The CompactLight Project (XLS) Gerardo D’Auria (Elettra-ST)

1. The CompactLight Project (XLS) Gerardo D’Auria (Elettra-ST) on behalf of the CompactLight Collaboration TIARA Collaboration Council CERN February 20th, 2019 XLS CompactLight@elettra.eu www.CompactLight.eu

2. Outline • Context • The XLS Collaboration • The CompactLight Project • Aims & Motivations • Timeline • Deliverables • Work Packages • Objectives • Expected performance • Ongoing activities

3. The XLS Collaboration is an initiative among several Intern. Labs aimed at promoting the construction of the next generation FEL based photon sources with innovative accelerator technologies The XLS Collaboration

4. List of Participants Italy 5 Neth. 3+1 UK 3 Spain 2 Australia 2 China 1 Greece 1+2 Sweden 1 Turkey 1 France 1 Germany 1 Switz. 1 Finland 1 Norway 0+1 Internat. 1

5. The CompactLight Project (XLS) http://CompactLight.eu Horizon2020 - Work Programme 2016 – 2017 Research & Innovation INFRADEV-1-2017 Design Studies • Proposal: 777431 — XLS • Starting date: 01-01-2018 • Duration of the action: 36 months • Maximum grant amount: • Total cost of the project: >3.5 M€ • EU contribution: 2,999,500 € EU Project Officer: Mina KOLEVA EU Legal Officer: Spyridon POLITOPOULOS

6. Objectives Our aim is to facilitatethe widespread development ofX-ray FEL facilitiesacross Europe andbeyond, by making them more affordable to construct and operate through an optimum combination of emerging and innovativeaccelerator technologies. • We plan to design a Hard X-ray Facility using the very latest concepts for: • High brightness electron photoinjectors • Very high gradient accelerating structures • Novel short period undulators

7. XLS Work Packages

8. WP1 Manag. & Coord. Process and WPs relations WP5 Und. & LP WP3 Gun & Inj. WP4 RF Systems Pre-Selection: risk-driven physics-driven   WP6 BD & S2E Simul. Filter: Beam quality, FEL specs WP2 FEL Sc. & Fac. Des. Filter: Self-consistency WP7 Integrat. in Res. Infr. Evaluation: Feasibility Cost Courtesy of S. Di Mitri

9. Time plan, Milestones and Deliverables M D II Midterm Rev. Meet. Kick-off Meeting Public WEB site I Midterm Rev. Meet. I Annual Meet. User Meet. & Req. Rep

10. Accomplished activities ➜ Kick-off Meeting: CERN Geneva, 25 January 2018 (during the CLIC 2018 Workshop) Official start of the project: to set plans, goals, deliverables….. ➜First Midterm Review Meeting Trieste, Italy, 19-20 June 2018 To review the work conducted during the first six months and to prepare the work plans for the next six months. ➜XLS Users Meeting, CERN Geveva, 27-28 November 2018 To collect the European User needs for the future FEL Facilities ➜First XLS Annual Meeting, ALBA, Barcelona, 10-12 December 2018 To review the work conducted during the 2018 and to prepare the work plans for the next six months.

11. List of Deliverables Coming 6 months!

12. D3.1 Evaluation report of the optimum e-gun and injector solution for the XLS CDR. D3.2 A review report on the bunch compression techniques and phase space linearization D4.1 Computer code report for RF power unit design and cost optimization. D5.1 A review report comparing the different technologies for the CompactLight undulator. D6.1 Review report on the most advanced computer codes for the facility design WP3 INFN ➜ WP4 CERN ➜ R-PU M18 WP5 ENEA ➜ WP6 UA-IAT ➜ Next Deliverables

13. Invited talks and meeting participations • Future Light Source 2018 Shanghai 5-9 March 2018 • High Gradient Workshop 2018 Shanghai 4-8 June 2018 • CLICWEEK 2019 CERN January 21-25, 2019 • Towards an Ultra-Compact X-ray Free-Electron Laser UCLA, January 22-25, 2019 + Meeting participations: Leaps, FELs of Europe, etc.

14. Work Packages: • Objectives • Ongoing Activities

15. WP1 and WP7 Objectives WP1: Project management and Technical Coordination (G. D’Auria, Elettra – ST). WP1 carries the overall management of the XLS Design Study to ensure timely achievement of project results through technical and administrative management. WP7: Global integration with new Research Infrastructures (R. Rochow, Elettra-ST) WP7 will address strategic issues related to the objectives of XLS, namely the impact and benefits for the user community, in both the public and private sectors, at the scientific and technical level. The results of this work package will be a series of reports which target funding agencies and policy makers in the decision making process for the approval of new research infrastructures or the upgrade of existing Facilities.

16. WP2 WP2: FEL science requirements and facility design (J. Clarke STFC - Daresbury) The objective of WP2 is to provide the overall design of the FEL. It will determine performance specification for the Facility“based on user-driven scientific requirements”. It will identify and choose the most appropriate technical solutions considering cost, technical risk and performance. • Survey with a specially developed questionnaire sent to over 50 European experts (October-November 2018). • CompactLight User Meeting: CERN, November 27th – 28th, 2018 D2.1: Science Requirements and Performance Specification for the CompactLight X-Ray Free-Electron Laser Courtesy of J. Clarke

17. XLS FEL Parameters Preliminary Parameters of the CompactLight FEL *A repetition rate of 1000 Hz would be a unique and desirable feature of our design! We recognise that this is a very challenging target that we may have to reduce during the study.

18. XLS FEL possible configuration 4.3 - 4.8 GeV 0.2 um 6 kA 5 fs fwhm 0.005% - 0.01% rms slice e.spr. 50 pC 160 MeV 0.2 um emit 60 A SX INJ 6.5 – 7.5 GeV 0.2 um 6 kA 5 fs fwhm 0.003% - 0.01% rms slice e.spr. HX BC1 BC2 Courtesy of N. Thompson, D. Dunning, S. Di Mitri

19. WP3 • WP3: Gun and injector (M. Ferrario, INFN - Frascati) • The objective of WP3 is to provide the technical specification and the optimum design of the Linac e-gun and injector.Options considered: • High-gradient injectors at existing gun frequencies, S and C bands (towards lower emittance). • A full-X-band solution, inclusive of higher-harmonic linearization in K band. • DC Gun • Injector diagnostics & beam manipulations based on X-band technology. Bunch compression techniques (compact magnetic chicanes, velocity bunching). • Gun design (RF, Solenoid, Cathode, Laser, Diagnostics) • S-Band Gun RF Design (CNRS + IASA+UAIAT-INFN+ALBA) • C-Band Gun RF Design (INFN +IASA+Sapienza) • X-Band Gun RF Design (CSIC-IFIC + UAIAT+ Sapienza) • DC Gun Design (TU/e) • Laser/Photocathode (IASA+CNRS+INFN) • Compressor Design (Velocity Bunching, Magnetic Chicane) • S-Band Velocity Bunching(TU/e + IASA+ALBA) • C-Band Velocity Bunching (INFN +IASA+TU/e ) • X-Band Velocity Bunching(Sapienza+CERN+IASA+INFN) • Magnetic Compressor (ST + CERN+INFN+CNRS) • X-Band Diagnostics (Transverse RF Deflector) • Transverse RF Deflector (Sapienza + IASA) • Linearizer Design (RF and passive linearizers) • X-Band RF Linearizer(Sapienza) • K-Band RF Linearizer (ULANC + Sapienza ) • Passive linearizers (CNRS) Main Tasks Courtesy of M. Ferrario

20. =3 Circ. P.C. X2.1 KLY 100 ns, 85 MW GUN Circ. 1-1.5 s, 40 MW WP3 - C-Band Ultra-Fast GUN Design (prel.) • The C-band injector is based on an ultra-high gradient C-band gun (1.6 cells) operating at 240 MV/m cathode peak field • We proposed to adopt an ultra-fast gun (rf pulses <150 ns) keeping under control all quantities that drive the breakdown phenomena (Modified Poynting vector, surface electric field, etc.) • The design of the overall system is based on commercially available components (klystrons, circulators, pulse compressors, ect…) • We have optimized the 2D profile of the cells and the input coupler exploring different solutions. An input coupler working on the TM020 mode on the full cell seems to be the best solution Courtesy of M. Croia

21. WP4 • WP4: RF systems (W. Wuensch, CERN) • The primary objective of WP4 is to define the RF system for the linac in the main and sub-design variants (specialized hardware for an eventual 36 GHz lineariser system, deflectors for profile measurement systems,…). • A key goal will be “todefine a standardized RF unit”: • Simplify the preparation of future construction projects. • Cost savings (industrialization of linac hardware). Courtesy of W. Wuensch

22. Beyond the state-of-the-art Examples of Linac gradientsfor most recent X-ray FELs Preliminary parameters of the X-band RF unit, compared with the C-band SwissFELtechnology. Preliminary parameters of an optimized RF structure (X-band)

23. 50 MW, 1.5 µs Trade-off between machine compactness and RF power requirements • Baseline accelerating gradient: 65 MV/m • RF system and pulse compressor characteristics • Average iris radius: 3.5 mm • Electromagnetic parametric study of the TW cell • Effective shunt impedance optimization by a 2D scan of the total length and the iris tapering • Check of modified Poynting vector values @ nominal gradient • Design a realistic RF module including power distribution network • Finalize the electromagnetic (input and output couplers) and mechanical design Beam dynamics requirements (BBU threshold) WP4 - X-band Accel. Struct. Design & Optim. Courtesy of A. Gallo

24. Freq. of 2π/3 mode [GHz] 11.9942 Average iris radius <a> [mm] 3.5 Total length of the TW structure Ls [m] 0.9 RF pulse [µs] 1.5 Average gradient <G> [MV/m] 65 Linac Energy gain Egain [GeV] 4.5 Linac active length Lact[m] 69.2 Unloaded SLED Q-factor Q0 180.000 External SLED Q-factor QE 21400 Iris radius a [mm] 4.3-2.7 Group velocity vg [%] 4.5-1.0 Effective shunt Imp. Rs [M/m] 389 Filling time tf [ns] 140 Input power per structure Pk_s [MW] 9.8 Structures per module Nm (input power per module Pk_m [MW]) 4 (39) Total number of structures Ntot 80 Total number of klystrons Nk 20 WP4 – RF structure Preliminary Parameters Compact Light optimum Best effective shunt impedance EuSPARC optimum EuSPARC working point (optimization of RF power splitting) Courtesy of A. Gallo

25. WP5 WP5: Undulators and light production (F. Nguyen, ENEA - Frascati) The primary objective of WP5 is to determine the undulator design for XLS. It will start by investigating state of art undulators and then consider on-going developments. “Ambitious undulators” will be compared with the boundary conditions of technologies available on 4-5 years time scale. These will include: • Novel short period undulators • Superconducting undulator • RF-microwave undulators. Task Leaders Different undulator solutions subject to the following investigations: a. Shortest possible wavelength for a given beam energy. b. Highest possible FEL performance (shortest gain length, highest saturation power) for a given target wavelength. c. Highest possible undulator performance (shortest longitudinal space per undulator module, shortest undulator gap width) for a given focusing scheme. Courtesy of F. Nguyen

26. HX preliminary Undulator Parameters Courtesy of F. Nguyen

27. SX preliminary Undulator Parameters Courtesy of F. Nguyen

28. XLS preliminary Parameters Courtesy of F. Nguyen

29. WP6 • WP6: Beam dynamics and start-to-end modelling (A. Aksoy, UAIAT - Ankara) • The main objective of WP6 is to provide key parameters and performance estimates of the Facility. Consistent tools for modelling the machine, as the basis for the integrated performance studies, will be developed. • S2E simulations from the cathode to the undulator exit. • Tolerance studies will be also performed. • Beam-based alignment and tuning methods that can relax the tolerances. Courtesy of A. Aksoy

30. CompactLight is funded by the European Union’s Horizon2020 Research and Innovation programme under Grant Agreement No. 777431