| Autor: |
Lodygin, A. N., Portsel, L. M., Beregulin, E. V., Astrov, Yu. A. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 11/7/2019, Vol. 126 Issue 17, pN.PAG-N.PAG, 7p, 1 Diagram, 6 Graphs |
| Abstrakt: |
The paper describes a study of the electron energy distribution function in the self-sustained direct current (dc) Townsend discharge. A three-electrode microdischarge structure with a plane-parallel arrangement of electrodes is applied in the experiments. The device comprises two discharge gaps of a small width having a common electrode in the form of a fine-grained metal mesh. A high-resistivity cathode to the first gap is applied, which ensures the spatial uniformity of the Townsend discharge in the gap. The second gap serves as a retarding field analyzer of energy of electrons that are generated in the region of the Townsend discharge and pass through cells in the grid electrode. Experiments are carried out for discharges in argon and nitrogen near the minimum of the Paschen curve. According to the data obtained, shapes of the distribution function for the investigated gases are different: for Ar, a local maximum at energies of 1–3 eV is observed in the distributions, in contrast to N 2. At the same time, the effective electron temperature—determined from the high-energy tail of a distribution—is close for both gases and lies in the range of 0.8–1.9 eV. This is significantly lower than electron energies that give numerical calculations for E / N values corresponding to the conditions of experiments. Among the possible reasons for the difference is the fundamental property of a dc Townsend discharge: electrons in the subanode layer—where they are accumulated and from where they pass to the analyzer—gain energy mainly on a relatively small ionization length in the gas. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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