This book (Practical Electron Microscopy and Database) is a reference for TEM and SEM students, operators, engineers, technicians, managers, and researchers.

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Similar to the effect of chromatic aberration, spatial resolution of EFTEM mapping is also affected by spherical aberration, given by,
Δd_{S} = 2C_{S}β^{3}  [1941a]
where,
β  The collection angle,
C_{S}  The spherical aberration.
For instance, assuming the spherical aberration constant is 0.7 mm, collection semiangle 15 mrad, the Δd_{S} is ~3.8 nm.
For thick specimens (with multiple scattering) the calculation in Equation 1941a predicts the C_{S}effect on the spatial resolution well, while for a thin specimen the characteristic inelastic scattering angle is much smaller, given by,
θ_{e} = γΔE/2E_{0}  [1941b]
where,
γ  The relativistic correction
factor (=(E_{0}+m_{e}c^{2})/(E_{0}+2m_{e}c^{2}), e.g. =0.61 for 300 kV).
θ_{e} is normally ≤0.6 mrad. Substituting θ_{e} for β in Equation 1941a, we can know that Δd_{S} is normally negligible for most microscope configurations.
