M. Ryšavý

Statistical tests of invariability of the measurement conditions in the β-ray spectroscopy

Statistical compatibility of parts of β-ray spectra collected during various time intervals was examined. Two methods based on the ratios and differences of the partial spectra were applied to both simulated and measured β-spectra of 241Pu. The tests were able to reveal small variations in the structure of radioactive sources as well as in the spectrometer settings.

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

Abstract The relative efficiency of a channel electron multiplier for 2–9xa0keV electrons was determined using the β-spectra of vacuum evaporated 241 Pu and 63 Ni sources. The results agreed within ±0.8% (1xa0 σ ). Conversion electron measurements of 57 Co and 169 Yb 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.

SCATTERING OF ELECTRONS IN BETA-SPECTROSCOPY SOURCES

Experimental spectra of the169Yb conversion lines having kinetic energies of 3.7–18.4 keV and the beta spectrum from the decay of241Pu are compared with calculations by the Monte Carlo method which take into account the individual elastic and inelastic scattering processes of the electrons in the source, in the substrate, and in a carbon layer contaminating the source. Good agreement is obtained between the theoretical and experimental results. It is also shown that the scattering of the electrons depends on their emission angle.