Spectroscopic diagnostics of preanode plasma in glow discharge of helium

A spectroscopic method has been used for the diagnostics of the preanode plasma in a glow discharge in helium, The method is based on the measurement of the absolute intensity of two wavelengths, one of which, lambda(1) = 525 nm, is from the continuous spectrum, and the other, lambda(2) = 587.6 nm, is from the discrete spectrum, The electron temperature and density have been determined in the anode region of helium for fixed discharge conditions (pressure = 25 mbar, current = 50 mA).