Tomographic image reconstruction techniques for spectroscopic sources—II. Instrumentation

Monnig, Curtis A.; Gebhart, B. D.; Marshall, K.A.; Hieftje, Gary M.

doi:10.1016/0584-8547(90)80102-o

Cited by 34 publications

(12 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Key parameters in this approach to plasma diagnostics are the electron number density (n e ), electron temperature (T e ), the gas kinetic temperature (T g ) and the argon atom number density (n Ar ). The methods employed involve a combination of Thomson scattering [20][21][22][23][24][25], Rayleigh scattering, computed emission topography [26][27][28] and laser-induced saturated fluorescence [29,30]. Thomson scattering enables measurement of T e and n e .…”

Section: Plasma Diagnostics: Active and Passive Spectroscopic Methodsmentioning

confidence: 99%

Plasma Diagnostics through Kinetic Modelling: Characterization of Matrix Effects during ICP and Flame Atomic Spectrometry in terms of Collisional Radiative Recombination Activation Energy?A Review

Zaranyika¹,

Mahamadi²

2013

J Anal Bioanal Tech

View full text Add to dashboard Cite

Section: Plasma Diagnostics: Active and Passive Spectroscopic Methodsmentioning

confidence: 99%

Plasma Diagnostics through Kinetic Modelling: Characterization of Matrix Effects during ICP and Flame Atomic Spectrometry in terms of Collisional Radiative Recombination Activation Energy?A Review

Zaranyika¹,

Mahamadi²

2013

J Anal Bioanal Tech

View full text Add to dashboard Cite

“…27,28 In essence, the optical system is akin to that in a conventional photographic camera, although here a monochromator stands in place of the aperture in the conventional photographic system. By placing the monochromator entrance slit at the aperture plane of the optical system, and by unscrambling the image of the entrance slit that appears at the exit slit, we are able to collect a full twodimensional image of the discharge at any desired wavelength.…”

Section: Methodsmentioning

confidence: 99%

“…To permit the full three-dimensional structure of the plasma to be unraveled, these images are then collected over a large number of angles spanning a range of 180 degrees. Computed tomography algorithms 28,29 then permit the three-dimensional structure to be displayed, regardless of the lack of plasma symmetry.…”

Section: Methodsmentioning

confidence: 99%

Toward a Fuller Understanding of Analytical Atomic Spectrometry

et al. 2002

View full text Add to dashboard Cite

“…Accordingly, a portion of this work involved the construction of a simple optical imaging spectrometer/spectrograph that included a relatively inexpensive CID surveillance camera. For obvious reasons, this simple set-up could not provide imaging capabilities comparable to an instrument using a spectroscopic grade CCD or CID [23][24][25][26][27][28][29][30][31][32][33], but it provided us with an opportunity to acquire a wealth of spatialresolved data for He ICP in a short time. For comparison, preliminary results also were obtained with a commercial CCD.…”

Section: Introductionmentioning

confidence: 99%

“…The use of charge transfer devices [23,24] such as the charge coupled detector (CCD) or the charge injection detector (CID) can reduce these limitations. Monning et al [25,26] reported the use of a CCD device to produce a three-dimensional structure of the Ar ICP. Hieftje and associates [19,27,28] used a monochromatic imaging spectrometer to investigate the effects of easily ionizable elements on calcium emission in an Ar ICP.…”

mentioning

confidence: 99%

Spectroscopic imaging of atmospheric-pressure helium inductively coupled plasma (ICP) discharges

et al. 1994

View full text Add to dashboard Cite

Spatially-resolved infcrmation from atmospheric-pressure helium inductively coupled plasmas (He ICP) was acquired with a simple, inexpensive optical imaging spectrometer. The system uses a 35-cm focal length Czerny-Turner monochromator/spectrograph and a solid state charge-injection device (CID) or a charge coupled device (CCD). Quantitative image maps of the plasmas were produced with good resolution. For example, when the CID was used, the entire plasma image could be monitored with a spatial resolution of 0. 13 and 0. 10 mm in the horizontal and vertical directions . The spectral resolution was 4 nm. Lateral distributions of emission intensities were converted, using an Abel inversion routine, to radial distributions. Some unique features of the He ICP, compared to the commonly used Ar ICP, were identified at or around analytical conditions for elemental analysis of gaseous and aqueous samples.Knowledge of spatial distributions of emission intensity is important for: 1) obtaining fundamental properties of plasmas (such as temperatures and electron number density), 2) identifying optimum operating conditions of plasma formed in a new torch, and 3) understanding mechanisms of desolvation-vaporizationatomization-excitation-ionization processes [1]. Images of the emission intensity distribution throughout a plasma can be acquired by a number of methods. With a traditional single channel, photomultiplier tube-based spectrometer, emission intensity is registered one point at a time, resulting in a tedious and time-consuming mapping process that often requires several hours to several days. Multichannel array detectors, however, have replaced the single-channel detector for such studies recently. The driving force behind these developments has been the ability to dramatically reduce the data collection time and minimize signal fluctuation which can result from changes in the operating conditions over time.Three types of multichannel array detectors have been evaluated for plasma diagnostics [2]: (a) photodiode arrays (PDAs), (b) silicon intensified target (SIT) vidicons and (c) charge transfer devices. Among these detectors, the PDA has been the most widely used device for fundamental studies of ICP discharges [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. The PDA, however, is a one-dimensional detector and cannot simultaneously capture vertically-and horizontallyresolved emission distributions from plasmas . Two-dimensional SIT vidicons have been used for the measurement of spatially-resolved emission intensities and electron number densities [18][19][20][21][22]. The electronics needed for vidicons are more complex than PDAs, and vidicons also display two undesirable characteristics (bloom and lag). Both bloom and lag can be reduced by programming, but additional time is required. The use of charge transfer devices [23,24] such as the charge coupled detector (CCD) or the charge injection detector (CID) can reduce these limitations. Monning et al. [25,26] reported the use of a CCD device to produce a three-...

show abstract

Tomographic image reconstruction techniques for spectroscopic sources—II. Instrumentation

Cited by 34 publications

References 10 publications

Plasma Diagnostics through Kinetic Modelling: Characterization of Matrix Effects during ICP and Flame Atomic Spectrometry in terms of Collisional Radiative Recombination Activation Energy?A Review

Plasma Diagnostics through Kinetic Modelling: Characterization of Matrix Effects during ICP and Flame Atomic Spectrometry in terms of Collisional Radiative Recombination Activation Energy?A Review

Toward a Fuller Understanding of Analytical Atomic Spectrometry

Spectroscopic imaging of atmospheric-pressure helium inductively coupled plasma (ICP) discharges

Contact Info

Product

Resources

About