US HG Research Collaboration Workshop, SLAC, 2011 PROGRESS ON HG WAKEFIELD ACCELERATOR DEVELOPMENT EUCLID&AWA COLLABORATION A. Kanareykin for Euclid/AWA Collaboration Euclid Techlabs LLC

US HG Research Collaboration Workshop, SLAC, 2011 Euclid Techlabs LLC: DLA collaboration Euclid Techlabs, Rockville, MD: - - C.Jing, S.Antipov, P.Schoessow, and A.Kanareykin -P. Avrakhov (FNAL) -S. Zou (NRL) AWA of Argonne Nat. Lab, Chicago: Argonne Wakefield Accelerator: M.Conde, J.G.Power, R.Conecny, Z.Yusof, AWA and W.Gai Naval Research Lab, Washington, DC -S.Gold - J. Butler FACET Collaboration: SLAC, UCLA J. Rosenzweig, G.Travish, M.Hogan… THz:

US HG Research Collaboration Workshop, SLAC, 2011 DLA Issues  Drive Beam – Beam Train - High Gradient DLA  Dielectric Material Beam Tests  Dielectric - Wakefield Power Extractor  Tunable Dielectric Based Accelerator  Energy Transfer: High Transformer Ratio  Beam Handling, Beam Breakup (BBU)  Dipole Mode Damping Dielectric Based Accelerator issues: high gradient – drive beam, power extraction, tuning, efficiency, beam control (BBU).

US HG Research Collaboration Workshop, SLAC, 2011 Outline  Transformer Ratio Experiment (C.Jing’s talk)  Tunable DLA (C.Jing’s talk) and Nonlinear Materials for DLA  26 GHz Power Extractor  BBU Studies for DLA  PETS power extractors  Short Pulse High Gradient DLA Structure (M.Conde’s talk)  Multipactor DLA Studies (S.Antipov’s talk)  GHz Diamond Based DLA Structure  FACET DLA

US HG Research Collaboration Workshop, SLAC, 2011 Single bunch operation –Q=1-150 nC –Energy=15 MeV –High Current = 10 kAmp Bunch train operation up to 64 bunches x 50 nC  50 ns long Materials for Dielectric Loaded Accelerator bb aa  Q Cu >100 MV/m gradient demonstrated

US HG Research Collaboration Workshop, SLAC, 2011 material  tan , X-band t thermo - conductivity diamond,  W/m/ 0 K material  tan , X-band t thermo - conductivity quartz,  W/m/ 0 K Dielectric Materials for the HG Accelerator Applications* Low loss microwave ceramic ( ) Composite ferroelectric ( ) CVD Diamond ( ) Quartz ( )

US HG Research Collaboration Workshop, SLAC, 2011 Euclid efforts in the WF experiments at Argonne  Experiment of 26GHz dielectric wakefield power extractor in 2009  16ns,1MW & 6ns, 20MW 26GHz rf pulse were measured.  BBU was observed.  Experiments of transformer ratio enhancement in 2007, 2010  Successfully enhanced the transformer ratio to 3.4 by using ramped bunch train technique.  The tunable DLA demonstration with the beam test in  Developed the tunable DLA structure, bench tested. Beam test has been completed few weeks ago. Tuning range of ½ λ has been demonstrated  The planned test of the GHz diamond structure  Finished simulation and engineering design. The planar structure is being assembled. Beam experiment - in Spring of Progress on cylindrical structure development.

US HG Research Collaboration Workshop, SLAC, 2011 Transformer Ratio Experiment by joint effort from Euclid Techlabs and AWA * Measured Enhancement factor of R 2 /R 1 =1.31 Inferred R 2 =2.3 Reference: Schutt et. al., Nor Ambred, Armenia, (1989) z d d W - W + d  (z) R 2 =3.4 (2007) (2010) * talk J.Jing

US HG Research Collaboration Workshop, SLAC, 2011 Temperature tuning of 14 MHz/ 0 K forsteriteBST(M) Tunable DLA Temperature Tuning* * C.Jing’s talk

US HG Research Collaboration Workshop, SLAC, 2011 Tunable DLA Beam Experiment * * C.Jing’s talk Temperature tuning of 14 MHz/ 0 K Wakefield Frequency Shift

US HG Research Collaboration Workshop, SLAC, 2011 BST(M) Ferroelectric Based L-band High Power Tuner 30 ns switching time Collaboration with Omega-P and FNAL Pulse steepening on NL planar transmission line

US HG Research Collaboration Workshop, SLAC, GHz Power Extractor and BBU Experiment BBU mitigation with quadrupole channel 20 nC beam; tapered F-D-F quad array

US HG Research Collaboration Workshop, SLAC, 2011 Transverse Beam Dynamics in the DLA Collaboration with Dynamic Software and ANL

US HG Research Collaboration Workshop, SLAC, 2011 Multibunch BBU in the DLA 3D beam implementation Phase space input/output Parmela files import opportunity Improving Particle Push Algorithm (3D) 2D FODO focussing F(x)~x, F(y)~y Improved results visualization Main parts to be ready by February 2008

US HG Research Collaboration Workshop, SLAC, GHz Transverse Mode Damped DLA Structure* A new transverse mode damped DLA structure has been proposed. A 7.8 GHz prototype has been built and bench tested. Beam test will be performed at AWA facility. Comparison of the 7.8GHz Conventional and the Transverse mode Damped DLA structure. Freq.Q in conventional DLA structure Q in transverse modes damped DLA structure Accelerating mode (TM 01 ) 7.8GHz6964*6738* Transverse modes (HEM 11 ) 6.34GHz6866*23* Collaboration with ANL *C.Jing, this workshop

US HG Research Collaboration Workshop, SLAC, 2011 Projects  Development of a Dielectric-Based Short RF Pulse Two Beam Accelerator Prototype Module Unlike the most of the present accelerator designs pulse with lengths of ns and gradients ~100 MV/m as the operational parameters, we propose a short pulse (~20 ns), high repetition rate (>1 kHz), high gradient (>200 MV/m) accelerator technology.  THz Dielectric Wakefield Accelerating Structure. This project will develop a manufacturing technology of artificial diamond fiber to be used in dielectric loaded accelerating structures. When developed, this structure will sustain a record high accelerating gradient in THz frequency range.  Development Of A 12 GHz Dielectric-Based Wakefield Power Extractor for Potential CLIC Applications Dielectric based high power radio frequency (rf) generator offers the possibility of reduced cost and higher efficiency for applications in the next generation high energy physics machine to meet the particular requirements of CLIC.  Multipactor Suppression In Dielectric Loaded Accelerating Structures Using Vacuum Channel Surface Modification This project will study ways to eliminate a form of energy absorption that is currently the main obstruction to widespread use of the dielectric based particle accelerators.  Dielectric Collimators for Linear Collider Beam Delivery this project will develop a special device to control electron bunch of the future linear collider. The use of new software and materials that our company has developed is expected to lead to improved performance and efficiency.

US HG Research Collaboration Workshop, SLAC, 2011 Developing a Dielectric PETS* (CLIC) * Funded by DoE SBIR Phase I. Thanks for help from AWA, CLIC, and SLAC. In order to have a high power rf test at SLAC, the 1st structure is scaled to GHz. 12GHz Quartz-Based Power Extractor Using CLIC Parameters: σz=1mm, Q=8.4nC, Tb=83ps Freq 12GHz Effective Length 23cm Beam channel 23mm Thickness of the dielectric tube 2.58mm Dielectric const. 3.75(Quartz) Q 7318 R/Q 2.171k  /m Vg c Peak surface Gradient 12.65MV/m Steady Power 142MW

US HG Research Collaboration Workshop, SLAC, GHz PETS is under construction: The rest of parts are on the lathe; will be done this week, then will be shipped for the brazing.

US HG Research Collaboration Workshop, SLAC, 2011 fast rf rise time ( 150MHz) less filling time  Large (~10%c) Vg. 3ns T rf =28ns T f =9ns T beam =16ns 6.5A 267MV/m 0.3m 1.264GW 16ns 25ns Development of a Short Pulse High Gradient DLA Structure* AWA/Euclid proposed a 26GHz short pulse collider concept. RF pulse structure Requirements for the accelerating structure * Funded by DoE SBIR Phase I. * M.Conde’s talk

US HG Research Collaboration Workshop, SLAC, 2011 Broad band  fast rise time 500MHz DLA structure ( const. impedance ) Design of the Short Pulse DLA Broadband coupler (scaled from SLAC X- band coupler) Vg~11%c; R/Q~22k  /m; R~50.5M  /m

US HG Research Collaboration Workshop, SLAC, 2011 Projected rf power and achievable gradient in AWA 75MeV beamline Estimated Power AWA facility 75MeV beam 16 bunches 60nC/per bunch  z=2mm 26GHz DWPE 767MW, 15ns, 26GHz rf (10MeV loss) 26GHz DLA Estimated Gradient 250 MV/m talk M.Conde

US HG Research Collaboration Workshop, SLAC, 2011 Multipactor Studies Simulations: Multipactor power loss decreases at HG Longitudinal Transverse groove type groove dimensions length TiN coating we are all set to test ~ 10 different configurations: S.Antipov’s talk Collaboration with UMD, NRL and ANL

US HG Research Collaboration Workshop, SLAC, 2011 Motivation for CVD Diamond for DLA Element Six CVD DIAMOND PROPERTIES: - DC BREAKDOWN THRESHOLD OF ~ 2 GV/m - LOSS FACTOR DOWN TO 5-9 x10 -5 AT GHz - HIGHEST THERMAL CONDUCTIVITY - DC CONDUCTIVITY - HIGH REPRATE. - MULTIPACTING CAN BE SUPPRESSED - CVD DEPOSITION NOW CAN BE USED TO FORM CYLINDRICAL WAVEGUIDES

US HG Research Collaboration Workshop, SLAC, GHz Diamond Based DLA Structure CVD diamond tube fabrication

US HG Research Collaboration Workshop, SLAC, 2011 High Electronic Quality Cylindrical Diamond DLA (I)

US HG Research Collaboration Workshop, SLAC, 2011 High Electronic Quality Cylindrical Diamond DLA (II) Laser light Daylight Outer surface facets facets cylindrical

US HG Research Collaboration Workshop, SLAC, 2011 Planar Diamond Structure Bunch length1.5 mm Beam gap4.0 mm D thickness1.2 mm width8 mm length5.0 mm First CVD diamond in a dielectric accelerating structure > 100 MV/m gradient using AWA beam Breakdown test using 20 micron – wide artificial scratch on the diamond surface (0.5 GV/m level fields) Structure is short, TM 110 – based. Wake is a single mode at ~ 26 GHz

US HG Research Collaboration Workshop, SLAC, 2011 Planar Structure Design Avoiding hot spots on diamond holder beam Diamonds E6...scratched There will be a ~500% field enhancement in the scratch / groove beam

US HG Research Collaboration Workshop, SLAC, 2011 Diamond Groove SEM Image SEM: Z. Yusof Cut: J. Butler (NRL) Image: “BEFORE”

US HG Research Collaboration Workshop, SLAC, 2011 The Structure Holder Most the holder parts are completed One modification needed (RF probe) Cleaning (parts, diamonds) S. Doran

US HG Research Collaboration Workshop, SLAC, 2011 SEE COEFFICIENT Multipacting is suppressed by treating the diamond surface during the CVD growth of the diamond, in particular, dehydrogenation of the surface to decrease the secondary electron yield. SEE coefficient is reduced ~ 1. I.L. Krainsky et al. NASA Report/TP— , (1999) Collaboration: - NRL, Surface Chemistry (J.Butler) - Genvac Aerospace Inc./NASA - Coating Technology Solutions, Inc. A.Kanareykin, P.Schoessow et al, EPAC 2006, Edinburgh, pp , (2006).

US HG Research Collaboration Workshop, SLAC, 2011 ID=80 μm (a=40 μm ) OD= 152 μm (b=76 μm) b - a= 30 μm (diamond thickness) Planar or Cylindrical THz DLA ? Gradient bb aa  Q w Both structures ~ 2 GV/m/nC 2a=80 μm, a= 40 μm, b= 70 μm b - a= 30 μm (diamond thickness) w= 300 μm 2 GV/m/nC

US HG Research Collaboration Workshop, SLAC, 2011 Conclusions  Transformer Ratio Experiment has demonstrated R>3.4 for two bunch train  Tunable DLA has been developed with the tuning range of 15 MHz/ 0  26 GHz Power Extractor has been demonstrated  BBU code has been developed and used for PE development  12 PETS power extractor for CLIC is under construction  High Gradient DLA Structure proposed for the new Short Pulse collider  GHz Diamond Based DLA Structure test are coming  Multipactor simulations showed reduced power loss at 150 MV/m  FACET DLA structure is being fabricated