Spin-polarized electron excitation of neon 3p ( J =1) states

Abstract

The angular momentum properties of incident transversely polarized electrons and radiated photons have been combined with scattering symmetries to reveal the effects of exchange and spin - orbit coupling as well as some propensity rules for excitation and decay of the 3p states of the neon atom. Integrated Stokes parameters, , and , have been measured for the decay radiations of wavelengths 616.4, 603.0, 626.7, 638.3 and 703.3 nm from the , , and states, respectively. While these states are intermediately (jl) coupled, their LS compositions partially explain some phenomena. For the states having a dominant triplet component, both the exchange and the spin - orbit interaction within the atom are important in the excitation, while the spin - orbit interaction plays the significant role for the state dominated by a singlet component. Decay photons from a common upper state with have larger linear polarization than those with and -1 while those from a core upper state have larger linear polarizations than those from a core upper state. The state multipoles are derived from the measured Stokes parameters. The influence of negative-ion resonances near threshold on the Stokes parameters and the state multipoles is very strong in some cases. The core state effects on the alignment of excited states are investigated.