1. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis EUROFEL DS3-DS4 TASK meeting Proposed synchronization schemes for 4GLS: impact on EUROFEL DS3 Mario Ferianis - Sincrotrone Trieste, Italy CEA, Saclay 16-17 May 2005 Synchronization issues Proposed schemes Workplan for EUROFEL DS3

2. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis Synchronization issues In 3GLS, synchronization is used for –Injector: tens of ps   s-band / 10  30ps –Injection and extraction systems: 100s of ps –Bunch diagnostics and feedback systems: few ps –Time-resolved experiments (laser to h synch.): few ps Being the bunch length t B  40ps FWHM, typically the required jitter is at the few ps RMS level In 4GLS, synchronization is a key feature due to: –sub-ps bunch length, achievable in single pass accelerator –extensive adoption of fs lasers, both embedded in the radiation production process and foreseen for time resolved experiments Minimum required synch. : <10fs level (i.e. seeding laser)

3. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis Synchronization issues: some thoughts from my “bulleted list”, 01/2004 The synchronization (after the greek verb:  =to be/to happen at the same time) of a system can be defined as its property of sharing a common time reference and distributed among its different sub-systems. Synchronous sub-systems, therefore, can operate at fixed relative time instants. The term “timing system” is frequently used as synonymous of synchronization system. The preservation of the synchronization over long terms is called stability: a synchronous system is also stable when its synchronization is kept over long times, order of magnitude larger than the “event”. Femto-second x-ray Light Source test stands have already proven to generate sub-picosecond (10 -14 s) x-ray pulses, at repetion rates of few Hertz (10 -2 s), to be delivered during User Shifts of many hours (10 4 s). Therefore, the synchronization of a femto-second x-ray Light Source has to deal with 18 order of magnitude, which calls for state of the art solutions.

4. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis Synchronization & Stability Do we really need both fs synchronization & stability ? During the 1 st FERMI User Workshop, there have been some discussions about it…turned out that: “each LINAC shot (FEL pulse) is like one experiment” So, what Users are really needing is fs synchronization, but relative to events within one machine cycle: t REP =20ms (50Hz) for FERMI What do they really care is that pump pulses are stable (<10fs RMS ) w.r.t. probe pulses, considered as associated pairs! Furthermore, both the physical phenomena and the related data taking techniques on fs experiments complete well before milliseconds repetition period

5. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis Synchronization issues: sequence of synchronous events Optical Reference laser pulse PC laser pulse on cathode Phase of accelerating voltage Laser Heater pulse Seed Laser pulse Cross-correlator Laser pulse Probe Laser pulse Pump Laser pulse ABSOLUTE STABILITY JITTER ns range ms range

6. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis Proposed schemes: a general layout for a 4GLS synchronization system 0.3 nm0.1 nm UV HallX-ray Hall Nanometer Hall SC Linac 4 GeV2 GeV1 GeV 1 nm 0.3 nm 100 nm 30 nm 10 nm 3 nm 1 nm Master oscillator Pump laser Seed laser Pump laser Fiber link synchronization Injector laser Undulators Future upgrade to 0.1 nm at 8 GeV SC Linac MIT Optics & Quantum Electronics Group 12/13/2014W.S. Graves, MIT Bates Laboratory

7. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis Synchronization issues: adopted optical techniques

8. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis

9. Synchronization issues: phase noise representation f 0 =carrier Sidebands Amplitude vs. carrier Amp. [dBc/Hz] “Phase Noise and Jitter”, N. Roberts, ZARLINK semicond. EE Design, July 14 2003

10. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis Synchronization issues: phase noise to jitter conversion 1/fm 0 White frequency: uncorrelated fluctuations of the osc. period; thermal noise Flicker noise “Phase Noise and Jitter”, N. Roberts, ZARLINK semicond. EE Design, July 14 2003

11. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis Synchronization issues “Phase Noise and Jitter”, N. Roberts, ZARLINK semicond. EE Design, July 14 2003

12. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis Synchronization issues “Phase Noise and Jitter”, N. Roberts, ZARLINK semicond. EE Design, July 14 2003 10dBc / 3 decades: L(f)=1/SQRT(f 3 )

13. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis SSB Phase noise measurement: effects due to Instrument powering cofiguration: ac vs. battery source

14. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis Proposal for fs synchronization: RLE @ MIT + DESY

15. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis Measured fiber laser performance F.O. Ilday et al. “Laser Technology for X-ray FELs: fs synchronization …” presented at Erl 2005 workshop, JLAB

16. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis Synchronization issues: stabilized FO link Lasers and RF-Timing, Franz X. Kaertner, RLE MIT Cross Correlator Fiber ML - Laser PZT Fixed Length L Far end local end

17. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis Proposed schemes: Optical to RF conversion RF synchronous to optical pulses

18. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis Proposed schemes: Optical to RF conversion

19. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis Locking of two fiber lasers F.O. Ilday et al. “Laser Technology for X-ray FELs: fs synchronization …” presented at Erl 2005 workshop, JLAB Reference laser: LOCAL Second laser: REMOTE Long FO link

20. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis Stabilization of reference signal distribution 25GHz, 1km of fiber, 15 hour test

21. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis

22. Stabilization of FO link: LBL proposal R. Wilcox, J. W. Staples LBL, R. Holzwarth, Menlo Systems “Optical Synchronization Systems for fs x-ray sources” PAC ‘05 far end close end

23. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis R. Wilcox, J. W. Staples LBL, R. Holzwarth, Menlo Systems “Optical Synchronization Systems for fs x-ray sources” PAC ‘05 Proof of principle of Mach-Zender interferometer: with 40m of fiber in one arm showing 100s fs of jitter, it has been reduced to 0.85fs!

24. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis Stabilization of FO link: LBL proposal R. Wilcox, J. W. Staples LBL, R. Holzwarth, Menlo Systems “Optical Synchronization Systems for fs x-ray sources” PAC ‘05 since heterodyning preserves phases, phase shifts in the 110MHz is reflected in identical phase shift in the optical signal: 1deg @110MHz==1 deg optical  0.014fs!!!

25. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis Multiple frequencies vs. Pulse train Multiple frequencies* –Lower peak optical power, below non-linear effects threshold (Brillouin, Raman) –With RF beat detection, optical to RF conversion efficiency is maximized, opposed to extraction of a high harmonic from a pulse train (losses in BP filter) –Phase detection is measuring very high frequency beat between optical waves rather than at lower  waves Pulse train –No need to delivery at the far end the 110MHz signal –Can distribute either 100MHz or 3GHz signal (direct O/E conversion for the RF plants) –Can be used as seed for other lasers and as ref pulse in diagnostics * R. Wilcox, J. W. Staples LBL, R. Holzwarth, Menlo Systems “Optical Synchronization Systems for fs x-ray sources” PAC ‘05

26. EUROFEL DS3-DS4 TASK meeting CEA - Saclay, 16-17 MAY 2005 M. Ferianis Workplan for EUROFEL DS3: demonstration of the Optical Clock REF. osc. Fiber laser O/E Conv. Remote fs laser Phase detect Stabilised Fiber links: star configuration L=300m Phase noise Cross- correlate Electrical signal Optical in fiber Optical in air RF: 100MHz or  -wave: 10GHz f PULSE