Lebensdauermessungen in 14N, 15N und 22Ne

Abstract

The Doppler shift attenuation method was used to measure the lifetimes of some excited states in 14N, 15N and 22Ne. The states of 14N were produced by the reaction 12C( 3He, p) 14N. The mean lifetimes of the J π = 0 + state at 2.31 MeV and J π = 1 + state at 3.95 MeV excitation were found to be τ = 0.083±0.019 ps and τ ≦ 0.087 ps, respectively. The 7.16 MeV and 7.57 MeV states in 15N, populated by the reaction 13C( 3He, p) 15N, were found to have mean lifetimes τ = 0.115±0.025 ps and τ = 0.15±0.05 ps, respectively. The first excited state of 22Ne was studied by the reaction 19Fe( 4He, p) 22Ne. The mean lifetime of this state is τ = 8±3 ps. The results obtained are compared with predictions of nuclear models.