ANGULAR-DISTRIBUTION IN THE 1S-]3P COHERENTLY EXCITED RESONANT KLL AUGER SPECTRUM IN NEON

Angular anisotropies, energies, and relative intensities have been stu died for the 1s --> 3p resonant KLL spectrum in neon. The resonant exc itation of the 1s2p(2)2p(6)3p configuration leads to a multiplet of fo ur levels with J = 0, 1, 2, and an energy splitting less-than-or-equal -to 35 meV which is much smaller than the natural level widths of abou t 250 meV. Thus, the various states of the multiplet are excited (more or less) coherently. To obtain the angular distribution of the Auger lines, knowledge of the density matrix is required. This matrix includ es all information about the specific excitation process, whereas the dynamics of the autoionization is described by the relative intensitie s and Auger angular parameters A2. Multiconfiguration Dirac-Fock wave functions have been used to calculate this set of coefficients in an i ntermediate coupling scheme including initial and final state correlat ions. The use of these data in the interpretation of an angular distri bution measurement is briefly discussed.