Progress at the XFELs in Europe and Japan Hans-H. Braun, PSI 48 th ICFA Advanced Beam Dynamics Workshop on Future Light Sources March 1-5, 2010 SLAC National Accelerator Laboratory

ProjectStatus First Lasing T e- λ min Driver technology (main linac) Overall length FLASHrunning 2005 (2000 TTF) 1.2 GeV50 Å Pulsed SC 1.3 GHz 315 m GeV30 Å Pulsed NC 3.0 GHz 375 m SCSSconstruction20118 GeV1 Å Pulsed NC 5.7 GHz 750 m European XFELconstruction GeV1 Å Pulsed SC 1.3 GHz 3400 m SPARX Waiting for approval 2015 ?2.4 GeV5 Å Pulsed NC 2.85 GHz 500 m SwissFEL Waiting for approval 2016 ?5.8 GeV1 Å Pulsed NC 5.7 GHz 715 m NLS Waiting for approval ?2.25 GeV12 Å C.W. SC 1.3 GHz 660 m XFELs overview

European XFEL FEL parameters

FLASH

400 m Accelerator Tunnel Undulator Hall Experimental Hall (under construction) Klystron Gallery Machine Assembly Hall XFEL/SPring-8 Building construction completed March 2009

SCSS

SCSS Test Accelerator Performance 2006 First lasing at 49 nm 2007 Full saturation at 60 nm 2008 User operation stat E-beam Charge: 0.3 nC Emittance: 0.7 .mm.mrad (measured at undulator) Four C-band accelerators 1.8 m x 4 Emax = 37 MV/m Energy = 250 MeV In-Vacuum Undulators Period = 15 mm, K=1.3 Two 4.5 m long. 500 kV Pulse electron gun CeB6 Thermionic cathode Beam current 1 Amp. 238 MHz buncher 476 MHz booster S-band buncher C-band accelerator In-vacuum undulator

Slide Courtesy of S. Di Mitri FEL1 FEL2 I/O mirrors & gas cells PADReS EIS DIPROI LDM Photon Beam Lines slits experimental hall undulator hall Transfer Line FEL1 FEL2 L1 X-band BC1 L2L3 L4 BC2 linac tunnel PI Laser Heater FERMI Layout

Electron beam parameters ParameterFEL - 1FEL - 2Units Wavelength nm Electron beam Energy1.21.7GeV Bunch Charge0.81nC Peak Current850500A Bunch Length (FWHM)400600fs Norm. Emittance (slice) mm mrad Energy Spread (slice) keV Repetition Rate Hz FEL parameters

Free Electron Laser ranging from 40 nm a 0.5 nm 4 different Beamlines with dedicated experimental stations Peak Brillance: sec.mrad².mm.0.1 % BW – fs pulses Site : Università di Roma Tor Vergata Costruction of the 500 m tunnel: Applications: Time-resolved X-ray techniques Coherent x-ray imaging Spectromicroscopy Structural studies of biological systems, allowing crystallographic studies on biological macromolecules

S-band Gun Velocity Bunching Long Solenoids Diagnostic and Matching Seeding THz Source 150 MeV S-band linac 12 m Undulators u = 2.8 cm K max = 2.2 r = 500 nm 15 m

Aramis: 1-7 Å hard X-ray SASE FEL, In-vacuum, planar undulators with variable gap. Athos: 7-70 Å soft X-ray FEL for SASE & Seeded operation. APPLE II undulators with variable gap and full polarization control. D’Artagnan: FEL for wavelengths above Athos, seeded with an HHG source. Besides covering the longer wavelength range, the FEL is used as the initial stage of a High Gain Harmonic Generation (HGHG) with Athos as the final radiator. SwissFEL 704 m

715m hard X_ray hall Undulator lines Linacs Injector SwissFEL soft X_ray hall

e - Parameters Nominal Operation Mode Upgrade Operation Mode Long Pulses Short Pulses Ultra-Short Pulses Charge per Bunch (pC)20010 Beam energy for 1 Å (GeV)5.8 Core Slice Emittance (mm.mrad) Projected Emittance (mm.mrad) Slice Energy Spread (keV, rms ) Relative Energy Spread (%) Peak Current at Undulator (kA) Bunch Length (fs, rms) Bunch Compression Factor Repetition Rate (Hz)100 Number of Bunches / Pulse222 Bunch Spacing (ns)50 SwissFEL electron beam parameters

Photon Nominal Operation Mode Upgrade Operation Mode Long Pulses Short Pulses Ultra-Short Pulses Undulator Period (mm)15 Undulator Parameter1.2 Laser Wavelength (Å)111 Maximum Saturation Length (m)50 Saturation Pulse Energy (µJ)6036 Effective Saturation Power (GW) Photon Pulse Length at 1 Å (fs, rms) Number of Photon at 1 Å (×10 9 ) Bandwidth (%) Peak Brightness (# photons.mm -2.mrad -2.s -1 /0.1% bandwidth) , Average Brightness (# photons.mm -2.mrad -2.s -1 /0.1% bandwidth) , , SwissFEL photon beam parameters (Aramis for 1 Å)

SwissFEL 250 MeV Injector Test Facility

Today

ProjectType Gun technology Laser type Cathode material FLASHRF gun Pulsed NC 1.3 GHz Nd:YLF 4 th harmonic Cs 2 Te SCSS Thermionic Diode with SHB Pulsed 500kV with SHB n.a.CeB 6 gun Pulsed NC 3.0 GHz Ti:Sa 3 rd harmonic Cu European XFELRF gun Pulsed NC 1.3 GHz Yb:YAG 4 th harmonic Cs 2 Te SPARC XRF gun Pulsed NC 2.85 GHz Ti:Sa 3 rd harmonic Cu SwissFELRF gun Pulsed NC 3.0 GHz Ti:Sa 3 rd harmonic Cu NLSRF gun C.W. SC 1.3 GHz ?Cs 2 Te Injectors

From PITZ, SSCS and LCLS injector data one could infer: No matter what you choose as injector, if you work hard enough you get ε ≈ 1 μm q B ½ (with q B in nC ) Open injector R&D issues how to get the same ε/q B ½ for c.w. operation how to improve one order of magnitude in ε/q B ½

Photon energy vs. electron beam power cold linac warm linac

Cost comparison linac technologies or Why doesn’t everybody take s.c. & c.w. Technology Linac investment cost w/o building Typical gradient Electric consumption Pulsed n.c. with SLED 10 M€/GeV 20 MV/m (S-band) 30 MV/m (C-band) 0.5 MW/GeV Pulsed superconducting 20 M€/GeV24 MV/m0.5 MW/GeV c.w. superconducting ? 30 M€/GeV ?18 MV/m5 MW/GeV Beware! This is not exact science !

Cost vs. gradient for S-band with 45 MW klystron, S-band with 80MW klystron and C-band with 50 MW klystron Advantage of C-band is in real-estate needs and electricity consumption

Talk Matthias Fuchs Thursday 10: :30

Many thanks to Reinhard Brinkmann, Jörg Rossbach, Massimo Ferrario, Florian Grϋner, Stephen Milton, Tsumoru Shintake, Richard Walker for providing information and materials