1 / 38

The LCLS at SLAC Linac Coherent Light Source

ANL. LLNL. UCLA. The LCLS at SLAC Linac Coherent Light Source. J. B. Hastings (for the LCLS group) January 31, 2007. LCLS. 2 compressors. one undulator. LCLS. X-FEL based on last 1-km of existing SLAC linac. 1.5-15 Å. Beam Transport from Linac Through X-Ray Halls.

heaton
Download Presentation

The LCLS at SLAC Linac Coherent Light Source

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. ANL LLNL UCLA The LCLS at SLAC Linac Coherent Light Source J. B. Hastings (for the LCLS group) January 31, 2007 LCLS

  2. 2 compressors one undulator LCLS X-FEL based on last 1-km of existing SLAC linac 1.5-15 Å

  3. Beam Transport from Linac Through X-Ray Halls Beam Transport Hall: 227-m, above-grade facility to transport electron beam Undulator Hall: 170-m, underground tunnel housing undulators Electron Beam Dump: 40-m long underground facility to separate electron and x-ray beams Near Experimental Hall: underground facility to house 3 experimental hutches, prep, and shops X-Ray Trans. & Diag. Tunnel: 210-m long underground tunnel to transport photon beams from NEH to FEH Front End Enclosure: 40-m long underground facility housing photon beamdiagnostic equipment Far Experimental Hall: underground 46’ cavern housing 3 experimental hutches and prep space

  4. LCLS Parameters

  5. 250 MeV z  0.19 mm   1.6 % 4.30 GeV z  0.022 mm   0.71 % 13.6 GeV z  0.022 mm   0.01 % 6 MeV z  0.83 mm   0.05 % 135 MeV z  0.83 mm   0.10 % Linac-X L =0.6 m rf= -160 Linac-0 L =6 m rf gun L0-a,b Linac-3 L 550 m rf  0° Linac-1 L 9 m rf  -25° Linac-2 L 330 m rf  -41° 25-1a 30-8c 21-3b 24-6d ...existing linac 21-1 b,c,d undulator L =130 m X BC1 L 6 m R56 -39 mm BC2 L 22 m R56 -25 mm DL1 L 12 m R56 0 DL2 L =275 m R56  0 Commission in Jan. 2008 Commission in Jan. 2007 SLAC linac tunnel research yard LCLS Accelerator Schematic

  6. LCLS Installation and Commissioning Time-Line Drive-Laser Commissioning LTU/und. Install LTU/und. hall “ready” Drive-Laser Installed Controls Checkout First Spont. Light A S O N D J F M A M J J A S O N D J F M A M J J 2006 2007 2008 Gun/Inj./BC1 Install (8/21 – 2/20) Gun/Inj./BC1 Commissioning Inj./Linac/BC2 Commissioning linac/BC2 Install LTU/und. Commissioning Oct. 19, 2006

  7. LCLS Installation and Commissioning Time-Line Drive-Laser Commissioning LTU/und. Install LTU/und. hall “ready” Drive-Laser Installed Controls Checkout First Spont. Light A S O N D J F M A M J J A S O N D J F M A M J J 2006 2007 2008 Gun/Inj./BC1 Install (8/21 – 2/20) Gun/Inj./BC1 Commissioning Inj./Linac/BC2 Commissioning linac/BC2 Install LTU/und. Commissioning Oct. 19, 2006

  8. gey= 1.06 μm Emittance Measurements with ‘Quad-Scan’ on OTR Screen OTR screen 95% area cut Gaussian used only as visual aid here 135 MeV, 1 nC, 100 A

  9. Projected Emittance Below 1 μm at 0.7 nC gex = 0.76 μm Q = 700 pC gey = 0.85 μm

  10. Emittance Measured Over 8 Hours gex gey 0.7 nC, 135 MeV, 70 A

  11. x & yemittance1.2 μm at 1 nC charge (design) <1.5% rms charge stability (design is 2%) Drive laser 98% up-time with 500 μJ (250 design) Bunch compression in BC1 fully demonstrated Accelerated LCLS beam to 16 GeV (13.6 design) X-band & 2 RF deflectors both operational New RF performing within spec (e.g., <0.1º rms) Feedback ON: launch, charge, energy, RF, & sz Robust, high-quality RF gun demonstrated Commissioning Results

  12. t= t=0 Science Opportunities Atomic, molecular and optical science (AMOS) Nano-particle and single molecule coherent x-ray imaging (CXI) Coherent-scattering studies of nanoscale fluctuations (XCS) Diffraction studies of stimulated dynamics (pump-probe) (XPP) High energy density science (HEDS) SLAC Report 611 Aluminum plasma classical plasma G G =1 =10 dense plasma G =100 high den. matter - 4 1 - 2 2 4 10 10 10 10 Density (g/cm-3)

  13. Very-intense, ultrashort x-ray pulses will interact with matter in new ways. Atomic strong-field effects may alter the properties of the materials. Atomic, molecular, and optical (AMO) physics

  14. - Ip - Ip 10x20 W/cm2 1015 W/cm2 - Ip 1013 W/cm2 Low-Frequency Physics → High Frequency IR: Low frequency regime VUV FEL: Intense photon source XFEL FEL: Highly ionizing source • Angstrom wavelength • Direct multiphoton ionisation • Secondary processes • Keldysh parameter >>1 • Multi-photon ionisation • Ponderomotive energy 10 meV • Keldysh parameter <<1 • Tunnel / over the barrier ionisation • Ponderomotive energy 10 – 100 eV   Optical Frequency = (Ip/2Up)1/2 -1; Up=I/4ω2 (au) Tunneling Frequency

  15. Microscopy image sample light • depth of field limit • lens-limited • direct lens Diffractive imaging Diffraction Microscopy • No depth of field limit • No lens-limited • Computer-limited Coherent-light Known: k-space amplitude: I Support (outline of the object) in real space s CCD Imaging with coherent x-rays

  16. X-ray free-electron lasers may enable atomic-resolution imaging of biological macromolecules One pulse, one measurement Particle injection 10-fs pulse Noisy diffraction pattern Combine 105-107 measurements Classification Averaging Orientation Reconstruction H. Chapman

  17. Motivation for even shorter x-ray pulses Further e- compression difficult: Radiation damage interferes with atomic positions and the atomic scattering factors • CSR in bends • Undulator wakefields Janos Hajdu Dt /fsec Coulomb Explosion of Lysozyme (50 fs)

  18. 1 micron SEM of structure etched into silicon nitride membrane First image reconstructed from an ultrafast FEL diffraction pattern 1st shot at full power 2nd shot at full power Reconstructed Image – achieved diffraction limited resolution! Wavelength = 32 nm Chapman et al. Nature Physics (2006) 1 micron Edge of membrane support also reconstructed

  19. LCLS Nanocrystal of lysozyme 5x5x5 LYSOZYMES 1 LYSOZYME

  20. Dynamics Silica: 2610 Å, ΔR/R=0.03, 10 vol% in glycerol, T=-13.6C,   56000 cp sample CCD 22µm direct illumination 1k x 1k CCD 1 MHz ADC 1 s exposure 4 s overhead today:  1 s V. Trappe and A. Robert

  21. XPCS Science Split & Delay High Time–average Brilliance Rep. Rate 120 Hz Sequential Mode High Peak Brilliance Short pulse duration 100fs Dedicated 2D-Detector LCLS Parameters Transverse Coherence 8 and 24 keV

  22. Ultrafast XPCS • Peak Brilliance & Pulse Duration • pulse duration < tC< several ns • Large Q’s accessible

  23. Split and Delay • Provided by DESY/SLAC MoU • Prototype existing • 1st Commissioning May 2007 • pulse duration < delay < 3 ns • based on Si(511) with 2θ= 90º • E=8.389 keV

  24. Traditional Pump-probe • Delay will be achieved by optical delay and/or RF phase shift • Resolution limited by LCLS/laser jitter ~ 1 ps limit

  25. Short Pulse Laser Excitation Impulsively Modifies Potential Energy Surfaces Non-thermal melting of InSb Coherent phonons in Bi

  26. Ultrafast X-ray Scattering Provides Direct Access to Atomic Motion on non-Equilibrium Potential Energy Surfaces …characterizes the shape of the potential A. Lindenberg, et al.Science 308, 392 (2005). D.M. Fritz, et al.Science 315, 633 (2007).

  27. 0 -300 -200 -100 100 SLFC LFC RPA -20 0 -60 -40 High brightness of LCLS will enable unique studies of in situ material failure Current: Post Processing x-ray scattering Future: Measure during pressure pulse Simulated x-ray scattering Shocked and incipiently fractured single crystal Al slug Bound e- Shift RPA Particle data SLFC LFC Free e- Te Energy shift (eV) APS Beam LCLS 3-D x-ray tomographic reconstruction of dynamic fracture Multiple and single bunch x-ray scattering from shock recovered samples in progress Collective • LCLS will provide unprecedented fidelity to measure dynamics of the microstate with sub-picosecond resolution • Diffraction  lattice compression and phase change • SAXS  sub-micron defect scattering • Diffuse  dislocation content and lattice disorder R. Lee

  28. Current Status Simulation Classical scattering • MD simulation of FCC copper Periodic features average distance between faults Diffuse scattering from stacking fault Peak diffraction moves from 0,0 due to relaxation of lattice under pressure 0 0 • X-ray diffraction image using LCLS probe of the (002) shows in situ stacking fault information LCLS enables real-time, in situ study of deformation at high pressure and strain rate Future with LCLS Unique capabilities • Imaging capability • Point projection imaging • Phase contrast • High resolution (sub-µm) • Direct determination of density contrast • Diffraction & scattering • Detection of high pressure phase transitions • Lattice structure, including dislocation & defects • Liquid structure • Electronic structure • Ionization • Te, f(v) These complement the standard instruments, e.g., VISAR and other optical diagnostics

  29. 2109 photons 380 as Attosecond Pulses Impact: X-ray pulses 500 times shorter than nominal LCLS (2-fsec already in baseline) Lag: 1 yr Level: Straightforward – Spoiler wakefield needs checking Ref:PRL 92:074801,2004, SLAC-PUB-10712. Be foil in BC2 chicane • Parameters: • <400 attosecond pulses • 2109 photons/pulse • 100 pC bunch charge SLAC Contacts: P. Emma, Z. Huang, et al.

  30. LCLS with Multiple Beamlines 535 m 330 m FFTB m-shielding 62 m 100 m Note: Design Hall A and Hall B compatible with LCLS II Expansion

  31. Multiple Undulators and Fast Multi-Bunch Switching Impact: Converts LCLS into a user facility with extended wavelength range, shorter pulses, and enhanced power levels Lag: ~10 yrs Level: Challenging – need multi-bunch E-compensation (variable spacing) Ref:SLAC-PUB-10133. 4.9 ns up to 60 bunches (same again on North side) • Parameters: • 1 to 60 bunches/RF pulse • Up to 8 undulators • Wavelengths below 1 Å? • Pulse lengths to 1 fsec SLAC Contacts: F.-J. Decker, P. Emma, et al.

  32. 13.6 GeV Long-Wavelength FEL Impact:Provide soft x-ray FEL in addition to hard x-rays Lag: ~5 yrs Level: Moderate Ref: (none yet) 10-50 Å 250 MeV 1.5-15 Å • Parameters: • I =3.4 kA • 1.2 mm-mrad emittance • σδ = 1x10-4 • β= 25m • λu = 10 cm • K = 5~12 • B= 0.53~1.28 T • λr = 10 -50 Å • Adjustable-Gap Undulator • Simultaneous Operation with 1.5-Å, but ½-rate SLAC Contacts: J. Arthur, J. Hastings, Z. Huang, PE

  33. 2 compressors one undulator LCLS X-FEL based on last 1-km of existing SLAC linac 1.5-15 Å ?

  34. LCLS Future Options: 27 GeV,ge= 0.8 mm, 6.0 kA: 14 GeV, ge = 1.2 mm, 3.4 kA: 27 GeV LCLS XFEL LCLS soft LCLS nom. • The SLAC linac can explore and reach the limits of FEL performance: • Peak brightness • Fluence • Pulse duration • These limits are primarily determined at LOW energy: • Gun • Bunch compression • This is an extraordinary scientific opportunity • Near- and long-term payoff Peak Brightness (phot./s/mrad2/mm2/0.1%-BW) Photon Energy (eV)

  35. By-Pass Line to Long-Wavelength FEL Impact:Provide soft x-ray FEL in addition to hard x-rays Lag: ~5 yrs Level: Moderate (use e+ PEP-II by-pass line) Ref: (none yet) ESA PEP-II e+ by-pass line 10-50 Å 250 MeV 4.3 GeV 10-50 Å 1.5-15 Å pulsed dipoles Parameters: ESB • Adjustable-Gap Undulator • Simultaneous Operation with 1.5-Å, but ½-rate • Possible after-burner undulator added • Possible locations: • Endstaion A or B SLAC Contacts: J. Arthur, J. Hastings, Z. Huang, PE

  36. Circular Polarization for Soft x-rays Impact: Provide variable polarization in the 1-5 nm wavelength range Lag: ~5 yrs Level: Moderate – new undulator Ref:none yet ~ 2 GW (linear polarized) planar helical Two sections Six 3.4m sections ~ 20 GW (90% circular polarized) Parameters: • Parameters: • Electron energy 4.3 GeV • 1.2 mm-mrad emittance • Energy spread 1 MeV • Standard LCLS undulator Contacts: Y. Ding, Z. Huang

  37. 30 fs Two-Stage SASE FEL Impact: Short pulse, or narrow bandwidth, & wavelength is more stable Lag: ~5 yrs Level: Moderate – new undulator line or upgrade Ref:SLAC-PUB-9370, TESLA-FEL-97-06E, SLAC-PUB-9633, SLAC-PUB-10310 30 Parameters: Contacts: C. Pellegrini

  38. eN = 1.2 mm P = P0 eN = 2.0 mm P = P0/100 courtesy S. Reiche Final Comments For LCLS, slice emittance >1.8mm will not saturate FEL… SASE FEL is not forgiving— instead of mild luminosity loss, power nearly switches OFF electron beammustmeet brightness requirements

More Related