Linear Collider – Next Steps in R&D

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Linear Collider Next Steps in R&D. Nan Phinney SLAC. many slides courtesy of G. Geshonke EPS 2009 C. Adolphsen, F. Zimmermann and others. Linear Collider Luminosity. n b : bunches / train N: Particles / bunch A: beam cross section at IP H D : beam-beam enhancement factor. where. - PowerPoint PPT Presentation

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  • Linear Collider Next Steps in R&DNan PhinneySLACmany slides courtesy of G. Geshonke EPS 2009 C. Adolphsen, F. Zimmermann and others

    2009 SLUO Meeting Sept 17, 2009

  • Linear Collider Luminositynb : bunches / trainN: Particles / bunchA: beam cross section at IPHD: beam-beam enhancement factorBUTPbeam = Pwall plug * conversion efficiency two-linac length 2L ~ ECM/(Ffilling factor x Ggradient)

    This points to the critical issues in optimizing the cost of the collider Efficiency sets the electrical power required for a given beam power Accelerating gradient sets the length required for a given energy

    ILC & CLIC take different routes to high efficiency and high gradientwhere

    2009 SLUO Meeting Sept 17, 2009

  • The ILC Reference Design200-500 GeV centre-of-massLuminosity: 21034 cm-2s-1Based on accelerating gradient of 31.5 MV/m (1.3GHz SCRF)~31 kmN.Walker

    2009 SLUO Meeting Sept 17, 2009

  • SCRF Technology RequiredA. Yamamoto

    ParameterValueC.M. Energy500 GeVPeak luminosity2x1034 cm-2s-1Beam Rep. rate5 HzPulse time duration1 msAverage beam current 9 mA (in pulse)Av. field gradient31.5 MV/m# 9-cell cavity14,560# cryomodule1,680# RF units560

    2009 SLUO Meeting Sept 17, 2009

  • R. Geng, JLabBREAKING NEWS !!!!JLAB press release today announced the first US built cavity to reach ILC specs

    2009 SLUO Meeting Sept 17, 2009

  • SRF Test FacilitiesA. Yamamoto

    2009 SLUO Meeting Sept 17, 2009

  • New L-Band Station at ESB: Marx Modulator and 10 MW Toshiba Multi-Beam KlystronC. Adolphsen

    2009 SLUO Meeting Sept 17, 2009

  • Sheet Beam Klystron DevelopmentAn elliptical beam is focused in a periodic permanent magnet stack that is interspersed with rf cavitiesElectronBeamPermanentMagnet CellRF cavityMagnetic ShieldingLead ShieldingGun in assembly

    2009 SLUO Meeting Sept 17, 2009

  • Coupler Assembly and ProcessingClass 10 Cleanroom @SLACProcessed in pairs shipped to FNAL

    2009 SLUO Meeting Sept 17, 2009

  • RF Distribution Modules with variable tap offVariable tap off allows power adjustment to each cavity 4 2-cavity modules sent to FNAL

    2009 SLUO Meeting Sept 17, 2009

  • Two 4.5 to 5.5 m diameter tunnels spaced by ~7 m.RDR Baseline Tunnel LayoutAccelerator TunnelService TunnelPenetrations(every ~12 m)one klystron feeding 26 cavitiesC. Adolphsen

    2009 SLUO Meeting Sept 17, 2009

  • Klystron Cluster ConceptRF power piped into accelerator tunnel every 2.5 km Service tunnel eliminatedElectrical and cooling systems simplifiedConcerns: power handling, LLRF control coarsenessSame as baselineC. Adolphsen

    2009 SLUO Meeting Sept 17, 2009

  • TDP Goals of ILC-SCRF R&DField Gradient 35 MV/m for cavity performance in vertical test (S0)31.5 MV/m for operational gradient in cryomodule to build two x 11 km SCRF main linacsCavity Integration with Cryomodule Plug-compatible development to: Encourage improvement and creative work in R&D phaseMotivate practical Project Implementation with sharing intellectual work in global effortAccelerator System Engineering and TestsCavity-string test in one cryomodule (S1, S1-global) Cryomodule-string test with Beam Acceleration (S2)With one RF-unit containing 3 cryomoduleA. Yamamoto

    2009 SLUO Meeting Sept 17, 2009

  • *ILC R&D plan

    2009 SLUO Meeting Sept 17, 2009

  • The CLIC Two Beam SchemeTwo Beam Scheme:Drive Beam supplies RF power

    12 GHz bunch structure low energy (2.4 GeV - 240 MeV) high current (100A)CLIC parameters:

    Accelerating gradient: 100 MV/m RF frequency: 12 GHzPulse length 240 ns, 50 Hz

    active length for 1.5 TeV: 15 kmG. Geshonke

    2009 SLUO Meeting Sept 17, 2009

  • CLIC Drive Beam generationEPS 2009 G.Geschonke, CERNAccelerate long bunch train with low bunch rep rate (500 MHz) with low frequency RF (1 GHz) (klystrons)interleave bunches between each otherto generate short (280 ns) trains with high bunch rep rate (12 GHz)G. Geshonke

    2009 SLUO Meeting Sept 17, 2009

  • The full CLIC schemeNot to scale!G. Geshonke

    2009 SLUO Meeting Sept 17, 2009

  • optimum CLIC: 100 MV/m at 12 GHzStructure limits: RF breakdown scaling RF pulse heating Optimisation:Beam dynamics: emittance preservation wake fields Luminosity, bunch population, bunch spacing efficiency total powerFigure of merit: Luminosity per linac input powertake into account cost model100 MV/m 12 GHz chosen,previously 150 MV/m, 30 GHzA. Grudiev

    2009 SLUO Meeting Sept 17, 2009

  • CLIC Accelerating Module*Main BeamTransfer linesMain BeamDrive BeamG. Riddone

    2009 SLUO Meeting Sept 17, 2009

  • CLIC Accelerating structuresTechnologies:Brazed disks - milled quadrantsObjective: Withstand 100 MV/m without damage breakdown rate < 10-7 Strong damping of HOMsCollaboration: CERN, KEK, SLACW. Wunsch

    2009 SLUO Meeting Sept 17, 2009

  • Nominal performance of Accelerating StructuresDesign@CERN, Built/Tested @KEK, SLACCLIC targetKEKSLAC

    2009 SLUO Meeting Sept 17, 2009

  • Power Extraction : PETS8 Sectorsdampedon-off possibilityStatus:CTF3: up to 45 MW peak (3 A beam,recirculation)SLAC: 125 MW @ 266 nsSpecial development for CLIC Travelling wave structures Small R/Q : 2.2 kW/m (accelerating structure: 15-18 kW/m) 100 A beam current136 MW RF @ 240 ns per PETS (2 accelerating structures)0.21 m active lengthtotal number : 35703 per linacI. Syratchev

    2009 SLUO Meeting Sept 17, 2009

  • Power Extraction Structures (PETS)(Previously considered PETS a significant risk)160180200Power [MW]12.05.09F. Zimmermann

    2009 SLUO Meeting Sept 17, 2009

  • CLIC Test Facility CTF3Provide answers for CLIC specific issues Write CDR in 2010Two main missions:Prove CLIC RF power source scheme: bunch manipulations, beam stability, Drive Beam generation 12 GHz extraction

    Demonstration of relevant linac sub-unit: acceleration of test beamProvide RF power for validation of CLIC components: accelerating structures, RF distribution, PETS (Power extraction and Transfer Structure)G. Geshonke

    2009 SLUO Meeting Sept 17, 2009

  • CTF3 building blocks150 MeV e-linacPULSE COMPRESSIONFREQUENCY MULTIPLICATIONCLEX (CLIC Experimental Area)TWO BEAM TEST STANDPROBE BEAMTest Beam Line3.5 A - 1.4 ms 28 A - 140 ns30 GHz test standDelay LoopCombiner Ringtotal length about 140 mmagnetic chicanePhoto injector tests,laserInfrastructure from LEPG. Geshonke

    2009 SLUO Meeting Sept 17, 2009

  • Delay Loopcircumference 42 m (140 ns)isochronous opticswiggler to tune path length (9 mm range)1.5 GHz RF deflectorDesigned and built by INFN FrascatiG. Geshonke

    2009 SLUO Meeting Sept 17, 2009

  • DRIVE BEAM LINACCLEXCLIC Experimental AreaDELAY LOOPCOMBINER RING4 A 1.2 ms120 Mev12 A6 ACTF3 Test FacilityG. Geshonke

    2009 SLUO Meeting Sept 17, 2009

  • Other R&D on performance issuesR&D on Damping Rings and Beam Deliveryin other test facilities:

    CESR-TA at Cornell: Electron Cloud mitigation and low emittance tuning

    ATF/ATF2 at KEK: Low emittance damping ringFinal focus test facility to demonstratenanometer beam sizes and stability

    2009 SLUO Meeting Sept 17, 2009

  • Electron cloud mitigation R&D: PEP-II chicaneTiN surface much reduced signal with respect to AlObserved new resonance: Electron current peaks at defined B values (n)Test chamber Al and TiN-coatedNew 4-dipole chicane in the PEP-II LER Mitigation tests in ILC magnetic fieldAluminum surfaceM. Pivi

    2009 SLUO Meeting Sept 17, 2009

  • ILC Damping Ring R&DLattice design for baseline positron ringLattice design for baseline electron ringDemonstrate < 2 pm vertical emittanceCharacterize single bunch impedance-driven instabilitiesCharacterize electron cloud build-upDevelop electron cloud suppression techniquesDevelop modelling tools for electron cloud instabilitiesDetermine electron cloud instability thresholdsCharacterize ion effectsSpecify techniques for suppressing ion effectsDevelop a fast high-power pulser11 very high priority R&D items to be addressed for the ILC technical design:Targeted for CesrTAEffort with Low Emittance e+ BeamTargeted for ATF EffortM. Palmer

    2009 SLUO Meeting Sept 17, 2009

  • Model of ILC final focusBeamline, January 2008May 2008Summer 2007HA PSFD integrationATF2 goals :(A) Small beam size ~37nm(B) nm stability of beam center ATF international collaboration: MOU signed by 20 institutions ATF2 constructed as ILC model, with in-kind contributions Start of beam commissioning: October 2008ATF2A. Seryi

    2009 SLUO Meeting Sept 17, 2009

  • ILC CLIC collaboration

    CLICILCPhysics & DetectorsL.Linssen, D.SchlatterF.Richard, S.YamadaBeam Delivery System (BDS) & Machine Detector Interface (MDI)D.Schulte, R.Tomas GarciaE.TsesmelisB.Parker, A.SeriyCivil Engineering &Conventional FacilitiesC.Hauviller, J.Osborne.J.Osborne,V.KuchlerPositron Generation (new)L.RinolfiJ.ClarkeDamping Rings (new)Y.PapaphilipouM.PalmerBeam DynamicsD.SchulteA.Latina, K.Kubo, N.WalkerCost & ScheduleP.Lebrun, K.Foraz, G.RiddoneJ.Carwardine, P.Garbincius, T.Shidara

    2009 SLUO Meeting Sept 17, 2009

  • GDE: ILC TimelineB. BarishApril 2009

    2009 SLUO Meeting Sept 17, 2009

  • Tentative long-term CLIC scenarioShortest, Success Oriented, Technically Limited ScheduleTechnology evaluation and Physics assessment based on LHC results for a possible decision on Linear Collider with staged construction starting with the lowest energy required by PhysicsFirst Beam?TechnicalDesignReport(TDR)ConceptualDesignReport(CDR)Project approval ?G. Geshonke