The effect of hydrogen and nitrogen on emission spectra of iron and titanium atomic lines in analytical glow discharges

2008 ◽  
Vol 23 (9) ◽  
pp. 1223 ◽  
Author(s):  
Petr Šmíd ◽  
Edward Steers ◽  
Zdeněk Weiss ◽  
Juliet Pickering ◽  
Volker Hoffmann
Keyword(s):  
Emission Spectra ◽  
Glow Discharges ◽  
Atomic Lines

scholarly journals Photolysis of SiH4 by the Third Harmonic of a Nd:YAG Laser at 355 NM

1996 ◽  
Vol 16 (4) ◽  
pp. 245-253
Author(s):  
K. Sentrayan ◽  
E. Haque ◽  
A. Michael ◽  
V. S. Kushawaha
Keyword(s):  
Laser Energy ◽  
Emission Spectra ◽  
Photon Absorption ◽  
Absorption Process ◽  
Third Harmonic ◽  
Two Photon Absorption ◽  
Two Photon ◽  
The Third ◽  
Atomic Lines ◽  
White Deposit

The photolysis of silane (SiH4) was carried out using the third harmonic of a Nd: YAG laser at 355 nm, at a fixed SiH4 pressure of 350 Torr, varying the laser energy fluence in the range of 30–300 Jcm-2. The emission spectra indicates that the photofragments formed are SiH2, SiH, Si, H2, and H. The (A1B1-X1A1) transitions at 552.7 nm, 525.3 nm, 505.6 nm, and 484.7 nm of SiH2 are due to a two photon absorption process. The (A2Δ-X2π) transitions of SiH at 425.9 nm, 418 nm, 414.2 nm, 412.8 nm and 395.6 nm are due to a three photon absorption process. The brownish white deposit on the cell windows indicates the presence of amorphous silicon (a:Si-H). The two atomic lines of Si(4s1P0→ 3p21D2) at 288.1 nm, and (4s3Pj→ 3P3Pj) at 251.6 nm are observed. The atomic Si transitions are due to a three photon absorption. We observed seven transitions due to molecular hydrogen at wavelengths 577.5 nm, 565.5 nm, 534.4 nm, 542.5 nm, 471 nm, 461.7 nm, and 455.4 nm. These bands are due to a four photon absorption proc6ss. In addition to the molecular bands we also observed hydrogen atomic lines Hβ, Hγ and Hδ.

A study of the light emitted from the initial stages of a spark discharge

1964 ◽  
Vol 278 (1373) ◽  
pp. 168-187 ◽  
Keyword(s):  
Threshold Voltage ◽  
High Speed ◽  
Homogeneous Field ◽  
Electrode Gap ◽  
Diffuse Discharge ◽  
Glow Discharges ◽  
Field Electrode ◽  
Atomic Lines ◽  
Chamber Studies ◽  
Spark Channel

Measurements have been made, by means of submicrosecond impulses, on the threshold voltage at which the first visible discharge occurs in a homogeneous field electrode gap. Various gases have been used at different values of gap and gas pressure. In most gases there is some indication of a change in the form of the initial discharge as the gap is varied. At a certain value of electrode gap, depending upon the impulse length and gap pressure, there is a change in slope of the threshold voltage-gap curve. Above this point the discharges are generally filamentary whereas at smaller gaps they are broad and diffuse. In air, nitrogen and oxygen the filamentary discharges are often constricted at a point in the gap. The position of this constriction depends on the impulse and gap length. It is suggested that the filamentary discharges correspond to a streamer type of discharge and are similar to the ones observed in the previous cloud chamber studies. The broad diffuse discharge which occurs at smaller gaps is probably the Townsend type of discharge In argon and hydrogen the evidence for the existence of two breakdown mechanisms is not very strong. High-speed streak photography has revealed that the filamentary glow discharges in air appear to grow towards the constriction. A spark channel then begins to form at the constriction and grows towards the electrodes. Spectroscopic examination of the various types of discharge shows the prominent second positive N 2 bands for discharges in air and nitrogen but with a continuum, N + 2 bands and atomic lines in the constriction. An estimate of the peak electron energy has been made for various discharges in air and nitrogen and found to be about 14eV.

Isotope shifts in the [10.1]4–X4 (0–0) and [10.5]3–X4 (0–0) transitions of NdOThis article is part of a Special Issue on Spectroscopy at the University of New Brunswick in honour of Colan Linton and Ron Lees.

2009 ◽  
Vol 87 (5) ◽  
pp. 537-541 ◽  
Author(s):  
Alain Bernard ◽  
Amanda J. Ross
Keyword(s):  
Near Infrared ◽  
Thermal Emission ◽  
Emission Spectra ◽  
Spectroscopic Constants ◽  
Isotopic Shifts ◽  
Oppenheimer Approximation ◽  
Global Fit ◽  
Atomic Lines ◽  
The University ◽  
Line Positions

High-resolution Fourier transform thermal emission spectra of NdO (natural isotopic composition) have been recorded in the near infrared. Rotational analyses of the 0–0 band of the [10.132]4–X(1)4 system have been performed for all seven isotopomers, and the 0–0 band of the [10.506]3–X(1)4 system has been analysed for 142NdO, 144NdO, and 146NdO. Experimental data have been merged into a global fit to obtain a unique set of isotopically consistent rotational spectroscopic constants, scaled to 142NdO by assuming isotopic relationships within the Born–Oppenheimer approximation, but with independent band origins. These vibronic energy shifts reflect the isotopic shifts observed in some atomic lines also seen in the spectrum. A catalogue of experimental line positions and o−c values is available as Supplementary data.

scholarly journals Excitation of higher levels of singly charged copper ions in argon and neon glow discharges

2014 ◽  
Vol 29 (12) ◽  
pp. 2256-2261 ◽  
Author(s):  
Zdeněk Weiss ◽  
Edward B. M. Steers ◽  
Juliet C. Pickering ◽  
Volker Hoffmann ◽  
Sohail Mushtaq
Keyword(s):  
Transition Rate ◽  
Copper Ions ◽  
Emission Spectra ◽  
Glow Discharges ◽  
Using Data ◽  
Singly Charged

Transition rate diagrams of copper ions in argon and neon glow discharges are presented, using data from Cu ii emission spectra.

Enhancement of analyte atomic lines with excitation energies of about 5 eV in the presence of molecular gases in analytical glow discharges

2014 ◽  
Vol 29 (11) ◽  
pp. 2022-2026 ◽  
Author(s):  
Sohail Mushtaq ◽  
Edward B. M. Steers ◽  
Juliet C. Pickering ◽  
Petr Šmid
Keyword(s):  
Excitation Energies ◽  
Molecular Gases ◽  
Glow Discharges ◽  
Atomic Lines

Small amounts of hydrogen or oxygen in either argon or neon plasmas cause previously unexplained enhanced excitation of various analyte atomic lines with upper energies close to 5 eV.

Mixed LTCC and LTTT Technology for Microplasma Generator Fabrication

2009 ◽  
Vol 6 (2) ◽  
pp. 101-107 ◽  
Author(s):  
Roberto K. Yamamoto ◽  
Mário R. Gongora-Rubio ◽  
Rodrigo S. Pessoa ◽  
Márcio R. Cunha ◽  
Homero S. Maciel
Keyword(s):  
Low Temperature ◽  
Sulfur Hexafluoride ◽  
Emission Spectra ◽  
Optical Emission ◽  
Fabrication Method ◽  
Device Structure ◽  
Glow Discharges ◽  
Silver Palladium ◽  
Optical Emission Spectra ◽  
Process Transfer

An issue of paramount importance for the fabrication of microplasma devices is internal structure flatness. To overcome this problem we devised a fabrication method using LTCC (Low Temperature Cofired Ceramic) and LTTT (Low Temperature Transfer Tape) technologies. The flexibility resulting from mixing these technologies could enable fabrication of certain microfluidic applications. In the present work, the fabrication of a microplasma generator using a mixed LTCC and LTTT technology is presented. Silver-palladium electrodes were screen printed on the green tapes and were cofired after machining of microchannels and other structures. Two electrode plates were obtained separately in this way using a setter powder sheet to ensure flatness. In the postfire process, transfer tapes were used to bind the two electrode plates and the electrode spacer together to make the final device structure. Uniform and stable glow discharges were obtained in argon, nitrogen, oxygen, and sulfur hexafluoride gases. Paschen's curves, V-I characteristics, and optical emission spectra were obtained in DC discharges. The fabrication method presented has been demonstrated to be very reproducible and produced very flat electrodes.

scholarly journals Процессы возбуждения при столкновениях электронов с молекулами глутамина

2020 ◽  
Vol 46 (16) ◽  
pp. 35
Author(s):  
Н.М. Эрдевди ◽  
А.И. Булгакова ◽  
О.Б. Шпеник ◽  
А.Н. Завилопуло
Keyword(s):  
Gas Phase ◽  
Emission Spectra ◽  
Optical Emission ◽  
Low Energy ◽  
Molecular Fragments ◽  
Hydrogen Atoms ◽  
Low Energy Electrons ◽  
Atomic Lines ◽  
Excitation Processes ◽  
Optical Emission Spectra

Excitation processes in collisions of low-energy electrons (1-100 eV) with glutamine molecules in the gas phase have been studied. The optical emission spectra were measured in the wavelength range from 250-520 nm and it was found that, as a result of the decomposition of glutamine molecules, OH molecular emissions and some other molecular fragments are most efficiently formed. And excited hydrogen atoms are also detected. It was found that the excitation thresholds of molecular emissions are 10–12 eV, while the atomic lines of hydrogen are 13–15 eV. The energy dependences of the excitation of individual emissions from a threshold to 50 eV are also presented.

Vacuum Ultraviolet and Visible Optical Emission Spectra from Laser Ablation of Graphite at 193 NM: Application to Carbon Nitride Thin Films Deposition

1998 ◽  
Vol 526 ◽  
Author(s):  
R. Henck ◽  
C. Fuchs ◽  
E. Fogarassy ◽  
J. Hommet ◽  
F. Le Normand
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Photoelectron Spectroscopy ◽  
Carbon Nitride ◽  
Emission Spectra ◽  
Optical Emission ◽  
Nitrogen Pressure ◽  
Visible Range ◽  
Atomic Lines ◽  
Optical Emission Spectra

AbstractOptical emission spectra in the ultraviolet and visible range (110-600 nm) were recorded during pulsed ArF laser ablation of graphite targets in vacuum and in low pressure N2 atmospheres. During graphite ablation in vacuo, the recorded spectrum consists only of several atomic lines lying below 300 nm. They are due to radiative transitions from upper carbon excited states down to the fundamental one. The most intense atomic lines are observed at 247.85 nm and near 165.5 and 156 nm. During ablation in increasing nitrogen pressure, the spectra are quickly dominated by the bands of the CN violet system whereas the intensity of the atomic lines only slightly increases. We have observed the bands corresponding to the vibrational sequences Δv = +1 (358.4-369.7 nm), Δv = 0 (384.7-394.4 nm) and Δv = -1 (414.3-421.6 nm). They already appear at nitrogen pressure as low as 0.05 mbar. Their intensity reaches a broad maximum between 0.5 and 0.8 mbar and slowly decreases.Taking into account the results of this optical study, the deposition of carbon nitride thin films has been undertaken. The surface analysis by X-ray photoelectron spectroscopy (XPS) of the obtained C1-xNx deposits shows a correlation law between the nitrogen incorporation (x) and the pressure of nitrogen.

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