Ewald's Sphere
The Ewald sphere is a geometric construct used in electron, neutron, and X-ray crystallography which demonstrates the relationship between:
-
- the wavevector of the incident and diffracted x-ray beams,
- the diffraction angle for a given reflection,
- the reciprocal lattice of the crystal
It was conceived by Paul Peter Ewald, a German physicist and crystallographer. Ewald himself spoke of the sphere of reflection.
Ewald's sphere can be used to find the maximum resolution available for a given x-ray wavelength and the unit cell dimensions. It is often simplified to the two-dimensional "Ewald's circle" model or may be referred to as the Ewald sphere.
Read more about Ewald's Sphere: Ewald Construction
Famous quotes containing the word sphere:
“Thought dissolves the material universe by carrying the mind up into a sphere where all is plastic.”
—Ralph Waldo Emerson (18031882)