BREMSSTRAHLUNG AND RECOMBINATION RADIATION OF NEUTRAL AND IONIZED NITROGEN

Continuum radiation measurements are presented for nitrogen over a spectral range from 975 to 37 000 for temperatures ranging from 9000 to 13 500°K and 1- and 2- atm pressure. The measurements were made using a plasma produced in a dc mechanically constricted arc generator. The data is separated by a temperature-dependence curve fit into the contributions from positive-ion and neutral-atom radiation. The N+ radiation is compared to an analytical calculation based on the Burgess and Seaton quantum-defect method for the free bound and on the Gaunt factors of Karzas and Latter for the free-free processes. The remaining radiation in the visible and infrared is ascribed to the neutral atom. This data is analyzed to derive the N- species responsible for the recombination radiation and to extract its ionization energy from the position of observed absorption edges. A value for the (N- D1) negative-ion cross section is obtained. Extraction of the neutral atom Z2g factor for the Bremsstrahlung process was made from the continuum data in the infrared. Comparison is also made to other experimental data. © 1969 The American Physical Society.