MEASUREMENTS OF THE AXIAL DENSITY PROFILES OF SPUTTERED CATHODE ATOMS IN A DC GLOW-DISCHARGE

The axial density distribution of sputtered cathode atoms has been measured for different discharge conditions in a low-pressure dc argon-iron glow discharge. The density distribution of sputtered Fe was measured in the ground state and in low lying metastable states for the different pressures of the discharge gas. These measurements were carried out by dye laser fluorescence spectroscopy with space resolution of 1 mm in the axial direction. The results show a density maximum near the cathode which depends strongly on the discharge current as well as on the electronic excitation state of the diffusing atoms. The results are compared with distributions calculated from existing theoretical treatments.