Postcollision interactions in the Auger decay of the ArLshell

The photoionization cross sections for Ar⁺ through Ar⁴⁺, produced by the Auger decay of a 2p hole in argon, have been measured between 242 eV and 253 eV by the use of synchrotron radiation. The high resolution of the monochromator has allowed a detailed study of the postcollision interactions that occur in this spectral region. The concept of photoelectron recapture by Ar²⁺ to produce the Ar⁺ continuum is studied. The relative values of the quantum-mechanical calculations of the photoelectron recapture probability are shown to be in excellent agreement with the present data. The magnitude and shape of the Ar²⁺ continuum has been explained on the basis that about 67% of the recaptured photoelectrons produce excited states of Ar⁺ which subsequently reemit the electrons by autoionization. {} 1996 The American Physical Society.