UV Radiation of Low Pressure XeCl* and KrCl* Glow Discharges

A dielectric barrier discharge (DBD) of coaxial geometry has been examined as source of intensive, short-lived UV radiation. A binary gas mixture consisting of 98% Xe + 2% Cl2 and a ternary composition of 96% Ne + 6% Xe + 0.2% HCl were investigated in the pressure range between 10 and 750 mbar. The discharge was excited by unipolar high voltage square pulses with amplitudes of 3 to 7 kV at a repetition rate of 100 Hz. UV radiation intensity is increased by combining 5 square pulses with a period of 1 μs each in one train (burst). Radiation decay on three orders of magnitude within 10 μs was obtained for both gas mixtures in burst mode. Maximum energy of the light pulse was the same for both gas mixtures and estimated as 40 nJ. It is shown that the optimum gas pressure for highest radiation intensity depends not only on gas composition but also on applied voltage and number of pulses in the train. A variation of the spectral band shape of XeCl emission during the pulse is detected.

Section: Variation Of the Xecl Band Shape With Experimental Conditionssupporting

confidence: 81%

Section: Variation Of the Xecl Band Shape With Experimental Conditionssupporting

confidence: 81%

A Miniaturized XeCl Dielectric Barrier Discharge as a Source of Short Lived, Fast Decaying UV Radiation

Bussiahn¹,

Pipa²,

Kindel³

2010

“…As already described in [3], at pressures above 10 mbar, the positive column constricts towards the discharge axis. The constricted column has a higher axis temperature and larger radial temperature gradients.…”

Section: N T E R F E R O M E T R I C S E T -U Pmentioning

confidence: 74%

“…In a preceeding paper [3] we reported measurements of the UV radiation power and the radial distribution of the emitting excimer molecules. Also, some characteristics of this discharge type, e.g.…”

Section: Introductionmentioning

confidence: 99%

Gas Density Distributions and Reduced Field Strenghts of the Positive Column of Low Pressure XeCl* Glow Discharges

Tiedtke

Schwabedissen

Schroder

et al. 1995

Self Cite

Interferometric measurements of radial gas density distributions have been performed on the cylindrical positive column of DC low pressure glow discharges (LPGD) in pure Xe and Xe/CI, gas mixtures. Absolute gas temperatures have been measured by thermocouples. In the mixtures, the gas temperature is several hundred Kelvin above the temperature in pure Xe. Additionally, the radial distribution of the gas density in the mixtures cannot be described by Bessel profiles, which would result from Schottky's diffusion theory. Combined with field strength measurements, radial profiles of E / N (electric field strength/neutral density) have been determined. Results of this work will be useful for model developments of LPGD in rare-gas/Cl, mixtures but also for the general understanding of the positive column in attaching gases.

“…It is clear that at low pressures, up to 30 mbar, which is used for cw XeCl lamps, the harpoon mechanism is dominant [26][27][28]. At high pressures, above atmospheric as in XeCl lasers, ion recombination is much more efficient [29][30][31].…”

Section: Decay Of the Xecl Excimer Radiationmentioning

confidence: 97%

Optimization of a Dielectric Barrier Discharge for Pulsed UV Emission of XeCl at 308 nm

Pipa

Bussiahn

2011

A pulsed dielectric barrier discharge (DBD) has been investigated in a wide range of experimental conditions with the purpose of optimization for XeCl excimer radiation. For that the following operation parameters had been considered: four different lamps of coaxial geometry with gas gaps in the range of 1.3 -6.5 mm; gas mixtures of xenon and chlorine containing admixtures of 1%, 2% and 4% Cl2 at total filling pressures between 5 mbar and 600 mbar; voltage rise times of 20 -50 ns and voltage amplitudes of up to 12 kV. A maximum radiation pulse energy of 1.8 μJ has been detected at 310 ± 10 nm with an estimated radiation decay by three orders of magnitude within about 5 μs. It was shown that the minimization of the voltage rise time is essential for enhancing the radiation pulse energy. Furthermore a correlation between the discharge geometry and the optimum pressure for maximum radiation output was observed. The decay characteristics of the excimer emission provides evidence of the harpoon reaction being the main channel of XeCl formation under our operation conditions.