A compact, soft X-ray FEL at KVI Hans Beijers Kernfysisch Versneller Instituut University of Groningen, The Netherlands Introduction Science drivers ZFEL characteristics Roadmap to ZFEL

Introduction Kernfysisch Versneller Instituut Zernike Institute for atomic, nuclear and (astro-) particle physics accelerator /radiation physics theoretical physics Kernfysisch Versneller Instituut F. Zernike (1888-1966) biomolecular and bio-inspired functionality nanostructured materials for electromagnetic functionality Zernike Institute for Advanced Materials

Hard and soft X-ray FELs SCSS Hard X-ray FEL’s LCLS: 15 GeV, NC, S-band SCSS: 8 GeV, NC, C-band SwissFEL: 5.8 GeV, NC, C-band Eur-XFEL: 20 GeV, SC, L-band FLASH: 1.2 GeV, SC, L-band FERMI@Elettra: 1.5 GeV, NC, S-band EU-XFEL Swiss-FEL Soft X-ray FEL’s FLASH FERMI@Elettra

Explosion of T4 lysozyme (C, N, O, S) induced by radiation damage. XFEL properties Short wavelengths: < 1 Å – 100 nm High transversal coherence and, when seeded, also longitudinal coherence Very intense: 1010 – 1013 photons/pulse Short pulse lengths: < 1 – 100 fs Explosion of T4 lysozyme (C, N, O, S) induced by radiation damage. R. Neutze, et al, Nature 406, 752 (2000). Gaffney et al., Science 316 (2007) 1444

Science drivers Hierarchical biology Chemical reactions Protein folding, ‘biological’ water, structure and function, membranes, viruses, cells Chemical reactions Catalysis, interfaces, combustion, molecular movies Matter in extreme conditions Phase diagram borders, end of scales Atoms to materials Inorganic/bio clusters Emergence of solid state properties from atom clusters Fundamental interactions QED and symmetries, axions, dark matter Correlated materials Phase transitions, emergent phenomena, high Tc superconductivity, magnetism Mesoscale physics Fatigue, fracture, strain, radiation damage, nucleation, disordered materials Complex materials New battery and photovoltaic materials, phase transitions

ZFEL characteristics Wavelength range: 0.8 – 50 nm  Emax= 2.1 GeV Repitition rate: 10 Hz – 1 kHz Total length: < 200 m  high accel-grad. structures

XFEL: lasing Self-Amplified Spontaneous Emission (SASE) ZFEL

SASE SASE has no longitudinal coherence ! Longitudinal coherence can be realized by Seeding at l1 Various schemes for harmonic generation Making very short electron bunches, i.e. < 1 fs

XFEL linac courtesy R. Bakker

XFEL: e- beam requirements FEL power gain length (1 D): High peak current: Ie~ 1 – 3 kA Excellent e- - g transverse overlap: small transversal emittance: Small energy spread: Small emittance and energy spread must be preserved during acceleration !

ZFEL parameters Stage 1 Stage 2 Beam energy (GeV) 1.0 2.1 Bunch charge (pC) 10 - 100 Norm. emittance (mm mrad) Peak current (kA) 1.5 Energy spread (MeV) 0.9 Rep. Frequency (Hz) 10 - 1000 Stage 1 Stage 2 Undulator period (mm) 15 Undulaor par. K 1.2 Pierce param. r 9.7e-4 4.6e-4 Gain length (m) 0.711 1.5 Saturation length (m) 13.3 27 Photon wavelength (nm) 3.4 0.8

ZFEL layout 3 S-band injector sections X-band linac section: 8 x 0.5 m TW = 400 MeV energy gain per section 2 X-band linearizer cavities Stage 1: 2 X-band linac sections Stage 2: 5 X-band linac sections Courtesy: Chr. Adolphsen

ZFEL RF Photogun Collaboration with TU Eindhoven (J. Luiten) 266 nm, 10 ps, 1 kHz rep. rate > 0.2 mJ/pulse E = 6.9 MeV Q = 0.1 – 1 nC en  1 mm mrad Courtesy: Jom Luiten

X-band accel. structures High-gradient accelerating structures for X-ray FEL 100 MV/m breakdown rate high beam quality has to be preserved during acceleration sensitivity of single-particle dynamics to various errors study of collective effects design optimization

Design studies Error budget of X-band linac B-field errors, magnet misalignments and chromatic aberrations Maximum-allowed emittance growth determines tolerances Collective effects short-range wakefields, CSR emission and beam instabilities S2E simulations

Road to ZFEL Submitting ZFEL proposal in the beginning of 2011 RF photogun and diagnostics, X-band test stand Build up expertise and setting up collaborations Design studies and developing subsystems, e.g. seed lasers, diagnostics, timing and synchronization systems, alignment and feedback etc. Construction First light 5 years after start project

Thank you for your attention ZFEL Thank you for your attention