An Introduction to Synchrotron Radiation

Preface xiii

Acknowledgements xv

1. Introduction 1

1.1 A Potted History of X-rays 5

1.2 Synchrotron Sources Over the Last 50 Years 10

References 14

2. The Interaction of X-rays with Matter 15

2.1 Introduction 15

2.2 The Electromagnetic Spectrum 16

2.3 Thomson Scattering 19

2.4 Compton Scattering 20

2.5 Atomic Scattering Factors 21

2.5.1 Scattering From a Cloud of Free Electrons 21

2.5.2 Correction Terms for the Atomic Scattering Factor 22

2.6 The Refractive Index, Reflection and Absorption 25

2.6.1 The Refractive Index 25

2.6.2 Refraction and Reflection 25

2.6.3 Absorption 28

2.7 X-ray Fluorescence and Auger Emission 32

2.7.1 X-ray Fluorescence 33

2.7.2 Auger Emission 35

2.7.3 Fluorescence or Auger? 36

2.8 Concluding Remarks 37

References 37

3. Synchrotron Physics 39

3.1 Introduction 39

3.2 Overview 39

3.3 Radiation From Relativistic Electrons 43

3.3.1 Magnetic Deflection Fields 46

3.3.2 Radiated Power Loss in Synchrotrons 47

3.4 Radio Frequency Power Supply and Bunching 48

3.5 Photon Beam Properties 50

3.5.1 Flux and Brilliance 50

3.5.2 Emittance 51

3.5.3 Coherence 53

3.5.4 Polarization of Synchrotron Radiation 54

3.6 Bending Magnets and Superbends 55

3.7 Insertion Devices 57

3.7.1 Wigglers 58

3.7.2 Worked Example: The SLS Materials Science Beamline Wiggler 60

3.7.3 Undulators 60

3.8 Future Sources of Synchrotron Light 68

3.8.1 The Energy Recovery Linac 68

3.8.2 The Free-Electron Laser 70

3.8.3 Tabletop Synchrotrons 81

3.9 Concluding Remarks 85

References 85

4. Beamlines 87

4.1 Introduction 87

4.2 Front End 87

4.2.1 Beam-Position Monitors 88

4.2.2 Primary Aperture and Front-End Slits 89

4.2.3 Low-Energy Filters 90

4.3 Primary Optics 91

4.3.1 X-ray Mirrors 91

4.3.2 Mirror Focal Lengths - The Coddington Equations 94

4.3.3 Monochromators 95

4.3.4 Focusing Geometry 105

4.4 Microfocus and Nanofocus