HIGH-RESOLUTION MEASUREMENT FOR PHOTOABSORPTION CROSS-SECTIONS IN THE AUTOIONIZATION REGIONS OF AR,KR AND XE

Photoabsorption cross sections in the autoionization regions of Ar, Kr and Xe have been measured with resolutions of 0.0045 angstrom for Ar and 0.0074 angstrom for Kr and Xe using a high-resolution spectrometer installed in the Photon Factory, a 2.5 GeV synchrotron radiation facility in Tsukuba. The cross sections are parametrized with the aid of a lineshape formula which is based on the multichannel quantum-defect theory and has a form analogous to Fano's resonance formula. These are compared in detail with other experimental data and theoretical predictions available in the literature.