1. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Introduction to X-Ray Optics, Coherence and Standing Waves David Attwood University of California, Berkeley 1

2. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx The short wavelength region of the electromagnetic spectrum 2 n = 1 – δ + iβ δ, β << 1

3. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Characteristic absorption edges for almost all elements in this spectral region 3

4. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Energy levels, quantum numbers, and allowed transitions for the copper atom 4

5. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Electron binding energies, in electron volts (eV), for the elements in their natural forms 5 www.cxro.LBL.gov

6. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Available x-ray optical techniques 6

7. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Wave propagation and refractive index at x-ray wavelengths 7

8. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Glancing Incidence Optics 8

9. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx 9 Total external reflection of soft x-ray and EUV radiation

10. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx 10 Total external reflection with finite 

11. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Buried, trace amounts of iron in a defective silicon solar cell 11

12. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx X-ray microprobe at SPring-8 12 Undulator DCM TC1Slit Incident Slit Ion chamber Mirror manipulator SDD Sample & Scanner PIN photodiode Beam monitor Optical microscope Front end Experimental hutch 98m f1: 252mm f2: 150mm 45m Courtesy of K. Yamauchi and H. Mimura, Osaka University. S. Matsuyama et al., Rev. Sci. Instrum. 77, 103102 (2006) Now focused to 7 nm

13. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Multilayer mirrors can provide high reflectivity at the Bragg condition 13

14. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx A High Quality Mo/Si Multilayer Mirror 14 N = 40 d = 6.7 Courtesy of Sasa Bajt (DESY) ˇ Small reflections at many interfaces add in phase at the Bragg angle

15. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Multilayer mirrors have achieved 70% reflectivity 15 Courtesy of Sasa Bajt, LLNL

16. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx A Fresnel zone plate lens 16

17. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx A Fresnel zone plate lens used as a diffractive lens for point to point imaging 17

18. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Depth of focus and spectral bandwidth 18

19. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx New x-ray lenses: Improving contrast and resolution for x-ray microscopy 19 C. Chang, A. Sakdinawat, P.J. Fischer, E.H. Anderson, D.T. Attwood, Opt. Lett. 2006; Sakdinawat and Liu, Opt. Lett. 2007; Sakdinawat and Liu, Opt. Express 2008

20. New ultra high aspect ratio, high efficiency, hard x-ray zone plates for high spatial resolution at 30-50 keV Courtesy of Anne Sakdinawat and Chieh Chang (SLAC) Δr = 100 nm Δh = 6.6 µm 3.4 µ 20

21. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Coherence 21

22. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Born and Wolf, Chapter 10 22

23. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Spatial and temporal coherence 23 Temporal Coherence Spatial Coherence Ability of a light beam to form fringes with a delayed version of itself Ability of spatially separated points in a wavefront to form fringes.

24. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Marching band and coherence lengths 24

25. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Spatial and spectral 25 Courtesy of A. Schawlow, Stanford

26. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Coherence, partial coherence, and incoherence 26

27. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Spatial and temporal coherence 27

28. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Spectral bandwidth and longitudinal coherence length 28

29. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx A practical interpretation of spatial coherence 29

30. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Partially coherent radiation approaches uncertainty principle limits 30

31. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Young’s double slit experiment: spatial coherence and the persistence of fringes 31

32. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Young’s double slit experiment: spatial coherence and the persistence of fringes 32

33. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Young’s double slit experiment: spatial coherence and the persistence of fringes 33

34. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx 34 Undulator beamline for high spatial coherence measurements

35. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Measuring the spatial coherence of undulator radiation: double pinhole experimental results 35

36. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Spatially coherent undulator radiation 36 Courtesy of Kris Rosfjord, UCB

37. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx 37 Coherent soft x-ray science beamline K. Rosfjord, Y. Liu, D. Attwood, “Tunable Coherent Soft X-Rays”, IEEE J. Sel. Top. Quant. Electr.10, 1405 (Nov/Dec 2004)

38. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx 38 Spatial coherence measurements of undulator radiation using the classic 2-pinhole technique = 13.4 nm, 450 nm diameter pinholes, 1024 x 1024 EUV/CCD at 26 cm ALS, 1.9 GeV, u = 8 cm, N = 55 Courtesy of Chang Chang, UC Berkeley and LBNL.

39. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx 39 Spatial coherence measurements of undulator radiation using the classic 2-pinhole technique Courtesy of Chang Chang, UC Berkeley and LBNL. = 13.4 nm, 450 nm diameter pinholes, 1024 x 1024 EUV/CCD at 26 cm ALS, 1.9 GeV, u = 8 cm, N = 55

40. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Lensless imaging of magnetic nanostructures by x-ray spectro-holography 40

41. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx Coherent power at BESSY II 41

42. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx 42

43. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx High spectral resolution (meV) beamline 43

44. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx 44 Beamline 7.0 at Berkeley’s Advanced Light Source

45. Professor David Attwood / UC Berkeley / ICTP-IAEA School, Trieste, November 2014 ICTP_Trieste_Lec2_Nov2014.pptx X-ray Standing Wave (XSW): Interference between the incident and reflected waves above a surface 45 d = λ/2sinθ

46. calibrated instrumentation well- known Reference-free GIXRF nanolayer characterisation X-ray and IR spectrometry R. Unterumsberger, B. Pollakowski, B. Beckhoff reference-free GIXRF analysis uses the XSW to characterize nanolayered samples (layer composition and thickness, surface and interface mass and composition) without any calibration samples nor reference materials XSW calculation using IMD or own software J. Anal. At. Spectrom. 23, 845 (2007) depth-dependent modification of the excitation conditions revealing information about the sequence of the layers 1.oxygen 2.carbon 3.boron 4.silicon (substate) carbon contamination at surface visible Anal. Chem. 83, 8623 (2011)

47. Synchrotron radiation based GIXRF depth profiling X-ray and IR spectrometry P. Hönicke, B. Beckhoff 3 keV As implant into Si, dose: 10 15 cm -2 TRIM SIMS MEIS STEM GIXRF Anal. Bioanal. Chem. 396, 2825 (2010) GIXRF can be used to depth profile gradient (e.g. ion implants) or nanolayered samples Calculation of the XSW using IMD software or iteratively based on X-ray reflectivity data 1 keV Al implant into Si, dose: 10 16 cm -2 TRIM GIXRF GIXRF+XRR J. Anal. At. Spectrom. 27, 1432 (2012)

48. Non-destructive interface speciation by GIXRF-NEXAFS X-ray and IR spectrometry B. Pollakowski, B. Beckhoff Development of a methodology for non-destructive interface analysis, which is traceable and reliable A priori X-ray standing wave analysis in order to keep the mean penetration depth constant when changing the photon energy during NEXAFS scans Methodology has been proven by a model system consisting of boron carbide and Nickel Anal. Chem. 85, 193-200 (2013) Application-oriented samples system: thin film Si photovoltaic -> interface between Si and TCO material J. Appl. Phys. 113, 044519 (2013)