  Properties of vacuum evaporated 83Rb/83mKr sources of low-energy conversion
electrons, which are under development for monitoring the energy scale
stability of the Karlsruhe Tritium Neutrino experiment KATRIN, were examined by
the Timepix pixel detector exhibiting the position resolution of at least 55
microm. No distinct local inhomogeneities in the surface distribution of
83Rb/83mKr were observed. The source diameter derived from the recorded image
agrees within 5 % with that expected from evaporation geometry. More precise
determination of the actual source diameter is complicated by Compton scattered
electrons caused by 83Rb gamma-rays.
