Search for superconducting effect on the decay of99m Tc

An experimental investigation of the influence of superconductivity on the decay rate of^99m Tc, _T, has been performed by means of a differential method. The^99m Tc samples containing⁹⁹Tc as a carrier were prepared by electrodeposition on a copper plated tungsten wire. For production of metallic technetium the samples were reduced in pure hydrogen gas at 800~1000°C. X-ray analysis of the samples showed they were surely metallic with anhcp structure. The lattice constants observed area=2.741 Å andc=4.398 Å. The transition temperature was found to be 7.5±0.2K. Comparison of two sources, normal (room temperature) and superconducting (4.2 K), did not show an appreciable effect of superconductivity on the decay rate of^99m Tc exceeding the limit of uncertainty of our experiment:/ _T=(1.1±2.7) × 10^–4.