Spectral Radiance of Strong Lines in Positive Column Mercury Discharges With Argon Carrier Gas
Craig J. Sansonetti, Joseph Reader
The spectral radiance of the 185-nm and 254-nm lines in two positive column mercury discharge lamps was measured over a wide range of operating conditions. The lamps had internal diameters of 5 and 23 mm. Argon was used as a carrier gas. The lamps were operated with cold-spot temperatures of 20 C, 40 C, and 60 C. At each of these temperatures, results were obtained for five currents ranging from 20 mA to 100 mA for the 5-mm lamp and from 200 mA to 1000 mA for the 23-mm lamp. For each current studied, results were determined for argon pressures ranging from 66.6 to 666 Pa (0.5 to 5.0 Torr) in the 5-mm lamp and 26.6 to 666 Pa (0.2 to 5.0 Torr) in the 23-mm lamp . An argon miniarc was used as the radiometric standard. By calibrating the spectral response of the optical system with a well-characterized mercury pencil lamp, results were obtained for twelve additional Hg lines from 289 to 579 nm. For the 23 mm lamp the electric field in the positive column was measured. For this lamp radiated power as a percentage of input power was also determined. The results provide an experimental basis for validating computer models of Hg fluorescent lamp discharges.