL + 2 fixed energy rings (accumulator & compressor)] which meet these requirements References: SPL based proton driver/ R. Garoby, talk at NuFact06, http://nufact06.physics.uci.edu/Workshop/Slides/RGaroby_SPL3_Pdriver.ppt Feasibility Study of Accumulator and Compressor for the 6-bunches SPL-based Proton Driver / M. Aiba, CERN-AB-2008-060 A first analysis of 3-bunches and 1-bunch scenario for the SPL-based Proton Driver / M. Aiba, CERN-AB-Note-2008-048-BI Beam Stability in the SPL Proton Driver Accumulator for a Neutrino Factory at CERN / E. Benedetto, http://nufact09.iit.edu/wg3/wg3_benedetto-splstability.ppt, to be published SPL-based Proton Driver for a Neutrino Factory at CERN, M. Aiba, E. Benedetto, R. Garoby, M. Meddahi, poster nb.25 (this workshop)

SPL-based proton driver: principle [2/8] Beam accumulation Accumulator ring Charge exchange injection ~nx100ms accumulation time Isochronous (h=0): beam frozen longitudinally to preserve Dp/p No RF (=> minimum impedance) 1-6 bunches of ~120 ns length Bunch compression Compressor ring Large RF voltage (large stored energy & minimum RF power) (=> bunch rotation on stored energy) Large slippage factor h => rapid phase rotation in few x10ms, ~2ns rms bunch length @ extraction to the target (=> moderate DQ because of dispersion) Synchronization between rings - Ratio of circumferences guaranteeing correct positioning of successive bunches inside the compressor without energy change in any ring SPL - based Proton Driver

SPL-based proton driver: principle - Generation of 6 bunches - [3/8] Accumulator SPL – based Proton Driver

SPL-based proton driver: principle - Generation of 6 bunches - [4/8] Accumulator [120 ns pulses - 60 ns gaps] Accumulation Duration = 400 ms Compression t = 0 ms t = 12 ms t = 24 ms t = 36 ms etc. until t = 96 ms SPL beam [42 bunches - 21 gaps] Compressor [120 ns bunch - V(h=3) = 4 MV] SPL – based Proton Driver Target [2 ns bunches – 6 times]

SPL-based proton driver: principle - Bunch rotation - [5/8] from M. Aiba SPL – based Proton Driver

SPL-based proton driver: principle - Ring parameters - [6/8] from M. Aiba SPL – based Proton Driver

SPL-based proton driver: principle - Alternatives with less bunches - [7/8] from M. Aiba SPL Accumulator SPL – based Proton Driver

SPL-based proton driver: principle - Alternatives with less bunches - [8/8] from M. Aiba Accumulator [~100 ns pulses ~110 ns gaps] Accumulation Duration = 400 ms Compression t = 0 ms t = 30 ms t = 60 ms etc. until t = 120 ms SPL beam [35 ± 7 bunches, 38 ± 7 gaps] Compressor [120 ns bunch - V(h=3) = 1.7 MV] SPL – based Proton Driver Target [2 ns bunches – 3 times]

R & D plans

R & D for a high power SPL Motivation Description Preserve potential for some alternative physics programmes (Neutrinos, RIB) Preserve possibility of new injectors at long term (e.g. DLHC option…) Update CERN competences in superconducting RF Synergy with other applications outside of CERN Description Focused on high beam power R & D only (no work on integration / civil engineering / environmental impact) SPL R & D status and plans

Organization Study leader: R. Garoby SPL Collaboration Coordinator External partners RF hardware (low level & high power) E. Ciapala Cockcroft Institute, ESS + (FNAL, SNS, JLAB, ANL) Cavities (structures & auxiliary equipment) W. Weingarten CEA-Saclay, CNRS-Orsay, TRIUMF, Stony Brook + (JLAB, SNS) Cryomodule (cryostat & cryogenics) V. Parma CEA-Saclay, CNRS-Orsay, Stony Brook + (FNAL) Beam dynamics (beam parameters) A. Lombardi CEA-Saclay, TRIUMF, Soltan Institute, ESS Architecture (layout & geometry, extraction, transfer) F. Gerigk Surface treatment and vacuum S. Calatroni Mechanical design and construction O. Capatina Working Groups SPL R & D status and plans Structured storage for all SPL documentation in EDMS Structured filing of all SPL meetings and workshops in Indico Structured filing of all collaboration meetings in Indico

Progress (from LP-SPL work) Choice of the main parameters of the SPL sc cavities (frequency, operating temperature and gradient) Choice of b=1 for the high energy cavities (F. Gerigk et al., “Choice of the optimum beta for the SPL SC cavities”) Debate & conclusion on HOMs damping needs [outcome of workshop on June 25-26 at CERN] Decision to pass one waveguide per cavity from technical gallery to accelerator tunnel Refinement of SPL beam parameters Updated accelerator layout with intermediate energy ejections Progress in the analysis of high power RF Start of work on SPL high power RF coupler Start of coordination of sc cavities development SPL R & D status and plans

Main meetings Six technical workshops: March 2010: Review of SPL RF couplers January 2010: RF needs for SPL sc cavities tests November 2009: Workshop on cryogenic and vacuum sectorisations of the SPL   September 2009: Mechanical issues SPL cavities/cryomodules   June 2009: SPL HOM workshop   April 2008: Status of analysis of SPL RF frequency and cooling temperature Three [4] Collaboration Meetings: [June 2010: 4th SPL Collaboration Meeting (Lund)] November 2009: 3rd SPL Collaboration Meeting (CERN) May 2009: 2nd SPL Collaboration Meeting (Vancouver) December 2008: 1st SPL Collaboration meeting (CERN) SPL R & D status and plans

R & D subjects until 2015 Partly addressed in sLHC-PP (in continuity with the work previously done for the LP-SPL) R & D towards a high duty cycle H- source (continued after end of SLHC-PP) Study of the optimum high power RF architecture for a high power SPL Design, construction and test of superconducting RF cavities (704 MHz – 5 cells – b=1) Development of high power RF coupler, HOM damper and adaptation of tuner Upgrade of the SM18 test place [2 K cooling + pulsed RF source at 704 MHz (1 MW @ 50 Hz )] Pulsed high power RF tests of contiguous cavities in a single cryostat Design, construction and test a high power klystron modulator Design, construction and test of a prototype cryomodule equipped with 8 b=1 cavities Treated in sLHC-PP Partly addressed in “EuCARD” Partly supported by French “in-kind” contrib. SPL R & D status and plans Partly supported by ESS

~ In-phase with ESS design update Planning for cavities and cryomodule 2011 2012 2013 2014 2015 Q1 Q2 Q3 Q4 SM18 - 2K Cryogenics V cryo. X SM18 modulator 1 2 SM18 - 704 MHz High Power RF High Power RF couplers 4 >4 >8 Superconducting cavities Assembled string of 4 cavities Horiz. short cryom. (4 cav.) Equipped horiz. short cryom. High power RF tests in short cryo. Assembled string of 8 cavities 8 cavities cryomodule Equipped cryomodule High power RF tests in full CM CERN design From ESS ~ In-phase with ESS design update

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ISOLDE & EURISOL RADIOACTIVE IONS LINAC EURISOL EXPERIMENTAL HALLS TARGETS EURISOL EXPERIMENTAL HALLS ISOLDE OR EURISOL HIGH ENERGY EXPERIMENTAL HALL TRANSFER LINE SPL to ISOLDE TRANSFER LINES SPL to EURISOL

MUON PRODUCTION TARGET ACCUMULATOR & COMPRESSOR Neutrino Factory MUON ACCELERATORS MUON PRODUCTION TARGET MUON STORAGE RING ACCUMULATOR & COMPRESSOR SPL