RESONANT INELASTIC-SCATTERING OF QUASI-FREE ELECTRONS ON C(5+)(1S)

We report on studies of resonant inelastic scattering of quasifree ele ctrons on C5+. The resolution of the electron spectrometer is sufficie nt to resolve the energy structure of electrons emitted as a result of decay of doubly excited 3l3l' configurations in C4+. The line energie s compare well with theoretical calculations, using the truncated-diag onalization method. Theoretical calculations based on the Hartree-Fock atomic model for the differential cross sections are also presented. The relative strength of these states within the 3l3l' manifold is mea sured as a function of scattering angle and compared with theory. The agreement is good for several states, but the 3s3d 3D and 3p3d 1F stat es show large deviations from the Hartree-Fock-model calculations. Goo d agreement is found between theory and experimental data for the F1 s tate when the autoionization rate to the ground state calculated with the truncated-diagonalization method is used in the calculations. It i s likely that strong correlation effects for the 3D state are not as w ell treated in the Hartree-Fock model as by the truncated-diagonalizat ion method.