Energy and angular analysis of ejected electrons (6-26 eV) from the autoionization regions of argon at incident electron energies 505 and 2018 eV

High resolution ejected electron spectroscopy has been used to investigate a large number of Ar autoionizing states producing ejected electrons in the energy range from 6 to 26 eV at impact electron energies of 505 and 2018 eV and ejection angles of 40 degrees, 90 degrees and 130 degrees. The full energy range has been divided into three regions which were analyzed separately. In the first one (6-9 eV) the obtained features are identified as the decay of the Ar + satellite states formed above the Ar2+(D-1) at 45.11 eV. In the second one (9-14 eV) all features are identified as due to the decay of excited states formed by the excitation of 3s electrons to ns, np and nd subshells. The most prominent features are those arising from the excitation of 3s to nd(D-3,D-1). In this series the 3s3p(6)3d(D-1) state with FWHM of 0.040 eV is used as the calibration point for all measured spectra. In the third energy region (14-26 eV) a large number of features is observed. Most of them are identified as the decay of excited states of the type 3s3p(5)nl and 3s(2)3p(4)nln'l'.