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The International Linear Collider and the Future of Accelerator-based Particle Physics ILC Barry Barish Caltech Lomonosov Conference 20-Aug-2015 Exploring the Terascale the tools The LHC » It is leading the way and has large reach » Quark-quark, quark-gluon and gluongluon collisions at 0.5 - 5 TeV » Broadband initial state A Lepton Collider (e.g. ILC or ?) » A second view with ‘high precision’ » Electron-positron collisions with fixed energies » Well defined initial state Together, these two types of accelerators are our tools for uncovering physics at the terascale 20 Aug 15 Barry Barish Lomonosov Conference 2 Why Linear? cost Circular Collider Linear Collider R Synchrotron Radiation ~ 200 GeV DE ~ (E4 /m4 R) Energy < 5 nm vertical • Low emittance (high brightness) machine optics • Contain emittance growth • Squeeze the beam as small as possible at collision point 20 Aug 15 Barry Barish Lomonosov Conference 3 A Global Initiative for an ILC International Committee for Future Accelerators (ICFA) representing major particle physics laboratories worldwide. Chose ILC accelerator technology (SCRF) Determined ILC physics design parameters Formed Global Design Effort and Mandate (TDR) 20 Aug 15 Barry Barish Lomonosov Conference 4 Lab-driven R&D Programs Room temperature copper structures (KEK and SLAC) OR Superconducting RF cavities (DESY) 20 Aug 15 Barry Barish Lomonosov Conference 5 ITRP in Korea 20 Aug 15 Barry Barish Lomonosov Conference 6 GDE -- Design a Linear Collider pre-accelerator few GeV source KeV damping ring few GeV few GeV bunch compressor 250-500 GeV main linac extraction & dump final focus IP collimation Superconducting RF Main Linac 20 Aug 15 Barry Barish Lomonosov Conference 7 7 ILCSC/ICFA Parameters Studies physics driven input Key Parameters ∫ » Luminosity Ldt = 500 fb-1 in 4 years » Ecm adjustable from 200 – 500 GeV » Ability to scan between 200 and 500 GeV » Energy stability and precision below 0.1% » Electron polarization of at least 80% Options – The machine must be upgradeable to 1 TeV – Positron polarization desirable as an upgrade 20 Aug 15 Barry Barish Lomonosov Conference 8 1.3 GHz Superconducting Cavities solid niobium standing wave 9 cells operated at 2K (LHe) 35 MV/m Q0 ≥ 1010 20 Aug 15 Barry Barish Lomonosov Conference 9 The Quest for High Gradient ILC 20 Aug 15 Barry Barish Lomonosov Conference 10 Progress in Cavity Gradient Yield Production yield: 94 % at > 28 MV/m, Average gradient: 37.1 MV/m 20 Aug 15 Barry Barish Lomonosov Conference 11 Cryomodule Construction 20 Aug 15 Barry Barish Lomonosov Conference 12 The Proposed International Linear Collider Damping Rings Polarised electron source Ring to Main Linac (RTML) (inc. bunch compressors) not too scale Polarised positron source e- Main Linac 20 Aug 15 Barry Barish Beam Delivery System (BDS) & physics detectors Lomonosov Conference e+ Main Linac Beam dump 13 Central Region 5.6 km region around IR Systems: Central Region » » » » » » electron source positron source beam delivery system RTML (return line) IR (detector hall) damping rings common tunnel Complex and crowded area Damping Rings detector e+ main beam dump RTML return line e- BDS muon shild e+ source e- BDS 20 Aug 15 Barry Barish Lomonosov Conference 14 Damping Rings Circumference Energy RF frequency Beam current Store time Trans. damping time Arc Cell Extracted Arc Cell emittance Magnets pre-assembled on I-Beam and transported into DR (normalised) Part I I - system T he I L C Baseline Reference 8.2. DR Lattice descr iption I-beam used inpre-assembled Arcs, Wiggleron Section, Chicane Magnets I-Beam and transported into Allows for most alignment takeinplace I-beam system to used Arcs,outside Wigglertunnel Section, Chicane No. cavities Allows for ed most alignment to Fig. take 8.2b. place outside tunnel elect ron ring as indicat in Fig. 8.2a and Total voltage RF power / coupler Positron ring (upgrade) 3.2 5 650 390 200 (100) 24 (13) ms x 5.5 mm y 20 nm 10 (12) 14 (22) MV 176 (272) kW No.wiggler 54 magnets Total length m Values in () are 113 for 10-Hz mode wiggler Wiggler field 1.5 (2.2) T Electron ring (baseline) Positron ring (baseline) Beam power 1.76 (2.38) MW Many similarities to (a) (b) modern 3rd-generation Arc quadrupole section Dipole section Three ring optional upgrade shown Figure 8.2: Damping ring arc magnet layout wit h posit ron ring at t he bot t om light and sources elect ron ring direct ly above. A second posit ron ring would be placed above t he elect ron Three ring optional upgrade shown April 24, 2012 km GeV MHz mA ms 4 April 24, 2012 20 Aug 15if required: Barry Barish Lomonosov Conference ring arc a) quadrupole sect ion layout and b) dipole sect ion layout . 4 15 Positron Source (central region) to Damping Ring not to scale! Photon collimator (pol. upgrade) aux. source (500 MeV) Pre-accelerator (125-400 MeV) Energy comp. RF SCRF booster (0.4-5 GeV) Target Flux concentrator spin rotation solenoid 150-250 GeV e- beam photon dump SC helical undulator Capture RF (125 MeV) e- dump 150-250 GeV e- beam to BDS located at exit of electron Main Linac 147m SC helical undulator driven by primary electron beam (150-250 GeV) produces ~30 MeV photons converted in thin target into e+epairs 20 Aug 15 Barry Barish Lomonosov Conference polarisation yield e+/e- yield = 1.5 16 Beam Delivery System Geometry ready for TeV upgrade e+ source e- BDS Electron Beam Delivery System 20 Aug 15 Barry Barish Lomonosov Conference 17 Final Focus R&D: ATF2 @ KEK Test bed for ILC final focus optics - strong focusing and tuning (37 nm) beam-based alignment stabilisation and vibration (fast feedback) instrumentation IP beam size monitor 20 Aug 15 Barry Barish Lomonosov Conference 18 ILC/TDR – 500 GeV Parameters Physics Beam (interaction point) Beam (time structure) Accelerator (general) 20 Aug 15 Barry Barish Max. Ecm Luminosity Polarisation (e-/e+) dBS 500 GeV 1.8×1034 cm-2s-1 80% / 30% 4.5% sx / sy sz gex / gey bx / by bunch charge 574 nm / 6 nm 300 mm 10 mm / 35 nm 11 mm / 0.48 mm 2×1010 Number of bunches / pulse 1312 Bunch spacing 554 ns Pulse current 5.8 mA Beam pulse length 727 ms Pulse repetition rate 5 Hz Average beam power Total AC power (linacs AC power Lomonosov Conference 10.5 MW (total) 163 MW 107 MW) 19 Interaction Region - Detectors Saturday 17.10 Keisuke Fujii (KEK) ILC physics, detectors and status of ILC project in Japan 20 Aug 15 Barry Barish Lomonosov Conference 20 Lepton Colliders Alternatives ILC < 1 TeV Technically possible ~ 2025 + ILC QUAD QUAD POWER EXTRACTION STRUCTURE Drive beam - 95 A, 300 ns from 2.4 GeV to 240 MeV CLIC ACCELERATING STRUCTURES Main beam – 1 A, 200 ns from 9 GeV to 1.5 TeV BPM Muon Collider Muon Collider < 4 TeV FEASIBILITY?? Much longer timescale Much R&D Needed • Neutrino Factory R&D + • bunch merging • much more cooling • etc 20 Aug 15 Barry Barish CLIC < 3 TeV Feasibility? Longer timescale Lomonosov Conference 21 Lepton and Hadron Colliders’ History and China Accelerator based High Energy Physics Development in the Future CEPC+SppC CEPC: Ecm=240GeV e+e- Circular Collider SppC: Ecm=50-100TeV pp Collider LC CEPC+SppC will be constructed with international collaboration and participation HIEPAF: High Intensity Electron BEPC BEPC II Positron Accelerator Facility History of BEPC and BEPC II 20 Aug 15 Barry Barish Lomonosov Conference 22 CEPC/SppC Layout e+ e- IP1 LTB High Energy Booster(7.2Km) BTC Medium Energy Booster(4.5Km) Low Energy Booster(0.4Km) IP4 e+ e- Linac (240m) Proton Linac (100m) BTC IP3 IP2 LTB : Linac to Booster BTC : Booster to Collider Ring 20 Aug 15 Barry Barish Lomonosov Conference 23 The Long Range Future of Accelerator Based Particle Physics? Future of Accelerators (eliminate materials!) Plasma/Laser Wakefield Acceleration 20 Aug 15 Barry Barish Lomonosov Conference 24 Compact Acceleration 50 GeV/meter has been achieved FFTB at SLAC FACET at SLAC 20 Aug 15 Barry Barish Lomonosov Conference 25 Controlling the beams LBNL Reducing energy spread to ~ percent level Reducing angular divergence (< 1 degree) 20 Aug 15 Barry Barish Lomonosov Conference 26 Conclusions The International Linear Collider • Strong Science Motivation: Higgs, Top physics ++ • Mature Technology; Well-reviewed Technical Design • Japan to host ??? 2025 + Other Options • CLIC -- ~ 2-3 Tev R&D? power consumption? 2030 + • Muon Collider R&D??? 2035 + • CEPC/SppC Large Ring in China 2035 Long Range Possibilities • Laser-driven or Beam-driven Plasma-Wakefield Accelerator 20 Aug 15 Barry Barish Lomonosov Conference 27