In-Beam α- and γ-Ray Spectroscopy for ²¹⁴Rn

Abstract

In-beam α- and γ-rays following a 208 Pb( 12 C, α2n) 214 Rn reaction were measured. A level scheme of 214 Rn is proposed up to the (8 + ) state. Two new longrange α-decays in 214 Rn were found to de-excite the (6 + ) and (8 + ) states. A half-life of the (8 + ) state was determined to be 7.3±1.5 ns from which the B(E2: 8 →6) values was obtained to be 209±63 e 2 f m 4 . The reduced α-width γ α 2 was also deduced as 3.2±1.0 keV for the α-decay from the (8 + ) state in 214 Rn to the ground state in 212 Po. Systematic trends of the B(E2: 8 →6) and γ α 2 values of the N=128 isotones, 212 Po, 214 Rn and 216 Ra, are discussed in terms of the simple shell model configurations.