Observation of two-α emission from high-lying excited states of Ne18 by complete-kinematics measurements

Two-alpha emission from high-lying excited states of Ne-18 was studied by complete-kinematics measurements. The 18Ne beam at the energy of 51.8 MeV/u was bombarding a Au-197 target to populate the excited states via Coulomb excitation. Products of two-alpha emission, C-10-alpha-alpha, were measured by an array of silicon strip detectors and a CsI + PIN telescope. With the help of Monte Carlo simulations, the experimental results show the characteristics of sequential two-alpha emission via O-14 excited states. Sequential two-alpha and two-proton emissions from 18Ne via one-particle daughter states are compared and the distinction of the opening angles of these two modes originates from the difference of the mass ratio of emitted particles to daughter nuclei.