Arc plasma in air with calcium and fluorine—II. Effect of fluorine on radial distribution of calcium particles

CaOH Molecular Emissions in Underwater Laser-Induced Breakdown Spectroscopy: Spatial–Temporal Characteristics and Analytical Performances

“…The band around 554 nm is assigned to the green system B 2 Σ + −X 2 Σ + of the triatomic radical CaOH, while the band around 623 nm is assigned to the orange-red system A 2 Π−X 2 Σ + of CaOH. 46,47 It is noticeable that the green and orange bands of CaO molecule lie in a similar region as CaOH, which are usually observed in arc-induced plasmas 48 or laser-induced plasmas 34−36 of calcium salts in air. The absence (or low abundance) of CaO bands in Figure 2 can be probably due to the fact that, for the dissociation of H 2 O molecules, more energy is required to dissociate H 2 O into H + H + O (218.3 kcal/mol) than into H + OH (118.2 kcal/mol).…”

Emission spectroscopy

“…Grampurohit and Dixit (120E) determined trace impurities in calcium fluoride using CuOF carrier, and Brown and Hillier (59E) determined trace impurities in high-purity zirconium using a carrier distillation technique in which the temperature was limited to 1300 °C by operating in an Ar atmosphere. Peric et al (254E,264E) observed changes in spectral intensities in the presence of ammonium fluoride owing to a possible chemical reaction in the discharge and possible changes in spatial plasma temperature distribution. Martell and Myers (207E) evaluated spectrographic standards for the carrier distillation analysis of plutonium dioxide.…”