Introduction to Synchrotron Radiation 4 th EIROforum School

Introduction to Synchrotron Radiation 4 th EIROforum School on Instrumentation (ESI 2015) Pablo Fajardo Instrumentation Services and Development Division ESRF, Grenoble

Outline OUTLINE Characteristics of synchrotron radiation (SR) SR Facilities Experimental techniques and fields of application 3 EIROforum School on Instrumentation – Garching – June 2015 P. Fajardo

SYNCHROTRON RADIATION (SR) Synchrotron radiation is produced by relativistic charged particles accelerated by magnetic fields. It is observed at particle accelerators. The emission is concentrated in the forward direction Natural SR divergence: 1/g ~ 100 mrad for electrons @ 5 Ge. V 4 EIROforum School on Instrumentation – Garching – June 2015 P. Fajardo

FIRST USE OF SYNCHROTRON RADIATION 1947 First observation of synchrotron radiation at General Electric (USA). Initially considered a nuisance by particle physicists, today synchrotron radiation is recognised as an exceptional means of exploring matter. First particle accelerators 1947 Particles with more and more energy bigger and bigger machines Particle physics 5 EIROforum School on Instrumentation – Garching – June 2015 P. Fajardo 1930 First observation of synchrotron radiation 1980 Construction of the first “dedicated” machines Synchrotron radiation

BRILLIANCE The singular characteristic of SR beams is their high brilliance. High brilliance beams = high flux of “useful photons” high photon fluxes at the sample and detector in particular when combined with high energy, spatial, angular or time resolution The brilliance of a SR beam depends inversely on the emittance of the electron beam. (low emittance = small cross-section and divergence of the particle beam) Both emittance and brilliance are invariant quantities in phase space optical techniques cannot improve them 6 EIROforum School on Instrumentation – Garching – June 2015 P. Fajardo

PROPERTIES OF SR LIGHT Brilliance average peak photons/s/mm 2/mrad 2/0. 1%BW 1035 4 th generation FELs • Very high brilliance • Wide spectrum (photon energy tunability) 1030 1025 planned But also : 1020 • Polarisation (selectable) • Spatial coherence (small source size) • Pulsed emission (e- 1015 bunches) undulator dedicated low emittance wiggler parasitic 105 2 nd generation X-ray tubes 1900 1920 1940 1960 1980 2000 2020 2040 Year 7 EIROforum School on Instrumentation – Garching – June 2015 P. Fajardo 3 rd generation 1 st generation Synchrotron sources 10 10 current

INSERTION DEVICES: UNDULATORS AND WIGGLERS Electrons (or positrons) emit SR as they wiggle across N magnetic field periods (transverse oscillations). Does each electron interfere with its own field? NO WIGGLER YES UNDULATOR 8 EIROforum School on Instrumentation – Garching – June 2015 emission ~ N 2 P. Fajardo

STORAGE RINGS VS. FREE ELECTRON LASERS Storage rings: electrons emit independently • non-amplified emission • High duty cycle is possible • Quasi-continuous (CW) source • Low energy losses magnet arrays electron beam Free-electron lasers: electrons emit coherently • SR Emission is strongly amplified (SASE) • Require very low electron emittance (LINAC) and long undulators • Very short pulses: low duty cycle but huge peak brilliance 9 EIROforum School on Instrumentation – Garching – June 2015 P. Fajardo

PERMANENT MAGNET UNDULATORS Arrays of rare earth magnets (Nd. Fe. B, Sm. Co) Standard undulators In-vacuum Cryogenic 10 EIROforum School on Instrumentation – Garching – June 2015 P. Fajardo

3 rd GENERATION SR SOURCES Low emittance storage rings operating electrons or positrons at few Ge. V. 11 EIROforum School on Instrumentation – Garching – June 2015 P. Fajardo

SYNCHROTRON RADIATION BEAMLINES e rin ag Stor g Optics cabin Experiments cabin Control room 12 EIROforum School on Instrumentation – Garching – June 2015 Simultaneous operation of beamlines P. Fajardo

SOME TYPICAL NUMBERS / ORDERS OF MAGNITUDE White beams: • Power: few k. W total power several 100 W/mm 2 power density • Beam size (at 20 m): few mm Monochromatic X-ray beams: • Energy bandwidth (d. E/E): 10 -4 (few e. V @ 20 ke. V) 13 • Photon flux (d. E/E = 10 -4): 1013 - 1014 ph/sec • Focused beam size: few mm (routinely achieved) sub-mm is more and more frequent EIROforum School on Instrumentation – Garching – June 2015 P. Fajardo

USING X-RAYS AS A PROBE The large majority of experiments use the beam as a probe to investigate properties of a sample under study by measuring the interaction processes 14 EIROforum School on Instrumentation – Garching – June 2015 P. Fajardo

A COMPLETE SUITE OF TECHNIQUES X-ray spectroscopy X-Ray Fluorescence • • • Composition Quantification Trace element mapping Short range structure Electronic structure Oxidation/speciation mapping Very specialised experimental stations and sample environments Absorption & phase contrast X-ray imaging • • • 2 D/3 D Morphology High resolution Density mapping Coherent scattering • • 15 Electron spectroscopy Very high spatial resolution Combines imaging and diffraction EIROforum School on Instrumentation – Garching – June 2015 P. Fajardo Molecular groups & structure High S/N for spectroscopy Functional group mapping X-ray diffraction & scattering • • Long/short range structure Electron density mapping Crystal orientation mapping Stress/strain/texture mapping

EXAMPLE OF SPECIALISED EXPERIMENTAL STATION X-ray beam A highly integrated instrument Raman spectrometer ID 20/ESRF 16 EIROforum School on Instrumentation – Garching – June 2015 P. Fajardo • • • KB focusing mirror Sample stage 6 moving vacuum chambers 72 bent analyser crystals 6 pixel detectors ~250 motors

FIELDS OF APPLICATION Material science Solid-state physics Environment Cultural heritage Engineering Solid-state Environment Cultural heritage Medicine Life sciences Chemistry Engineering Material science Earth sciences physics Chemistry • Non-destructive X-ray imaging New manufacturing / • Protein Bacteria Structure ofbehaviour Earth’s crust • • • High-performance materials molecules • • • Structure Atomic structure Palaeontology • Pharmaceutical crystallography / dynamics of materials processing technologies • Protein Effect heavy metals Geo-dynamics • • Soft-condensed matter therapy protocols Magnetic & of electronic properties • New • • Structure of dynamics interfaces • Material failure in the Environment Life sciences Medicine 17 Earth sciences EIROforum School on Instrumentation – Garching – June 2015 P. Fajardo

A BROAD RANGE OF APPLICATIONS Other: Training, feasibility tests, proprietary research 4% Surfaces & Interfaces 10% Soft Condensed Matter 10% Medicine 4% 18 Chemistry 12% Electronic & Magnetic Properties 12% Crystals &Ordered Structures 10% Methods & Instrumentation 2% Macromolecular Crystallography 15% Beamtime used at the ESRF (2010 data) Environment & Culture 7% EIROforum School on Instrumentation – Garching – June 2015 P. Fajardo Disordered Systems 4% Applied Materials, Engineering 10%

A LAST EXAMPLE: EXTREME CONDITIONS (EARTH AND PLANETARY SCIENCE) 45 mm Diamond anvil cell (DAC) 19 ü Very small sample volume (~100 mm) ü Pressure control up to ~1 Mbar ü Temperature up to 3000 °C (laser heating) EIROforum School on Instrumentation – Garching – June 2015 P. Fajardo

THANK YOU! 20 EIROforum School on Instrumentation – Garching – June 2015 P. Fajardo