PHIN

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PHIN

• R. Losito
• CERN AB/ATB
• 13/09/2006

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CNRS-LOA

• Courtesy of V. Malka

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Low energy (lt200 MeV) spectrometers
B1 T
B0.41 T
Design of a new magnet up to 400 MeV
Previous Magnet home made, up to 100 MeV
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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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Data from the manufacturer
Simulations of the longitudinal magnetic field
Transverse magnetic field
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Tests Experimental setup
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Detector composition
Composition of the scintillating screen
The surface loading of Gadolinium Oxysulfide in
the urethane binder is 33 mg/cm2
Schach von Wittenau et al., Med. Phys. 29 pp.
2559-2570 (2002)
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Absolute calibration of the LANEX KODAK FINE
In collaboration with ELYSE

• Calibration of the scintillator response on a RF
  accelerator
• ELYSE a laser-triggered picosecond electron
  accelerator

Independence of the yield with electron energy
Linearity with charge
Previously checked for Imaging Plate (Fuji
BAS-SR2025) Tanaka et al., Rev. Sci. Instr.
(2005)
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Absolute calibration (in ELYSE)
30 pC in the bunch
250 pC in the bunch
63 pC in the bunch
dE/E 6
5 pC in the bunch
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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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INFN-Frascati

• Courtesy of C. Vicario

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Picture of the TiSa-based laser system _at_ Sparc
LNF
NdYAG pumps
oscillator
amplifiers
UV stretcher
Harmonics generator
C. Vicario, G. Gatti, S. Cialdi, M. Petrarca, M.
Bellaveglia and A. Ghigo
oscillator
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Layout and performances of the laser system
gt105 fs, 0.5 TW 800 nm
10 ns 560 mJ 532 nm
100 ns 7 mJ 532 nm
Regen 2 mpass Amplifier
5 W CW
THG
Pulse shaper
oscillator
UV stretcher
Mira
100 fs pulse, low energy
5-12 ps, 1 mJ 266 nm
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Comparative study between temporal pulse shaping
techniques
Liquid crystal mask spectral manipulation
Acousto-optic pulse shaper
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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 ?
To be publ. Opt. Lett vol. 31, 19 (2006)
? Preprint LNF-INFN SPARC-LS-06-002 (2006)
Further activities to reduce the rise time within
the spec (1 ps) are in progress
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RF to Laser synchronization tests on 10 Hz UV
pulses
Record of the laser phase
Statistics
On time scale of few minutes the phase jitter is
within sRMS0.61 ps ?. (1ps required) The
synchronization is confirmed by the stability of
the e-beam parameters.
Number of pulses
? Preprint LNF-INFN SPARC-LS-06-001 (2006)
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CERN
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CERN main topics

• Photocathode studies
• Design, construction, installation and
  commissioning of the CTF3 photo-injector

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CERN Photoemission Laboratory

• Co-Deposition Setup Evaluated
• Te Absolute Thickness Calibration
• Calibration of Quartz measurements

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Co-Deposition Setup Evaluation

• Co-Deposition Setup
• Isolation for each Quartz

Te
Cs
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Te Thickness Calibration

• Te double Coating for CERN Optical Profiler
  (TS/MME)
• Cross-Measurement with Stylus Profiler (Data to
  be analysed yet)

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Te Thickness Calibration with Quartz 1

• Same Calibration factor (1.70) that previous
  measurements with Au (Sept. 2003)

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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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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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RAL

• Courtesy of G. Hirst and G. Kurdi

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Planned layout of the system
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LAL

• Courtesy of G. Bienvenu

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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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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.