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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 PHIN R. Losito CERN – AB/ATB 13/09/2006
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 CNRS-LOA Courtesy of V. Malka
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 Low energy (<200 MeV) spectrometers Previous Magnet home made, up to 100 MeV Design of a new magnet up to 400 MeV 10 cm 5 cm B=0.41 T B=1 T
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 Datasheet Constraints : ● Gap = 1cm ● Magnetic field ~ 1T ● Length = 10 cm ● Large slit required ● Compact spectrometer Solution : ● Good homogeneity due to a special arrangement of magnet poles
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 Data from the manufacturer Simulations of the longitudinal magnetic field Transverse magnetic field
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 Tests : Experimental setup Photons Electrons Laser CCD Andor ICT Lanex Magnet Nozzle
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 Detector composition Schach von Wittenau et al., Med. Phys. 29 pp. 2559-2570 (2002) Composition of the scintillating screen The surface loading of Gadolinium Oxysulfide in the urethane binder is 33 mg/cm 2
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 Absolute calibration of the LANEX KODAK FINE Calibration of the scintillator response on a RF accelerator ELYSE : a laser-triggered picosecond electron accelerator Linearity with charge Independence of the yield with electron energy Previously checked for Imaging Plate (Fuji BAS- SR2025) : Tanaka et al., Rev. Sci. Instr. (2005) In collaboration with ELYSE
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 Absolute calibration (in ELYSE) 250 pC in the bunch dE/E ~ 6% 30 pC in the bunch 63 pC in the bunch 5 pC in the bunch
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 Conclusion and Perspectives I – Needs for a compact single shot spectrometer Requirements Acceleration of electrons up to 200 MeV. Adapted to high repetition rate : no film processing. Solution chosen Design and purchase of a strong permanent magnet Purchase of 16 bits Andor CCD cameras. Development of analytical formulaes for spectrum deconvolution Purchase of a hall probe for magnet characterization Estimation of the efficiency of the scintillator, absolute calibration II – Further developments The present work will help the design of a larger magnet for GeV acceleration experiments
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 INFN-Frascati Courtesy of C. Vicario
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 Picture of the Ti:Sa-based laser system @ Sparc LNF oscillator Nd:YAG pumps amplifiers Harmonics generator UV stretcher C. Vicario, G. Gatti, S. Cialdi, M. Petrarca, M. Bellaveglia and A. Ghigo
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 Regen + 2 mpass Amplifier Mira oscillator Verdi VerdiPump Evolution Diode Pump 100 fs pulse, low energy >105 fs, 0.5 TW 800 nm 5 W CW Continuum Flashed Pump 10 ns 560 mJ 532 nm Pulseshaper 100 ns 7 mJ 532 nm THG UV stretcher 5-12 ps, 1 mJ 266 nm Layout and performances of the laser system
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 Comparative study between temporal pulse shaping techniques Dazzler Half-wave plate From oscillaot To amplifier Telescopes Phase mask Lens Grating INPUT OUTPUT Acousto-optic pulse shaper Liquid crystal mask spectral manipulation
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 AO Shaped time profile after amplification and third harmonic conversion The distortions from amplification and the THG has been studied*. The UV pulse is 10 ps long and with rise time of 2.5 ps For the UV pulse characterization a remote-controlled, multishot cross-correlator has been built ♦ Further activities to reduce the rise time within the spec (1 ps) are in progress * To be publ. Opt. Lett vol. 31, 19 (2006) ♦ ♦ Preprint LNF-INFN SPARC-LS-06-002 (2006)
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 RF to Laser synchronization: tests on 10 Hz UV pulses 2856 MHz cavity High energy UV @ 10 Hz ♦ On time scale of few minutes the phase jitter is within σ RMS = 0.61 ps ♦. (1ps required) The synchronization is confirmed by the stability of the e-beam parameters. Record of the laser phase Statistics Number of pulses ♦ ♦ Preprint LNF-INFN SPARC-LS-06-001 (2006)
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 CERN
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 CERN main topics Photocathode studies Design, construction, installation and commissioning of the CTF3 photo- injector
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 CERN Photoemission Laboratory Co-Deposition Setup Evaluated Te Absolute Thickness Calibration Calibration of Quartz measurements
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 Co-Deposition Setup Evaluation Co-Deposition Setup Isolation for each Quartz Te Cs
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 Te double Coating for CERN Optical Profiler (TS/MME) Cross-Measurement with Stylus Profiler (Data to be analysed yet) Te Thickness Calibration
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 Te Thickness Calibration with Quartz 1 Same Calibration factor (1.70) that previous measurements with Au (Sept. 2003)
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 Te Calibration with Quartz 2 Problem: Ratio Quartz2/Quartz1 not constant (Without mask) Quartz2 (Te dedicated) not ideally positioned (poor design) Te Boat vapor flux geometry changes over different depositions
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 Conclusion Co-Deposition setup ready for Stochiometric Ratio Measurement -Masks defined and tested -Quartz Isolation OK Thickness Measurement by Quartz understood Te Thickness Calibration done Cs Thickness Calibration not available -Assume same calibration factor that Te -Relative Comparison of Stochiometric Ratio will be possible -Collaboration with FZR for Cs Calibration Ready for photocathodes and electrons production after Bake Out (Autumn 2006)
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 RAL Courtesy of G. Hirst and G. Kurdi
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 Planned layout of the system Table at CERN Table at RAL HighQ laser Faraday isolator Beam size provided for 1st amplifier 1st amplifier 2nd amplifier Thermal lensing compensation Pockels cell(s) for generating 1.5 us train Feedback stabilisation Coding Delay line Beam size provided for SHG Diagn. Beam size provided for FHG Diagn. Breadboard Amplifier beam heights ~ 12 cm Beam size provided for 2 nd amplifier Laser beam to cathode 350 cm 150 cm
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 LAL Courtesy of G. Bienvenu
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 RF GUN The last cells of guns should be at LAL at the end of the week 37 Coils with modified cooling channels (reduced in length) should arrive next week (W38) The leak of the backing and vacuum model after brazing will be fixed in the next week with a special UHV and high temperature glue A new design of ionic pump support to allow that coils have a larger translation possibility is ready Tapered waveguides drawings have been approved by S. Mathot
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R. Losito CERN-AB-ATBCARE Steering committee 13/09/06 NEPAL TEST ROOM The laser has been fixed by the manufacturer and (re)delivered at LAL. It will be (re)tested by the end of September. Civil engineering to upgrade the radiation safety of experimental area has ordered. It should beginning this month. All components of high power RF modulator are ordered and delivered by the end of this year. Low level RF is completed.
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