High precision half-life measurement of ${}^{147}$Sm $\alpha$ decay from thin-film sources

An investigation of the {\alpha}-decay of ${}^{147}$Sm was performed using an ultra low-background Twin Frisch-Grid Ionisation Chamber (TF-GIC). Four natural samarium samples were produced using pulsed laser deposition in ultra high vacuum. The abundance of the ${}^{147}$Sm isotope was mea- sured using inductively coupled plasma mass spectrometry. A combined half-life value for 147Sm of $1.079(26)\times {10}^{11}$ years was measured. A search for the {\alpha}-decay into the first excited state of ${}^{143}$Nd has been performed using $\gamma$-spectroscopy, resulting in a lower half-life limit of $T_{1/2} > 3.1 \times{}10^{18}$ years (at 90% C.L.).