1. Anandh Subramaniam & Kantesh Balani
MATERIALS SCIENCE
&
ENGINEERING
Anandh Subramaniam & Kantesh Balani
Materials Science and Engineering (MSE)
Indian Institute of Technology, Kanpur
URL: home.iitk.ac.in/~anandh
AN INTRODUCTORY E-BOOK
Part of
A Learner’s Guide

2. 2 Incoherent Scattering (Compton modified) From loosely bound charges
Coherently scattered X-rays contribute to X-ray diffraction.
Incoherently scattered X-rays darken the background and are not useful from a XRD point of view.
In Compton modified scattering, X-rays are incoherently scattered on the interaction with loosely bound electrons in the material. This leads to a increase in the wavelength of the X-rays and a decrease in the energy.
Here the particle picture of the electron & photon comes handy
Electron knocked aside 2
No fixed phase relation between the incident and scattered waves Incoherent  does not contribute to diffraction.
(Darkens the background of the diffraction patterns).

3. Fluorescent X-rays Energy levels
This signal is produced akin to the way the original X-ray beam was produced; just that the input now is not electrons but X-rays.
The fluorescent X-rays can be used for spectroscopy (X-ray Fluorescence Spectroscopy, XRF). However, in an XRD experiment it is an nuisance and leads to an increase in the background level. E.g. Fe sample studied with Cu k radiation leads to fluorescence.
Knocked out electron from inner shell
Vacuum
Energy levels
Characteristic X-rays (Fluorescent X-rays)
(10−16s later  seems like scattering!)
Nucleus