Atomic form factor

Summary

In physics, the atomic form factor, or atomic scattering factor, is a measure of the scattering amplitude of a wave by an isolated atom. The atomic form factor depends on the type of scattering, which in turn depends on the nature of the incident radiation, typically X-ray, electron or neutron. The common feature of all form factors is that they involve a Fourier transform of a spatial density distribution of the scattering object from real space to momentum space (also known as reciprocal space). For an object with spatial density distribution, \rho(\mathbf{r}), the form factor, f(\mathbf{Q}), is defined as :f(\mathbf{Q})=\int \rho(\mathbf{r}) e^{i\mathbf{Q} \cdot \mathbf{r}}\mathrm{d}^3\mathbf{r}, where \rho(\mathbf{r}) is the spatial density of the scatterer about its center of mass (\mathbf{r}=0), and \mathbf{Q} is the momentum transfer. As a result of the nature of the Fourier transform, the broader

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