Monochromatic imaging studies of sustained metal vapor arcs burning on 150 mm diameter molten iron electrodes

Monochromatic imaging was used to investigate the excited-state density distributions of Fe and Fe⁺ in the inter-electrode gap region of a 3,100 A DC metal vapor arc burning between molten iron surfaces in a vacuum arc furnace. Multiple images were acquired at four wavelengths. The images were corrected and Abel inverted to yield the absolute radial intensity distributions for Fe and Fe⁺ in the inter-electrode gap region. The results show a structured, axisymmetric plasma consisting of a high density “core” of Fe⁺ emitters centered between the electrode surfaces situated against a relatively broad, flat excited-state Fe distribution