Einfach- und Doppelphotoionisation an den 3D-Uebergangselementen im Bereich der 3P-Anregung (Single and Double Photoionization on Three Dimensional Elements in the Range of the 3P-Excitation)

摘要

Partial cross sections A(++) and A(+) for single and double ionization on 3d-transition elements were measured using a time of flight mass spectrometer. A photon energy between 30 and 100 eV was obtained by monochromatic synchrotron radiation. The light beam was crossed with the metal vapor beam from a high temperature oven. The dependence of the ratio A(++) and A(+) on the photon energy allows the interpretation of the double ionization. Apart from one exception, all elements show a constant ratio below the 3p-ionization threshold, including the 3p to 3d excitation. The exception is Rydberg series of unoccupied ns, nd orbitals. In the range of direct double ionization, this ratio is below 0.07 for Ca and Cr, and is above 0.1 for Mn, Fe, Co and Ni. The maximum ratio decreases strongly from Ca(35) to Ni(0.37). Good agreement is found between the measured cross sections and those determined by absorption measurements.