# What is the definition of Lorentz factor?

## Main Question or Discussion Point

Can anyone explain how Lorentz factor is defined (the one from theory of diffraction,
not special relativity)? I read that intensity of diffracted beam is proportional to
Lorentz factor, but I could not find its definition.
On what parameters does the Lorentz factor depend? How does the Lorentz factor change inside a polycrystal sample? Does it belong to the whole sample, one grain or part of a grain?