Efficiency calibration of low-energy electron detectors by means of β-ray emitters

The relative efficiency of a channel electron multiplier for 2–9 keV electrons was determined using the β-spectra of vacuum evaporated 241Pu and 63Ni sources. The results agreed within ±0.8% (1 σ). Conversion electron measurements of 57Co and 169Yb supported the result. The electron scattering and energy losses within the sources were taken into account by means of Monte Carlo simulations of individual elastic and inelastic collisions. The detector was calibrated in the same geometry as it works inside the cylindrical mirror analyzer.