excitation error

"Excitation error," expressed as s_g, means a deviation from a Bragg condition for a certain reflection g. The excitation error is defined as the distance from the reciprocal lattice point g to a point on the Ewald sphere measured along the vertical direction to the upper surface of the specimen. When the Bragg condition is accurately satisfied, s_g = 0. When the reciprocal lattice point is located outside the Ewald sphere, s_g>0, whereas the reciprocal lattice point is located inside the Ewald sphere, s_g<0. s_g is an observable quantity with dimension of [length]^-1. A dimensionless parameter (tilt parameter) "w = s_g ・ξ_g," whereξ_g is the extinction distance, is used instead of s_g as a useful parameter in the theoretical treatment. However, it should be noted that w is a non-observable quantity.

Related Term(s)