On the density of argon metastables in a cylindrical magnetron discharge

The experimental results are presented regarding spatial distribution of the argon metastable atoms density and corresponding temperature in a cylindrical magnetron discharge with aluminium target. The measurements were performed using a tunable diode laser system with narrow line width (1 MHz), allowing us to obtain good resolution of the absorption spectral line. The main broadening process of the spectral lines in the discharge is Doppler one due to the thermal energy of the particles and rather low gas pressure. The laser was tuned linearly around wavelength 811.531 nm, which corresponds to the absorption wavelength for argon metastables atoms.