Polarised Electron Study of Angular Momentum Coupling in the Neon 3p States

The excitation of the 2p(5)3p[5/2](3) and 2p(5)3p'[1/2](1) states in the neon 3p manifold by transversally polarised electrons is studied in the electron energy region near threshold and beyond. The spin-orbit and exchange interactions during the excitation are explored by the measurement of integrated Stokes parameters P-2 and P-3 for the decay radiation from these states. Experimental evidence is given for the breakdown of LS coupling for the neon 3p (J = 1) state and the important role of spin-orbit and exchange interactions of the atomic electrons for the excitation of the state. Negative ion resonances strongly influence the polarisations of the decay radiations.