Observation of electron impact inner-shell excitation of argon by means of satellite Auger spectra

We have studied the inner-shell excited states of argon below the 2p thresholds for electron-impact excitation in the range of the incident energy E(0) = 275-1700 eV. We carried this out through the measurement of the electrons emitted during the decay of the states. The corresponding satellite peaks in the spectra of the emitted electrons were separated from the normal (diagram) LMM Auger peaks by a special evaluating process. We observed the satellite peaks coming from the 2p(-1)(P-2(3/2))4s --> 3p(-2)(D-1)4s, 2p(-1)(P-2(3/2))4p --> 3p(-2)(D-1)4p; and 2p(-1)(P-2(3/2))3d --> 3P(-2)(D-1)4d transitions at all applied incident energies. The intensity of the satellite peaks increased approaching the ionization threshold (E(0) = 275-300 eV). Nevertheless in the range E(0) = 1000-1700 eV we could identify more satellites due to the lower continuous background and the smaller post-collision interaction effects.