Akira Hochi

Application of vane-type resonator to microwave powered electrodeless HID lamp

Summary form only given. A vane-type resonator is generally known as an anode of a magnetron, which controls the oscillation frequency of the magnetron. The vane-type resonator, made of aluminum and so on, forms a structure in which vanes protrude toward the center of a cylinder. A microwave resonant electric field is generated inside of a space formed by the vane protuberant portions, where ther is an electrodeless high intensity discharge (HID) lamp. The inner diameter of the resonant space can be 10 mm and below at 2.45 GHz. Compared with the cavity resonator, the resonant electric field generated at the center of vane-type resonator can be concentrated in a very small space. Therefore, a much smaller plasma arc can be maintained by using the vane-type resonator. We used a 3D finite element method simulation for the design of a vane-type resonator with a parabolic reflector to obtain the desired resonant frequency. According to the results of the simulation, the size of a 4-vanes resonator with a parabolic reflector were decided, and the resonator made of aluminum and copper was prepared. An electrodeless lamp with InBr and Ar gas enclosed in a spherical quartz glass tube having an inner diameter of about 4 mm was also prepared, and was set at center portion of the resonator. The total luminous flux was about 2150 lm at a microwave input of 27 W. The CRI and Tc for this lamp were 93 and 10200 K, respectively.

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 Elenbaass 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.