1. Where do photons go When they come out of the beamline and hit my crystal

2. Elastic scattering

4. Inelastic scattering

5. Photonuclear absorption

7. Photoelectric absorption

8. e-e- +

9. Fluorescence +

10. e-e- +

11. Photoelectric absorption

12. e-e- +

13. Secondary ionization e-e-

14. e-e- e-e- +

17. e-e- +

18. e-e- e-e- e-e- e-e- e-e- e-e- +

19. e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- + + + + + + + + +

20. e-e- e-e- e-e- e-e- e-e- e-e- + + + + + + + + e-e- e-e- + e-e-

21. e-e- e-e- e-e- e-e- e-e- e-e- + + + + + + + + +

24. Where do photons go? beamstop Transmitted (98%) Protein 1A x-rays

25. Where do photons go? beamstop elastic scattering (6%) Transmitted (98%) Protein 1A x-rays

26. Where do photons go? beamstop elastic scattering (6%) Transmitted (98%) inelastic scattering (7%) Protein 1A x-rays

27. Where do photons go? beamstop elastic scattering (6%) Transmitted (98%) inelastic scattering (7%) Protein 1A x-rays Re-emitted (99%)Absorbed (~0%)

28. Where do photons go? beamstop elastic scattering (6%) Transmitted (98%) inelastic scattering (7%)Photoelectric (87%) Protein 1A x-rays Re-emitted (99%)Absorbed (~0%)

29. Where do photons go? beamstop elastic scattering (6%) Transmitted (98%) inelastic scattering (7%)Photoelectric (87%) Protein 1A x-rays Re-emitted (~0%)Absorbed (99%) Re-emitted (99%)Absorbed (~0%)

30. Where do photons go? beamstop elastic scattering (6%) Transmitted (98%) useful/absorbed energy: 7.3% inelastic scattering (7%)Photoelectric (87%) Protein 1A x-rays Re-emitted (~0%)Absorbed (99%) Re-emitted (99%)Absorbed (~0%)

31. Where do photons go? beamstop elastic scattering (6%) Transmitted (97%) useful/absorbed energy: 7.6% inelastic scattering (5%)Photoelectric (88%) SelenoProtein 1A x-rays Re-emitted (~0%)Absorbed (99%) Re-emitted (99%)Absorbed (~0%)

32. Where do photons go? beamstop elastic scattering (2%) Transmitted (91%) useful/absorbed energy: 5.1% inelastic scattering (2%)Photoelectric (96%) SelenoProtein 0.92A x-rays Re-emitted (57%)Absorbed (44%) Re-emitted (99%)Absorbed (~0%) just above the edge

33. Where do photons go? beamstop elastic scattering (2%) Transmitted (90%) useful/absorbed energy: 5.1% inelastic scattering (2%)Photoelectric (96%) SelenoProtein 0.97A x-rays Re-emitted (60%)Absorbed (40%) Re-emitted (99%)Absorbed (~0%) far above the edge

34. Background scattering Resolution (Ǻ) Electron equivalents The form-factor of the cryostream 20 10 5 4 3 2.5 2 1.8 1.6 1.4 1.2 1 0 2 4 6 8 10 12 14 16 measured theoretical

35. Background scattering Resolution (Ǻ) Photons/s/pixel Se edge with detector at 100 mm  7.5 3.8 2.5 1.9 1.5 1.2 1.1