Characterization of Hollow-Cathode DC Discharge Growth of Diamond: Rotational Vibronic Emission In A CH4-H2 Discharge

1989 ◽  
Vol 162 ◽  
Author(s):  
H. N. Chu ◽  
A. R. Lefkow ◽  
E. A. Den Hartog ◽  
J. Jacobs ◽  
P. Sandstrom ◽  
...  
Keyword(s):  
Hollow Cathode ◽  
Rotational Temperature ◽  
Optical Emission ◽  
Vibronic Band ◽  
Dc Discharge

ABSTRACTExperiments to study the temperature in the discharge produced using a dc spiral hollow cathode with CH4-H2 as the feed gas have been carried out during the rowth of diamond. Optical emission from the R branch of the 3d1 Σ v-O-2p Σ v-O rotational vibronic band are used to determine a rotational temperature. Limitations of this method are discussed.

scholarly journals T- and H- forms of dc oxygen discharge at medium pressures: spectroscopic study

2014 ◽  
Vol 13 (1) ◽  
Author(s):  
Lukáš Schmiedt ◽  
Matěj Jan Morávek ◽  
Adolf Kaňka ◽  
Věra Hrachová
Keyword(s):  
Rotational Temperature ◽  
Optical Emission ◽  
Spectral Lines ◽  
Pure Oxygen ◽  
Non Invasive ◽  
Layer Deposition ◽  
Electric Measurement ◽  
Order Of Magnitude ◽  
Oxygen Discharge

AbstractThe active DC glow discharge sustained in the pure oxygen can be employed in various technological applications, such as thin layer deposition or sterilization. Considering applied pressures of hundreds of Pascals, two different forms of the positive column of the discharge can co-exist: T- and H-form. These forms are commonly distinguished according to the values of the axial electric field strength: values in the H-form are generally one order of magnitude higher compared to the T-form. However, electric measurement itself may often affect the discharge plasma. Optical emission spectroscopy as a non-invasive diagnostic was therefore employed as an alternate characterization of both forms.We found that the H- and T-forms can be clearly recognized by values of intensities of particular oxygen spectral lines. This characterization enabled us to observe transition between the both particular forms when spatial distribution measurements were employed. Moreover, transition in the rotational temperature Trot was also observed.

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.

Characterization of ultraintense laser produced fast electron propagation in insulatorsvs.conductors by optical emission diagnostics

2006 ◽  
Vol 133 ◽  
pp. 499-502 ◽  
Author(s):  
M. Manclossi ◽  
J. J. Santos ◽  
J. Faure ◽  
A. Guenmie-Tafo ◽  
D. Batani ◽  
...  
Keyword(s):  
Fast Electron ◽  
Optical Emission ◽  
Electron Propagation

scholarly journals Comparison of Elemental Analysis Techniques for the Characterization of Commercial Alloys

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 736
Author(s):  
Peter Seidel ◽  
Doreen Ebert ◽  
Robert Schinke ◽  
Robert Möckel ◽  
Simone Raatz ◽  
...  
Keyword(s):  
Accurate Determination ◽  
Analytical Techniques ◽  
Optical Emission ◽  
Breakdown Spectroscopy ◽  
General Evaluation ◽  
Sample Composition ◽  
Laser Induced Breakdown ◽  
Copper Aluminum

Better quality control for alloy manufacturing and sorting of post-consumer scraps relies heavily on the accurate determination of their chemical composition. In recent decades, analytical techniques, such as X-ray fluorescence spectroscopy (XRF), laser-induced breakdown spectroscopy (LIBS), and spark optical emission spectroscopy (spark-OES), found widespread use in the metal industry, though only a few studies were published about the comparison of these techniques for commercially available alloys. Hence, we conducted a study on the evaluation of four analytical techniques (energy-dispersive XRF, wavelength-dispersive XRF, LIBS, and spark-OES) for the determination of metal sample composition. It focuses on the quantitative analysis of nine commercial alloys, representing the three most important alloy classes: copper, aluminum, and steel. First, spark-OES is proven to serve as a validation technique in the use of certified alloy reference samples. Following an examination of the lateral homogeneity by XRF, the results of the techniques are compared, and reasons for deviations are discussed. Finally, a more general evaluation of each technique with its capabilities and limitations is given, taking operation-relevant parameters, such as measurement speed and calibration effort, into account. This study shall serve as a guide for the routine use of these methods in metal producing and recycling industries.

scholarly journals Merits of microwave plasmas for optical emission spectrometry – characterization of an axially viewed microwave-sustained, inductively coupled, atmospheric-pressure plasma (MICAP)

2020 ◽  
Vol 35 (10) ◽  
pp. 2369-2377
Author(s):  
Helmar Wiltsche ◽  
Matthias Wolfgang
Keyword(s):  
Atmospheric Pressure ◽  
Atmospheric Pressure Plasma ◽  
Optical Emission ◽  
Plasma Source ◽  
Optical Emission Spectrometry ◽  
Emission Spectrometry ◽  
Icp Oes ◽  
Microwave Plasmas ◽  
Inductively Coupled

The MICAP is a microwave driven plasma source employing nitrogen as the plasma gas. In this work we compare LODs and LOQs obtained in axial viewing with those obtained by ICP-OES and evaluate the effect of air instead of nitrogen as the plasma gas.

Experimentelle Bestimmung innerer und äußerer Parameter des negativen Glimmlichtplasmas einer zylindrischen Hohlkathodenentladung in Argon / Plasma Diagnostic Measurements in the Negative Glow of a Cylindrical Hollow Cathode Discharge

1972 ◽  
Vol 27 (10) ◽  
pp. 1425-1433 ◽  
Author(s):  
F. Howorka ◽  
M. Pähl
Keyword(s):  
Hollow Cathode ◽  
Argon Plasma ◽  
Cathode Current Density ◽  
Plasma Diagnostic ◽  
Negative Glow ◽  
Dc Discharge ◽  
Pressure Discharge ◽  
Glow Plasma ◽  
Langmuir Probe Measurements ◽  
Cylindrical Hollow Cathode

Abstract The negative glow plasma of a cylindrical hollow cathode dc discharge (0.05 - 1 Torr Argon, 1-30 mA) is investigated as to the position of the glow edge, the axial dependence of the cathode current density, the axial and radial potential distributions, the density and energy of electrons (from Langmuir probe measurements) as dependent on pressure, discharge current and position, etc. It is found that two groups of electrons exist whose energies are < 0.5 eV ~ 3 eV and the ratio of their denisties being 3 up to 20. A phenomenological explanation is given for the relatively high denisty of the fast group, The results are compared with those of other auhors concerning hollow-cathode and linear discharges.

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