SPATIAL CHARACTERIZATION OF EMISSION INTENSITIES AND TEMPERATURES OF A HIGH-POWER NITROGEN MICROWAVE-INDUCED PLASMA

The spatial characterization of a high power nitrogen microwave-induce d plasma (N-2-MIP), using an Okamoto cavity, was undertaken, The plasm a operating conditions were fixed during all the experiments at a micr owave frequency of 2.45 GHz, an incident power of 1.3 kW, a plasma gas flow rate of 11.01 min(-1), a carrier gas flow rate of 1.01 min(-1) a nd a sample uptake rate of 1.6 mi min(-1), A Ca solution was used to m easure the emission intensity distribution for both Ca atom and ion li nes in the N-2-MIP, and an Fe solution was used to determine the excit ation temperature distribution of the N-2-MIP, which was obtained by u sing a Boltzmann plot under the assumption of LTE, In addition, rotati onal temperature measurements were carried out using the N-2(+) (0-0): B-2 Sigma(u)(+) --> X(2) Sigma(g)(+) band. Because the H-beta line (48 6.13 nm) could not be excited in the N-2-MIP, measurement of the elect ron number density was carried out by a method involving the Saha equa tion using both the emission intensity ratio (Ca II:Ca I) and the exci tation temperature of the N-2-MIP, The degree of ionization of various elements in the N-2-MIP was also calculated. The spatial characterist ics of the N-2-MIP were compared with those of the Ar-ICP.