(β, γ)-Richtungskorrelationen im Zerfall des Tm¹⁷⁰

Abstract

Measurements of the beta-gamma directional correlation in the decay of Tm¹⁷⁰ were performed as a function of the time delay inserted in the fast coincidence circuit. Various chemical compounds of Thulium were used to study the influences of the crystal fields and the chemical bonds on the directional correlation. Attenuations up to 40% were observed. The largest anisotropy was found with a liquid source of a Ga-Tm alloy. Also the intensity and directional correlation of the internal brems-strahlung was measured. Since there is a pronounced angular dependence of the internal bremsstrahlung relative to the direction of the emitted beta-particle, the directional correlation measurement can be disturbed seriously even if the intensity of the internal bremsstrahlung is weak.