Mössbauer spectroscopy of 170Yb through internal conversion of electrons

This paper describes the first observation of the Mossbauer scattering for the 84.3 keV gamma-ray transition in ytterbium Yb-170, made by detecting the low-energy electrons emitted after resonant absorption of gamma-rays. The measurements were performed in sideways scattering geometry using a 50 mCi (TmAl2)-Tm-170 source, a 5 mg/cm2 Yb metal absorber enriched in 67% Yb-170 and a channel electron multiplier kept at liquid helium temperature, in close proximity to the source and absorber. A resonant signal of up to 1.5% was obtained, despite the presence of unfavorably strong background.