Fig. 19.

(a) Comparison of the measured $(\circ )$$\mathrm{DQE}(\omega )$ at 300 keV of the MAPS detector with the results of calculations using the FMC (dashed) and the clamped FMC approximations (solid) described in text. The dotted line gives the calculated FMC clamped $\mathrm{DQE}(\omega )$ for a detector backthinned (by the removal of the substrate) to a total thickness of $35\mathrm{\mu }\mathrm{m}$. (b) Comparison of the probability distributions for the signal collected from a single incident 300 keV electron, obtained using the FMC approximation energy loss and the corresponding clamped FMC approximation.