Dynamic Behavior in the Angular Distribution of Emission from a Micrometer-Sized Asymmetric Liquid Jet

Abstract

An isomer has been detected in 171 Hf with a half-life of T 1/2 = 29.5(9) s. The state was populated in the 170 Yb(α,3n) 171m Hf reaction at a beam energy of E α = 50 MeV in an on-line ion guide isotope separator. The isomeric 171m Hf + beam was extracted from the ion guide, mass-analysed and implanted in the surface of a microchannel-plate. The half-life of the collected activity was measured from the decay of the microchannel-plate count rate. We associate the isomer with the first excited state in 171 Hf with spin 1/2 − at an excitation energy of 22(2) keV.