Division of Environmental Physics - User: student
Faculty of Mathematics, Physics and Informatics, Comenius University Bratislava

The Dual Mode Microwave Afterglow Apparatus for Measuring the Electron Temperature Dependence of the Electron-Ion Recombination

Mikuš O., Lukáč P., Morva I., Morvová M., Foltin V.
Contributions to Plasma Physics 48 (4), 311-325 (2008)

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Abstract:

Three dual mode microwave apparatus (one using S-band and two using X-band) have been
developed to determine ambipolar diffusion and electron-ion recombination rates under conditions such
that T_gas = 300 K and T_e is varied from
300 K to 6300 K, in the afterglow period of the dc glow discharge. The
TM₀₁₀ cylindrical cavity (in S-band) and TM₀₁₁ open
cylindrical cavity (X-band) are used to determine the electron density during the afterglow
period and a non-resonant waveguide mode is used to apply a constant microwave heating field to the
electrons. To test the properties of the apparatus the neon afterglow plasma has been investigated.
At T_e = 300 K a value of
α(Ne⁺₂) = (1.7±0.2)×10^-7 cm³/s is
obtained which is in good agreement with values of other investigators. Also similar variations of as
T^-0.4_e (S-band) and as T^-0.42_e
(X-band) obeyed over the range 300≤T_e≤6300K are in good agreement with
some other previous measurements. The simplicity of the X-band microwave apparatus also allows the
measurements of the gas temperature dependency and the study of electron attachment and may be used
simultaneously with optical or mass spectrometry investigations.