On the use of two hydrogen bands for spectroscopic temperature measurement in a low-pressure gas discharge

2012 ◽  
Vol 36 (1) ◽  
pp. 1-12 ◽  
Author(s):  
G. Lj. Majstorović ◽  
N. M. Šišović
Keyword(s):  
Optical Emission Spectroscopy ◽  
Rotational Temperature ◽  
Energy Levels ◽  
Optical Emission ◽  
Low Pressure ◽  
Line Intensities ◽  
Hydrogen Molecules ◽  
Diagonal Band ◽  
Relative Line ◽  
Titanium Cathode

Abstract We report the results of the optical emission spectroscopy measurements of rotational Trot and translational temperature Ttr of hydrogen molecules. The light source was hollow cathode glow discharge with titanium cathode operated in hydrogen at low pressure. The rotational temperature of excited electronic states of H2 was determined either from the relative line intensities of R branch of the GK → B band or from the P, Q and R-branches of the Fulcher-α diagonal band. The population of excited energy levels, determined from the relative line intensities was used to derive rotational temperature of the ground state of hydrogen molecule.

scholarly journals Rotational and gas temperatures of molecular deuterium in a hollow cathode glow discharge

2015 ◽  
Vol 38-39 (1) ◽  
pp. 11-22 ◽  
Author(s):  
G. Lj. Majstorović ◽  
N. M. Šišović
Keyword(s):  
Glow Discharge ◽  
Hollow Cathode ◽  
Low Voltage ◽  
Rotational Temperature ◽  
Energy Levels ◽  
Optical Emission ◽  
Gas Temperature ◽  
Line Intensities ◽  
Relative Line ◽  
Deuterium Molecule

Abstract We report the results of optical emission spectroscopy measurements of rotational Trot and translational (gas) temperature of deuterium molecules. The light source was a low-voltage high-pressure hollow cathode (HC) glow discharge with titanium cathode operated in deuterium. The rotational temperature of excited electronic states of D2 was determined from the intensity distribution in the rotational structure of Q-branches of the two Fulcher-α diagonal bands: [ν′ = ν″ = 2] and [ν′ =ν″ = 3]. The population of the excited energy levels, determined from relative line intensities, was used to derive the radial distributions of the temperature of the excited and the ground state of the deuterium molecule.

Measurement of vibrational and rotational temperature in spark-discharge plasma by optical emission spectroscopy: Change in thermal equilibrium characteristics of plasma under air flow

2018 ◽  
Vol 20 (7) ◽  
pp. 746-757 ◽  
Author(s):  
Masao Kinoshita ◽  
Takayuki Fuyuto ◽  
Hiroshi Akatsuka
Keyword(s):  
Thermal Equilibrium ◽  
Optical Emission Spectroscopy ◽  
Discharge Plasma ◽  
Vibrational Temperature ◽  
Rotational Temperature ◽  
Air Flow ◽  
Optical Emission ◽  
Spark Discharge ◽  
Spark Plug ◽  
Spark Discharge Plasma

The vibrational and rotational temperatures in a spark-discharge plasma were measured using optical emission spectroscopy, and the influence of the air flow velocity and ambient pressure on these temperatures was investigated. The optical emissions from the plasma were led to an imaging spectroscope through an optical fiber. The temperature was estimated by fitting a theoretically calculated spectrum to that which had been acquired experimentally, formed by nitrogen molecule emission from 372 to 382 nm. The spark-discharge plasma was examined with a flow of ambient air at a discharge energy of 80 mJ. The air flow caused the spark-discharge channel to elongate downstream. At the center of the spark plug gap, the vibrational temperature in the plasma was 4000 K, whereas the rotational temperature was 2000 K. This plasma can be regarded as being in non-thermal equilibrium because the vibrational temperature was higher than the rotational temperature. At a position approximately 3 mm downstream from the spark plug gap, the vibrational and rotational temperatures increased to 4500 and 4000 K, respectively, while approaching each other. Both temperatures reached a maximum value. These results show that the plasma transitions from non-thermal equilibrium to thermal equilibrium as it is elongated by the air flow. Ignition efficiency improvements can be expected if the time required to transition from non-thermal to thermal equilibrium can be shortened.

Characterization of a low-pressure argon plasma using optical emission spectroscopy and a global model

2007 ◽  
Vol 101 (5) ◽  
pp. 053306 ◽  
Author(s):  
A. Palmero ◽  
E. D. van Hattum ◽  
H. Rudolph ◽  
F. H. P. M. Habraken
Keyword(s):  
Emission Spectroscopy ◽  
Optical Emission Spectroscopy ◽  
Argon Plasma ◽  
Optical Emission ◽  
Low Pressure ◽  
Global Model
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