Fundamental properties of helium inductively coupled plasmas measured by high-resolution Fourier transform spectrometry (original) (raw)
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Spectrochimica Acta Part B: Atomic Spectroscopy, 1990
The high-resolution Fourier transform spectrometer (FIX) of the Los Alamos National Laboratory was used for diagnostic studies of Ar-N, ICP discharges, High-resolution FIS data were obtained to: (a) conduct analysis of line widths and line shapes for Fe lines to ascertain contributions from the Gaussian and Lore&an components; (b) to calculate the Doppler or translational temperatures of emitting species by using the half width of the Gaussian component; and (c) to determine excitation temperatures based on the relative intensities of many spectral lines. The effect of gas composition and plasma operating ~nditions on line widths, Doppler and excitation temperatures were examined.
Plasma Sources Science and Technology, 2011
The aim of the paper is to test the accuracy of classical spectroscopic methods in the visible domain dedicated to measurements of temperature and electron density in order to conclude about the validity of thermal disequilibrium. The influence of various factors is studied: accuracy of the intensity calibration, Abel inversion of the experimental spectra, excitation temperature deduced from the relative method, absolute excitation temperature, influence of the transition probability accuracy, influence of the Biberman factor value, electron temperature from the line-to-continuum intensity ratio, electron density deduced from Stark broadening, and electron density deduced from the continuum intensity. This spectroscopic investigation is carried out for argon plasma and argon copper plasma both produced by means of an ICP torch operating at atmospheric pressure. Results are given with uncertainties for each evaluated parameter. We show that, first, the electron temperature deduced from the line-to-continuum intensity ratio has to be considered with great care; second, for argon plasma no evidence of thermal disequilibrium can be discerned, whereas for argon copper plasma a small disequilibrium of 1.2 to 1.4 at most is experimentally observed.
Temperature and velocity distributions in an inductively coupled plasma
Spectrochimica Acta Part B: Atomic Spectroscopy, 1981
A~~~omputer simulations of inductively coupled plasma discharges (ICP) with flow patterns similar to those found in spectrochemical analysis were reported previously. In this investigation temperature and velocity distributions are measured under conditions which allow direct comparison with computer calculations for pure argon central gas flows without solution aerosols. Based upon these comparisons, a refined ICP gas flow model is proposed and its application provides agreement within experimental error between measured and calculated velocity and temperature profiles in most regions of the discharge. 1. INTRODUDION THE ABIL.ITY to model an inductively coupled plasma (ICP) discharge provides an efficient approach to the simulation of experimental conditions during the testing of new designs or evaluating of operating conditions for spectrochemical analysis. Models based upon early work of MILLER and AYEN [l] were described previously for argonand nitrogen-supported ICP discharges operating over a 15-70 MHz frequency range and 0.5-5 kW power domain with the injection of dried powder aluminum oxide sample into torch configurations commonly employed in spectrochemical analysis [2-51. At that time few experimental measurements of the temperature or velocity distributions in spectrochemical ICP discharges were available, and models of central stream flow were based upon empirical observations. In the meantime, spatial temperature and atom and electron number density distributions were reported by KALNICKY et al. [6,7], MERMET et al. [S-12], KORNBLUM and DE GALAN [13,14], and ALDER et al. [15]. Experimental velocity distributions, in contrast, have not been reported for a spectrochemical ICP, although KLUBNIKIN et al. [l&17] and others as cited in references [18] and [19] have reported velocity distributions in non-spectrochemical ICP discharges.
Applied Spectroscopy, 2001
In order to investigate evaporation and desolvation capacities of the enclosed inductively coupled plasma discharge, rotational temperatures (which are com monly considered a good approximation of the heavy particle temperature or gas temperature) were determined as a function of their spatial distribution and their dependence on physical parameters such as gas ows (80-740 mL/min), moisture load, etc. The procedure utilizes the ne structure of the (A 2 S 1 ® X 2 P i ) O H band having its band head at 306.4 nm. The rotational temperatures were obtained from the slopes of their Boltzmann plots. Spatial resolution and simultaneous line detection was possible by using a charge-coupled device (CCD) cam era in the focal plane of the removed exit slit of a Czerny-Turner m onochromator. An interactive data language (ID L) program was developed to calculate the temperature distribution from the received CCD images. Results of the measurement show that the rotational temperatures are between 3750 and 4350 K . They further show the Mshaped spatial pro le of analyte intensities and temperature. In the examined gas ow range (80-740 mL/min) the dependence on absolute gas ows and moisture load (5 mg/L) is negligible.
Journal of Applied Physics, 2009
The CN ͑B 2 ⌺ +-X 2 ⌺ + ͒ molecular emission spectrum is used to measure both the vibrational and rotational temperatures in atmospheric pressure arc jet discharges. The vibrational and rotational temperature effects on the synthetic diatomic molecular spectra were investigated from the ͑vЈ , vЉ͒ = ͑0,0͒ band to the ͑5,5͒ band. The temperatures obtained from the synthetic spectra compared with the experimental result of a low-frequency arc discharge show a vibrational temperature of ͑4250-5010͒ K and a rotational temperature of ͑3760-3980͒ K for the input power in the range of ͑80-280͒ W. As the ͑0,0͒ band is isolated from other vibrational transition bands, determination of the rotational temperature is possible based only on the ͑0,0͒ band, which simplifies the temperature measurement. From the result, it was found that the CN molecular spectrum can be used as a thermometer for atmospheric pressure plasmas containing carbon and nitrogen.
Plasma diagnostic on a low-flow plasma for inductively coupled plasma optical emission spectrometry
Spectrochimica Acta Part B-atomic Spectroscopy, 2008
In order to elucidate the fundamental properties of a low-flow inductively coupled plasma (ICP) operated under total Ar consumption of 0.6 L min − 1 , excitation temperatures, rotational temperatures, ionization temperatures, electron temperatures, and electron number densities were studied with optical emission based methods. The plasma was operated in the SHIP torch (Static High Sensitivity ICP), which was designed for optical emission spectrometric detection. For the first time, this plasma was studied in a laterally resolved manner and at selected observation heights. The Boltzmann plot method was used to obtain excitation and rotational temperatures in the range of 5000-8000 K and 3100-4000 K, respectively. Electron temperatures were determined from the line-to-continuum method to be as high as 9000 K in the analytical channel. The electron number densities were determined with the hydrogen-beta line method and found to be in the range of 5-8×10 15 cm − 3 at 1.1 kW radio frequency (rf) power. Ionization temperatures between 6250 and 7750 K were found at different observation heights in the plasma. The influence of applied rf powers between 0.9 and 1.2 kW on selected key parameters was investigated. The low-flow plasma exhibited temperature ranges similar to those prevailing in conventional ICP sources.
… Acta Part B: Atomic …, 2007
In Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) spectrochemical analysis, the MgII(280.270 nm)/MgI(285.213 nm) ionic to atomic line intensity ratio is commonly used as a monitor of the robustness of operating conditions. This approach is based on the univocal relationship existing between intensity ratio and plasma temperature, for a pure argon atmospheric ICP in thermodynamic equilibrium. In a multielemental plasma in the lower temperature range, the measurement of the intensity ratio may not be sufficient to characterize temperature and electron density. In such a range, the correct relationship between intensity ratio and plasma temperature can be calculated only when the complete plasma composition is known. We propose the combination of the line intensity ratios of two test elements (double ratio) as an effective diagnostic tool for a multi-elemental low temperature LTE plasma of unknown composition. In particular, the variation of the double ratio allows us discriminating changes in the plasma temperature from changes in the electron density. Thus, the effects on plasma excitation and ionization possibly caused by introduction of different samples and matrices in non-robust conditions can be more accurately interpreted. The method is illustrated by the measurement of plasma temperature and electron density in a specific analytic case.
The Astrophysical Journal, 2000
On 1999 May 9 the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) spectrometer on the Solar and Heliospheric Observatory (SOHO) recorded spectra from a high-temperature region located in the solar corona above the west limb. These spectra contain lines from rather less-abundant elements in solar plasmas. In this paper we present identiÐcations of the high-temperature K) Ne, (T e º 3 ] 106 Na, Mg, Ar, K, Ca, Ti, Cr, Mn, Fe, Co, and Ni lines that were detected in the 500È1600 spectral range A of SUMER. In addition, accurate wavelength measurements have been obtained with uncertainties varying between 0.015 and 0.040
Plasma Formed in Argon, Acid Nitric and Water Used in Industrial ICP Torches
Plasma Science and Technology, 2012
Inductively coupled plasmas (ICPs) are used in spectrochemical analyses. The introduction of the sample by means of an aerosol are widely used. The introduction and the total evaporation of the aerosol is required in order to obtain a good repeatability and reproducibility of analyses. To check whether the vaporization of the aerosol droplets inside the plasma is completed, a solution could be used to compare the experimental results of the emission spectral lines with theoretical results. An accurate calculation code to obtain monatomic spectral lines intensities is therefore required, which is the purpose of the present paper. The mixtures of argon, water and nitric acid are widely used in spectrochemical analyses with ICPs. With these mixtures, we calculate the composition, thermodynamic functions and monatomic spectral lines intensities of the plasma at thermodynamic equilibrium and at atmospheric pressure. To obtain a self sufficient paper and also to allow other researchers to compare their results, all required data and a robust accurate algorithm, which is simple and easy to compute, are given.