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Advanced Accelerator R&D. Outlook and Strategy. Eric R. Colby Department Head, Advanced Accelerator Research May 4, 2011. Advanced Accelerator R&D Mission. Market for Advanced Accelerator R&D. Long-time primary customer (HEP) is changing course ILC is receding further into the future
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Advanced Accelerator R&D Outlook and Strategy Eric R. Colby Department Head, Advanced Accelerator Research May 4, 2011
Advanced Accelerator R&D Mission SLAC pre-SPC Meeting Page 2
Market for Advanced Accelerator R&D • Long-time primary customer (HEP) is changing course • ILC is receding further into the future • Muon collider is rising in visibility and funding • HEP’s stewardship role of accelerator science is vital, but resource constraints force a narrow interpretation • Recent customer (BES) has different expectations • Expect Return On Investment (ROI) in 2-5 years • Starting to invest in high risk R&D such as Echo-7 • Other customers (DARPA, DHS, NCI) are being courted • Some awareness that prime funding source (DOE-HEP) is narrowing focus SLAC pre-SPC Meeting Page 3
Status of the Advanced Concepts IntellectualMarketplace • Field Leader • Partner of choice • Interested observer Four primary areas of research worldwide: • High Gradient RF • centered at a range of small- and medium-sized labs, and industry • Laser Wakefield Acceleration • centered at medium-to-large labs because >100TW driver lasers are needed • Beam-driven Wakefield Accelerators • centered at medium-to-large labs because >100MeV driver linacs are needed • Beam-driven Plasma Wakefield Acceleration • centered at large labs because >GeV driver linacs are needed And a fifth, developing area: • Direct Laser Acceleration • centered at small labs SLAC pre-SPC Meeting Page 4
Advanced Accelerator Research Efforts Worldwide • (excluding HGRF) Direct Laser Accel Expt.
Balancing Risk and Potential Payoff We are addressing the needs for: shorter beams (<fsec), higher rep rates (>kHz) compactness, lower cost With R&D on technologies that span a range of risk/payoff: SLAC pre-SPC Meeting Page 6
Program Evolution SLAC pre-SPC Meeting Page 7
High Gradient RF • Why SLAC? • Core competency • SLAC operates the highest energy microwave linacs in the world • Unique test facilities-ASTA, NLCTA, ITF • Scope • Material science • Comprehensive source-to-beam component R&D • New RF source technologies • Current Issues • Availability is essential for wider acceptance • HGRF uneconomic without more efficient rf sources • Developing other applications: RF Undulator, Medical Linac, etc. SLAC pre-SPC Meeting Page 8
The Cockcroft Institute INFN International HGRF Collaboration SLAC pre-SPC Meeting Page 9
High Gradient Research |E| |H| Intergranular fractures 500X material sample • Basic R&D on Breakdown • Geometry: Have tested ~40 different types of accelerator structures • Fields: Magnetic field and pulsed RF heating are key to breakdown • Materials: New materials have shown promise • Developing novel RF sources: new simulation tools, entirely new topologies • Muon Collider R&D: RF breakdown in strong magnetic fields, cavity design • Structures for HG proton acceleration SLAC pre-SPC Meeting Page 10
Plasma Wakefield Acceleration Program • Why SLAC? • Unique facilities and expertise • Goldmine of science—plasma refraction, ion channel laser, etc. • Scope • Basic physics driving beam quality • Energy efficiency/high transformer ratio • Positron dynamics; Engineering issues • PWFA Current Issues • Need “sailboat chicane” for full PWFA program; funding (13M$) may be an issue • LCLS-II installations will change linac during program • FACET will operate 5 years (2017) SLAC pre-SPC Meeting Page 11
Beam Parameters FACET (2012-2017) FACET—Facility for Advanced aCceleratorExperimental Tests
Possible “FACET-II” (2017 on) LCLS-II Sector 10 Experimental Area Injector Test Facility The proposed Injector Test Facility is a candidate for FACET-II • Better bunch shaping, bunch trains, and staging of PWFAs • Need to do e-driven positron acceleration at FACET-II if no sailboat • Better quality beams will enable broader FACET science program • Synergy of FACET programs with FEL R&D program
Plasma Wakefield Collaboration Current PWFA Collaboration has more than a decade’s experience with GeV-scale experiments and has a strongly academic focus • SLAC • ARD: Beam dynamics, experiment • TF: Experimental Area, Safety • UCLA • C. Joshi, EE – Plasma Sources • W. Mori, EE – Theory, Simulations • J. Rosenzweig, A&P – Dielectric Wakefield Devices • USC • P. Muggli, EE -- Experiment • Duke • T. Katsouleas – Theory, Simulation SLAC pre-SPC Meeting Page 14
Lp ~ 1m PWFA Experiments are aimed at understanding the essential physics required to design a Linear Collider • Commission FACET this summer • Following commissioning, the PWFA program expects to demonstrate: • Energy doubling of a 25 GeV Beam in ~1m • Efficient Energy Transfer of ~30% with small energy spread • Emittance preservation for electrons • The sailboat chicane will enable detailed studies of electron-driven PWFA of positrons • Efficient energy transfer, emittance preservation • FACET will be the only facility that can address these questions SLAC pre-SPC Meeting Page 15
SLAC Accelerator Research Experimental program Committee (SAREC) Review The Closeout Report (March 9, 2011)highly ranked the PWFA and DWA proposals: About PWFA: “The proposal is well-organized, the collaboration has extensive experience, and the experiments are supported by extensive simulations which have been well-benchmarked in the FFTB experiments.” SLAC pre-SPC Meeting Page 16
Direct Laser Accelerator (DLA) Program Input waveguide Electron beam • Why SLAC? • First experimental efforts where at Stanford • Stanford leadership in lasers, photonics, and semicon fabrication; SLAC’s expertise in linacs • Scope • Design, fabrication, and testing of DLA structures, waveguides, lenses, diagnostics • Current Issues • Although early in R&D cycle, need to define applications concretely SLAC pre-SPC Meeting Page 17
Direct Laser Acceleration Collaboration • SLAC • AARD: Beam dynamics, structure design, experiment design, integration, and execution at E163 • (TF, LCLS-laser: Accelerator interface, operations & safety oversight) • Stanford • B. Byer, AP – Laser R&D, Materials • M. Kasevich – Electron sources • Tech-X Inc. • VORPAL simulations of fibers, woodpiles, including tolerance analysis & design • UCLA • G. Travish – MAP structure • Karlsruhe Institute of Technology • I. Staude – Woodpile fabrication • Incom Inc. • Fiber Pulling • Q-Peak, Inc. • 2 micron laser development • KLA-Tencor • T. Plettner – DLA Undulator Design • IIT-Technion • L. Schachter – Theory • MPQ-Muenich • P. Hommellhoff – Electron sources • NTHU-Taiwan • Y-C Huang – IR sources • LLNL • Photonic Crystal Fiber Pulling (July 2011--) • U. Sydney • CUDOS Design code for PCF fibers SLAC pre-SPC Meeting Page 18
Growing the technology and the R&D community • Concept is at proof-of-principle step : • Two key milestones: GeV/m Gradient, MeV energy gain • Current worldwide level of effort is small, needs to expand • Growth in the level of effort/number of investigators • Once gradient and fabrication are demonstrated, others will join • Photonics and novel optical materials communities already interested • Growth in the technology base • Laser vendors already performing needed R&D (DOE, DARPA) • 3 SBIR proposals in FY10 to make structures, 1 funded • Developing fabrication process that industry can adopt directly • SU is patenting core structure concepts now • Pursuing DARPA funding through AXiS program SLAC pre-SPC Meeting Page 19
Direct Laser Acceleration Applications • Early days yet, but identifying the potential applications and customers is essential • HEP: linear collider • BES • High average fluence narrowband x-ray source • Unique source of attosecond beams • Solid-state replacement for low- to moderate-current electron linacs • Medical Linacs • Solid state replacement for 25 MeV linacs (Industry) • Endoscopic accelerator-based electron and x-ray sources • Narrowband x-ray source for differential phase contrast imaging (DARPA) • Security • Ultracompact radiography linacs SLAC pre-SPC Meeting Page 20
Direct Laser Acceleration Structure Fabrication and Beam Testing • Substantial progress on fabricating 100-1000l long optical waveguides • Silicon Woodpile: 9 of 17 layers completed at Stanford • Silica Grating: 0.8 mm structures fabricated at Stanford • Silica fiber: drawn photonic band gap fibers down to ~4mm (Incom SBIR) TEbandgapregion • Substantial beam testing progress • Attosecond bunch train production at 0.8 mm (PRST-AB, 2008) • Staged laser acceleration at 0.8 mm (PRST-AB, 2008) • Focusing of 60 MeV/10m/15pC beams to 8x8 mm (2010) • Initial observation of beam-driven TM modes in a PBG fiber (2011) SLAC pre-SPC Meeting Page 21
DLA DrivingApplications • Linear Collider – low charge high frequency format will provide very low detector background • Solid-State Low-power linacs (~100 W) – ultracompact, low-cost replacement for microwave linacs • Novel Applications • Examples: • 106 T/m quadrupoles • Attosecond pulsed electron and radiation sources • Optically undulators lw~100 mm • Deflectors with <100 fsecrisetimes • Streak cameras with fsec resolution • BPMs with nm resolution • Accelerators small enough to insert endoscopically Optical Undulator Woodpile-based quadrupole Optical BPM MAP structure for IBRT (UCLA) SLAC pre-SPC Meeting Page 22 Woodpile based deflector
AAR is a great environment for students Basic R&D and applied technology Research R&D groups are small (~8) AAR hosts 8 (of 10) graduate students, 4 (of 5) postdocs Working to expand accelerator physics curriculum at SU Test facilities offer tremendous teaching opportunity Efforts are interdisciplinary and experiment-oriented, resulting in students with broad training and significant hands-on experience Lack of faculty in AAR is an issue (have 1) SLAC pre-SPC Meeting Page 23
Some Alumni of Stanford Accelerator Physics Tomas Plettner—Researcher at KLA-Tencor Chris Barnes—Researcher at Solyndra Boris Podobedov— APS Thesis Award, Scientist, Brookhaven Zhirong Huang— APS Thesis Award, Scientist, SLAC Ben Cowan— Scientific code developer at Tech-X Caolionn O’Connell— Dept. of Defense David Pritzkau— APS Thesis Award, Big Bear Networks Themis Mastoridis—ToohigFellow SLAC Walt Zacherl— Instructor at West Point Jiquan Guo— Scientist, SLAC Devon MacDonald—Strategic Planning, KLA-Tencor Ian Blumenfeld Scientist, Archimedes Group Boaz Nash— Scientist, Brookhaven Nat’l Lab Chris Sears— Researcher at KLA-Tencor Bruce Rohrbough—Instructor at West Point Dmitry Teytelman—APS Thesis Award, Founder of Dimtel, Inc. Neil Kirby— Postdoc, UCSF Greg Schussman— Scientist, SLAC Rod Loewen— Scientist at Lyncean Technologies Current Careers: Blue=Industry 40% Red=Academia 20% Gold=Nat’l Labs 40% ShyamPrabhakar— APS Thesis Award Scientist, LBNL JiaxingXu— Postdoc, SLAC SLAC pre-SPC Meeting Page 24
Fostering a Culture of Innovation “Culture eats strategy for breakfast.”—Peter Drucker • Hosting a significant number of graduate students and postdocs helps! • Aggressively look outside canonical accelerator science for innovations that will provide new capabilities • Encourage an outward-looking culture • Hire from beyond accelerator physics • Increase personnel turnover • Expand collaborations • Complete near-term applications SLAC pre-SPC Meeting Page 25
Roles in more immediate projects Maintaining focus in long-term R&D requires setting and maintaining near-term milestones, and is further enhanced by contributing to short-term tasks. • HGRF • X-band deflector cavities for Echo-7, LCLS • X-band RF Undulator R&D • mm-wave antennae for CMB • HGRF for proton therapy machines • PWFA • Diagnostics for ultrashort beams (eg. OTR screens and CTR bunch length monitor pioneered at FFTB/E164) • THz radiation generation, transport, and diagnostics • DLA • Collaborated in first phases of seeding demonstration Echo-7 • Accelerator physics leadership of Bay Area Hadron Therapy Center SLAC pre-SPC Meeting Page 26
AAR Strengths, Opportunities, Risks AAR is interdisciplinary and innovative Research is fundamental, uncovering mechanisms for high field interactions with metals, plasmas, and dielectrics Develop synergies with the BES, DARPA, DHS program, seek out industrial applications Combination of fundamental R&D + applied technology provides excellent graduate training Test facilities (ASTA, NLCTA, FACET) are central to this work, but are expensive to operate SLAC pre-SPC Meeting Page 27
Growing the User Community • Provide a Supportive User Environment • Test Facilities Department • Advertise the opportunities • FACET has been prominently featured in invited talks • NLCTA & E163 advertised through conference talks • ASTA through HGRF collaboration meetings • Satellite FACET meetings at PAC, IPAC • Host User Workshops • First FACET User’s Workshop held March 18-19, 2010 • Second Workshop planned for late August 2011, after first beam results • Other topicals planned: Novel undulators; DLA Workshop • SLAC will host Advanced Accelerator Concepts Workshop in 2014 • User contact maintained through SLAC User Organization (SLUO) SLAC pre-SPC Meeting Page 28
Closing Thoughts Opportunities which overlap with SLAC’s strengths and unique, accessible expertise (e.g. Stanford, Silicon Valley) should be exploited Program growth requires the applications case and support base to broaden beyond what has been traditionally pursued AAR has a vibrant program spanning a range of risk and potential impact that has consistently delivered leading experimental results and trained sought-after accelerator physicists SLAC pre-SPC Meeting Page 29
R&D Status Gain in performance, Progress towards realization, New scientific knowledge Microwave Acceleration Operational Improvements Concept implemented as a working machine Major Project Engineering Begins Engineering Tests Underway Physics Largely Understood RESEARCH DEVELOPMENT Plasma Wakefield Acceleration Direct Laser Acceleration Critical Mass of Experimental Effort Achieved (people+facilities) Proof-of-Principle Experiments Community Develops Concept Time & funding 10-20 years SLAC pre-SPC Meeting Page 31
PWFA: Positron R&D • e+/plasma interaction much less studied than e-/plasma • Focusing force on e+ bunches is nonlinear • e+ can be accelerated with in e+ driven plasma wakes, but accelerating force is also nonlinear • Emittance growth for single, long e+ bunch in uniform plasma • Possible remedies include hollow plasma channel, linear wake
DLA: Motivation • Motivation • High gradient and high efficiency acceleration is possible • Fundamentally different accelerator technology • Laser-powered, but solid-state, so accelerator is the “same” on every shot • Low-charge high-repetition-rate technology quasi-CW beam format • Accelerators made like computer chips—mass production techniques that will be significantly less expensive and more flexible than machined metal • Breaks repetition rate and duty factor limitations set by high peak power tubes and lasers • Connection to DOE HEP Mission • Low charge, very-high-repetition rate beam format is the only scheme that has reasonable background at 10 TeV cm energies and is not practical with either microwave or plasma technologies • Benefits from large industrial effort in lasers and semiconductors to make efficient use of DOE resources
Injector Test Facility at Sector 0 • Highlights of Changes for Echo-100/HHG: • Add injector laser room and laser • Remove ~15 m of sector 0 injector, reusing many components • Install LCLS gun, K02, K01, and laser heater with configuration similar to LCLS • Remove 50m (4 RF stations) of linac in sector 3 (or 8) to make the experimental area • Install small laser room and Echo/HHG laser system near S3 (or S8) • Optionally install BC1 and linearizer • Upgrade diagnostics to support low-emittance, Echo-100 operation S8 Exp Area
Worldwide Direct Laser Acceleration Efforts Welding/Cutting Industry Defense Laser Accelerator Structures Telecom Industry Chip Woodpile Stanford/SLAC U. Hiroshima Pohang Light Source Indiana U Grating Stanford/SLAC UCLA MAP Cornell Foxhole NTHU-Taiwan Focusing & BPMs Stanford/SLAC Fiber 1D Bragg Fiber IIT-Technion 2D Photonic Band Gap Stanford/SLAC Drive Laser Technology dOPO Stanford Lockheed-Martin Tm:Fiber Stanford Q-Peak IMRA IPG Photonics NuFern others… KGW/KYW Disk many others… Related Photonics (MOEMS) Other Polaritonic Resonance Materials UT-Austin Corrugated Plasma Waveguides U Maryland Fibers Incom LLNL-Dawson Group NKT Photonics many others… Gratings Benchmark Technologies Woodpiles U Pennsylvania U Arizona U Colorado Aerospace Corp many others… Laser Accelerator Structure Testing with Beam – SLAC Particle Sources Electron Sources Vanderbilt—field emission UCLA—ferroelectric emission MPQ-Muenich—field emission Stanford—photo-assisted FE Simulation Software developed specifically for Photonic Band Gap Systems FEM SLAC—ACE3P FDTD Rsoft—BandSolve Tech-X—Vorpal PWD MIT Photonic Bands Other U. Sydney— CUDOS Microwave Analogs MIT X-band PBG LANL PBG TWT circuit
Facilities according to NH NC LC Tech (ESB) HPRF (KTL) HG (ASTA?) FACET Laser (E163) Test beams (ESTB) Presentation Title Page 36
PWFA • Where do we want the program to go? • 5 years—Addressed beam quality issues, developed near-term apps: ion channel laser? Chirp silencer? • 10 years—Staging demonstration, engineering issues understood, PWFA afterburner for XFEL • 20 years—based LC under construction • How do we get there? • 5 years—FACET-1, current collaboration (SLAC-UCLA-USC-DUKE), drawing in LC experts as needed • 10 years—FACET-2, expanded collaboration, drawing in more LC and PS communities as collaborators (and users) • 20 years—LC construction, HEP community drawn in for detectors SLAC pre-SPC Meeting Page 37