Analyzers, electron energy slit width

For slits placed at Rfj from the center of curvature, the electrons passed by this analyzer follow the equipotential surface described by Rq. With an acceptance angle 8a shown in Figure 22 and a slit width w, the energy resolution of the CHA is given by... 

The broadening due to the analyzer depends on the energy at which the electrons travel through the analyzer and the width of the slits between the energy filter and the actual detector. The analyzer contribution to the line width becomes irrelevant at low pass energies, however, at the cost of intensity. 

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