In this paper, numerical and experimental investigations of high-frequency (HF) electrodeless lamps in argon–mercury mixtures are performed. The intensities of the mercury spectral lines having wavelengths λ = 404.66, 435.83, 546.07 nm (7 3S1–6 3P0,1,2) and the resonance line λ = 253.7 nm (6 3 P1–6 1S0) are measured at a wide range of mercury pressures, varying the HF generator current and argon filling pressure. A stationary self-consistent model of HF electrodeless discharge lamp is developed including kinetics of the excited mercury and argon atomic states. Based on the developed model, the radiation characteristics of the discharge plasma are calculated. Numerical simulation of the line intensities behaviour in dependence on the mercury pressure, HF generator current and argon filling pressure is performed. The model results are in qualitative agreement with the experimental data. The calculations of the relative intensities of the visible triplet lines 7 3S1–6 3P0,1,2 are presented for the first time in this paper.

This work is devoted to the diagnostics of interaction between hydrogen and argon with the surface of SiO2 glass walls. For diagnostics of the interaction, special high‐frequency electrodeless light sources were prepared, filled with pure argon of 1 Torr or argon‐hydrogen of total pressure of 1 Torr (Ar/H2 mixing ratio is 9:1). Besides the mostly used spherical and cylindrical lamps, dumbbell type lamps have also been investigated. The spectroscopic and AFM measurements showed that in comparison with pure argon plasma, the argon‐hydrogen plasma causes non‐uniform changes of the SiO2 surface. For these modifications active OH are primarily responsible molecules, created in the reactions of hydrogen molecules with oxygen molecules, adsorbed from the walls.

The high‐frequency electrodeless light sources (HFELS) are widely used as bright radiators of narrow and intense spectral lines covering the region from VUV to IR. Special HFELS filled with pure helium at pressures from 0.2 to 5 Torr were prepared for diagnostics of interaction between the filling element and the wall material (glass). Pollution of the discharge plasma with the oxygen admixture was studied by spectroscopy. Atomic force microscopy experiments were performed to find modification of the wall surface at the nanoscale level. Release of oxygen by the walls is found to depend strongly on the discharge conditions and significant changes of the surface structure are detected after plasma treatment.

Our work is connected with the preparation of different type of electrodeless discharge lamps. In this work we investigate the influence of the SiO2 glass wall treatment procedures on the inner surface of the electrodeless lamps. Three different treatment procedures were applied: vacuum cleaning, vacuum‐thermal cleaning and training in the high frequency discharge. The surface modification has been investigated by means of atomic force microscopy. Substantial changes of the SiO2 glass surface have been observed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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