Temperature distributions in a free-burning arc. IV. Results in argon at elevated pressures

For pt.III see Appl. Phys. Lett., vol.45, p.24-5 (1984). Measured temperature profiles are presented for free-burning argon arcs at pressures from 1 to 5 atm and comparisons are made with prediction based on the theoretical models of Kovitya and Cram and Hsu and Pfender. Evidence is presented for departures from local thermodynamic equilibrium (LTE) in the region near the cathode of the arc in agreement with previous results and it is also suggested that the assumption of LTE in the outer regions of the arc may not be valid.