scholarly journals REDUCING THE DETECTION LIMITS OF SPECTROMETER WITH NITROGEN MICROWAVE PLASMA «GRAND-SVCH»

2020 ◽  
Vol 8 (1) ◽  
pp. 108-117
Author(s):  
Oleg V. Komin ◽  
Oleg V. Pelipasov

The article presents the results of a study of the effect of the power supplied to the microwave plasma and the nebulizer gas flow rate on the detection limits of the spectrometer with nitrogen microwave plasma «Grand-SVCH». It is shown that a change of the spectral lines intensity of the elements being determined with varying parameters of the spectra excitation source is related to their excitation energy. The maximum intensities of the lines are achieved at a power of 1700 W and a nebulizer gas flow of 0,4 l/min and 0,6 l/min for lines with excitation energies of 4-15 eV and 3,5-4 eV, respectively. Using the obtained values of the parameters of the excitation source of the spectra allows reducing the detection limits of elements by 1,5-4 times.

1981 ◽  
Vol 35 (3) ◽  
pp. 292-302 ◽  
Author(s):  
Akbar Montaser ◽  
V. A. Fassel ◽  
J. Zalewski

Ar-N2 plasmas generated by introducing N2 into the outer and the aerosol carrier gas flows were investigated using a 5 kW, 27.12 MHz crystal-controlled rf generator. The dependence of plasma geometry, plasma background intensity, net analyte emission intensity, signal/background ratio, signal/noise ratios, and the detection limits on forward power (1000 to 4000 W), the outer gas flow (15 to 50 liters/min) and aerosol carrier gas flow (1 to 2.5 liters/min), sample uptake rate (1 to 5 ml/min), and gas composition (0 to 100% N2) were studied for observation heights of 5 to 40 mm. Measurements were conducted simultaneously for 20 ion and neutral atom spectral lines. Ultrasonic nebulization, with aerosol desolvation, was employed. Except for the observation height, which was 10 mm, the optimum conditions for Ar-N2 plasmas containing 5 to 15% N2 in the outer gas flow were roughly identical to those of a conventional Ar plasma. When pure N2 was used in the outer flow, two sets of optimum conditions, quite different than the optimum conditions for the conventional Ar plasma, were found for the high and medium excitation energy lines. Detection limits and signal/background ratios of ion and neutral atom lines of the high excitation energies, excited in a pure Ar plasma, were superior to the results obtained in the Ar-N2 plasma when pure N2 was used in the outer flow. The opposite trend was observed for neutral atom lines of medium excitation energies. The use of N2 aerosol carrier gas, when the outer gas flow was pure Ar, deteriorated the detection limits of all elements.


MRS Advances ◽  
2018 ◽  
Vol 3 (3) ◽  
pp. 165-170
Author(s):  
Shumpei Ogawa ◽  
Tatsuya Kuroda ◽  
Ryuga Koike ◽  
Hiroki Ishizaki

AbstractRecently, Plasma Assisted Atomic Layer Deposition Technique will easily control the thickness and the composition of semiconductor films. The radical generated by using the plasma techniques, gave the decrease of the defect into the semiconductor films. In this investigation, the relationship between microwave plasma power, nitrogen gas flow rate and concentration of generated nitrogen radical, was evaluated. At the first, Plasma emission spectrum at microwave plasma power (0 to 400W) was measured using a mixed 200sccm argon gas and 10sccm nitrogen gas. Next, the plasma emission spectrum was measured in the mixing of nitrogen gas flow rate (0 to 40sccm) with 200sccm argon gas flow rate. At that time, the microwave plasma power was set to 200W. Nitrogen radical spectrum were identified from all the emission spectrum, and the nitrogen radical intensity was calculated. As a result, the nitrogen radical intensity became the largest at 200sccm argon gas flow rate and 10sccm nitrogen gas flow rate. In addition, the nitrogen radical intensity increased in proportion to the microwave plasma power. The concentration of generated nitrogen radical could be controlled by changing the microwave plasma power and the nitrogen gas flow rate. Mentioned above, nitride thin films will be obtained on Si Substrates by microwave generated remote plasma assisted atomic layer deposition technique.


2006 ◽  
Vol 515 (4) ◽  
pp. 1970-1975 ◽  
Author(s):  
W. Chen ◽  
X. Lu ◽  
Q. Yang ◽  
C. Xiao ◽  
R. Sammynaiken ◽  
...  

1999 ◽  
Vol 8 (2-5) ◽  
pp. 189-193 ◽  
Author(s):  
V Ralchenko ◽  
I Sychov ◽  
I Vlasov ◽  
A Vlasov ◽  
V Konov ◽  
...  

2018 ◽  
Vol 15 (1) ◽  
pp. 81-86 ◽  
Author(s):  
Baghdad Science Journal

In this paper, a construction microwave induced plasma jet(MIPJ) system was used to produce a non-thermal plasma jet at atmospheric pressure, at standard frequency of 2.45 GHz and microwave power of 800 W. The working gas Argon (Ar) was supplied to flow through the torch with adjustable flow rate using flow meter regulator. The influence of the MIPJ parameters such as applied voltage and argon gas flow rate on macroscopic microwave plasma parameters were studied. The macroscopic parameters results show increasing of microwave plasma jet length with increasing of applied voltage, argon gas flow rate where the plasma jet length exceed 12 cm as maximum value. While the increasing of argon gas flow rate will cause increasing into the argon gas temperature, where argon gas temperature the exceed 350 ? as maximum value and study the effect of gas flow rate on the optical properties


2006 ◽  
Vol 13 (05) ◽  
pp. 585-592
Author(s):  
M. RUSOP ◽  
S. ABDULLAH ◽  
A. M. M. OMER ◽  
S. ADHIKARI ◽  
T. SOGA ◽  
...  

We have studied the influence of the methane gas ( CH 4) flow rate on the composition and structural and electrical properties of nitrogenated amorphous carbon ( a - C : N ) films grown by surface wave microwave plasma chemical vapor deposition (SWMP-CVD) using Auger electron spectroscopy, X-ray photoelectron spectroscopy, UV-visible spectroscopy, four-point probe and two-probe method resistance measurement. The photoelectrical properties of a - C : N films were also studied. We have succeeded to grow a - C : N films using a novel method of SWMP-CVD at room temperature and found that the deposition rate, bonding and optical and electrical properties of a - C : N films are strongly dependent on the CH 4 gas sources, and the a - C : N films grown at higher CH 4 gas flow rate have relatively high electrical conductivity for both cases of in dark and under illumination condition.


Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 354 ◽  
Author(s):  
Mehrnoush Narimisa ◽  
František Krčma ◽  
Yuliia Onyshchenko ◽  
Zdenka Kozáková ◽  
Rino Morent ◽  
...  

In this work, the potential of a microwave (MW)-induced atmospheric pressure plasma jet (APPJ) in film deposition of styrene and methyl methacrylate (MMA) precursors is investigated. Plasma properties during the deposition and resultant coating characteristics are studied. Optical emission spectroscopy (OES) results indicate a higher degree of monomer dissociation in the APPJ with increasing power and a carrier gas flow rate of up to 250 standard cubic centimeters per minute (sccm). Computational fluid dynamic (CFD) simulations demonstrate non-uniform monomer distribution near the substrate and the dependency of the deposition area on the monomer-containing gas flow rate. A non-homogeneous surface morphology and topography of the deposited coatings is also observed using atomic force microscopy (AFM) and SEM. Coating chemical analysis and wettability are studied by XPS and water contact angle (WCA), respectively. A lower monomer flow rate was found to result in a higher C–O/C–C ratio and a higher wettability of the deposited coatings.


Author(s):  
B.S. Soroka ◽  
V.V. Horupa

Natural gas NG consumption in industry and energy of Ukraine, in recent years falls down as a result of the crisis in the country’s economy, to a certain extent due to the introduction of renewable energy sources along with alternative technologies, while in the utility sector the consumption of fuel gas flow rate enhancing because of an increase the number of consumers. The natural gas is mostly using by domestic purpose for heating of premises and for cooking. These items of the gas utilization in Ukraine are already exceeding the NG consumption in industry. Cooking is proceeding directly in the living quarters, those usually do not meet the requirements of the Ukrainian norms DBN for the ventilation procedures. NG use in household gas stoves is of great importance from the standpoint of controlling the emissions of harmful components of combustion products along with maintenance the satisfactory energy efficiency characteristics of NG using. The main environment pollutants when burning the natural gas in gas stoves are including the nitrogen oxides NOx (to a greater extent — highly toxic NO2 component), carbon oxide CO, formaldehyde CH2O as well as hydrocarbons (unburned UHC and polyaromatic PAH). An overview of environmental documents to control CO and NOx emissions in comparison with the proper norms by USA, EU, Russian Federation, Australia and China, has been completed. The modern designs of the burners for gas stoves are considered along with defining the main characteristics: heat power, the natural gas flow rate, diameter of gas orifice, diameter and spacing the firing openings and other parameters. The modern physical and chemical principles of gas combustion by means of atmospheric ejection burners of gas cookers have been analyzed from the standpoints of combustion process stabilization and of ensuring the stability of flares. Among the factors of the firing process destabilization within the framework of analysis above mentioned, the following forms of unstable combustion/flame unstabilities have been considered: flashback, blow out or flame lifting, and the appearance of flame yellow tips. Bibl. 37, Fig. 11, Tab. 7.


Sign in / Sign up

Export Citation Format

Share Document