Angular momentum partitioning in the impulsive excitation of the intermediately coupled 4P(5)5P manifold of krypton.

摘要

We have determined that the dynamics of the polarized electron impact excitation of the 4p55p manifold of krypton can be characterized using 12 relative multipoles of angular momentum. This set of relative multipoles is restricted by the assumption that the spin- and orbital-degrees of freedom are conserved separately during the collision. In this system, relativistic spin-orbit effects produce intermediately-coupled states where L and S are indistinct quantum numbers, fulfilling conditions presented in Bartschat and Blum [K. Bartschat, K. Blum, G. F. Hanne and J. Kessler, J. Phys. B 14 (1981), 3761–76] for observing the integrated Stokes parameter P2 in the subsequent resonance fluorescence. These non-zero values of P₂ were observed experimentally, but to predict them using the formalism of relative multipoles it was necessary to include “non-diagonal” elements which describe coherent excitation of more than one L or S state simultaneously. Special attention is given to the physics and interpretation of “non-diagonal” multipoles and the importance of intermediate-coupling in producing P₂.