Secondary electron emission and the detection of the vacuum level in ESCA

Samples irradiated in an ESCA spectrometer emit and receive intense electron fluxes due to secondary emission. Charging and surface potential of non conducting sample is mainly determined by these electron fluxes. The measurement of the secondary electron emission energy distribution (SEED) allows the determination of the sample vacuum level and in particular its work function in the case of conducting samples. Criteria to check the correctness of (SEED) measurements are presented.