The Upgraded Argonne Wakefield Accelerator Facility (AWA) Argonne National Laboratory: Euclid Techlabs LLC: Students: W. Gai , M. Conde, S. Doran, W. Liu, J. G. Power, C. Whiteford S. Antipov, S. Baryshev, C. Jing, J. Qiu , R. Konecny, A.Kanareykin, P.Schoessow E. Wiesniewski (IIT), C. Li, H. Zha (Tsinghua), G. Ha(POSTECH). A testbed for the development of high-gradient accelerating structures and wakefield measurements. HG2013, Trieste, Italy, June 4th, 2013 Go to "View | Header and Footer" to add your organization, sponsor, meeting name here; then, click "Apply to All"

Primary mission R&D Beam Driven Dielectric Wakefield Acceleration Funding  High Energy Physics

Wakefields in Dielectric Structures 2b 2a e Q Cu short Gaussian beam Key to the success: Drive beam, drive beam and drive beam! Charge  sr  (Energy  or Emittance ) Bunch length  Go to "View | Header and Footer" to add your organization, sponsor, meeting name here; then, click "Apply to All"

Dielectric-Loaded Accelerator Structure Simple geometry Inexpensive Capable of high gradients Easy to damp dipole modes Tunable Electric Field Vectors

outline High Gradient Concepts Applications Collinear wakefield acceleration Two beam acceleration (a.k.a. Parallel wakefield acceleration) Applications A high energy physics collider An x-ray free electron laser THz generation The Argonne Wakefield Accelerator Facility Then Now outline

concepts Collinear wakefield acceleration & Two-beam acceleration (Parallel wakefield acceleration) concepts

Collinear Wakefield Acceleration Dielectric Vacuum Metal Drive Beam (EM power source) Witness Beam (accelerated beam) Recent results (obtained for Linear Collider development): 1000MV/m level in the THz domain (UCLA/SLAC group) 100 MV/m level in the MHz domain (AWA/ANL group)

Two-beam acceleration (Parallel wakefield acceleration) 3. High Gradient Acceleration Modulator Klystron 250KV, 25MW, 8us 1.3GHz, 250AMPs Mode Locked 2. RF power generation UV Laser 1. Drive beam generation

e+ e- linear collider (a few) applications X-ray light source THz generation (a few) applications

HEP 1. e+ e- collider Current Approach: superconducting RF 25 MV/m, 0.5 TeV, 31 km Current Approach: superconducting RF

Argonne Approach: Flexible Linear Collider* HEP 250 MV/m, 3 TeV, 18 km two-beam acceleration Core of the two-beam acceleration concept: Short rf pulse: tens of nanosecond Modular TBA scheme: energy scalable easily *(See C. Jing’s talk)

2. Multiuser X-ray FEL User Facility BES Capable of serving ~2000 scientists/year Laser-like X-rays (like 4th generation light sources) (like 3rd generation light sources) Beam Spreader ~100 kHz X-rays ~1 MHz injector 50 MeV 2 GeV experimental end stations —Current Approach— superconducting RF $$$ Flexible x-ray beamlines (Tunable pulse length, seeded, 2 color seeded, SASE)

Argonne Approach dielectric wakefield accelerating linacs BES Collinear wakefield acceleration ~50 m 350m 750m experimental end stations ~30 m 1. High Gradient (100 MV/m) DWFA linac 2. Room Temperature dielectric ~100 m 2 GeV 200 MeV extremely low-cost alternative ~50 m ~50 m Facility Footprint 350m x 250m ~25 m 3. Low Energy Beam Spreader

Ultra-flexible facility Collinear wakefield acceleration dielectric wakefield accelerating linacs Flexible accelerator beamlines Flexible x-ray beamlines 1.2 GeV 100 pC 0.5 keV X-rays … 2.4 GeV 50 pC End Stations 1 keV X-rays … Configurable DWFA Accelerator Configurable FEL Array

3. THz generation: Capability gap BES 7.8GHz power extractor (40MW) 100MV/m gradient demonstration Enhanced Transformer Ratio: 3.4 Tunable DLA structure 26GHz power extractor Diamond breakdown experiment (300MV/m) Bunch Train generation at the AWA Wakefield Mapping diamond THz source at AWA Chirp correction Tunable THz GV/m Tunable 0.3-10 THz High power (155 mJ) Narrow band (1% BW) 1GHz 10GHz 30GHz 100GHz 300GHz 1THz 3THz AWA ATF BNL FACET SLAC 1515 Go to "View | Header and Footer" to add your organization, sponsor, meeting name here; then, click "Apply to All"

Argonne Approach: dielectric wakefield accelerator-based AWA (10nC / 6.3mm) 0.5 GW peak, 0.3THz, 320ps pulse, 1%BW, 155mJ pulse Stage I Stage II Stage III Energy modulation via self-wakefield Chicane energy modulation conversion to bunch train THz radiation wakefield structure THz Flexible: each step has a tuning range Measured beam spectrum Energy chirped rectangular beam Energy modulated rectangular beam Bunch train frequency content Tunable 100% source: Range: 0.3-1.5 THz Pulse bandwidth: 1% Energy in pulse: ~ mJ narrow-band, tunable, ultra-high power THz source Go to "View | Header and Footer" to add your organization, sponsor, meeting name here; then, click "Apply to All"

Then The awa facility

Highlights of the Accelerator R & D group in the past Invented the direct wakefield measurement technique. First demonstration of collinear Wakefield Acceleration: Dielectric Structures, Metallic Structures, and Plasmas First Ever plasma wakefield acceleration in underdense regime (non-linear) (with UCLA). First Ever 100 nC RF photocathode gun and Linac. First Ever high power RF generation from dielectric wakefield structure accelerator. First Ever dielectric based two beam acceleration experiment. Discovered new multipactoring regime in dielectric structure. Collinear wakefield Drive beam generation RF generation Two-beam

The AWA facility (PAST, ca. 2008) ~ 1 meter 8 MeV 15 MeV Experimental Area soleniod lenses YAG1 YAG2 Quads Spectrometer rf-gun Laser In Linac Direction of beam propagation AWA Laser System Single bunch operation Q = 1-100 nC (reached 150 nC, World record?) 15 MeV, 2-2.5 mm bunch length (rms), emittance < 200 mm mrad (at 100 nC) High Current: ~10 kA Bunch train operation 4 bunches x 20 nC (current) 16 bunches x 5 nC (current)

RF power generation (PAST) Dielectric Power Extractors Dielectric-Loaded deceleration waveguide 7.8 GHz 40 MW TM01-TE10 coupler rf output port Downconverted signal 26 GHz 20 MW 11.44+14.576=26.016 GHz  Power limited by drive beam

High Gradient Dielectric Wakefield Test (PAST) #4 Q3.8-25.4 Quartz 3.75 8.6 GHz 1.9 mm 7.49 mm 25.4 mm 1.33 MV/m/nC 75 nC 100 MV/m Wakefield Measurements: Q=75 nC e Cu 8.6 GHz 100 MV/m  Gradient limited by drive beam

Now The awa facility

Key components of the AWA Upgrade 15 MeV beam Mg photocathode Drive beam: 15 MeV  75 MeV Restore two beam accelerator capability Beamline switchyard High quantum efficiency cathode …Before 4. Cs2Te photocathode After… 2. 15 MeV witness beam 1. 75 MeV drive beam: RF gun & six rf cavities 3. beamline switchyard

Capabilities of the AWA Upgraded Facility Higher RF power generation: 40 MW  ~ GW level Higher gradients:100MV/m  0.5 GV/m in long structures Sustained acceleration: witness DE: 1MeV  ~ 100 MeV Restore two beam accelerator capability: Drive bunches to excite wakefields & acceleration of witness bunch. Beamline switchyard two-beam-acceleration staging collinear wakefield acceleration phase space manipulation

The AWA Upgrade drive beam 75 MeV Direction of beam propagation drive gun Upgrade Goals Original Drive Beam (Achievements) Upgraded Drive Beam (Targets) Single bunch operation 75 MeV Q = 0.1-100 nC @ 100 nC sz = 2 mm High Current: ~16 kA emittance < 200 um Bunch train operation 10 bunches x 100 nC 32 bunches x 30 nC Train Length = 10 - 50 ns Single bunch operation 15 MeV Q = 0.1-100 nC @ 100 nC sz = 3 mm High Current: ~11 kA emittance < 200 um Bunch train operation 4 bunches x 20 nC 16 bunches x 5 nC Train Length = 10 - 25 ns

The AWA upgrade beamlines experimental area RF power generation Collinear Wakefield TBA Wakefield Measurement EEX Bunch compression 75 MeV drive beam 15 MeV witness beam 75 MeV drive beamline installed Feb 2013 Go to "View | Header and Footer" to add your organization, sponsor, meeting name here; then, click "Apply to All"

Planned RF Power Generation 26GHz power extractor Dielectric Freq. (GHz) Aperture (mm) L (cm) Q (nC) z (mm) Form factor Grad. (MV/m) Power (MW) C-Band (7.8) 12 30 100 2.5 0.92 62 1107 X-Band (11.7) 10 80 0.83 79 1012 Ku-Band (15.6) 8 60 2.3 0.75 88 766 K-Band (26) 6 1.7 0.65 75 276 W-Band (91) 2 1 0.16 50 14 11.7GHz metallic power extractor is under development Metallic (2pi/3 mode) X-Band (11.7) 8.7 30 60 2.3 0.85 90 441 K-Band (26) 7.5 40 2 0.55 100 410

Planned Two Beam Acceleration Experiment 26GHz Stage I DWPE a=3.5mm; b=4.53mm; eps=6.64; L=30cm drive (75MeV) 16 bunches x 60nC/bunch, z=2mm drive (65MeV) -10MeV (loss) RF Power Generation 767MW x15ns 26GHz rf 26GHz Stage II DLA a=3mm; b=5.03mm; eps=9.7; Vg=11%c; L=30cm witness (10 MeV) Q=1nC, z=1mm, e=1.5 um witness (85 MeV) +75 MeV (gain) Ez = 250MV/m

Development of 26GHz short pulse DLA structure parameters value ID / OD of dielectric tube 3 mm /5.025 mm Dielectric constant 9.7 Length of dielectric tubes 105 mm Vg 11.13%c R/Q 21.98 k/m Q (loss tan=10^-4) 2295 Shunt impedance 50.44 M/m Eacc for 316MW input 158 MV/m

Longer Term Goal: Staging for Two Beam Acceleration Reverse the beam Option 1 Drive Beam stage I stage II Witness Beam Drive Witness 2m 0.5m =2 Witness Beam Drive Beam Option 2 Reverse the RF Delay the RF Witness Drive *Option 3: Delay the beam Go to "View | Header and Footer" to add your organization, sponsor, meeting name here; then, click "Apply to All"

Planned collinear wakefield acceleration @ AWA drive z-direction witness z-direction Structure Parameters Beam Parameters Estimated Gradient 75MeV beam 8 bunches 40nC/per bunch σz=2mm Beam hole=3mm Quartz tube Freq.=29.9GHz ~500MV/m on axis

Planned demonstration of bunch shaping using a double-dog leg EEX beamline for high R at the AWA Facility The Argonne Wakefield Accelerator Facility  Low Energy (15 MeV) beamline TDC B1 B2 RF Photocathode Gun 8 MeV 15 MeV Linac Quads 20 deg B4 B2 B3 B1 chirp multiple masks on motorized actuator x’ slope x, y beam size Key tunable parameters

Planned demonstration of bunch shaping using a double-dog leg EEX beamline Example: Experiment I - Shaping capability Multiple masks will be used to study the bunch shaping capability of the double dog-leg EEX beamline

Drive Diagnostic Beamline To be installed Summer 2013 TEST AREA 75 MeV Longitudinal: Dp, p [MeV] 0.762m dump DIAGX8 1m 0.762m End of linac DIAGX7 0.4 m 1.5 m 1.0 m 1.0 m A 1m A 15 deg Cav 6 A A dump 2m DIAGX3 DIAGX2 1m DIAGX6 DIAGX5 DIAGX4 Def Cav DIAGX1 Longitudinal: sz [mm] Q[nC] Transverse: ey,rms,normalized [mm] Transverse: sx,y[mm] USAF target YAG+ mirror DIAGNOSTIC CROSS A Slit Trim OTR BPM ICT Quad

summary AWA facility capabilities Applications Next steps 75 MeV Drive Microbunch charge: 100 nC Train charge: 1000 nC (10 x 100 nC, 32 x 30 nC) Ramped trains & single bunches 15 MeV Witness (1-100 nC) Applications e+ e- collider XFEL RF-THz power generation High Transformer Ratio Two-beam acceleration Collinear wakefield acceleration Next steps Drive and witness beamlines are installed, Awaiting final safety approval Drive beamline commisioning – Summer-Fall 2013 Generate and characterize single bunches and trains Condition 6 RF cavities Install diagnostic beamline Begin full beam commissioning at 75 MeV First wakefield experiments – Fall 2013 Wakefield measurement system– 2014 summary