High precision half-life measurement of ~(147)Sm α decay from thin-film sources

摘要

An investigation of the α decay of ~(147)Sm was performed using an ultra-low-background twin Frisch-grid ionization chamber (TF-GIC). Four natural samarium samples were produced using pulsed laser deposition in ultrahigh vacuum. The abundance of the ~(147)Sm isotope was measured using inductively coupled plasma mass spectrometry. A combined half-life value for ~(147)Sm of 1.079(26) × 10~(11) yr was measured. A search for the α decay into the first excited state of ~(143)Nd has been performed using γ spectroscopy, resulting in a lower half-life limit of T_(1/2) > 3.1 × 10~(18) yr (at 90% C.L.).