Synchrotron Devices

Abstract

The fourth generation synchrotron source has added several prominent features to light sources, such as ultrahigh brilliance, spectral tunability, coherence, stability, high intensity, monochromaticity, high degree of collimation and wavelength in the range from the vacuum ultraviolet to hard X-rays (from lower emittance rings) and a short wavelength, free electron laser (FEL) using both rings (10–50 ps pulses) and linear accelerator (linacs, sub picosecond pulses) as drivers. Furthermore, the energy of the emitted beam could be tuned to obtain signals with a high signal to noise ratio in a addition to a high degree of polarization of the photon beam in the plane of the electron orbit enabling placing a detector at 90° to the plane of the electron orbit to reduce the background signal, thereby improving the detection limits substantially. SR based (X-rays) characterization techniques include SR-X ray fluorescence (SRXRF), X-ray powder diffraction (XRPD), X-ray absorption spectroscopy (XAS), small and wide-angle X-ray scattering (SAXS and WAXS), X-ray photoelectron spectroscopy (XPS), grazing incidence XRD (GIXRD), and X-ray micro- or nano-probes. 116 keV or higher energy X-rays are most suitable even exciting K emission lines of U, rare earths, and several heavy elements. SR XRF is used for geological, geochemical, and archaeological samples.