1. Electro-optic characterisation of bunch longitudinal profile
LC-ABD2: WP8.2 EO
Electro-optic characterisation of bunch longitudinal profile
LC-ABD
P.J. Phillips, W.A. Gillespie (University of Dundee)
S. P. Jamison (ASTeC, Daresbury Laboratory)
A.M. Macleod (University of Abertay)
Collaborators
G. Berden, A.F.G. van der Meer (FELIX)
B. Steffen, E.-A. Knabbe, H. Schlarb, B. Schmidt,
P. Schmüser (DESY)

2. ERLP Diagnostic station
Recent and current activities
ERLP Diagnostic station
Development of Fibre laser for EO measurements
Experiments aimed at dual EO probe and Synchronisation
Publication of past and recent work
FELIX FEL Experiments
Testing of fundamentals of EO theory

3. ERLP Diagnostic station
Laser beam line to be completed in two weeks
Working diagnostic to advance ERLP full operation
Laser lab of ERLP expanded
Ti:S / Fibre distribution experiment
THz test-bed operational

4. ERLP E-O laser diagnostics schematic

5. ERLP Hall and EO Diagnostic station
Ti:S Laser

6. ERLP E-O CRYSTAL HOLDER
Vacuum Chamber
Motorised Drive
Camera
Mirror and Crystal Assy
Crystal
beam direction
Mirror
Laser Exit Port

7. Fibre laser E-O MEASUREMENTS
Original plans:
Migrate world leading Ti:S diagnostic technique to reliable / turnkey
fibre system
Phase 1: (Fibre oscillator)
Standalone bunch length measurement using spectral decoding
Reliability, bunch length at higher rep rate, intra-macrobunch measurements
Phase 2: (Fibre Amplifier)
Optimisation / minimisation of required fibre laser power
Requirements for temporal decoding - currently 100uJ Ti:Sapphire
Aiming for 10 J - needs development

8. Fibre laser systems Er:b fibre system for timing
In house build demonstrated
YB fibre best matched for EO diagnostic
Short pulses , 30 fs (Time resolution)
l ~ 1 mm (Phase matching)
Everything ready to build

9. Optical time stamping of EO profile measurement
Measure timing jitter between two synchronised lasers
of different wavelengths
Use optical cross correlation in a BBO crystal
Understanding of these issues will lead to better relative timing of different laser experiments when using fibre lasers in future
accelerators

10. Synchronisation issues with other lasers

11. Integration with timing distribution systems...
probe laser
bunch
gate laser
timing distribution laser
Integration with timing distribution systems...
to be tested on ERLP
amplified Er-fibre
system

12. Publications:
Recent papers published

13. Manuscripts underway FELIX Data …………aiming for PRL
EPAC08
Single-shot Longitudinal Bunch Profile Measurements at FLASH Using Electro-optic Detection Techniques  Presenter               Paul Jonathan Phillips (University of Dundee, Nethergate, Dundee, Scotland)      Authors         Paul Jonathan Phillips, William Allan Gillespie (University of Dundee, Nethergate, Dundee, Scotland), Vladimir Arsov, Holger Schlarb, Bernhard Schmidt, Peter Schmüser (DESY, Hamburg), Bernd Steffen (DESY, Hamburg; PSI, Villigen), Giel Berden, Alexander van der Meer (FOM Rijnhuizen, Nieuwegein), Steven Jamison (STFC/DL/ASTeC, Daresbury, Warrington, Cheshire), Allan MacLeod (UAD, Dundee)                 
Limitations of Electro-optic Longitudinal Electron Bunch Length Measurements   Presenter               Steven Jamison (STFC/DL/ASTeC, Daresbury, Warrington, Cheshire)  Authors         Steven Jamison (STFC/DL/ASTeC, Daresbury, Warrington, Cheshire), Giel Berden (FOM Rijnhuizen, Nieuwegein), Allan MacLeod (UAD, Dundee), William Allan Gillespie, Paul Jonathan Phillips (University of Dundee, Nethergate, Dundee, Scotland)   
FELIX Data …………aiming for PRL
DESY Collobration …..PRl-Special topics Draft
Applied Physics B Summary of EO experiments and Theory

14. ILC OPERATION Vs Demonstrated results
Higher bunch charge
Higher energy
Lead to larger field strength in EO diagnostic
Is standard theory valid for all fields strengths? ….. NO
When does it breakdown………..?
How is theory corrected and experimental interpretation
We observed a breakdown of standard theory in preliminary results
obtained at FELIX
This in no way effects our current results.

15. FELIX Experiments at High field EO effects
1 Depletion of optical probe through THz-laser interaction
2 Phase matching….(not just high field)
Assumption of Phase matching:
Taylor expansion leads too
Standard model assumes these terms are negligible
Future experiments are planned at FELIX (May 2008 ).

16. Summary Test system setup at Daresbury Fibre laser system built
Papers published and several being written
Studies undertaken to extend to standard EO theory
Synchronisation of lasers