The dispersive element of electron energy analysers

In order to analyse electrons with respect to their kinetic energy, an energy dispersive element is needed which separates the electrons according to their energy. For this purpose one of the following properties of moving electrons can be used (non-relativistic electrons only are considered)  

The prerequisite for such a measurement is information about the starting time. This can be provided by the pulsed time structure of the primary photon beam (single-bunch mode for operating the electron storage ring), or by a reaction product of the photoprocess which is in coincidence with the emitted electron and can be another electron or a photon. More details on time-of-flight electron spectrometry are given in Section 10.1. 

In Fig. 4.1 four electrostatic deflection analysers are shown. They are classified according to the geometrical part that determines the electric field inside the 

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