PAC07 - List of Authors (Rosenzweig, J. B.)

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Rosenzweig, J. B.

Paper	Title	Page
MOOAAB02	Experimental Results with the SPARC Emittance-meter	80
	M. Ferrario, D. Alesini, M. Bellaveglia, S. Bertolucci, R. Boni, M. Boscolo, M. Castellano, A. Clozza, L. Cultrera, G. Di Pirro, A. Drago, A. Esposito, D. Filippetto, V. Fusco, A. Gallo, G. Gatti, A. Ghigo, M. Incurvati, C. Ligi, M. Migliorati, A. Mostacci, E. Pace, L. Palumbo, L. Pellegrino, R. Ricci, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, F. Tazzioli, S. Tomassini, C. Vaccarezza, M. Vescovi, C. Vicario INFN/LNF, Frascati (Roma) A. Bacci, S. Cialdi, A. R. Rossi, L. Serafini INFN-Milano, Milano L. Catani, E. Chiadroni, A. Cianchi INFN-Roma II, Roma A. M. Cook, M. P. Dunning, P. Frigola, J. B. Rosenzweig UCLA, Los Angeles, California L. Giannessi, M. Quattromini, C. Ronsivalle ENEA C. R. Frascati, Frascati (Roma) P. Musumeci, M. Petrarca INFN-Roma, Roma
	The SPARC project foresees the realization of a high brightness photo-injector to produce a 150-200 MeV electron beam to drive a SASE-FEL in the visible light. As a first stage of the commissioning a complete characterization of the photoinjector has been done with a detailed study of the emittance compensation process downstream the gun-solenoid system. For this purpose a novel beam diagnostic device, called emittance meter, has been developed and used at SPARC. This device has allowed to measure the evolution of beam sizes, energy spread and rms transverse emittances at different location along the beamline, in the region where space-charge effects dominate the electron dynamics and the emittance compensation process takes place. In this paper we report our commissioning experience and the results obtained. In particular a comparison between the performances of a Gaussian laser pulse versus a Flat Top laser pulse will be discussed. We report also the first experimental observation of the double emittance minima effect on which is based the optimised matching with the SPARC linac.
	Slides
TUOBAB02	Experimental Characterization of the Transverse Phase Space of a 60-MeV Electron Beam through a Compressor Chicane	788
	F. Zhou, A. C. Kabel SLAC, Menlo Park, California R. B. Agustsson, G. Andonian, D. B. Cline, A. Y. Murokh, J. B. Rosenzweig UCLA, Los Angeles, California V. Yakimenko BNL, Upton, Long Island, New York
	Funding: U. S. DOE of Sciences Space charge and coherent synchrotron radiation may deteriorate electron beam quality when the beam passes through a magnetic bunch compressor. This paper presents the transverse phase-space tomographic measurements for a compressed beam at 60 MeV, around which energy the first stage of magnetic bunch compression takes place in most advanced linacs. Transverse phase-space bifurcation of a compressed beam is observed at that energy, but the degree of the space charge-induced bifurcation is appreciably lower than the one observed at 12 MeV. The Trafic4 simulation confirms the observation. The paper was published at PRST-AB, November 2006
	Slides
TUPMN038	Coherent Cherenkov Radiation as a Temporal Diagnostic for Microbunched Beams	998
	G. Gatti INFN/LNF, Frascati (Roma) A. M. Cook, J. B. Rosenzweig, R. Tikhoplav UCLA, Los Angeles, California
	Cherenkov radiation of a relativistic e-beam traversing a thin section of aerogel is analized, putting the stress on the coherent contribution due to the intra-beam, transverse and longitudinal structure. The use of this tool as a temporal diagnostic for micro-bunched beams makes possible to improve the amount of collected power at the microbunching frequency several orders of magnitude more respect to the uncoherent Cherenkov contribution. The non-idealities of a real beam are taken in account, and some techniques aimed on enhancing the coherent part of radiation are proposed and analized analitically and through simulation codes.
TUPMS028	Commissioning of a High-Brightness Photoinjector for Compton Scattering X-Ray Sources	1242
	S. G. Anderson, C. P.J. Barty, D. J. Gibson, F. V. Hartemann, M. J. Messerly, M. Shverdin, C. Siders, A. M. Tremaine LLNL, Livermore, California H. Badakov, P. Frigola, A. Fukasawa, B. D. O'Shea, J. B. Rosenzweig UCLA, Los Angeles, California
	Funding: This work was performed under the auspices of the U. S. Department of Energy by University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48. Compton scattering of intense laser pulses with ultra-relativistic electron beams has proven to be an attractive source of high-brightness x-rays with keV to MeV energies. This type of x-ray source requires the electron beam brightness to be comparable with that used in x-ray free-electron lasers and laser and plasma based advanced accelerators. We describe the development and commissioning of a 1.6 cell RF photoinjector for use in Compton scattering experiments at LLNL. Injector development issues such as RF cavity design, beam dynamics simulations, emittance diagnostic development, results of sputtered magnesium photo-cathode experiments, and UV laser pulse shaping are discussed. Initial operation of the photoinjector is described and transverse phase space measurements are presented.
TUPMS034	Seeded VISA: A 1064 nm Laser-Seeded FEL Amplifier at the BNL ATF	1257
	M. P. Dunning, G. Andonian, E. Hemsing, S. Reiche, J. B. Rosenzweig UCLA, Los Angeles, California M. Babzien, V. Yakimenko BNL, Upton, Long Island, New York
	An experimental study of a seeded free electron laser (FEL) using the VISA undulator and a Nd:YAG seed laser will be performed at the Accelerator Test Facility at Brookhaven National Laboratory. The study is motivated by the demand for a short Rayleigh length FEL amplifier at 1 micron for high power transmission with minimal damage of transport optics. Planned measurements include transverse and longitudinal coherence, angular distribution, and wavelength spectrum of the FEL radiation. The effects of detuning the electron beam energy will be studied, with an emphasis on control of the radiation emission angles and increase of the amplifier efficiency. Results of start-to-end simulations will be presented with preliminary experimental results.
TUPMS035	The FINDER Photoinjector	1260
	A. Fukasawa, H. Badakov, E. Hemsing, B. D. O'Shea, J. B. Rosenzweig UCLA, Los Angeles, California S. G. Anderson LLNL, Livermore, California
	The FINDER project at LLNL is an inverse-Compton scattering demonstration, aimed at creating MeV-class, narrow band photons for interrogation of nuclear materials. The requirements experiment requires a state-of-the-art photoinjector. Such a device is under development by a UCLA/LLNL collaboration. We report on a number of design innovations, such as photocathode gun RF symmetrization and large mode separation, which sets this device apart from previous generations of the BNL/SLAC/UCLA 1.6 cell gun. Measurements characterizing the RF photocathode gun and emittance compensation solenoid are presented.
TUPMS036	Characterization of Orbital Angular Momentum Modes in FEL Radiation	1263
	E. Hemsing, G. Andonian, J. B. Rosenzweig UCLA, Los Angeles, California M. Babzien, V. Yakimenko BNL, Upton, Long Island, New York A. Gover University of Tel-Aviv, Faculty of Engineering, Tel-Aviv
	Optical guiding of the radiation pulse through the source electron bunch in a free-electron laser is a well known phenomena that suppresses diffraction of the output radiation, and thus enhances the gain. The resulting radiation can be described by an expansion of orthogonal modes that are also composed of eigenstates of orbital angular momentum (OAM). In the VISA-FEL experiment at the ATF-BNL, gain guiding has been observed under self-amplified spontaneous emission conditions at 840 nm with a strongly chirped input electron beam. The resulting far-field transverse radiation profiles are observed to contain multiple modes in the angular intensity spectrum, and exhibit both hollow and spiral structures characteristic of single or multiply interfering OAM modes. Current efforts to characterize the transverse radiation profile both experimentally and through start-to-end simulations are presented.
WEOAKI02	Observations of Underdense Plasma Lens Focusing of Relativistic Electron Beams	1907
	M. C. Thompson, M. C. Thompson LLNL, Livermore, California H. Badakov, J. B. Rosenzweig, R. Tikhoplav, G. Travish UCLA, Los Angeles, California R. P. Fliller, G. M. Kazakevich, J. K. Santucci Fermilab, Batavia, Illinois J. L. Li Rochester University, Rochester, New York P. Piot Northern Illinois University, DeKalb, Illinois
	Funding: This work was performed under the auspices of the US Department of Energy under Contract No. DE-FG03-92ER40693 and W-7405-ENG-48. Focusing of a 15 MeV, 19 nC electron bunch by an underdense plasma lens operated just beyond the threshold of the underdense condition has been demonstrated in experiments at the Fermilab NICADD Photoinjector Laboratory (FNPL). The strong 1.9 cm focal-length plasma-lens focused both transverse directions simultaneously and reduced the minimum area of the beam spot by a factor of 23. Analysis of the beam-envelope evolution observed near the beam waist shows that the spherical aberrations of this underdense lens are lower than those of an overdense plasma lens, as predicted by theory. Correlations between the beam charge and the properties of the beam focus corroborate this conclusion. Time resolved measurements of the focused electron bunch are also reported and all results are compared to simulations.
	Slides
WEPMS034	Mitigation of Electric Breakdown in an RF Photoinjector by Removal of Tuning Rods in High-Field Regions	2415
	A. M. Cook, M. P. Dunning, J. B. Rosenzweig, K. M. Serratto UCLA, Los Angeles, California P. Frigola RadiaBeam, Los Angeles, California
	Funding: United States Department of Energy The pi-mode resonant frequency of the 1.6 cell SLAC/BNL/UCLA style RF photoinjector electron gun is conventionally tuned using cylindrical copper tuning pieces that extend into the full-cell cavity through holes in the side of the gun. This design begins to fail in many versions of this popular gun design at higher voltage levels, when the cavity undergoes electric breakdown in the vicinity of the tuners. In order to remove the tuners from the region of high electric field, mitigating this problem, the full cell geometry must be changed significantly. We report on a method of accomplishing this, in which we use a mechanical device of custom design to stretch the cavity structure of an existing photoinjector in order to tune the resonant frequency up by over 2 MHz. We present results of testing the modified photoinjector in an RF test bed with both copper and magnesium cathodes, succeeding in putting approximately 8 - 10 MW of RF power into the gun. This is an improvement over the 4 MW routinely achieved in a similar gun using conventional tuning methods installed at the UCLA Neptune laboratory.
WEPMS035	Measurement of the UCLA/URLS/INFN Hybrid Gun	2418
	B. D. O'Shea, A. Boni, A. Fukasawa, J. B. Rosenzweig UCLA, Los Angeles, California D. Alesini, M. Ferrario, B. Spataro INFN/LNF, Frascati (Roma) L. Ficcadenti, A. Mostacci, L. Palumbo Rome University La Sapienza, Roma
	Funding: This work performed under the auspices of the U. S. Department of Energy under contract numbers DE-FG-98ER45693 and DE-FG03-92ER40693. The hybrid photoinjector is a high current, low emittance photoinjector/accelerator and is under design and collaboration at Roma University La Sapienza, INFN - Laboratori Nazionali di Frascati and the UCLA Particle Beam Physics Lab. The hybrid standing wave-traveling wave photoinjector uses a coupling cell to divide power between a high-field 1.6 cell standing wave photoinjector, for electron emission and collection, and a low power traveling wave accelerator, for acceleration to desired energies at low emittances. Simulation results show promising beam properties of less than 4 mm-mrad emittance, energy spreads of 1.5%, and currents as high as 1.2 kA at energies of 21 MeV. We report on the progress of RF design and results of cold test RF measurements at the UCLA Pegasus Laboratory, including methods for measurements and difficulties arising in the transition from simulation to physical measurements.
THPMS015	Observation of Multi-GeV Breakdown Thresholds in Dielectric Wakefield Structures	3026
	M. C. Thompson, M. C. Thompson LLNL, Livermore, California H. Badakov, J. B. Rosenzweig, G. Travish UCLA, Los Angeles, California M. J. Hogan, R. Ischebeck, N. A. Kirby, R. Siemann, D. R. Walz SLAC, Menlo Park, California P. Muggli USC, Los Angeles, California A. Scott UCSB, Santa Barbara, California R. B. Yoder Manhattan College, Riverdale, New York
	Funding: This work was performed under the auspices of the US Department of Energy under Contracts No. DE-FG03-92ER40693, DE-AC02-76SF00515, W-7405-ENG-48, and DE-FG02-92-ER40745. The breakdown threshold of a dielectric subjected to the GV/m-scale electric-fields of an intense electron-beam has been measured. In this experiment at the Final Focus Test Beam (FFTB) facility, the 30 GeV SLAC electron beam was focused down and propagated through short fused-silica capillary-tubes with internal diameters of as little as 100 microns. The electric field at the inner surface of the tubes was varied from about 1 GV/m to 22 GV/m by adjusting the longitudinal compression of the electron bunch. The onset of breakdown, as indicated by a bright discharge, was found to correlate to a surface field of about 4 GV/m. An analysis of the damage sustained to the beam-exposed fibers, and its correlation to field amplitude, is also reported.
THPMS018	High Average Current Betatrons for Industrial and Security Applications	3035
	S. Boucher, R. B. Agustsson, P. Frigola, A. Y. Murokh, M. Ruelas RadiaBeam, Los Angeles, California F. H. O'Shea, J. B. Rosenzweig, G. Travish UCLA, Los Angeles, California
	Funding: DOE Grant DE-FG02-04ER84051 The fixed-field alternating-gradient (FFAG) betatron has emerged as a viable alternative to RF linacs as a source of high-energy radiation for industrial and security applications. For industrial applications, high average currents at modest relativistic electron beam energies, typically in the 5 to 10 MeV range, are desired for medical product sterilization, food irradiation and materials processing. For security applications, high power x-rays in the 3 to 20 MeV range are needed for rapid screening of cargo containers and vehicles. In a FFAG betatron, high-power output is possible due to high duty factor and fast acceleration cycle: electrons are injected and accelerated in a quasi-CW mode while being confined and focused in the fixed-field alternating-gradient lattice. The beam is accelerated via magnetic induction from a betatron core made with modern low-loss magnetic materials. Here we present the design and status of a prototype FFAG betatron, called the Radiatron, as well as future prospects for these machines.
THPMS020	Beam-Driven Dielectric Wakefield Accelerating Structure as a THz Radiation Source	3041
	A. M. Cook, H. Badakov, R. J. England, J. B. Rosenzweig, R. Tikhoplav, G. Travish, O. Williams UCLA, Los Angeles, California A. Kanareykin Euclid TechLabs, LLC, Solon, Ohio M. C. Thompson LLNL, Livermore, California
	Funding: United States Department of Energy Experimental work is planned to study the performance of a beam-driven cylindrical dielectric wakefield accelerating structure as a source of THz coherent Cerenkov radiation. For an appropriate choice of dielectric tube geometry and driving electron bunch parameters, the device operates in a single-mode regime, producing narrow-band radiation in the THz range. This source can potentially produce high power levels relative to currently available sources, with ~50 μJ radiated energy per pulse achievable using the electron beam currently in operation at the Neptune Advanced Accelerator Research Laboratory at UCLA (~13 MeV beam energy, ~200 μm RMS bunch length, ~500 pC bunch charge). Preparations underway for installation of the experiment are discussed.
THPMS021	Optimum Electron Bunch Creation in a Photoinjector Using Space Charge Expansion	3044
	J. B. Rosenzweig, A. M. Cook, M. P. Dunning, R. J. England, P. Musumeci UCLA, Los Angeles, California M. Bellaveglia, M. Boscolo, G. Di Pirro, M. Ferrario, D. Filippetto, G. Gatti, L. Palumbo, C. Vicario INFN/LNF, Frascati (Roma) L. Catani, A. Cianchi INFN-Roma II, Roma S. M. Jones Jet Propulsion Laboratory, Pasadena, California
	Recent studies have shown that by illuminating a photocathode with an ultra-short laser pulse of appropriate transverse profile, a uniform density, ellipsoidally shaped electron bunch can be dynamically formed. Linear space-charge fields then exist in all dimensions inside of the bunch, which minimizes emittance growth. Here we study this process, and its marriage to the standard emittance compensation scenario that is implemented in most modern photoinjectors. We show that the two processes are compatible, with simulations indicating that a very high brightness beam can be obtained. An initial time-resolved experiment has been performed at the SPARC injector in Frascati, involving Cerenkov radiation produced at an aerogel. We discuss the results of this preliminary experiment, as well as plans for future experiments to resolve the ellipsoidal bunch shape at low energy. Future measurements at high energy based on fs resolution RF sweepers are also discussed.
THPMS026	The UCLA Helical Permanent-Magnet Inverse Free Electron Laser	3055
	R. Tikhoplav, J. T. Frederico, G. Reed, J. B. Rosenzweig, S. Tochitsky, G. Travish UCLA, Los Angeles, California G. Gatti INFN/LNF, Frascati (Roma)
	The Inverse Free Electron Laser (IFEL) is capable, in principle, of reaching accelerating gradients of up to 1 GV/m making it a prospective accelerator scheme for linear colliders. The Neptune IFEL at UCLA utilizes a 15 MeV Photoinjector-generated electron beam of 0.5 nC and a CO2 laser with peak energy of up to 100 J, and will be able to accelerate electrons to 100 MeV over an 80 cm long, novel helical permanent-magnet undulator. Past IFELs have been limited in their average accelerating gradient due to the Gouy phase shift caused by tight focusing of the drive laser. Here, laser guiding is implemented via an innovative Open Iris-Loaded Waveguide Structure scheme which ensures that the laser mode size and wave front are conserved through the undulator. The results of the first phase of the experiment are discussed in this paper, including the design and construction of a short micro-bunching undulator, testing of the OILS waveguide, as well as the results of corresponding simulations.
TUPMN028	The New Photoinjector for the Fermi Project	974
	G. D'Auria, D. Bacescu, L. Badano, F. Cianciosi, P. Craievich, M. B. Danailov, G. Penco, L. Rumiz, M. Trovo, A. Turchet ELETTRA, Basovizza, Trieste H. Badakov, A. Fukasawa, B. D. O'Shea, J. B. Rosenzweig UCLA, Los Angeles, California
	FERMI@ELETTRA is a single-pass FEL user facility covering the spectral range 100 10 nm. It will be located near the Italian third generation Synchrotron Light Source facility ELETTRA and will make use of the existing 1.0 GeV normal conducting Linac. To obtain the high beam brightness required by the project, the present Linac electron source will be substituted with a photocathode RF gun now under development in the framework of a collaboration between Sincrotrone Trieste (ST) and Particle Beam Physics Laboratory (PBPL) at UCLA. The new gun will use an improved design of the 1.6 cell accelerating structure already developed at PBPL, scaled to 2998 MHz. We expect that the new gun design will allow a beam brightness increase by a factor 3-4 over the older version of the device. Some technical choices of the new design, including the enhancement of the mode separation, removal of the RF tuners, full cell symmetrization to limit the dipole and quadrupole RF field as well as an improved solenoid yoke design for multipole field corrections, will be discussed.
TUPMN039	Status of the SPARC-X Project	1001
	C. Vaccarezza, D. Alesini, M. Bellaveglia, S. Bertolucci, R. Boni, M. Boscolo, M. Castellano, A. Clozza, L. Cultrera, G. Di Pirro, A. Drago, A. Esposito, M. Ferrario, L. Ficcadenti, D. Filippetto, V. Fusco, A. Gallo, G. Gatti, A. Ghigo, C. Ligi, M. Migliorati, A. Mostacci, E. Pace, L. Palumbo, L. Pellegrino, M. A. Preger, R. Ricci, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stella, F. Tazzioli, M. Vescovi, C. Vicario INFN/LNF, Frascati (Roma) F. Alessandria, A. Bacci, R. Bonifacio, I. Boscolo, F. Broggi, F. Castelli, S. Cialdi, C. De Martinis, A. F. Flacco, D. Giove, C. Maroli, V. Petrillo, A. R. Rossi, L. Serafini INFN-Milano, Milano M. Bougeard, P. Breger, B. Carre, D. Garzella, M. Labat, G. Lambert, H. Merdji, P. Monchicourt, P. Salieres, O. Tcherbakoff CEA, Gif-sur-Yvette L. Catani, E. Chiadroni, A. Cianchi, E. Gabrielli, C. Schaerf INFN-Roma II, Roma F. Ciocci, G. Dattoli, A. Dipace, A. Doria, F. Flora, G. P. Gallerano, L. Giannessi, E. Giovenale, G. Messina, P. L. Ottaviani, S. Pagnutti, G. Parisi, L. Picardi, M. Quattromini, A. Renieri, G. Ronci, C. Ronsivalle, M. Rosetti, E. Sabia, M. Sassi, A. Torre, A. Zucchini ENEA C. R. Frascati, Frascati (Roma) M.-E. Couprie SOLEIL, Gif-sur-Yvette P. Emma SLAC, Menlo Park, California M. Mattioli, D. Pelliccia Universita di Roma I La Sapienza, Roma P. Musumeci, M. Petrarca INFN-Roma, Roma C. Pellegrini, S. Reiche, J. B. Rosenzweig UCLA, Los Angeles, California A. Perrone INFN-Lecce, Lecce
	SPARC-X is a two branch project consisting in the SPARC test facility dedicated to the development and test of critical subsystems such as high brightness photoinjector and a modular expandable undulator for SASE-FEL experiments at 500 nm with seeding, and the SPARX facility aiming at generation of high brightness coherent radiation in the 3-13 nm range, based on the achieved expertise. The projects are supported by MIUR (Research Department of Italian Government) and Regione Lazio. SPARC has completed the commissioning phase of the photoinjector in November 2006. The achieved experimental results are here summarized together with the status of the second phase commissioning plans. The SPARX project is based on the generation of ultrahigh peak brightness electron beams at the energy of 1 and 2 GeV generating radiation in the 3-13 nm range. The construction is at the moment planned in two steps starting with a 1 GeV Linac. The project layout including both RF-compression and magnetic chicane techniques has been studied and compared, together with the feasibility of a mixed s-band and x-band linac option.
TUPMS033	Chicane Radiation Measurements with a Compressed Electron Beam at the BNL ATF	1254
	G. Andonian, R. B. Agustsson, A. M. Cook, M. P. Dunning, E. Hemsing, A. Y. Murokh, S. Reiche, J. B. Rosenzweig UCLA, Los Angeles, California M. Babzien, K. Kusche, R. Malone, V. Yakimenko BNL, Upton, Long Island, New York
	The radiation emitted from a chicane compressor has been studied at the Brookhaven National Laboratory (BNL) Accelerator Test Facility (ATF). Coherent edge radiation (CER)is emitted from a compressed electron beam as it traverses sharp edge regions of a magnet. The compression is accompanied by strong self-fields, which are manifested as distortions in the momentum space called beam bifurcation. Recent measurements indicate that the bunch length is approximately 100 fs rms. The emitted THz chicane radiation displays strong signatures of CER. This paper reports on the experimental characterization and subsequent analysis of the chicane radiation measurements at the BNL ATF with a discussion of diagnostics development and implementation. The characterization includes spectral analysis, far-field intensity distribution, and polarization effects. Experimental data is benchmarked to a custom developed start-to-end simulation suite.
THPMS027	Dielectric Wakefield Accelerator Experiments at the SABER Facility	3058
	G. Travish, H. Badakov, A. M. Cook, J. B. Rosenzweig, R. Tikhoplav UCLA, Los Angeles, California M. K. Berry, I. Blumenfeld, F.-J. Decker, M. J. Hogan, R. Ischebeck, R. H. Iverson, N. A. Kirby, R. Siemann, D. R. Walz SLAC, Menlo Park, California A. Kanareykin Euclid TechLabs, LLC, Solon, Ohio P. Muggli USC, Los Angeles, California M. C. Thompson LLNL, Livermore, California
	Funding: Work supported in part by Department of Energy contracts DE-AC02-76SF00515, DE-FG02-92-ER40745, DE-FG03-92ER40693 and W-7405-ENG-48 Electron bunches with the unparalleled combination of high charge, low emittances, and short time duration, as first produced at the SLAC FFTB, are foreseen to be produced soon at the SABER facility. These types of bunches have enabled wakefield driven accelerating schemes of >10 GV/m. In the context of the Dielectric Wakefield Accelerators (DWA) such beams, having rms bunch length as short as 20 um, have been used to drive 100 μm and 200 μm ID hollow tubes above 20 GV/m surface fields. These FFTB tests enabled the measurement of a breakdown threshold in excess of 4 GV/m (2 GV/m accelerating field) in fused silica. With the construction and commissioning of the SABER facility at SLAC, new experiments are made possible to test further aspects of DWAs including materials, tube geometrical variations, direct measurements of the Cerenkov fields, and proof of acceleration in tubes >10 cm in length. The E169 collaboration will investigate breakdown thresholds and accelerating fields in new materials including CVD diamond. Here we describe the experimental plans, beam parameters, simulations, and progress to date as well as future prospects for machines based of DWA structures.
THPMS071	Laser-Powered Dielectric Structure as a Micron-Scale Electron Source	3145
	R. B. Yoder Manhattan College, Riverdale, New York J. B. Rosenzweig, G. Travish UCLA, Los Angeles, California
	We describe a resonant laser-powered structure, measuring 1 mm or less in every dimension, that is capable of generating and accelerating electron beams to low energies (~1-2 MeV). Like several other recently investigated dielectric-based accelerators,* the device is planar and resonantly excited with a side-coupled laser; however, extensive modifications are necessary for synchronous acceleration and focusing of nonrelativistic particles. Electrons are generated within the device via a novel ferroelectric-based cathode. The accelerator is constructed from dielectric material using conventional microfabrication techniques and powered by a 1μm gigawatt-class laser. The electron beams produced are suitable for a number of existing industrial and medical applications. *R. Yoder and J. Rosenzweig, Phys. Rev. STAB 8, 111301 (2005); Z. Zhang et al., Phys. Rev. STAB 8, 071302 (2005); A. Mizrahi and L. Schachter, Phys. Rev. E 70, 016505 (2004).
THPAS052	Charge and Wavelength Scaling of the UCLA/URLS/INFN Hybrid Photoinjector	3609
	A. Fukasawa, A. Boni, B. D. O'Shea, J. B. Rosenzweig UCLA, Los Angeles, California D. Alesini, M. Ferrario, B. Spataro INFN/LNF, Frascati (Roma) L. Ficcadenti, A. Mostacci, L. Palumbo Rome University La Sapienza, Roma
	Short-bunched beam is required for the improving the emission of the free electron laser and wakefield accelerations, as well as low emittance beam. To achieve both of short length and low emittance, we are developing SW/TW Hybrid gun. Two standing wave cells make a photocathode RF gun and the gun is connected directory to the input coupler of the traveling wave structure, and the total length is about 3 m. The low emittance beam produced in the RF gun is bunching in the traveling wave structure in the scheme of, so called, "velocity bunching". PARMELA simulation shows that 1 nC bunch can be achieve 3.0 mm.mrad for the normalized rms emittance and 0.14 mm for the rms bunch length, simultaneously. We also calculates the cases of 1 pC bunch in S-band and 250 pC bunch in X-band to get shorter bunch length and lower emittance. 1 pC bunch is scaled to 1/1000 in its volume (one-tenth for each dimension). It can result in 0.0047 mm short while the emittance is 0.091 mm.mrad. In X-band case, where the structures are scaled down one-fourth in the length and four times in the field strength, the bunch length and the emittance are 0.027 mm and 1.1 mm.mrad, respectively.
FRPMN030	RF measurements results of the final brazed SPARC RF Deflector	3994
	L. Ficcadenti, A. Mostacci, L. Palumbo Rome University La Sapienza, Roma D. Alesini, G. Di Pirro, C. Vaccarezza INFN/LNF, Frascati (Roma) J. B. Rosenzweig UCLA, Los Angeles, California
	The longitudinal phase space and the horizontal beam slice emittance measurements of the SPARC 150MeV-1nC electron beam, foresee the use of a RF deflector. The device is a five cells standing wave structure operating on the TM110-like dipole mode at 2.856GHz and allows reaching a longitudinal resolution of 12μm with 2MW of peak input power. In the paper we illustrate the RF measurements on the final copper device. This work has been partially supported by the EU in the sixth framework program, Contract no. 011935 EUROFEL-DS1.
FRPMS060	Commissioning of the UCLA Neptune X-Band Deflecting Cavity and Applications to Current Profile Measurement of Ramped Electron Bunches	4135
	R. J. England, B. D. O'Shea, J. B. Rosenzweig, G. Travish UCLA, Los Angeles, California D. Alesini INFN/LNF, Frascati (Roma)
	Funding: Department of Energy Grant # DE-FG02-92ER40693 A 9-cell standing wave deflecting cavity has recently been constructed and installed at the UCLA Neptune Laboratory for use as a temporal diagnostic for the 13 MeV, 300 to 700 pC electron bunches generated by the Neptune photoinjector beamline. The cavity is a center-fed Glid-Cop structure operating in at TM110-like deflecting mode at 9.59616 GHz with a pi phase advance per cell. At the maximum deflecting voltage of 500 kV, the theoretical resolution limit of the device is 50 fs, although with current beam parameters and a spot size of 460 microns RMS the effective resolution is approximately 400 fs. We discuss the operation and testing of the cavity as well as its intended application: measuring the temporal current profile of ramped electron bunches generated using the Neptune dogleg compressor, and we present the first measurements of the electron beam current profile obtained using the deflecting cavity.