ANGULAR-DEPENDENCE OF PHOTOFRAGMENTS FROM K-SHELL EXCITED N-2 AND O-2 - PHOTOABSORPTION ANISOTROPY AND EXCITED-STATE SYMMETRY

The symmetry of excited states reached by photoexcitation of K-shell electrons of N2 and O2 is identified from the fragmentation anisotropy. For each molecule, ion yield excitation spectra were obtained at 90°, 54.7°, and 0° relative to the axis of soft x-ray polarization. The degree of polarization of the synchrotron radiation was determined experimentally. From this determination and the angular dependence of the ion yield, the photoabsorption anisotropy parameter β is obtained as a function of photon energy. Variations in the β spectra are discussed in terms of previously assigned spectral features and are compared with other experimental results. A comparison also is made with theoretical calculations, which are available for the case of N2. © 1990 American Institute of Physics.