Wyniki wyszukiwania - BazTech

1

Diagnostics of non - equilibrium plasma generated in dielectric barrier discharges

Janus H. W., Musielok J.

Nukleonika

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2012

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Vol. 57, No. 2

253-256

EN

Results of electrical and spectroscopic diagnostics of dielectric barrier discharges by applying ceramic plates made of high permittivity material are presented. The spectroscopic diagnostic is based on analysis of spectral and spatial distribution of the hydrogen H alfa emission in the gas gap. From these measurements, e.g. the distributions of electric field strength and kinetic energy of excited hydrogen atoms in the discharge volume have been determined.

2

Wyznaczenie elektrycznego momentu dipolowego kationu ARH+

Molski M.

Wiadomości Chemiczne

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2006

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[Z] 60, 5-6

423-439

EN

Determination of the electric dipolar moment of a molecule is one of the most important procedures applied to characterize the molecule spectral activity, type of the chemical bonds between atoms forming the molecule and its geometry. Electric dipolar moment can be determined by making use of the Stark or Zeeman effects, quantum-mechanical ab initio calculations or from highly resolved MW and IR rotation-vibrational spectra using spectroscopic methods. Each of the methods mentioned has advantages and disadvantages. For example, the Stark method cannot be applied to molecular ions as under external electric field they are accelerated towards the wall of the discharge tube. In 1955 Townes et al., developed the method of determination of the dipolar moment using the Zeeman effect. This approach has been generalized in 1987 by Laughlin et al., and applied to ArH+ cation. They obtained the values: 1.4(4) D, 1.59(40) D and 3.0(6) D, which seriously differed from the ab initio result 2.2(1) D provided by Rosmus in 1979. The additional ab initio calculations performed by Pyykko et al., and then by Geertsen and Scuseria in 1989, confirmed the correctness of the result obtained earlier by Rosmus. In such circumstances only the application of a third independent method could provide a correct value of the electric dipolar moment of ArH+. Following this suggestion, Molski in 2001 applied the spectroscopic method to evaluate dipolar moment of ArH+ from highly resolved MW and IR spectra including pure rotational and vibration-rotational lines. The result obtained 2.12(55) D confirmed that ab initio calculations provided a reliable value of the dipolar moment of ArH+, whereas the experimental values obtained by Laughlin et al., were less accurate. The supplementary calculations performed for KrH+ and HeH+ indicate that the method of Laughlin et al. does not produce reliable values of the electric dipolar moment for diatomic ions, where as for polyatomic molecules this method is reliable.

3

Stark effect in He I in extremely high electric field

Windholz L, Drozdowski R, Wasowicz T J, Kwela J

Optica Applicata

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2006

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Vol. 36, nr 4

s. 569--574

EN

In the spectral range between 480–630 nm the Stark effect of the transitions n1Q–21S, n1Q–21P and n3Q–23P (n = 3–10, Q = S, P, D, ...) was studied in atomic helium using electric field up to 1500 kV/cm. For such an extremely high field the Stark splitting becomes greater than the simple structure of the atom. In consequence, anticrossings of the Stark components of the same magnetic quantum number occur. The experimental results have been compared with the theoretical shifts. The results of calculations show good agreement with observation not only for low field values, but also for those in high fields and in the case of level anticrossings.

4

Determination of the parameters of a plasma JET generated by a capillary discharge

Sandolache G., Fleurier C., Bauchire J. -M., Gentils F., Zoita V.

Nukleonika

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2001

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Vol. 46, suppl. 1

21--23

EN

A pulsed capillary discharge has been the subject of various experimental and theoretical studies. A jet of copperhydrogen plasma with a cylindrical symmetry has been developed as a light source for spectroscopic measurements. The electron density of the plasma was obtained by using the Hβ spectral line of the hydrogen component plasma. The electron temperature was determined by means of the Boltzmann method applied to the copper profiles emitted by the plasma jet. The copper and hydrogen lines were broadened principally by the Stark effect. The electron density of the plasma was found to be about 2×1017 cm–3 and the electron temperature about 20000K.