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P: Plasmaphysik

P 16: Plasma Diagnostics

P 16.5: Vortrag

Donnerstag, 20. März 2003, 16:50–17:10, FO2

Investigation of Xe 1s₃ atoms in low pressure glow discharges by LAAS — •Rene Bussiahn — Institut f. Niedertemperatur-Plasmaphysik, F.-L.-Jahn Str. 19, D-17489 Greifswald

The particle number density of the metastable Xe-1s₃-state in the positive column of a cylindrical glow discharge (tube diameter 16 and 22 mm) was investigated by means of Laser Atom Absorption Spectroscopy. The plasma was driven at discharge currents in the range from 5 - 150 mA DC at gas pressures of 1.0 and 2.5 Torr in a He-Xe atmosphere (p_Xe = 2 %).

A tunable diode laser with external cavity was scanned over the 2p₄ − 1s₃ transition in xenon (λ = 820.6 nm). The wide tunability of the laser enables direct measurements of the line profile function of the investigated transition. This line profile function is needed to calculate particle number densities of exited atomic states.

Radial profiles (spatial resolution approx.1 mm) of metastable atoms are analyzed for discharge currents of 20, 40 and 60 mA and follow nearly a BESSEL-function. Axial particle number densities where investigated as a function of the discharge current.