Optical and electrical diagnostics of microdischarges at moderate to high pressure in argon



Document title: Optical and electrical diagnostics of microdischarges at moderate to high pressure in argon
Journal: Brazilian journal of physics
Database: PERIÓDICA
System number: 000334085
ISSN: 0103-9733
Authors: 1
1
2
2
3
Institutions: 1Instituto Tecnologico de Aeronautica, Departamento de Fisica, Sao Jose dos Campos, Sao Paulo. Brasil
2Comando-Geral de Tecnologia Aeroespacial, Laboratorio de Optica e Espectroscopia, Sao Jose dos Campos, Sao Paulo. Brasil
3Bulgarian Academy of Sciences, Institute of Electronics, Sofia. Bulgaria
Year:
Season: Dic
Volumen: 40
Number: 4
Pages: 459-463
Country: Brasil
Language: Inglés
Document type: Artículo
Approach: Experimental
English abstract Microdischarges at moderate to high pressure in argon were investigated. A hole opening diameter of 500 µm direct current (dc) microhollow cathode discharges (MHCD) were characterized by electrical measurements and optical emission spectroscopy (OES) for pressures ranging between 90 and 800 Torr and current from 5 to 20 mA. Current-voltage characteristic curves were obtained as a function of the pressure for this hole diameter. MHCD enables stable dc discharges for molybdenum electrodes material at constant Ar + 2%H2 flow of 0.03 l/min. Optical emission spectroscopy and analysis of the spectral line broadening of plasma line emissions were performed in order to measure gas discharge parameters. Electron number densities were obtained from Hβ Balmer line ( ~ 1014 cm-3). For the above mentioned discharge conditions, gas temperature was estimated to be 550 - 850 K from OH rotational bands. Excitation temperature was measured based on two lines method (from atomic Mo lines) and from 4p - 4s and 5p - 4s Ar radiative transitions. Hydrogen atom temperature was measured for 800 Torr ( ~ 12000 K)
Disciplines: Física y astronomía
Keyword: Física atómica y molecular,
Optica,
Teoría cinética y plasmas,
Microdescargas,
Descargas microcavidad de cátodo,
Espectroscopio de emisión óptica
Keyword: Physics and astronomy,
Atomic and molecular physics,
Kinetic theory and plasma,
Optics,
Microdischarges,
Microhollow cathode discharges,
Optical emission spectroscopy
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