1. due to the oscillating charge in the antenna Along this line one does not observe any acceleration Radiation from a dipole-antenna To get the dimension right ! Electromagnetic radiation Here one observes the full acceleration, but delayed in time by R/c ! Guess that 2

2. Polarisation P=cos 2 (ψ) P=1

3. Interference (mathematical) z r k’ Q Number density many wavecrest k 1 2 as drawn #2 is behind #1 for ”in” but ahead for ”out”, therefore ” – ” Phase 0.      1,2 … many

4. The dream experiment

6. 1,2 … many

7.  Detector Viewing Field Detector X-ray beam Kr Gas cell Measuring atomic and molecular formfactors from gas scattering

8. a=[15.2354 6.70060 4.35910 2.96230]; b=[3.0669 0.241200 10.7805 61.4135]; c=1.71890; % Ga a=[16.6723 6.0710 3.4313 4.27790]; b=[2.63450 0.2647 12.9479 47.7972]; c=2.531; % As

9. Unit sphere dd dd  r Q r

10. Fourier transform of a Gaussian

12. Convolution of 2 Gaussians i.e. h(x) is also Gaussian with

14. Side View Top View Ring wave (2D) or Spherical wave (3D) Energy density Surface area locally a plane wave

15. Aperture d Almost plane wave when Perfect plane wave k’ k A point scatterer in the beam Spherical wave Defines the scattering cross section Area is scattering length

16.  2L L =(N+1)(  2L L =N No real beam is perfectly monochromatic From the 2 equations, derive the longitudinal coherence length P(   wavelength band

17. No real beam is perfectly collimated P(    D LTLT Here  and B beams in phase A and B out-of-phase show from the figure that With R being the distance from to source observation point A B The transverse coherence length

18. Absorption

20. The experimental setup X-rays Sample Rotation Scintillator 20  m CCD  < 2 mdeg E = 8-27 keV 0.7 x 0.7 mm

21. Tomography Study the bulk structures, 3D Nondestructive Small lengthscales (350 nm) Fra http://www.unge-forskere.dk/ Galathea III Single slice 100 microns

22. Compton Scattering Energy and momentum conservation