New nuclide Pm-129 near the proton drip line

The very neutron- deficient nuclide (129) pm was produced via the Mo-92( Ca-40, p2n) reaction and identified for the first time by using the X-gamma coincidence in combination with a He-jet tape transport system. From the decay of a 99keV gamma ray which corresponds to the 5/2(-)-->1/2(-) transition in the daughter nucleus Nd-129 following the (EC + beta(+)) decay of Pm-129, the half-life of Pm-129 was determined to be 2.4(6)s.