Topic 3 Videos: An Introduction to Diffraction
Video 3.0: Fourier SeriesThis video discusses Fourier series and how they can be used to build complex functions from simple periodic functions, like sines and cosines.Click here for the note page associated with this video. 

Video 3.1: General Theory of DiffractionWe discuss the general theory of diffraction and build an expression for intensity which can be tested experimentally. We also build a delta k vector which is critical to our understanding of diffraction.Click here for the note page associated with this video. 

Video 3.2: Scattering DensityWe discuss scattering density and create a mathematical description of this concept.Click here for the note page associated with this video. 

Video 3.3: Exploring the Diffraction Equation when ΔK=GWe consider the impact of different source and detector positions (setting deltaK) on the measured intensity. We find the condition for strong constructive interference is the condition that deltaK must equal a G vector of the crystal. Later, we'll show that this is a necessay, but insufficient criteriom when we consider structure factor. 

Video 3.4: Structure FactorWe now discuss how, given a structure and a basis, we can predict the spacing, position and magnitude of the intensity. We find that, in practice, we have no idea where atoms sit in a lattice. So we take a guess, use the structure factor to calculate the intensity and compare that to experimental data. We also go through the structure factor and how to use it mathematically.Click here for the note page associated with this video. 

Video 3.5: Centered LatticesWe briefly discuss centered lattices and the information they can give us.Click here for the note page associated with this video. 