Resistivity study on the production and migration of helium inLuTr(r≤0.20)

${}_{}{}^3{}_{}{}^{}\mathrm{He}$ was produced in tritium-doped lutetium specimens by the ${\beta }^{\mathrm{-}}$ decay of tritium. This transmutation caused a time-linear increase of the residual electrical resistivity at a rate which indicates that the resistivity per produced He defect is about twice that of T. This result was independent of the speed at which the specimens were cooled to 4.2 K. Recovery in a subsequent annealing experiment started around 26 K, which is attributed to He atoms becoming mobile. Further recovery showed differences between quenched and slowly cooled specimens, indicating that the mobility of helium is strongly affected by short-range ordering of the tritium atoms.