Coherent Single Particle Imaging WBS 1 3 J

Coherent Single Particle Imaging (WBS 1. 3) J. B. Hastings* LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu

Science Team Specifications and instrument concept developed with the science team. The team Janos Hajdu, Photon Science-SLAC, Upsala University (leader) Henry Chapman, LLNL John Miao, UCLA LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu

A 3 D dataset can be assembled from diffraction patterns in unknown orientations Diffraction from a single molecule: Noisy diffraction pattern FEL pulse Unknown orientation Combine 105 to 107 measurements into 3 D dataset: Classify Average The highest achievable resolution is limited by the ability to group patterns of similar orientation Gösta Huldt, Abraham Szöke, Janos Hajdu (J. Struct Biol, 2003 02 -ERD-047) LCLS FAC April 17, 2007 Coherent X-Ray Imaging Combine Reconstruct Miao, Hodgson, Sayre, PNAS 98 (2001) J. B. Hastings jbh@slac. stanford. edu

The diffraction imaging interaction chamber and detector arrangement Particle injection Pixel detector Intelligent beam-stop Hartman Wavefront Mask XFEL beam (focussed, possibly Compressed) Potential. Particle orientation beam To mass spectrometer LCLS FAC April 17, 2007 Coherent X-Ray Imaging Optical and xray diagnostics Readout and reconstruction J. B. Hastings jbh@slac. stanford. edu

Wavefront sensor 1 micron KB system 0. 1 micron KB system Coherent X-ray Imaging Instrument Sample chamber Detector LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu

Detector geometry ‘Hole’ in detector to pass Incident beam Tiled detector, permits variable ‘hole’ size: • Ideally the hole is ~ x 2 bigger than incident beam at most • Dead area at edges of detector tiles limits minimum ‘hole’ size • Alternate approach: larger ‘hole’ and a single tile forward direction Simulations required LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu

1. 3. 2 X-ray Optics X-ray optics (1. 3. 2) Focusing K-B systems for 1 and 0. 1 micron foci Be lens for 10 micron focus Slits, attenuators, ‘pulse picker’ Pulse compression optic LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu

1. 3. 2 X-ray Optics - focusing Two approaches: separate optical components for 10, 1, 0. 1 micron focii or a single 0. 1 micorn optic and work out of focus for ‘variable’ spot size Separate optics: Ideally wavefront is ‘flat’ Complicated motion for sample chamber-detector system Single optic: Simple ‘translation of sample varies focus’ Wavefront curavture when ‘out of focus, is this harmful? LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu

1. 3. 2 X-ray Optics - focusing Focusing optics Be Lens FEL source Sample handler KB Mirrors 1 µm 0. 1 µm Offset mirror pair Monochromator/ pulsecompressor f 1 µm f 0. 1 µm zd Pixel detector Beamstop Sample chamber & diagnostics zs ≈ 400 m Image reconstruction LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu

Kirkpatrick Baez (KB) focusing mirrors 1. 3. 2. 2 Mirror system (1 µm and 0. 1 µm KB) KB mirrors have produced 50 nm focuses of SR(Yamauchi et al. , SRI 2006). Can use bent plane mirrors – plane mirrors most accurate polishing. Achromatic focusing. Use B 4 C as coating Damage resistant Good reflectivity LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu

KB Pair for 1 μm focus Grazing angle 0. 2 Deg B 4 C coating Horz. Mirror 20 cm Vert. Mirror 10 cm Focal spot size (FWHM in microns) Horz: 0. 6 Vert: 0. 9 LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu

KB Pair for 0. 1 μm focus Grazing angle 0. 2 Deg B 4 C coating Horz. Mirror 20 cm Vert. Mirror 10 cm Focal spot size (FWHM in microns) Horz: 0. 097 Vert: 0. 083 LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu

1. 3. 2 X-ray Optics - focusing Focusing optics Be Lens FEL source Sample handler KB Mirrors 1 µm 0. 1 µm Offset mirror pair Monochromator/ pulsecompressor f. Be lens zd Pixel detector Beamstop Sample chamber & diagnostics zs ≈ 400 m Image reconstruction LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu

1. 3. 2 X-ray Optics - focusing 1. 3. 2. 2 – Beryllium lens focusing optic ~ 10µm FWHM focal spot size Positioning resolution and repeatability to 1 µm LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu

Be lens calculation for 10 micron focus Focal spot size including diffraction and roughness FWHM in microns: Horiz: 12. 0 Vert: 10. 1 http: //www. institut 2 b. physik. rwth-aachen. de/xray/applets/crlcalc. html LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu

1. 3. 2 X-ray Optics – pulse picker 1. 3. 2. 1. 2 – Pulse picker Permit LCLS operation at 120 hz Single pulses. Useful for samples supported on substrates Reduced rate ex. 10 hz operation High damage threshold Use rotating discs, concept already in use at ESRF LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu

1. 3. 2 X-ray Optics - compressor 476 µm λ (nm) d (nm) θ φ b Sin β H* (mm) Δλw/λ (%) 0. 15 2. 0 2. 1º -90º +1 0. 03 2600 0. 5% Henry Chapman LLNL LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu

1. 3. 3 Sample environment - Vacuum requirements Assumptions: ‘unshielded’ beam path of 10 cm for 1 µm 2 beam bio-molecule ~ 500 k. Da ~ 5 x 104 atoms Background scatter 1% 500 atoms in path Atoms in background gas same z as in the molecule p ≤ 1 x 10 -7 torr LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu

1. 3. 3 Sample environment – detector position Sample environment (1. 3. 3) Sample chamber (vacuum better than 10 -7 torr) Detector positioning 50 -4000 mm from sample Sample diagnostics - ion and electron To. F Cryo-EM stage LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu

The number and solid angle of the detector elements are dependent on particle size and resolution N x f x fmax D = N x / s Real space samples: x Smallest period sampled: 2 x = d or fmax = 1/d Oversampling (per dimension): s Array size: N = D s / x = 2 D s / d E. g. D = 57 nm, d = 0. 3 nm, s = 2 N = 760 = 0. 15 nm pix= 1. 3 mrad LCLS FAC April 17, 2007 Coherent X-Ray Imaging Henry Chapman LLNL J. B. Hastings jbh@slac. stanford. edu

Detector size fixes resolution E. g. , d = 0. 3 nm, s = 2 , = 0. 15 nm, N = 760 D ≈57 nm 110 m pixels 2 = 30º zd = 83. 6 mm, 760 pixels D = 57 nm LCLS FAC April 17, 2007 Coherent X-Ray Imaging zd zd =1450 mm, 760 pixels D = 1000 nm, d=5. 2 nm J. B. Hastings jbh@slac. stanford. edu

1. 3. 3 Sample environment (1. 3. 3) Sample chamber (vacuum better than 10 -7 torr) Detector positioning 50 -4000 mm from sample Sample diagnostics - ion and electron To. F Cryo-EM stage LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu

1. 3. 3 Sample environment - Sample diagnostics 3 x 1012 photons in 100 nm spot (a) 2 fs pulse (b) 10 fs pulse (c) 50 fs pulse Provide diagnostics to understand the ‘explosion’ Electron and Ion To. F detectors able to resolve single atom fragments (1 AMU) 1/1000 in electron energy LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu

System Specifications Item Purpose Specification Focusing optics Produce required flux. Focal spot sizes of 10, 1, 0. 1 micron Sample chamber Vacuum sample env. , reduced background Vacuum below 10 -7 torr Detector Measurement of diffraction pattern 2 -D, 760 x 760 pixels, 110 µm pixel size, with central hole (shared LCLS det. ) Sample diagnostic Ion TOF analysis of sample fragments Resolution of one mass unit up to 100 AMU Sample diagnostic Electron TOF analysis of sample fragments Resolution of 10 -3 Optical Compressor Reduce pulse length 20 fs pulse length LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu

1. 3. 3 Sample environment – cryo-EM stage Sample environment (1. 3. 3) Sample chamber (vacuum better than 10 -7 torr) Detector positioning 50 -4000 mm from sample Sample diagnostics - ion and electron To. F Cryo-EM stage LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu

1. 3. 3 Sample environment - Cryo-EM stage Cryo-EM Goniometer All motion drives outside vacuum In use on SR sources for STXM Provides full angularspatial degrees of freedom to collect 3 D data LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu

Summary Instrument concept advancing well Near term issues: detector hole, single versus multiple optics Sample chamber: design should accommodate Raster system (samples on substrate) Particle injector Cryo-EM stage Data acquisition-storage-analysis are challenging Diagnostics-wavefront in particular are challenging LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu

LCLS FAC April 17, 2007 Coherent X-Ray Imaging J. B. Hastings jbh@slac. stanford. edu