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The angular disbibution of photwlectrons produced by excitation of polarized atoms to autoionizing states is analysed. In particular. core-excited nutoionizing states produced in absorption of synchrotron radiation by laser-pumped excited atoms are considered. A general expression for the angular distribtltion of arbiharily oriented laser and synchrotron beams is obtained and further reduced to a simpler form for a micular geomemy used in experiments. A case of an isolated autoionizing state (resonance) interacting with several continua is considered and parametrization of the observable parameters in the region of the resonance is discussed. Peculiarities of the circular dichroism in the region of autoionizing resonances are analysed. Formulae suitable for particular resonances with J < are presented and d p m t e r s necessary for analysis of experimental angular distributions are tabulated. As examples, excitations of autoionizing 2ps3s3p and 7.~38 states in Na and 3p53d4s4p states in Ca are considered. Theoretical angular distributions are compared with recent experimental data.

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Spectra and angular distributions of photoelectrons from ionization of atoms by a combination of two short pulses in the XUV and IR range are theoretically considered. The transition from the streaking regime for ultrashort XUV pulses to the sideband formation for longer pulses is discussed. For photoelectrons of sufficiently high energy (a few hundreds of eV), the peculiarity of the angular distribution and the gross structure of the sidebands are investigated.

We have observed the direct L 2;3 MMM double Auger transition after photoionization of the 2p shell of argon by angle-resolved electron-electron coincidence spectroscopy. The process is responsible for about 20% of the observed Auger electron intensity. In contrast to the normal Auger lines, the spectra in double Auger decay show a continuous intensity distribution. The energy and angular distributions of the emitted electrons allow one to obtain information on the electron correlations giving rise to the double Auger process as well as the symmetry of the associated two-electron continuum state.