Scattering in electron spectrometers, diagnosis and avoidance. I. Concentric hemispherical analysers

摘要: The unwanted scattering of electrons in electron spectrometers leads to a loss sensitivity, distortion the spectral background and problems calibrating spectrometer intensity/energy transmission functions. Here we develop three methods analyse extent contribution how reduce it an insignificant level. diagnostic involve either measurement region M4,5VV Auger peaks from Ag AES, or reflection beam biased sample, 3p1/2 photoelectron peak irradiated with Mg Kα x-rays. In this work analyses are made for concentric hemispherical analysers. Part II, cylindrical mirror analysers studied. It appears that our spectrometers, modified VG scientific Escalab II original analyser 210 analyser, major contributions arise high-energy strike outer hemisphere giving rise spectrum secondary electrons. These cause scattered vary approximately as E, where Ep is pass energy, increae proportion input slit area AES studies, fall inversely increase lens magnification 1 3 and, constant ΔE mode, analysed energy. Thus, each magnification, there exists range slits energies which may be maintained at <1%. ≥50 eV generally safe, whereas ΔE/E retardation ratios ≤4 required.