Advanced Accelerator R&D Outlook and Strategy Eric R. Colby Department Head, Advanced Accelerator Research May 4, 2011
Feb 25, 2016
Advanced Accelerator R&DOutlook and Strategy
Eric R. ColbyDepartment Head, Advanced Accelerator Research
May 4, 2011
Advanced Accelerator R&D Mission
SLAC pre-SPC MeetingPage 2
Grow into the premier Photon Science Laboratory
Maintain our position as the premier [electron] accelerator laboratory
Build targeted programs in particle physics, particle astrophysics & cosmology
Seeding schemes that will change FEL designs
R&D Program @LCLS LC, Beam Manipulation
Next Generation Injectors Injector Test Infrastructure LC, Super KEKB, Ultra short pulses Laser Acceleration.
Diagnostics.LC
User adapted applications Linac designs for specific needs
LC, MC
Enabling Technology RF Power (at any band) and new power sources
LC, MAP, Project X, everywhere
The “ultimate” storage ring Beam Dynamics and Feedback systems
Super B / Super KEK B
“Doubling the energy” Plasma Wake Field Acceleration
FACET and its experimental program
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 MeetingPage 3
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
Status of the Advanced Concepts Intellectual Marketplace
SLAC pre-SPC MeetingPage 4
• Field Leader• Partner of choice• Interested observer
Advanced Accelerator Research Efforts Worldwide (excluding HGRF)
Direct Laser Accel Expt.
Balancing Risk and Potential PayoffWe 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:
Gradient[GeV/m]
Working Wave-length
Bunch Length
Bunch Repetition Frequency
Highest useful bunch
harmonicTime to ‘market’
High Gradient RF 0.1 1 cm 1 ps 102-104 Hz 1 THz 2-5 yrs
Beam Driven Plasma Wakefield 10 100 mm 10 fs 102-104 Hz 100 THz 10-15
yrs
Dielectric Laser Acceleration 1 1 mm 0.1 fs 106-1010 Hz 10 PHz
(150 eV)15-20 yrs
SLAC pre-SPC MeetingPage 6
Program Evolution
SLAC pre-SPC MeetingPage 7
Now 5 Years Long term applications
HGRF • Structure Testing• Materials Testing• Novel Applications• ASTA
3 M$/yrHEP
• New rf Sources• Materials Testing• Novel Applications• KTL? NLCTA? ITF?
HEP, BES, Industry
• Driver linac (XFEL, PWFA)• HGRF-LC??• Medical• Novel Apps (E dither, RF-U)
PWFA • Beam Dynamics• Plasma Science• FACET-I
2 M$/yrHEP
• BD & PS• Plasma Engineering• FACET-II (ITF?)
HEP,BES,DARPA
• XFEL Afterburner• PWFA-LC??• Ion Channel Laser
DLA • Gradient/Voltage• In-house Fab.• NLCTA-E163
2 M$/yrHEP
• Integrated Devices• Vendor Fab.• Beam dynamics• 1 GeV attosec facility
HEP, DARPA,Industry
• SS replacement linac• DLA-LC??• Medical• Novel Apps
High Gradient RF• Why SLAC?
– Core competency– SLAC operates the highest energy microwave linacs in the world– Unique test facilities-ASTA, NLCTA, ITF
• Scope– Material science– Comprehensive source-to-beam component R&D– New RF source technologies
• Current Issues– Availability is essential for wider acceptance– HGRF uneconomic without more efficient rf sources – Developing other applications: RF Undulator, Medical Linac, etc.
SLAC pre-SPC MeetingPage 8
International HGRF Collaboration
The Cockcroft Institute
INFN
SLAC pre-SPC MeetingPage 9
• Basic R&D on Breakdown– Geometry: Have tested ~40 different types of
accelerator structures– Fields: Magnetic field and pulsed RF heating are key to
breakdown– Materials: New materials have shown promise
• Developing novel RF sources: new simulation tools, entirely new topologies
• Muon Collider R&D: RF breakdown in strong magnetic fields, cavity design
• Structures for HG proton acceleration
High Gradient Research
|E|
|H|
material sample
Intergranular fractures 500X
SLAC pre-SPC MeetingPage 10
Plasma Wakefield Acceleration Program• Why SLAC?
– Unique facilities and expertise– Goldmine of science—plasma refraction, ion channel laser, etc.
• Scope– Basic physics driving beam quality– Energy efficiency/high transformer ratio– Positron dynamics; Engineering issues
• PWFA Current Issues– Need “sailboat chicane” for full PWFA program; funding (13M$) may be an
issue– LCLS-II installations will change linac during program– FACET will operate 5 years (2017)
SLAC pre-SPC MeetingPage 11
Beam Parameters
Energy 23 GeV
Charge 3 nC
Sigma z 14 µm
Sigma r 10 µm
Peak Current 22 kAmps
Species e- & e+
FACET (2012-2017)FACET—Facility for Advanced aCcelerator Experimental Tests
Energy 10 GeVCharge 3 nC
Species e- & e+
Possible “FACET-II” (2017 on)
Injector Test Facility
LCLS-II
Sector 10 Experimental Area
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
• 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 MeetingPage 14
Current PWFA Collaboration has more than a decade’s experience with GeV-scale experiments and has a strongly academic focus
• 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
Lp ~ 1m
PWFA Experiments are aimed at understanding the essential physics required to design a Linear Collider
SLAC pre-SPC MeetingPage 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 MeetingPage 16
Direct Laser Accelerator (DLA) Program• 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 MeetingPage 17
Input waveguide
Electron beam
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 MeetingPage 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 MeetingPage 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 MeetingPage 20
Direct Laser Acceleration Structure Fabrication and Beam Testing
• 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)
TE bandgap region
• 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)
SLAC pre-SPC MeetingPage 21
DLA Driving Applications
Optical BPM
Optical Undulator
Woodpile based deflector
Woodpile-based quadrupole
MAP structure for IBRT (UCLA)
• 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
SLAC pre-SPC MeetingPage 22
Examples:• 106 T/m quadrupoles• Attosecond pulsed electron and
radiation sources• Optically undulators lw~100 mm• Deflectors with <100 fsec risetimes• Streak cameras with fsec resolution• BPMs with nm resolution• Accelerators small enough to insert
endoscopically
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 MeetingPage 23
Some Alumni of Stanford Accelerator Physics
Current Careers:Blue=Industry 40%Red=Academia 20%Gold=Nat’l Labs 40%
Tomas Plettner—Researcher at KLA-Tencor
Caolionn O’Connell—Dept. of Defense
Chris Barnes—Researcher at Solyndra
Devon MacDonald—Strategic Planning, KLA-Tencor
Bruce Rohrbough—Instructor at West Point
Walt Zacherl—Instructor at West Point
Ben Cowan—Scientific code developer at Tech-X
Chris Sears—Researcher at KLA-Tencor
Neil Kirby—Postdoc, UCSF
Ian BlumenfeldScientist, Archimedes Group
Themis Mastoridis—Toohig FellowSLAC
Dmitry Teytelman—APS Thesis Award,Founder of Dimtel, Inc.
David Pritzkau—APS Thesis Award,Big Bear Networks
Boris Podobedov—APS Thesis Award,Scientist, Brookhaven
Boaz Nash—Scientist, Brookhaven Nat’l Lab
Rod Loewen—Scientist at Lyncean Technologies
Jiquan Guo—Scientist, SLAC
Greg Schussman—Scientist, SLAC
Shyam Prabhakar—APS Thesis AwardScientist, LBNL
Jiaxing Xu—Postdoc, SLAC
Zhirong Huang—APS Thesis Award,Scientist, SLAC
SLAC pre-SPC MeetingPage 24
Fostering a Culture of Innovation
• 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
“Culture eats strategy for breakfast.”—Peter Drucker
SLAC pre-SPC MeetingPage 25
Roles in more immediate projects
• 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 MeetingPage 26
Maintaining focus in long-term R&D requires setting and maintaining near-term milestones, and is further enhanced by contributing to short-term tasks.
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 MeetingPage 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 MeetingPage 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 MeetingPage 29
BACKUP SLIDES
RESEARCH DEVELOPMENT
R&D StatusGain in performance,Progress towards realization,New scientific knowledge
Concept
Proof-of-PrincipleExperiments
CommunityDevelops
Critical Mass of Experimental Effort Achieved (people+facilities)
Physics Largely Understood
Engineering Tests Underway
Major Project Engineering Begins
Concept implemented as a working machine
Time & funding10-20 years
Direct Laser Acceleration
Plasma Wakefield Acceleration
Microwave Acceleration
OperationalImprovements
SLAC pre-SPC MeetingPage 31
• 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
PWFA: Positron R&D
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
S8 Exp Area
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
Worldwide Direct Laser Acceleration EffortsLaser Accelerator Structures
Particle Sources
Microwave AnalogsMIT X-band PBGLANL PBG TWT circuit
Telecom IndustryWelding/Cutting IndustryDefense Chip
Woodpile Stanford/SLAC U. Hiroshima Pohang Light Source Indiana UGrating Stanford/SLAC UCLA MAP Cornell Foxhole NTHU-TaiwanFocusing & BPMs Stanford/SLAC
Fiber1D Bragg Fiber IIT-Technion2D Photonic Band Gap Stanford/SLAC
OtherPolaritonic Resonance Materials UT-AustinCorrugated Plasma Waveguides U Maryland
Related Photonics (MOEMS)Fibers Incom LLNL-Dawson Group NKT Photonics many others…Gratings Benchmark TechnologiesWoodpiles U Pennsylvania U Arizona U Colorado Aerospace Corp many others…
Electron SourcesVanderbilt—field emissionUCLA—ferroelectric emissionMPQ-Muenich—field emissionStanford—photo-assisted FE
Drive Laser TechnologydOPO Stanford Lockheed-MartinTm:Fiber Stanford Q-Peak IMRA IPG Photonics NuFern others…KGW/KYW Disk many others…
Simulation Software developed specifically for Photonic Band Gap Systems
FEM SLAC—ACE3PFDTD Rsoft—BandSolve Tech-X—Vorpal
PWD MIT Photonic BandsOther U. Sydney—CUDOS
Laser Accelerator Structure Testing with Beam – SLAC
• Facilities according to NH• NC LC Tech (ESB)• HPRF (KTL)• HG (ASTA?)• FACET• Laser (E163)• Test beams (ESTB)
Presentation TitlePage 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 MeetingPage 37