Experimental Stark Widths and Shifts in the 3p3D – 3d 3Fo O III Transition

Abstract

Stark widths (W) and shifts (d) of 3 doubly ionized oxygen (O III) spectral lines (326.085 nm, 326.532 nm and 326.720 nm) in the 3p3D-3d 3Fo transition have been measured in the optically thin helium-oxygen plasma created in a linear, low-pressure, pulsed arc discharge at a 26 000 K electron temperature and 1.1 · 1023 m−3 electron density. Our Stark shifts are the first measured data at an electron temperature smaller than 30 000 K. No theoreticalW and d data exist in this O III transition. Our W and d values are compared with the existing experimental data. On the basis of the found agreement among the experimental W and d values at a 26 000 K electron temperature we have evaluated their dependence on the electron temperature ranged between 10 000 K and 50 000 K