Continuum Radiation from Arc Heated Plasmas

Measurements of the spectral continuum of arc heated nitrogen plasma have been made using high dispersion spectroscopic equipment. These measurements cover a wavelength range of 2700 Å to 44t,000 Å and a temperature range of 9500°K to 12,000°K. The measurements have been compared with a number of theoretical studies of both the spectral and total emissivity. An estimate of the contribution to the continuum of the negative nitrogen ion has been included, and a new value of the effective nuclear charge for Kramers free-free radiation has been measured.