Alignment of atoms following photoionisation: Cd+(4d −1 2 D 5/2,2 D 3/2) and Zn+(3d −1 2 D 3/2)

The linear polarisation of fluorescence radiation following the photoionisation in the 4d _5/2 and 4d _3/2 subshells of Cd and in the 3d _3/2 subshell of Zn has been measured in the energy range of primary photons from threshold up to about 40 eV. The experimental values of the linear polarisation found for the fluorescence radiation of Cd⁺(4d ^?1) ions are in essential agreement with theoretical results obtained by an RRPA calculation (Johnson et al.). For the case of Zn⁺(3d ^?1) on the other hand, no theoretical data are presently available. Using the experimental values of linear polarisation of fluorescence radiation the values of the alignment tensorA ₂₀ have been evaluated for the ions Cd⁺(4d ^{?1 2} D _5/2,² D _3/2) and Zn⁺(3d ^{?1 2} D _3/2).