Intensity Ratios Of Spectral Lines Research Articles

Mode Transition in an Inductively Coupled Argon–Mercury Mixture Discharge Studied by Interferometer and Optical Emission Spectroscopy

The E–H-mode-transition process in an inductively coupled argon–mercury mixture discharge plasma was investigated by an interferometer and a spectrometer. The transition powers upon different natural pressures and mercury content were studied. The electron density versus input power under several discharge conditions in the E mode and H mode was measured detailedly by the interferometer. These results suggested that the nonlinear effects of power absorption and dissipation play a significant role in the mode transition process. In addition, the optical emission system was employed to obtain the intensity ratios of spectral lines at different mercury proportions, which shed light on the mechanism of stepwise ionization and the variability of H-to-E-mode-transition powers in the argon–mercury mixture discharge.

Real-time identification of plastics by types using laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy was applied for real-time identification of different types of plastics. The plasma emission spectra of polypropylene, acrylonitrile–butadiene–styrene, polystyrene, and polyethylene terephthalate, the most commonly used plastics in black household appliances, were studied. It was confirmed that the C/H spectral line intensity ratio varies depending on the type of plastics. Aliphatic and aromatic polymers were discriminated owing to the presence of delocalized C–C bonds in the aromatic fragments, revealing a correlation between the chemical structure and emission of the C2 Swan bands. Plastics containing a heteroatom could be selectively detected by monitoring the emission line characteristics of the heteroatom. Four types of plastics were successfully identified despite their similar chemical structure.

Simulating a low-temperature Maxwellian plasma using SH-HtscEBIT

This paper reports an experimental realization of a low-temperature quasi-Maxwell–Boltzmann plasma in an electron beam ion trap (EBIT) by employing a special energy sweep technique. A Maxwellian C IV plasma with electron temperatures in the range 10–40 eV is simulated in the Shanghai high-temperature superconducting EBIT (SH-HtscEBIT), which requires stable performance of the EBIT under the extreme condition of ultralow electron beam energy. The C IV spectra are obtained by an extreme ultraviolet spectrometer in the wavelength region 290–400 Å. The measured spectral line intensity ratios are compared with the results of calculations using a collisional-radiative model. The mean difference between the experimental and theoretical results in the simulated temperature region is about 14%.

Development of the Method of Calibration Equations for the X-Ray Fluorescence Analysis of Multicomponent Samples in the Presence of Undetectable Elements

New calibration equations are proposed based on the use of intensity ratios of spectral lines and peaks of coherently and incoherently scattered characteristic radiation of an X-ray tube. Prospects for their application to the X-ray fluorescence analysis of samples containing undetectable light elements are shown. The proposed method ensures high precision of determination and performance of analysis in the lack of adequate reference samples. The method was tested on an example of analysis of standard samples of bronze and samples of iron oxide materials.

Effects of temperature and pressure on luminescent properties of Sr2CeO4:Eu3+ nanophosphor

In this paper we describe the synthesis and characterization of the Sr2CeO4:Eu3+ nanopowder and possibilities of its application for temperature and high pressure sensing. The material was prepared using simple solution combustion synthesis. X-ray powder diffraction (XRD), scanning electron microscope (SEM) and photoluminescence (PL) techniques have been used to confirm and characterize the prepared material. Time resolved analysis of emission spectra was achieved by using the streak camera system. Measured lifetime values of luminescence emission and the intensity ratios of spectral lines were used for determining the calibration curves for remote temperature sensing. We have analyzed sensitivity improvement of the intensity ratio method by using a temporal evolution of emission lines and simulation of delayed gating of one of them. Pressure effects on optical properties of Sr2CeO4:Eu3+ nanophosphor are also investigated.

Plume transition from solid to hollow with increasing the bias value of a sinusoidal voltage applied to an argon plasma jet

In this paper, a detailed study is carried out on an argon plasma jet excited by a biased sinusoidal voltage. Results indicate that, with increasing the biased voltage from negative polarity to positive one, the resultant plume transits from solid to hollow. Through implementing fast photography, a plump guided bullet is found to propagate in the solid plume, in which a negative streamer mechanism is involved. However, a positive streamer mechanism is involved in the hollow plume. It behaves as a thin guided streamer starting out from the driven electrode end, which subsequently evolves into branching streamers propagating in the flow periphery. To investigate the formation mechanism of the two plumes, the intensity ratio of spectral lines is investigated.

Absolute sensitivity calibration of an extreme ultraviolet spectrometer for tokamak measurements

An extreme ultraviolet spectrometer installed on the Tore Supra tokamak has been calibrated in absolute units of brightness in the range 10–340 Å. This has been performed by means of a combination of techniques. The range 10–113 Å was absolutely calibrated by using an ultrasoft-X ray source emitting six spectral lines in this range. The calibration transfer to the range 113–182 Å was performed using the spectral line intensity branching ratio method. The range 182–340 Å was calibrated thanks to radiative-collisional modelling of spectral line intensity ratios. The maximum sensitivity of the spectrometer was found to lie around 100 Å. Around this wavelength, the sensitivity is fairly flat in a 80 Å wide interval. The spatial variations of sensitivity along the detector assembly were also measured. The observed trend is related to the quantum efficiency decrease as the angle of the incoming photon trajectories becomes more grazing.

Detection of water molecules in inert gas based plasma by the ratios of atomic spectral lines

A new approach is considered to detect the water leaks in inert plasma-forming gas present in the reactor chamber. It is made up of the intensity ratio of Dα and Hα spectral lines in combination with O, Ar and Xe lines intensity. The concentrations of H2O, O, H and D particles have been measured with high sensitivity. At the D2 admixture pressure = 0.025 mbar, we used the acquisition time of 10 s to measure the rate of water molecules injected from the outside, Γ0 = 1.4 · 10−9 mbar · m3 · s−1, and the incoming water molecules to plasma, Γ = 5 ·10−11 mbar · m3 · s−1. The scaling proves that at small D2 admixtures (10−4 mbar), the leaks with the rates Γ0 ≈ 6 · 10−12 mbar · m3 · s−1 and Γ ≈ 2 · 10−13 mbar · m3 · s−1 can be detected and measured. The difference between Γ0 and Γ values is due to the high degree of H2O dissociation, which can be up to 97–98%.

Spectroscopic and probe measurements of the electron temperature in the plasma of a pulse-periodic microwave discharge in argon

A pulse-periodic 2.45-GHz electron-cyclotron resonance plasma source on the basis of a permanent- magnet mirror trap has been constructed and tested. Variations in the discharge parameters and the electron temperature of argon plasma have been investigated in the argon pressure range of 1 × 10–4 to 4 × 10–3 Torr at a net pulsed input microwave power of up to 600 W. The plasma electron temperature in the above ranges of gas pressures and input powers has been measured by a Langmuir probe and determined using optical emission spectroscopy (OES) from the intensity ratios of spectral lines. The OES results agree qualitatively and quantitatively with the data obtained using the double probe.

Measurements of the populations of metastable and resonance levels in the plasma of an RF capacitive discharge in argon

The behavior of the populations of two metastable and two lower resonance levels of argon atoms in the plasma of an RF capacitive discharge was studied. The populations were measured by two methods: the method of emission self-absorption and the method based on measurements of the intensity ratios of spectral lines. It is shown that the populations of resonance levels increase with increasing power deposited in the discharge, whereas the populations of metastable levels is independent of the RF power. The distribution of the populations over energy levels is not equilibrium under these conditions. The population kinetics of argon atomic levels in the discharge plasma is simulated numerically. The distribution function of plasma electrons recovered from the measured populations of atomic levels and numerical simulations is found to be non-Maxwellian.

Analysis of relative standard deviation of spectral line intensity and intensity ratio in laser-induced breakdown spectroscopy using CuIn1−xGaxSe2 thin film samples

The precision of laser induced breakdown spectroscopy (LIBS) measurement is analyzed in consideration of both the shot noise of the detector and the shot-to-shot fluctuation noise of the laser plasma.

Studying the effect of zeolite inclusion in aluminum alloy on measurement of its surface hardness using laser-induced breakdown spectroscopy technique

Laser-induced breakdown spectroscopy (LIBS) has been used to study the surface hardness of special aluminum alloys containing zeolite. The aluminum alloy has acquired pronounced changes in its metallurgical properties due to the zeolite inclusion. The surface hardness of the samples under investigation is determined by measuring the spectral intensity ratios of the ionic to atomic spectral lines in the LIBS spectra of samples having different surface hardness values that have been conventionally measured before for comparison. The presence of aluminum silicate mineral in the studied alloys enabled material volume to expand under compression. This feature gave new results in the measurement of hardness via LIBS. It has been proven that the trend of the alloy density change complies with the increase of ionic to atomic spectral line intensity ratio.

The anomalous sodium doublet D2/D1spectral line intensity ratio – a manifestation of CCD's presaturation effect

Download options Please wait... Article information DOI https://doi.org/10.1039/C2JA30239J Article type Paper Submitted 20 Jun 2012 Accepted 24 Oct 2012 First published 24 Oct 2012 Download Citation J. Anal. At. Spectrom., 2013,28, 92-97 BibTex EndNote MEDLINE ProCite ReferenceManager RefWorks RIS Permissions Request permissions The anomalous sodium doublet D2/D1 spectral line intensity ratio – a manifestation of CCD's presaturation effect B. Kasalica, S. Stojadinović, I. Belča, M. Sarvan, L. Zeković and J. Radić-Perić, J. Anal. At. Spectrom., 2013, 28, 92 DOI: 10.1039/C2JA30239J To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page. If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given. If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page. Read more about how to correctly acknowledge RSC content. Social activity Tweet Share Search articles by author Bećko Kasalica Stevan Stojadinović Ivan Belča Mirjana Sarvan Ljubiša Zeković Jelena Radić-Perić

Use of additional helium puffing for the diagnostics of plasma parameters at the FT-2 tokamak

The experiments carried out at the FT-2 tokamak in which additional pulsed puffing of helium into the hydrogen plasma was used for diagnostic purposes are considered. To estimate the necessary content of helium ions in the experiments on studying short-scale plasma oscillations, the ionization-recombination balance was simulated numerically under the assumption of a toroidally homogeneous influx of the working gas onto the boundary of the plasma column. In these simulations, the effective density of the neutral gas incident on the plasma boundary was determined by the iteration method, which made it possible to provide agreement between the obtained solution and the experimental discharge conditions. In particular, the correspondence of the determined admixture content to both the plasma quasineutrality condition and the value of the effective charge Zeff, as well as agreement between the calculated and measured plasma density profiles, was ensured. The simulations were performed under the assumption of anomalous diffusion coefficients for all plasma components. The temporal variations of the ionization-recombination balance were checked by comparing them with the measured spectra of radiation in the HeI, HeII, and Hα lines. In the current drive experiments, variations in ne(r) at the discharge periphery were examined by the method based on the proportionality of the intensity ratio of the helium spectral lines, HeI(668 nm)/HeI(728 nm), to the plasma density. In these calculations, the factors relating the intensity ratio of these lines to the plasma density were taken from the literature on spectral diagnostics.

Using FES in Measuring the BOF Temperature

The endpoint carbon content and temperature prediction of basic oxygen furnace (BOF) steelmaking is an important component part of BOF steelmaking process control. The flame temperature indirectly reflects the molten steel temperature and the temperature of the furnace slag. The flame spectrum consists of the background spectrum and the characteristic emission spectrum. The pairs of atomic emission spectral lines of sodium (589.03nm) and potassium (766.4nm and 769.78nm) exist in the flames of basic oxygen furnace. The flame temperature relies on the ratio of the relative intensities of the spectral lines. This paper presents a method for flame temperature measurement by calculating the intensity ratio of the emission spectral lines of potassium, and then analyzes the error transfer. The results indicate that the temperature calculated by the characteristic emission spectrum is inosculated to the temperature obtained by sub-lance equipment comparatively.

Analysis of C V Ions by Measuring Line Ratios in the LHD

We measured time-dependent extreme ultraviolet spectra to carry out a quantitative study of impurity spectral lines of C V in the Large Helical Device (LHD) at the National Institute for Fusion Science. In order to analyze these C V spectra, we calculated the intensity ratios of spectral lines of C V using our collisional-radiative model and compared the results to observed time-dependent intensity ratios. We derived the electron temperature from the measured intensity ratio and estimated the location of the C V emitting region by comparing the derived temperature with the electron temperature distribution measured by the Thomson scattering. Through the C V emitting region, we see that the C V appears just after carbon pellet ablation caused by the bulk plasma at 2.8 s and moves toward the wall until ∼3.0 s.

Real Time Cr Measurement Using Optical Emission Spectroscopy During Direct Metal Deposition Process

Real-time chromium composition analysis during direct metal deposition of pure chromium and H13 tool steel materials was performed using optical emission spectroscopy of the laser-induced plasma. Four second-order polynomial calibration curves were constructed using spectral line intensity ratios between two neutral chromium lines and two neutral iron lines. Second-order polynomial calibration curves were also formed using plasma temperature and electron density. The plasma temperature was obtained using Boltzmann plot of nine neutral iron lines between 370 nm and 390 nm. The electron density was estimated using Stark broadening of Fe-I line at 426.047 nm. Chromium concentration in the range from 10% to 60% was measured using these calibration curves in real-time during synthesis process and verified from energy dispersive X-ray spectroscopy of the manufactured parts. The measurement from line intensity ratio calibration curve is more accurate and has less standard deviation than that from plasma temperature and electron density calibration curves. The accuracy of the measured chromium concentration is within 2.78% in at.% and the average resolution of the measurement is around 5.12% in at.% from the averaged values of four line intensity ratio calibration curves.

Plasma parameters of square superlattice pattern in a dielectric barrier discharge

Dielectric barrier discharge is an important method of producing nonequilibrium low-temperature plasma. Measurement of the plasma parameters is highly valuable for its industrial application. Plasma parameters of square superlattice pattern are investigated by optical emission spectroscopy in a dielectric barrier discharge by using a two-liquid-electrode dielectric barrier discharge device in argon at atmospheric pressure. It is found that the light intensity of the large diameter microdischarge channel(big dot) is different from that of the small diameter channel (small dot). Vibrational temperature is investigated by using the N_{2} second positive spectrum. Electronic excitation temperature is measured by means of spectral line intensity ratio. Electron density is obtained by using the stark broadening of Ar atom 696.54 nm spectral line. The results show that the electron density and the vibrational temperature of the small dot are larger than those of the big dot but the electronic excitation temperature is lower than that of the big dot. It is suggested that the plasma state of the big dot is different from that of the small dot in the stable square superlattice pattern.

An analysis of VUV C IV emission from the JET divertor giving measurements of electron temperatures

A description of the radiation emitted by impurities from within a plasma is crucial if spectral line intensities are to be used in detailed studies, such as the analysis of impurity transport. The simplest and most direct check that can be made on measurements of line intensities is to analyse their ratios with other lines from the same ion. This avoids uncertainties in determining the volume of the emitting plasma and the absolute sensitivity calibration of the spectrometer and, in some cases, the need even for accurate measurements of parameters such as electron density. Consistency is required between the measured line intensity ratios and the theoretical values. The expected consistency has not been found for radiation emitted from the JET scrape-off layer (e.g. Lawson et al 2009a JINST 4 P04013), meaning that the description of the spectral line intensities of impurity emission from the plasma edge is incomplete. In order to gain further understanding of the discrepancies, an analysis has been carried out for emission from the JET divertor plasma and this is reported in this paper.Carbon was the main low Z intrinsic impurity in JET and an analysis of spectral line intensity ratios has been made for the C IV radiation emitted from the JET divertor. In this case, agreement is found between the measured and theoretical ratios to a very high accuracy, namely to within the experimental uncertainty of ∼±10%. This confirms that the description of the line intensities for the present observations is complete. For some elements and ionization stages, an analysis of line intensity ratios can lead to the determination of parameters such as the electron temperature of the emitting plasma region and estimates of the contribution of recombination to the electron energy level populations. This applies to C IV and, to show the value and possibilities of the spectral measurements, these parameters have been calculated for a database of Ohmic and additionally heated phases of a large number of pulses. The importance of dielectronic, radiative and charge-exchange recombination as well as ionization has been investigated. In addition, the development of Te throughout two example discharges is illustrated. The presented results indicate a number of areas for further investigation.

Spectroscopic study of electrolytic plasma and discharging behaviour during the plasma electrolytic oxidation (PEO) process

In this study, a plasma electrolytic oxidation (PEO) process was used to produce oxide coatings on commercially pure aluminium (1100 alloy) at a pulsed dc power mode. The effects of process parameters (i.e. current density and treatment time) on the plasma discharge behaviour during the PEO treatment were investigated using optical emission spectroscopy (OES) in the visible and near ultraviolet (NUV) band (285–800 nm). The elements present in the plasma were identified. Stark shifts of spectral lines and line intensity ratios were utilized to determine the plasma electron concentrations and temperatures, respectively. The plasma electron temperature profile, coating surface morphology and coating composition were used to interpret the plasma discharging behaviour. The different coating morphologies and compositions at different coating surface regions are explained in terms of three types of discharge, which originate either at the substrate/coating interface, within the upper layer, or at the coating top layer. The high spike peaks on the plasma intensity and temperature profiles corresponded to discharges originated from the substrate/coating interface, while the base line and small fluctuations were due to discharges at the coating/electrolyte interface.