KαhHypersatellite Spectrum and Electron Double Ionization Cross Section of theK-Shell in Magnesium

The K α h hypersatellite spectrum of Mg metal has been measured in electron excitation with excitation voltages from 4 to 32 kV. The spectrum shows lines with initial K -2 ( K α h 2 ) and K -2 L -1 holes. The energies of these lines as well as the K -2 binding energy have been determined and compared with theoretical calculations. The intensity of the line group with K -2 L -1 initial states relative to the K α h 2 line has been measured and found to be in good agreement with simple shake-off calculation. The electron double ionization cross section (EDC) of the K - shell has been determined from these thick target measurements using the method developed by Saijonmaa and Keski-Rahkonen. The EDC has also been calculated theoretically using classical and quantum mechanical binary encounter approximations as devised by Saijonmaa. Theory reproduces fairly well the magnitude but not the shape of the EDC-curve as a function of energy.