Paper | Title | Page |
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MOOAAB02 | Experimental Results with the SPARC Emittance-meter | 80 |
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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. | ||
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TUPMN034 | Comparison Between SPARC E-Meter Measurements and Simulations | 986 |
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For the SPARC photoinjector commissioning the emittance compensation process has been studied experimentally under different beam conditions (variation of charge, spot size, beam shape ) by a novel device called "emittance-meter", consisting in a movable emittance measurement system based on the 1D pepper pot method scanning a region 1.2 m long downstream the RF-gun. The results of a detailed comparison between the measurements and beam dynamics simulations performed by the different codes(PARMELA, HOMDYN, TREDI) employed for SPARC design are presented and discussed here. | ||
TUPMN039 | Status of the SPARC-X Project | 1001 |
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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. | ||
WEPMS035 | Measurement of the UCLA/URLS/INFN Hybrid Gun | 2418 |
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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. |
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THPAS052 | Charge and Wavelength Scaling of the UCLA/URLS/INFN Hybrid Photoinjector | 3609 |
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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 |
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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. |