Carsten Hast User Facilities for HEP and Photon Science at SLAC FACET ● NLCTA ● ASTA ● ESTB Carsten Hast SLAC National Accelerator Laboratory John Adams Institute, Oxford, UK, September 2010 SLAC User Facilities Carsten Hast - ARD Test Facilities Department

Carsten Hast - ARD Test Facilities Department FACET ESB & NLCTA ESA SLAC User Facilities Carsten Hast - ARD Test Facilities Department

SLAC Test Facilities’ Goals High Energy Physics Support Research for Linear Collider High and Ultra High Gradients Plasma Acceleration Direct Laser Acceleration Machine Detector Interface Studies Detector Development LC Detectors B-Factories Others Photon Science Gun Development New Materials New Designs Different Frequencies Novel Seeding Techniques for FELs and other FEL Fundamentals Echo Enabled Harmonic Generation Emittance exchange THz Radiation etc. SLAC User Facilities Carsten Hast - ARD Test Facilities Department

Carsten Hast - ARD Test Facilities Department Let’s talk about: How to make a Linear Collider shorter Higher Gradients (ASTA, NLCTA) New Acceleration Techniques Plasma Wakefield (FACET) Direct Laser (NLCTA) How to make FELs “better” Brighter Guns (ASTA, NLCTA) Coherent laser light (seeding) (NLCTA) …and more…(ESA, ESB) SLAC User Facilities Carsten Hast - ARD Test Facilities Department

Beam Driven Plasma Wakefield Accelerator Two-beam, co-linear, plasma-based accelerator Plasma wave/wake excited by relativistic particle bunch Deceleration, acceleration, focusing by plasma Accelerating field/gradient scales as ne1/2 Typical: ne≈1017 cm-3, λp≈100 µm, G>MT/m, E>10 GV/m High-gradient, high-efficiency energy transformer * Get us all on the same page SLAC User Facilities Carsten Hast - ARD Test Facilities Department

E-167: Energy Doubling with a Plasma Wakefield Accelerator @ FFTB Acceleration Gradients of ~50GeV/m (3,000 x SLAC) Doubled energy of 45 GeV electrons in 1 meter plasma Single Bunch Nature 445 741 15-Feb-2007 SLAC User Facilities Carsten Hast - ARD Test Facilities Department

Many FACET transparencies courtesy of Mark Hogan 7 SLAC User Facilities Carsten Hast - ARD Test Facilities Department M.J. Hogan, FACET Users Workshop March 18-19, 2010, Page

Beam Parameters Driven by Science Needs FACET @ SLAC FACET Sector 10 FFTB < 2006 FACET Sector 20 FACET Beam Parameters Energy 23 GeV Charge 3 nC Sigma z 14 µm Sigma r 10 µm Peak Current 22 kAmps Species e- & e+ Beam Parameters Driven by Science Needs Delivered to 100m area with three distinct functions: Chicane for final stage of bunch compression Final Focus for small spots at the IP Experimental Area Advantageous location: Preserves e+ capability No bypass lines or interference with LCLS Linac setup virtually identical to SPPS/FFTB SLAC User Facilities Carsten Hast - ARD Test Facilities Department

FACET Uses a Three Stage Compression Process b a c d e f g end of FACET sector 20 chicane SLAC User Facilities Carsten Hast - ARD Test Facilities Department

Carsten Hast - ARD Test Facilities Department Generate Two Bunches by Selectively Collimating During Bunch Compression Process Exploit Position-Time Correlation on e- bunch to create separate drive and witness bunch Modeled using similar analytic framework (CSR) as LCLS as well as tracking/shower codes x ∝ ΔE/E ∝ t Disperse the beam in energy Adjust final compression ...selectively collimate x [mm] dp/p [%] z [mm] SLAC User Facilities Carsten Hast - ARD Test Facilities Department

Carsten Hast - ARD Test Facilities Department FACET Design is Forward Looking and Flexible e.g. Sailboat Chicane Upgrade Extract e- & e+ from damping rings on same linac pulse Accelerate bunches to sector 20 while 5cm apart Use ‘Sailboat Chicane’ to put them within 100µm at entrance to plasma Large beam loading of e- wakes with high charge e+ beams Opens up many new avenues of research: Positron acceleration on electron driven wakes Positron Driven-PWFA Fast magnetic switching with delay between opposite field signs SLAC User Facilities Carsten Hast - ARD Test Facilities Department

Carsten Hast - ARD Test Facilities Department FACET Experiments Plasma Wakefield Acceleration PW Acceleration of positrons Positron driven plasmas Ultrafast magnetic switching experiments After burner studies based on stimulated emission of radiation Many technical questions for future linacs based on wakefield acceleration will be addresses (Optical diffraction, Smith-Purcell Radiation...) SLAC User Facilities Carsten Hast - ARD Test Facilities Department

Please keep them coming! FACET Status Approved, funded (not enough…) and under construction Construction schedule will allow first electron beam May / June 2011 Need to checkout and establish decent beams June / July Run beam for users starting July or August 4 month of user runs per year for the next 5 years FACET will provide 23 GeV electron and positron beams with 20 kA peak current with spot size of 10x10 microns Integrated many experimentally diagnostics into FACET facility (BLM, OTRs, X-ray stripe) for improved reliability and shared benefit Beam parameters are flexible and adaptive to a wide range of users Good access for people and equipment Flexible area for experimenters with space to accommodate new hardware/ideas First round of proposals was received, but: Please keep them coming! SLAC User Facilities Carsten Hast - ARD Test Facilities Department

Carsten Hast - ARD Test Facilities Department End Station B (ESB) SLAC User Facilities Carsten Hast - ARD Test Facilities Department

Carsten Hast - ARD Test Facilities Department ESB NLCTA TTF Couplers Marx Modulator X-Band Plasma Switches L-Band Laser E-163 DLA S-Band Gun Echo-7 RF Testing XBTA SLAC User Facilities Carsten Hast - ARD Test Facilities Department

Carsten Hast - ARD Test Facilities Department NLCTA 45m long, e- beam, 60-120 MeV (maybe 400 later), xy-emittance 1 to few microns, bunch length 0.5 psec, 5 -100 pC, dp/p≤10-4 LCLS style S-Band Injector 10 GW-class Ti:Sapphire system (800nm, 4 mJ) KDP/BBO Tripler for photocathode (266nm, 0.4 mJ) Active and passive stabilization techniques 5 GW-class Ti:Sapphire system (800nm, 1.2 mJ) For E-163 and Echo-7 100 MW-class OPA (1000-3000 nm, 80-20 mJ) 5 MW-class DFG-OPA (3000-10,000 nm, 1-3 mJ) Bend to Experimental Hall (currently E-163 DLA) Laser Seeding Test Area (currently Echo-7 Echo Enabled Harmonic Generation ) Lots of diagnostics Two x-band RF test stations for High Gradient research X-Band Test Area (X-Band gun and 100 MeV accelerator next year) SLAC User Facilities Carsten Hast - ARD Test Facilities Department

NLCTA Experimental Hall: E-163 Direct Laser Acceleration High gradient, power-efficient, economical acceleration  high energy physics and industrial applications Attosecond pulse generation from point-like sources  photon science applications Transition Radiation Accelerator stage Undulator + Chicane Optical Buncher First Staging of Laser Accelerator Sections Beam SLAC User Facilities Carsten Hast - ARD Test Facilities Department

E-163: Beam Tests of Microstructures Several types of accelerator structures to be tested Photonic Bandgap Fiber e-beam profile image at PMQ focus SEM image of HC-1550 fiber ThorLabs HC-1550-02 10 µm Planar-Waveguiding 8 x 8 µm RMS Achieved about 10 MeV/m (but the structures are tiny…) Goal is ~1GeV/m and having multiple stages Planar-Grating SLAC User Facilities Carsten Hast - ARD Test Facilities Department

NLCTA: X-Band Accelerator Length: 75 cm Operating gradient: 80 MV/m Max gradient: 100 MV/m Our plan is to make NLCTA an X-Band show case: higher energy, better beams SLAC User Facilities Carsten Hast - ARD Test Facilities Department

High Gain Harmonic Generation (HGHG) NLCTA: FEL Seeding High Gain Harmonic Generation (HGHG) laser Laser beam interacting. First undulator tuned to amply this interaction called a modulator. Chicane r56 moves modulations together. dE = laser modulations, E being the beam energy. Second undulator tuned to nw to amplify this harmonic Energy modulation in the modulator Energy modulation converted to density modulation 20 SLAC User Facilities Carsten Hast - ARD Test Facilities Department 20

Echo Enabled Harmonic Generation EEHG HGHG seed laser 2 laser 1 Extend the HGHG scheme with another modulator and chicane. N,m can be negative. Challenge is to preserve this phase space correlations First laser to generate energy modulation in electron beam First strong chicane to split the phase space Second laser to imprint certain correlations Second chicane to convert correlations into density modulation SLAC User Facilities Carsten Hast - ARD Test Facilities Department 21

EEHG FEL: Promises and Challenges Promises (in theory) Remarkable up-frequency conversion efficiency allows the generation of soft X-rays from UV seed lasers in a single stage Peak currents are NOT significantly enhanced, which mitigates collective effects Challenges Control & preservation of the phase space correlations CSR & ISR in the chicanes Quantum diffusion in the undulators from ISR Path length difference for particles with different betatron amplitude Unwanted x-z coupling from field errors, high order field components Small payments SLAC User Facilities Carsten Hast - ARD Test Facilities Department 22

Carsten Hast - ARD Test Facilities Department ECHO-7 at NLCTA existing New ECHO beam line Install X2 to boost beam from 60 MeV to 120 MeV Laser transport Construction of three undulators, three chicanes Add new or move existing quadrupoles, correctors, etc. New power supplies New diagnostics: OTRs, YAGs, cameras, movers, DAQ Add beam line spectrometer dipole 23 SLAC User Facilities Carsten Hast - ARD Test Facilities Department 23

Carsten Hast - ARD Test Facilities Department Echo-7 Beam Line SLAC User Facilities Carsten Hast - ARD Test Facilities Department

Parameters of ECHO-7 (July 2010) Beam Energy 120 MeV Bunch length 0.5 ps Normalized Emittance 8 mm-mrad Bunch charge 20-40 pC Laser wavelength in U1 795 nm NIR Laser wavelength in U2 (seed) 1590 nm IR Slice energy spread ~ 1 keV Np x lu for U1 10 x 3.3 cm K=1.82 Np x lu for U2 10 x 5.5 cm K=2.09 Np x lu for U3 10 x 2 cm Peak energy modulation in U1 and U2 10-40 keV R56 for C1 and C2 1.0 ~ 9.0 mm Radiation wavelength in radiator >318 nm UV SLAC User Facilities Carsten Hast - ARD Test Facilities Department 25

Carsten Hast - ARD Test Facilities Department Spatial overlap Beam on OTR1 Beam on OTR2 OTR1 OTR2 The spatial overlap is achieved by steering the laser to the same position as the electron beam on the OTR screens upstream and downstream of the undulators Laser on OTR1 Laser on OTR2 Additional trans for otr hardware and specs. 107 attenuation SLAC User Facilities Carsten Hast - ARD Test Facilities Department 26

Wavelength calibration Incoherent undulator radiation 1590 nm laser on (a) 795 nm laser on H2 (b) 395 nm bandpass filter in 531 nm bandpass filter in Precursor transp about what we expect to measure and how. Bandwidth limitation. Enough periods to see signal. The radiation spectrum [350, 600] nm can be measured in a single shot 27 SLAC User Facilities Carsten Hast - ARD Test Facilities Department 27

First ECHO signal! H2 E-1,5 H2 (a) (b) (c) 350 400 450 500 550 600 1590 nm laser only But attenuated No HGHG (a) 795 nm laser only HGHG signal H2 (b) Both lasers on with no 1590 nm HGHG (c) Pictures from the actual experiment. Attenuated 1590 to kill HGHG. Tiurned on 795 nm only (no 530 nm). Both on but with 1590 attenuated no HGHG . Spot at 530 belived to be echo. E-1,5 H2 350 400 450 500 550 600 Radiation wavelength (nm) 28 SLAC User Facilities Carsten Hast - ARD Test Facilities Department 28

ECHO signals when beam has an energy chirp Radiation wavelength (nm) H2 1590 nm laser on 795 nm laser on HGHG HGHG + EEHG E1 E2 E3 350 400 450 500 550 600 H4 H3 1590 nm seed laser on Both lasers on HGHG and combined spectra changes. More echo signals come out of hiding. SLAC User Facilities Carsten Hast - ARD Test Facilities Department 29

EEHG comparison with Monte Carlo Published PRL in August 350 400 450 500 550 600 H4 H3 H2 Both lasers on (b) simulation Simulation matches the data except for the mystery peaks. Published PRL in August SLAC User Facilities Carsten Hast - ARD Test Facilities Department 30

Your ideas and contributions are most welcome NLCTA Plans Improve NLCTA Control System, more uniform DAQ Better beam diagnostics Fix Phase jitter (between klystrons and lasers) And many more Ongoing Program Repeat Echo 2-4 Continue E-163 Continue X-Band RF tests New Experiments Echo 7-15 Narrow-band beatwave THz emission Studies COTR properties and micro-bunching instabilities Install transverse cavities for increased slice energy spread and redo EEHG Emittance Exchange with transverse cavities FEL gain (use an LCLS undulator) RF Undulator test with and without beam Increase beam energy up to 400 MeV and more… New X-Band Test Area for structure testing and an X-Band gun and 100 MeV linac Your ideas and contributions are most welcome SLAC User Facilities Carsten Hast - ARD Test Facilities Department

Application example: Soft X-Ray Linac Ultra High Gradients Goal is to design a “conventional” accelerator with loaded gradients of 150MeV/m (~7 times SLAC linac) Material and geometry simulations, fabrication and of course testing (ASTA and NLCTA) Achieved working beam loaded structures of 100MeV/m (routinely operating 80MeV/m structure in NLCTA) Application example: Soft X-Ray Linac ~40m ~30m Based on X-Band with 100MeV/m 50m 100m Based on SLAC Linac 20MeV/m SLAC User Facilities Carsten Hast - ARD Test Facilities Department

ASTA Test Facility 50 MeV e-beam capability RF component testing Rapid modifications possible Working on modernization of control system and a more universal LLRF system Future photocathode R&D New Laser Room Gate Valves Variable Delay line length through variable mode converter RF in from two 50 MW Klystrons Two experimental stations inside the bunker, one with compressed pulse and the other without the benefit of the pulse compressor. SLAC User Facilities Carsten Hast - ARD Test Facilities Department

ASTA has a “bright” future ASTA Test Facility High Gradient RF development (ongoing) Two XL-4 X-Band klystrons with pulse length up to 1.5 us Very flexible X-Band RF pulse compression system compressing the combined power from both klystrons producing a variable pulse from 1.5 us to 62 ns output powers from 100 MW to > 600 MW Thermionic electron gun is available Cathode and Gun research for high brightness low emittance electron sources (future) One S-Band and both X-Band klystrons New laser system for the cathode and gun tests ASTA has a “bright” future SLAC User Facilities Carsten Hast - ARD Test Facilities Department

End Station A Test Beam (ESTB) Test beam activities have been interrupted by ending PEP II operation and start of LCLS ESTB will be a unique HEP resource World’s only high-energy primary electron beam for large scale Linear Collider MDI and beam instrumentation studies Exceptionally clean and well-defined secondary electron/positron beams, secondary hadron beams, and photon beams available for detector development Huge experimental area, good existing conventional facilities, and historically broad user base SLAC User Facilities Carsten Hast - ARD Test Facilities Department

Kick 13.6 GeV LCLS beam to ESA ESA Test Beam provides electrons up to 13.6 GeV at full beam intensity… Kick 13.6 GeV LCLS beam to ESA 2 - 6 x 109 e-/pulse @ 5 Hz SLAC User Facilities Carsten Hast - ARD Test Facilities Department

Carsten Hast - ARD Test Facilities Department … Electrons/Hadrons up to 13.6 GeV, from single particles to full beam intensity Clean secondary electrons/positrons p<13.6 GeV, 0.1/pulse to 2 x 109 e-/p Secondary hadrons (later stage) ~1  / pulse < 12 GeV/c SLAC User Facilities Carsten Hast - ARD Test Facilities Department

Carsten Hast - ARD Test Facilities Department ESA Experimental Area Beam SLAC User Facilities Carsten Hast - ARD Test Facilities Department

Carsten Hast - ARD Test Facilities Department ESA Infrastructure Available Instrumentation Trigger counters Halo veto counters High resolution beam hodoscope Particle ID (Cerenkov, TOF, shower counter) Small, high field solenoid sturdy support table with remote movers Cranes 15 and 50-ton cranes available SLAC User Facilities Carsten Hast - ARD Test Facilities Department

ESA Primary Beam Equipment Layout 18 feet Wakefield box Wire Scanners rf BPMs T-487: long. bunch profile “IP BPMs” T-488 Ceramic gap for EMI studies BPM energy spectrometer (T-474/491) Synch Stripe energy spectrometer (T-475) Collimator design, wakefields (T-480) Bunch length diagnostics (T-487) Smith-Purcell Radiation IP BPMs—background studies (T-488) LCLS beam to ESA (T490) Linac BPM prototypes EMI (electro-magnetic interference) Irradiation Experiments Dipoles + Wiggler SLAC User Facilities Carsten Hast - ARD Test Facilities Department

Secondary Electrons and Positrons Inserting a thin foil in the transport line to ESA, and using the beamline as a spectrometer, creates a clean secondary electron/positron beam over the full range of energies (<13.6GeV) and a wide range of intensities down to ~1/pulse x,y~ 1 mm p/p ~  1% SLAC User Facilities Carsten Hast - ARD Test Facilities Department

from Jerry Va’vra’s Focusing DIRC Tests… SLAC 10 GeV/c electron beam Beam enters bar at 90º angle. Prototype is movable to 7 beam positions along bar. Time start from the LINAC RF signal, but correctable with a local START counter Beam spot: s < 1mm Lead glass: Local START time: s ~36ps SLAC User Facilities Carsten Hast - ARD Test Facilities Department

KPiX64-4 BNL, UC Davis, Oregon, SLAC Power-pulsed ILC readout chip From Timothy Nelson (ILC-SiD) 43 KPiX64-4 BNL, UC Davis, Oregon, SLAC Power-pulsed ILC readout chip Three vertically oriented planes Not a telescope: Goal is to test KPiX acquisition in ILC-like conditions, verify output normalization We now have high- precision measurements of silicon positions: can perform 3-d tracking and reconstruct vertical beam profile

ESTB Stage II Hadron Production Add Be target, beam dump, analyzing magnet, momentum slit, and quadrupole doublets to produce a secondary hadron beam in ESA Production angle = 1.35O and Acceptance = 10 sr SLAC User Facilities Carsten Hast - ARD Test Facilities Department

Secondary Hadron Beam Properties Beam Properties at Detector Plane x=1mm y=1.4mm E/E=1.3% Energy 0.1–12 GeV Particles per pulse 0.1–10 / nC Bunch repetition rate 5 Hz Precise beam trigger Yes rms x, y spot size 1-2 mm Momentum analysis p/p ~ 1% x,y,z space available 5 m, 5 m, 15 m Rate for p, K,  0.1-0.01/ SLAC User Facilities Carsten Hast - ARD Test Facilities Department

First beam early summer 2011 ESTB Status New BSY kicker magnets, power supply and vacuum chambers All items are in the design stage (based on existing hardware) Will be installed during the down March/April 2011 New small beam dump for ESA Design is clear Radiation protection calculations are ongoing Will be installed early 2011 New Personnel Protection System (PPS) Is the most complicated of the needed upgrades Design has started and implementation plan is under development My hope is to get it done until early 2011 We are planning on a User Workshop in conjunction with another meeting late this year or early 2011 First beam early summer 2011 SLAC User Facilities Carsten Hast - ARD Test Facilities Department

ESTB Time Line for Hadrons Funding will be made available after we have had beam in ESA June2011 primary beam to ESA  Additional funds may be released… Need about 4-6 month to design and build hadron target and auxiliary infrastructure, new magnet stands, beam pipe About 2 month to install equipment in ESA During short winter shutdown 2011/2012 install target in A-line Hadron Beam to ESA Winter 2011/12 Carsten Hast - ARD Test Facilities Department

Need electron beam? Come to SLAC! Conclusions 2011 will be an exciting year at SLAC LCLS and SPEAR continue marvelous things FACET and ESTB coming on line But hurry LCLS II is getting ready to take over the Linac NLCTA and possibly ASTA upgrades Very long term plans are in the making Need electron beam? Come to SLAC! SLAC User Facilities Carsten Hast - ARD Test Facilities Department