An excimer emitter with pumping by barrier discharge in mixtures of zink diiodide vapors with inert gases

Abstract

An experimental investiga9tion is performed of the output characteristics of an excimer lamp utilizing mixtures of zinc diiodide vapors with inert gases and excited by a barrier discharge (BD) with the repetition rate of sine voltage pulses f ≤ 130 kHz. Radiation spectra of BD plasma in the range of 200-900 nm with resolution of 0.05 nm are studied, as well as the time characteristics of voltage and current and the dependence of radiation intensity on the composition of mixtures. The radiation of ZnI(B-X) excimer molecules is revealed with a maximum at λ = 602 nm, as well as of excimer molecules, lines of inert gases, and, in mixtures with xenon, of XeI* excimer molecules. The composition and pressure of gas components of mixture are optimized. It is found that the most intense radiation of ZnI* in binary mixtures is observed when helium or neon is used as buffer gas. The specific average radiation power in the visible range is 23 mW/cm 2 .

Characterization of a white-colour DBD-driven cadmium bromide exciplex lamp

“…In the study of the electric characteristics of a DBD with CdBr 2 vapour-rare gas mixtures, we observed regularities similar to ZnI 2 vapour [21]. At low pulse repetition rates (f ∼ 5-10 kHz), a series of sharp spikes of conductive current was observed on the curve of the displacement current in every half-period of the applied voltage U 0 .…”

“…Similarly to previous studies with mercury halides [22] and zinc diiodide [20,21], immediately after the ignition observation was made of the filamentary mode of the atmospheric-pressure DBD with mixtures of cadmium dibromide vapour with rare gases or nitrogen. An increase in the pump pulse repetition frequency f resulted in a change in the shape of the microdischarges.…”

“…The characteristics of the exciplex lamp were studied on the experimental setup, which has been described in detail in [20,21]. A small-sized cylindrical radiator made of a UV grade quartz tube with an outer diameter of 6 mm and having one dielectric barrier with a capacitance of C d = 6 pF was used (figure 1).…”

“…The radiation was analysed in the spectral range 200-900 nm. The emission spectra were recorded with a Jobin Yvon TRIAX 550 monochromator (equipped with a grating of 1200 grooves mm −1 , a quartz optical fibre and a liquidnitrogen-cooled Spectrum ONE CCD detector) [24]. The spectral resolution of the recording system was 0.05 nm.…”

“…transition) [18] and has reasonable vapour pressures at low temperatures (∼300-400 • C) [19]. From this viewpoint the radiation of CdBr * molecules is shifted to longer wavelengths compared with the previously studied mercury halides and zinc diiodide [20][21][22] and a higher temperature is required for the necessary vapour pressures of CdBr 2 . The aim of this work is to study the emission and electrical characteristics of a small-sized exciplex lamp operated with mixtures of cadmium dibromide vapour and rare gases or nitrogen excited by a dielectric barrier discharge (DBD).…”