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Although diamonds (top left) and graphite (top right) are identical in chemical composition—being both pure carbon—X-ray crystallography revealed the arrangement of their atoms (bottom). In diamond, the carbon atoms are arranged tetrahedrally and held together by single covalent bonds .
As the common visible-light laser transitions between electronic or vibrational states correspond to energies up to only about 10 eV, different active media are needed for X-ray lasers. Between 1978 and 1988 in Project Excalibur the U.S. military attempted to develop a nuclear explosion-pumped X-ray laser for ballistic missile defense as part ...
The operation of the diamond anvil cell relies on a simple principle: =, where p is the pressure, F the applied force, and A the area. Typical culet sizes for diamond anvils are 100–250 micrometres (μm), such that a very high pressure is achieved by applying a moderate force on a sample with a small area, rather than applying a large force on a large area.
In one study, a thin 50 nanometres (2.0 × 10 −6 in) foil of aluminium was irradiated with soft X-ray laser radiation (wavelength 13.5 nm). The short laser pulse knocked out core L-shell electrons without breaking the crystalline structure of the metal, making it transparent to soft X-rays of the same wavelength for about 40 femtoseconds.
The boiling removes most of the metal contamination, originating from the chamber materials, and non-diamond carbon. Various measurements, including X-ray diffraction [1] and high-resolution transmission electron microscopy, [2] revealed that the size of the diamond grains in the soot is distributed around 5 nm. The grains are unstable with ...
EELS is spoken of as being complementary to energy-dispersive x-ray spectroscopy (variously called EDX, EDS, XEDS, etc.), which is another common spectroscopy technique available on many electron microscopes. EDX excels at identifying the atomic composition of a material, is quite easy to use, and is particularly sensitive to heavier elements.
Jim Gensheimer/SLAC National Accelerator LaboratoryYou might have gotten an X-ray at the dentist’s or after a broken bone before—but that was child’s play compared to what they have at Menlo ...
An important application of mosaic crystals is in monochromators for x-ray and neutron radiation. The mosaicity enhances the reflected flux, and allows for some phase-space transformation. Pyrolitic graphite (PG) can be produced in form of mosaic crystals (HOPG: highly ordered PG) with controlled mosaicity of up to a few degrees.