Search results
Results from the WOW.Com Content Network
As electron kinetic energy and undulator parameters can be adapted as desired, free-electron lasers are tunable and can be built for a wider frequency range than any other type of laser, [3] currently ranging in wavelength from microwaves, through terahertz radiation and infrared, to the visible spectrum, ultraviolet, and X-ray.
Serial femtosecond crystallography (SFX) is a form of X-ray crystallography developed for use at X-ray free-electron lasers (XFELs). [1] [2] [3] Single pulses at free-electron lasers are bright enough to generate resolvable Bragg diffraction from sub-micron crystals. However, these pulses also destroy the crystals, meaning that a full data set ...
This article describes the x-ray lasers in plasmas, only. The plasma x-ray lasers rely on stimulated emission to generate or amplify coherent, directional, high-brightness electromagnetic radiation in the near X-ray or extreme ultraviolet region of the spectrum, that is, usually from ~3 nanometers to several tens of nanometers (nm) wavelength.
Electron orbital imaging is an X-ray synchrotron technique used to produce images of electron (or hole) orbitals in real space. It utilizes the technique of X-ray Raman scattering (XRS), [ 1 ] also known as Non-resonant Inelastic X-Ray Scattering (NIXS) [ 2 ] to inelastically scatter electrons off a single crystal .
The mean free path turns out to be minimal (5–10 Å) in the energy range of low-energy electrons (20–200 eV). [1] This effective attenuation means that only a few atomic layers are sampled by the electron beam, and, as a consequence, the contribution of deeper atoms to the diffraction progressively decreases.
Furthermore, a Patterson map of N points will have N(N − 1) peaks, excluding the central (origin) peak and any overlap. The peaks' positions in the Patterson function are the interatomic distance vectors and the peak heights are proportional to the product of the number of electrons in the atoms concerned.
The sample is first prepared in an excited state by a laser pulse and then probed by an X-ray pulse. With the advent of XFELs, sources that can provide extremely brilliant (more than five orders of magnitude larger than synchrotron sources) and extremely short X-ray pulses, X-ray spectroscopies performed in a pump and probe fashion are nowadays ...
Free-electron lasers have been developed for use in X-ray diffraction and crystallography. [27] These are the brightest X-ray sources currently available; with the X-rays coming in femtosecond bursts. The intensity of the source is such that atomic resolution diffraction patterns can be resolved for crystals otherwise too small for collection.