Plasma spectroscopic study of an electrodeless HID lamp contained with TII and Zn

Summary form only given, as follows. Recently the electrodeless HID lamps excited by microwave have been studied intensively. TII is well known as a material having a strong green emission line. In this study, TII spectra excited by microwave are reported in the cases of TII only and TII+Zn. The electrodeless lamp consisted of vitreous silica tube, 30 mm in diameter, contained with TII was excited by 500 W microwaves of 2.45 GHz using a magnetron. TII was found to have continuous spectrum in the visible region by this excitation. The luminous efficiency was 56 Im/W, and it increased up to 78 Im/W by adding In metal. Moreover 491 nm and 636 nm emissions of Zn metal could not be observed, just continuous emission of TII was increased. Using the Elenbaas´s method of high pressure Hg lamp, a cause of TII continuous spectrum was examined. From the ratio of radiative intensities of two lines, 351.9 nm and 535.0 nm, radiated from each different excitation level to the same level, an average arc temperature in the bulb was estimated. Then the excitation level of the continuous emission spectrum near 600 nm wavelength, in that region there was no line peak was calculated from the dependence of the radiative intensities on these are temperatures. The calculated excitation level of this continuous spectrum was 4.3/spl sim/4.6 eV, rather smaller than an ionization potential of 6.1 eV in TI metal.