X-band FEL Project: Tests at Califes Latina (CERN) for the X-band FEL Collaboration

1. X-band FEL Project: • Tests at Califes • Latina (CERN) • for the X-band FEL Collaboration

2. The X-band FEL Collaboration The XbFEL Collaboration is an initiative started between 2013-2014, among several International Labs and Industries aimed at promoting the use and application of X-band technology for the construction of the next generation FEL based photon sources. STElettra - Sincrotrone Trieste, Italy. CERNCERN Geneva, Switzerland. TUEindhoven Technical Univeristy, Netherlands STFCDaresbury Laboratory Cockcroft Institute, Daresbury, UK SINAPShangai Institute of Applied Physics, Shanghai, China. VDL VDL ETG T&D B.V., Eindhoven, Netherlands. OSLOUniversity of Oslo, Norway. IASANational Technical University of Athens, Greece. UUUppsala University, Uppsala, Sweden. ASLSAustralian Synchrotron, Clayton, Australia. UA-IATInstitute of Accelerator Technologies, Ankara, Turkey. ULANCLancaster University, Lancaster, UK. LNF Frascati National Laboratory, INFN, Italy Kyma Undulators production, Italy-Slovenia http://xbandfel.web.cern.ch/

3. Now: CompacLight • Collaboration dedicated to the development of inexpensive and compact X-ray sources, Compton scattering and XFEL, for national, university and industrial scale facilities. • Exploit recent developments of X-band and high-gradient technology to: • increase short pulse and high repetition rate performance • decrease size and cost of photon-science infrastructure. XBox test facility 100 MV/m accelerating structure Bunch characteristics in X-band FEL

4. Objectives • Overall goals: • Compact • Cheap • “High” rep rate, short pulses • Power conscious FEL(s) • Consistent design(s) • Project “ambition” from gun to light • Industry availability of components.

5. New opportunities Horizon2020 Work Programme 2016‐2017 Research Infrastructures (RIs) 5 Calls – 15 topics 1. Development and long-term sustainability of new pan-European RIs 2. Integrating and Opening RIs of European Interest 3. e-Infrastructures 4. Fostering the innovation potential of RI 5. Support to Policy and International cooperation (RI/e-RI)

6. Kick-off Face-to-face meeting at CERN in June • Confirmed Labs/teams availability • Extended collaboration to new partners • Discussed how to improve an extend the previous proposal • Defined roles and strategies • Started to organize working groups https://indico.cern.ch/event/521539

7. Potential tests for an X-band FEL using Califes Hardware already available New hardware required

8. FERMI@Elettra & SwissFEL Linearizers FERMI@Elettra layout SwissFEL layout G. D’Auria LINAC12, XXVI Linear Accelerator Conference, Tel Aviv, Israel, September 9-14, 2012

9. Perspectives: WFM characterization at CALIFES • Current Situation • Within EuCARD 2, developing electro-optical front end for WFMsintegrated in in X band phase space linearizer structure. First tests with beam were done in SwissFEL Test Injector Facility (SITF). • SITF stopped operation end of october ‘14, components to be transferred to SwissFEL injector, planned to start operation end of 2015/beginning of 2016 (started September 9 2016) • No beam time for WFM front end characterization and tests in 2015, rather limited time later. • Using CALIFES as a test bed for WFM • Using X band linearizer currently at CERN (which developed alignment kinks during brazing), active length 750mm, total 1000 mm • Do standard tests moving either structure or beam • Kinks in alignment ideal to test advanced measurement modes to determine the internal cell to cell alignment from signal spectra. • Open questions: Available space, necessary to condition structure before insertion into CALIFES? • Test WFM front end together with WFMs of CLIC accelerating structure: Interesting option due to other signal spectrum. • Synergies with CLIC related research (in discussion with Erik Adli and Reidar Lillestol, Olso University) • Modest requirements on beam: orbit control with resolution ~ 5um, beam charge > 100 pC Courtesy of M. Pedrozzi, M. Dehler, M. Leich

10. Clock to Cavity Synchronization Optical clock signal LLRF control - feedforward to next pulse based on last pulse and environment measurements Locked microwave oscillator Solid state amplifier Extremely sensitive to modulator voltage Considerable effort is required to get femto second stability in the current RF systems used to deliver 50 MW at X band. Once stability is achieve one then needs to perfect a method of measuring and correcting timing errors, IQ modulator Solid state amplifier TWT amplifier Klystron Waveguide Absolute timing impossible as every component and connector adds phase uncertainty Waveguide Pulse compressor Waveguide sensitive to temperature Cavity Courtesy of A. Dexter

11. CLIC Crab Cavity • Transverse Deflecting Cavity (TDC) resolution is proportional to frequency x Voltage. • X-band TDC lead to better resolution. • Lancaster’s X-band “crab” cavity currently running on XBOX2 to measure the maximum possible transverse gradient. Courtesy of G. Burt

12. Dt±0.6 ps Measuring Bunch Arrival Time Jitter (LCLS) e- BPM V(t) • We can also use two cavities to measure phase synchronisation between two RF sources. • If we have two cavities in anti-phase the transverse kick’s will cancel out. • Any phase error between the two cavities will result in a transverse momentum. • This can be used to accurately measure synchronisation systems required for FELs • X-band would allow femtosecond time resolution slope = -2.34 mm/deg (from P. Emma) Courtesy of A. Dexter

13. Advanced Beam Physics • Compare the performances of a purely-magnetic compression scheme, w.r.t. one including velocity bunching, both in terms of macroscopic properties of the beam as well as in terms of micro-bunching • Micro-bunching gain measurements and comparison with analytical models • Electron beam shot-noise bunching suppression + lasing (some undulators would be needed) • Tests of Double-Bend Achromat (DBA) with CSR suppression • Electron comb generation using masks in a dispersive region, and transport control • Tests of bunch compression with sextupoles in the dispersive region (verify the impact on the longitudinal phase space) • Measurement of emittance scaling with the photo-injector charge (models predict a shift from power of ½ to 1/3 but needs more accurate studies) Inputs from S. Di Mitri

14. Conclusions • Califes would be a fundamental test bed for X-band components with beam: transverse defecting cavities, phase-space linearisers, wakefield-monitors, phase-measurement and correction, diagnostics, impedance measurements • What Califes can do for XbFEL: • An extension of Califes would play a crucial role for the development of the X-band technology, for the X-band community of today and of tomorrow • What XbFEL can do for Califes:The X-band FEL Collaboration and proposal could be the focus and the source for funding experiments related to X-band components at Califes http://xbandfel.web.cern.ch/

15. Extra Slides

16. D. Schulte, CERN, September 2013 Electron Linac RF Unit Layout 2x ScandiNova solid state modulators based on the existing (industrialized) RF sources (klystron and modulator) 2x CPI klystrons 410 kV, 1.6 s flat top 50 MW 1.5 s (Operated @45MW) I. Syratchev, D. Schulte X 5.2 100 (90) MW 1.5 s ~11 m, 16.3 cm TE01 transfer line (RF=0.9) Inline RF distribution network TE01 900 bend Common vacuum network Preliminary 468 MW (418 MW) 150 ns x 10 accelerating structures @68.8MV/m (65MV/m) 46.8MV (41.8MW) input power 10 m, 7.5 active This unit should provide ~488MeV acceleration beam loading. Need 12RF units. Cost 51.7 a.u., 4% more than optimum

17. Topics Call INFRADEV– Development and long-term sustainability of new pan-European RIs To support the development of a comprehensive landscape of new sustainable world-class research infrastructures in Europe, helping to respond to challenges in science, industry & society. Emphasis on long-term sustainability, efficient operation, data management and on fostering the innovation potential. 1. Design studies 2. Preparatory Phase of ESFRI projects 3. Individual support to ESFRI & OWCRI 4. Pilot action for a European Open Science Cloud for Research

18. Aim • INFRADEV-01-2017 - Design studies • Support the conceptual and technical design of new research infrastructures, which are leading-edge user facilities of a clear European dimension and interest : • Bottom-up call, aimed at identifying the RIs that really have the potential to become the next generation of European world-class RI • Total budget 20 M€ - EU contribution per proposal (RIA) between 1-3 M€ • Leading to a 'conceptual or technical design report' through • Scientific & technical work: drafting of concepts & engineering plans for the construction; creation of prototypes; work to ensure the take-up and theefficiency of the services provided to scientific communities and • Conceptual work: plans to integrate the new RI into the European RI landscape; estimation of budget for construction and operation; plans for an international governance structure; planning of research services to be provided; procedure and criteria to choose the RI site.

19. Budgets + 5 M€ Call INFRADEV Summary

20. Workpackages • General question: • RF improvements (power and cost) – into WP4, from baseline to improved RF systems • Spain, KIT, Desy/PSI, INFN ok, France ? Singapore, update inst. list • Next steps: • Establish team for proposal prep (overall lead and WP) and WGs/studies where needed • First meeting in November