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Papers by Nikola Konjevic

We report results of optical emission spectroscopy measurements of rotational Trot and translatio... more We report results of optical emission spectroscopy measurements of rotational Trot and translational temperature Ttr of hydrogen molecules. The light source was hollow cathode glow discharge with titanium cathode operated in hydrogen at low pressure. The rotational temperature of excited electronic states of H2 was determined either from relative line intensities of the R branch of the GK → B band or from the Q branch of the Fulcher-α diagonal band. The population of excited energy levels, determined from relative line intensities, was used to derive ro-vibronic temperature of the ground state of hydrogen molecule.

The presented results are concerned with the shape of Balmer alpha line emitted from a low pressu... more The presented results are concerned with the shape of Balmer alpha line emitted from a low pressure DC glow discharge with aluminum (Al) and copper (Cu) hollow cathode (HC) in pure H2 and Ar-Hi gas mixture. The analysis indicates that the line profile represents a convolution of Gaussian profiles resulting from different collision excitation processes.

Journal of Physics B: Atomic and Molecular Physics, 1977

The halfwidths of seven Si III and four Si IV lines have been measured in a pulsed arc. The elect... more The halfwidths of seven Si III and four Si IV lines have been measured in a pulsed arc. The electron density of 5.8*1016 cm-3 was determined by laser interferometry, while the electron temperature of 25600 K was measured from a Boltzmann plot of the relative intensities of the Cl III lines. The experimental Si III and Si IV Stark-profile halfwidths were compared with calculated values obtained from Baranger's semiclassical (1962) and Griem's semiempirical (1968) approaches. The agreement between experiment and semiempirical (1968) approaches. The agreement between experiment and semiempirical results is within 15%.

The European Physical Journal D, 2005

Results of a Doppler spectroscopy study of hydrogen and deuterium Balmer lines in the stainless s... more Results of a Doppler spectroscopy study of hydrogen and deuterium Balmer lines in the stainless steel and copper hollow cathode glow discharge, operated in pure hydrogen, deuterium and mixtures of inert gases with hydrogen, are reported. For all gases and gas mixtures plasma observations perpendicular to electric field revealed the excessively large Doppler broadening. By changing mode of glow discharge operation, the Doppler broadened line profiles in helium-hydrogen mixture are recorded parallel to the discharge electric field as well. The excessively broadened part of the Hα line profile is shifted towards blue or red wavelength by changing the direction of electric field vector. The presence of large excessive Balmer lines broadening in pure hydrogen and in its gas mixture with neon as well as shifting of the excessively broadened part of line profile by means of electric field is in contradiction with the resonance transfer model proposed by Mills et al. in several publications, see e.g. [IEEE Trans. Plasma Sci. 31, 338 (2003)].

Journal of Analytical Atomic Spectrometry

Looking “behind” the negative glow plasma: can we unveil the parameters describing the electric f... more Looking “behind” the negative glow plasma: can we unveil the parameters describing the electric field distribution in the cathode sheath of the Grimm-type glow discharge source using standard end-on optical emission spectroscopy? We believe we can.

AIP Advances, 2021

We present the results of an experimental study of Ar II line shapes emitted side-on from the cat... more We present the results of an experimental study of Ar II line shapes emitted side-on from the cathode sheath (CS) region of an abnormal glow discharge operating in pure argon with different cathode materials. The shape of Ar II lines is recorded side-on to the discharge axis and parallel to the plane cathode surface by using the optical emission spectroscopy technique. Our experimental line shape analysis shows that the atomic line shapes can be used for determination of the electric field strength distribution and the thickness of the CS region, whereas the broadened wings of the Ar II lines provide an insight into line shape formation as a result of electric field strength distribution, which is essential for discharge particle dynamics, and interaction with the discharge gas and sputtered cathode material. The results are summarized in two analytic formulas: one for the half width of wings as a function of the cathode distance from the recording position and the other for correlation between Ar II line width and electric field strength.

Journal of Quantitative Spectroscopy and Radiative Transfer, 2021

Plasma Sources Science and Technology, 2020

We report results of an experimental and theoretical study of complex UV line shapes of Ne II 369... more We report results of an experimental and theoretical study of complex UV line shapes of Ne II 369.421 nm, Ne II 371.308 nm and Ne II 372.711 nm lines in the cathode sheath (CS) region of an abnormal glow discharge in pure neon. The experimental profiles were studied by means of the optical emission spectroscopy (OES) in conjunction with an iterative CS kinetic model. It is shown that our theoretical model describes the experimental line shapes and that, with the aid of the measured Stark shifts of atomic neon lines, it can be used for the determination of the most important CS parameters (e.g. the thickness of the CS region, distribution of electric field, and the gas temperature). We draw attention to the possibility of determining the electric field strength in CS from the width of the pedestal of the complex line profiles

Journal of Quantitative Spectroscopy and Radiative Transfer, 2020

Abstract In this paper, we present results of rotational, vibrational, and gas temperature distri... more Abstract In this paper, we present results of rotational, vibrational, and gas temperature distribution study in the cathode-sheath region of an abnormal glow discharge in hydrogen and hydrogen-argon mixture. For this purpose, we used Q-branch of the Fulcher-α diagonal bands d3Π−u, ν′=0, 1, 2, 3→ a3Σ+g, ν″=0, 1, 2, 3. The boundary between the cathode sheat and negative glow region is determined as the position where the electric field strength falls to zero. For the electric field measurement Stark polarization spectroscopy of hydrogen Balmer alpha line was employed and the thickness of cathode sheat is estimated by fitting the experimentally obtained distribution of electric field strength to a suitable model function.The temperature values, measured in the cathode sheath from different vibrational bands, decrease with vibrational quantum number v′ increase. The vibrational temperature is determined from the relative intensities of vibrational bands of the Fulcher-α system (d3Π−u→ a3Σ+g electronic transition; Q-branch v′= v″=2 and v′= v″=3). Temperature distributions along the axis of the cathode sheath are also reported and discussed. The distributions of rotational temperature show that all three temperatures (gas, rotational and vibrational) vary along the cathode sheath region of discharge and that all four bands give consistent values for the rotational temperature. The measurements performed with high spectral resolution provide further insight into understanding or modelling the DC glow discharge. The reported results represent the contribution to the development of the spectroscopic method for gas temperature measurement.

EPL (Europhysics Letters), 2018

We report results of the experimental study of the singly charged beryllium spectral line 436.1 n... more We report results of the experimental study of the singly charged beryllium spectral line 436.1 nm, transition , and forbidden component, transition , which is for the first time identified in this work. Beryllium lines are recorded from gas discharge, after ablation of a beryllium oxide discharge tube, running in pulsed regime with the following gases: helium with traces of hydrogen, argon with traces of hydrogen and pure krypton. The ratio of line intensities and wavelength separation of the Be II 436.1 nm line and neighbouring line located at the blue wing are followed in the electron density range (1.16–6.4) × 10 22 m −3 determined from the hydrogen Balmer beta line ( ) in the electron temperature interval between 10500 K and 15500 K. The functional dependence of the wavelength separation range and peak intensity ratio of these lines upon electron number density suggests the complex profile of the forbidden and allowed line, which can be used for diagnostics of low-temperature beryllium containing plasmas.

E3S Web of Conferences, 2019

Cruise tourism, most often, is related to the landing of a ship in one or more ports, i.e. touris... more Cruise tourism, most often, is related to the landing of a ship in one or more ports, i.e. tourist destinations, in which passengers and crew go ashore. In the richness of the offer that a port in the Adriatic and the Mediterranean offers to cruise tourists is certainly the part that can be called: culture, tradition, monuments, by which the areas on the map of world cruises are recognized. The port of Kotor, which is the main port for the reception of cruise ships in Montenegro, has for years achieved significant results in the reception and dispatch of cruise ships. Thus, through the port of Kotor, during 2018, 412 ships carrying 492, 475 passengers visited Montenegro. The paper, through the example of the Roman Mosaic site in Risan in the Bay of Boka Kotorska, analyses the effects of organized visits by tourists from cruise ships arriving to Kotor, and the importance and value of archeological sites in tourist cruising offer and the interaction between business and culture. The a...

EPL (Europhysics Letters), 2017

We present a study of argon glow discharge which shows that measured wavenumber DC Stark shifts o... more We present a study of argon glow discharge which shows that measured wavenumber DC Stark shifts of two neutral argon lines, Ar I 518.75 nm and Ar I 522.127 nm, can be used for reliable determination of the electric field strength F distribution in the cathode sheath region of the discharge. In order to experimentally determine the coefficient c in quadratic correlation , manifested in a low field range (up to 15 kV/cm), the discharge is seeded with a small admixture of hydrogen, and the values of F are measured via Stark polarization spectroscopy of the hydrogen Balmer beta line. Once known, this can be used for the determination of F by a simple and inexpensive spectroscopic Stark shift measurement in discharges with other argon admixtures or pure argon. Reported shift results are in good agreement with data extrapolated from measurements performed at high electric fields (over 100 kV/cm) by Windholz ( Phys. Scr. , 21 (1980) 67).

Journal of Physics D: Applied Physics, 2017

We present the results of an experimental study of the DC Stark shift for seven visible NeI lines... more We present the results of an experimental study of the DC Stark shift for seven visible NeI lines in the plane cathode sheath region of an abnormal glow discharge operated in neon with a small admixture of hydrogen. The electric field (up to 13.4 kV cm−1) in the cathode sheath region is measured from the π-polarized profile of the H alpha line of hydrogen using the Stark polarization spectroscopy technique. Within the realized range of the electric field, the NeI lines exhibit a quadratic Stark effect. The values of coefficients, correlating Stark shift and electric field strength, were determined, enabling their future use for unknown electric field strength measurements. Among the studied lines, so far only the Stark effect analysis of the NeI 511.367 nm line has been reported, in which case our results are in good agreement with the best fit formula proposed by Jager and Windholz (1984 Phys. Scr. 29 344) for one out of three Stark components detected under our experimental conditions.

Spectrochimica Acta Part B: Atomic Spectroscopy, 2017

In this work we summarize, analyze and critically evaluate experimental procedures and results of... more In this work we summarize, analyze and critically evaluate experimental procedures and results of LIBS electron number density plasma characterization using as examples Stark broadened Si I and Si II line profiles. Selected publications are covering the time period from very beginning of silicon LIBS studies until the end of the year 2015. To perform the analysis of experimental LIBS data, the testing of available semiclassical theoretical Stark broadening parameters for Si I and Si II lines was accomplished first. This is followed by the description of experimental setups, results and details of experimental procedure relevant for the line shape analysis of spectral lines used for plasma characterization. Although most of results and conclusions of this analysis are related to the application of silicon lines for LIBS characterization they are of general importance and may be applied to other elements and different low-temperature plasma sources. The analysis of experimental procedures used for LIBS diagnostics from emission profiles of non-hydrogenic spectral lines is carried out in the following order: the influence of laser ablation and crater formation, spatial and temporal plasma observation, line selfabsorption and experimental profile deconvolution, the contribution of ion broadening in comparison with electron impacts contributions to the line width in case of neutral atom line and some other aspects of line shape analysis are considered. The application of Stark shift for LIBS diagnostics is demonstrated and discussed. Finally, the recommendations for an improvement of experimental procedures for LIBS electron number density plasma characterization are offered.

AIP Conference Proceedings, 2004

A short review of experiments dealing with excessive Doppler broadening of hydrogen and deuterium... more A short review of experiments dealing with excessive Doppler broadening of hydrogen and deuterium Balmer lines in various gas discharges is presented. Both old and new experimental data of excessive line broadening are discussed from the point of view of the collision model and the resonance transfer model. The results of several new experiments reported here, like the earlier ones, clearly support the collision model of excessive broadening.

Publications De L Observatoire Astronomique De Beograd, Nov 1, 1999

We report results of optical emission spectroscopy measurements of rotational Trot and translatio... more We report results of optical emission spectroscopy measurements of rotational Trot and translational temperature Ttr of hydrogen molecules. The light source was hollow cathode glow discharge with titanium cathode operated in hydrogen at low pressure. The rotational temperature of excited electronic states of H2 was determined either from relative line intensities of the R branch of the GK → B band or from the Q branch of the Fulcher-α diagonal band. The population of excited energy levels, determined from relative line intensities, was used to derive ro-vibronic temperature of the ground state of hydrogen molecule.

The presented results are concerned with the shape of Balmer alpha line emitted from a low pressu... more The presented results are concerned with the shape of Balmer alpha line emitted from a low pressure DC glow discharge with aluminum (Al) and copper (Cu) hollow cathode (HC) in pure H2 and Ar-Hi gas mixture. The analysis indicates that the line profile represents a convolution of Gaussian profiles resulting from different collision excitation processes.

Journal of Physics B: Atomic and Molecular Physics, 1977

The halfwidths of seven Si III and four Si IV lines have been measured in a pulsed arc. The elect... more The halfwidths of seven Si III and four Si IV lines have been measured in a pulsed arc. The electron density of 5.8*1016 cm-3 was determined by laser interferometry, while the electron temperature of 25600 K was measured from a Boltzmann plot of the relative intensities of the Cl III lines. The experimental Si III and Si IV Stark-profile halfwidths were compared with calculated values obtained from Baranger's semiclassical (1962) and Griem's semiempirical (1968) approaches. The agreement between experiment and semiempirical (1968) approaches. The agreement between experiment and semiempirical results is within 15%.

The European Physical Journal D, 2005

Results of a Doppler spectroscopy study of hydrogen and deuterium Balmer lines in the stainless s... more Results of a Doppler spectroscopy study of hydrogen and deuterium Balmer lines in the stainless steel and copper hollow cathode glow discharge, operated in pure hydrogen, deuterium and mixtures of inert gases with hydrogen, are reported. For all gases and gas mixtures plasma observations perpendicular to electric field revealed the excessively large Doppler broadening. By changing mode of glow discharge operation, the Doppler broadened line profiles in helium-hydrogen mixture are recorded parallel to the discharge electric field as well. The excessively broadened part of the Hα line profile is shifted towards blue or red wavelength by changing the direction of electric field vector. The presence of large excessive Balmer lines broadening in pure hydrogen and in its gas mixture with neon as well as shifting of the excessively broadened part of line profile by means of electric field is in contradiction with the resonance transfer model proposed by Mills et al. in several publications, see e.g. [IEEE Trans. Plasma Sci. 31, 338 (2003)].

Journal of Analytical Atomic Spectrometry

Looking “behind” the negative glow plasma: can we unveil the parameters describing the electric f... more Looking “behind” the negative glow plasma: can we unveil the parameters describing the electric field distribution in the cathode sheath of the Grimm-type glow discharge source using standard end-on optical emission spectroscopy? We believe we can.

AIP Advances, 2021

We present the results of an experimental study of Ar II line shapes emitted side-on from the cat... more We present the results of an experimental study of Ar II line shapes emitted side-on from the cathode sheath (CS) region of an abnormal glow discharge operating in pure argon with different cathode materials. The shape of Ar II lines is recorded side-on to the discharge axis and parallel to the plane cathode surface by using the optical emission spectroscopy technique. Our experimental line shape analysis shows that the atomic line shapes can be used for determination of the electric field strength distribution and the thickness of the CS region, whereas the broadened wings of the Ar II lines provide an insight into line shape formation as a result of electric field strength distribution, which is essential for discharge particle dynamics, and interaction with the discharge gas and sputtered cathode material. The results are summarized in two analytic formulas: one for the half width of wings as a function of the cathode distance from the recording position and the other for correlation between Ar II line width and electric field strength.

Journal of Quantitative Spectroscopy and Radiative Transfer, 2021

Plasma Sources Science and Technology, 2020

We report results of an experimental and theoretical study of complex UV line shapes of Ne II 369... more We report results of an experimental and theoretical study of complex UV line shapes of Ne II 369.421 nm, Ne II 371.308 nm and Ne II 372.711 nm lines in the cathode sheath (CS) region of an abnormal glow discharge in pure neon. The experimental profiles were studied by means of the optical emission spectroscopy (OES) in conjunction with an iterative CS kinetic model. It is shown that our theoretical model describes the experimental line shapes and that, with the aid of the measured Stark shifts of atomic neon lines, it can be used for the determination of the most important CS parameters (e.g. the thickness of the CS region, distribution of electric field, and the gas temperature). We draw attention to the possibility of determining the electric field strength in CS from the width of the pedestal of the complex line profiles

Journal of Quantitative Spectroscopy and Radiative Transfer, 2020

Abstract In this paper, we present results of rotational, vibrational, and gas temperature distri... more Abstract In this paper, we present results of rotational, vibrational, and gas temperature distribution study in the cathode-sheath region of an abnormal glow discharge in hydrogen and hydrogen-argon mixture. For this purpose, we used Q-branch of the Fulcher-α diagonal bands d3Π−u, ν′=0, 1, 2, 3→ a3Σ+g, ν″=0, 1, 2, 3. The boundary between the cathode sheat and negative glow region is determined as the position where the electric field strength falls to zero. For the electric field measurement Stark polarization spectroscopy of hydrogen Balmer alpha line was employed and the thickness of cathode sheat is estimated by fitting the experimentally obtained distribution of electric field strength to a suitable model function.The temperature values, measured in the cathode sheath from different vibrational bands, decrease with vibrational quantum number v′ increase. The vibrational temperature is determined from the relative intensities of vibrational bands of the Fulcher-α system (d3Π−u→ a3Σ+g electronic transition; Q-branch v′= v″=2 and v′= v″=3). Temperature distributions along the axis of the cathode sheath are also reported and discussed. The distributions of rotational temperature show that all three temperatures (gas, rotational and vibrational) vary along the cathode sheath region of discharge and that all four bands give consistent values for the rotational temperature. The measurements performed with high spectral resolution provide further insight into understanding or modelling the DC glow discharge. The reported results represent the contribution to the development of the spectroscopic method for gas temperature measurement.

EPL (Europhysics Letters), 2018

We report results of the experimental study of the singly charged beryllium spectral line 436.1 n... more We report results of the experimental study of the singly charged beryllium spectral line 436.1 nm, transition , and forbidden component, transition , which is for the first time identified in this work. Beryllium lines are recorded from gas discharge, after ablation of a beryllium oxide discharge tube, running in pulsed regime with the following gases: helium with traces of hydrogen, argon with traces of hydrogen and pure krypton. The ratio of line intensities and wavelength separation of the Be II 436.1 nm line and neighbouring line located at the blue wing are followed in the electron density range (1.16–6.4) × 10 22 m −3 determined from the hydrogen Balmer beta line ( ) in the electron temperature interval between 10500 K and 15500 K. The functional dependence of the wavelength separation range and peak intensity ratio of these lines upon electron number density suggests the complex profile of the forbidden and allowed line, which can be used for diagnostics of low-temperature beryllium containing plasmas.

E3S Web of Conferences, 2019

Cruise tourism, most often, is related to the landing of a ship in one or more ports, i.e. touris... more Cruise tourism, most often, is related to the landing of a ship in one or more ports, i.e. tourist destinations, in which passengers and crew go ashore. In the richness of the offer that a port in the Adriatic and the Mediterranean offers to cruise tourists is certainly the part that can be called: culture, tradition, monuments, by which the areas on the map of world cruises are recognized. The port of Kotor, which is the main port for the reception of cruise ships in Montenegro, has for years achieved significant results in the reception and dispatch of cruise ships. Thus, through the port of Kotor, during 2018, 412 ships carrying 492, 475 passengers visited Montenegro. The paper, through the example of the Roman Mosaic site in Risan in the Bay of Boka Kotorska, analyses the effects of organized visits by tourists from cruise ships arriving to Kotor, and the importance and value of archeological sites in tourist cruising offer and the interaction between business and culture. The a...

EPL (Europhysics Letters), 2017

We present a study of argon glow discharge which shows that measured wavenumber DC Stark shifts o... more We present a study of argon glow discharge which shows that measured wavenumber DC Stark shifts of two neutral argon lines, Ar I 518.75 nm and Ar I 522.127 nm, can be used for reliable determination of the electric field strength F distribution in the cathode sheath region of the discharge. In order to experimentally determine the coefficient c in quadratic correlation , manifested in a low field range (up to 15 kV/cm), the discharge is seeded with a small admixture of hydrogen, and the values of F are measured via Stark polarization spectroscopy of the hydrogen Balmer beta line. Once known, this can be used for the determination of F by a simple and inexpensive spectroscopic Stark shift measurement in discharges with other argon admixtures or pure argon. Reported shift results are in good agreement with data extrapolated from measurements performed at high electric fields (over 100 kV/cm) by Windholz ( Phys. Scr. , 21 (1980) 67).

Journal of Physics D: Applied Physics, 2017

We present the results of an experimental study of the DC Stark shift for seven visible NeI lines... more We present the results of an experimental study of the DC Stark shift for seven visible NeI lines in the plane cathode sheath region of an abnormal glow discharge operated in neon with a small admixture of hydrogen. The electric field (up to 13.4 kV cm−1) in the cathode sheath region is measured from the π-polarized profile of the H alpha line of hydrogen using the Stark polarization spectroscopy technique. Within the realized range of the electric field, the NeI lines exhibit a quadratic Stark effect. The values of coefficients, correlating Stark shift and electric field strength, were determined, enabling their future use for unknown electric field strength measurements. Among the studied lines, so far only the Stark effect analysis of the NeI 511.367 nm line has been reported, in which case our results are in good agreement with the best fit formula proposed by Jager and Windholz (1984 Phys. Scr. 29 344) for one out of three Stark components detected under our experimental conditions.

Spectrochimica Acta Part B: Atomic Spectroscopy, 2017

In this work we summarize, analyze and critically evaluate experimental procedures and results of... more In this work we summarize, analyze and critically evaluate experimental procedures and results of LIBS electron number density plasma characterization using as examples Stark broadened Si I and Si II line profiles. Selected publications are covering the time period from very beginning of silicon LIBS studies until the end of the year 2015. To perform the analysis of experimental LIBS data, the testing of available semiclassical theoretical Stark broadening parameters for Si I and Si II lines was accomplished first. This is followed by the description of experimental setups, results and details of experimental procedure relevant for the line shape analysis of spectral lines used for plasma characterization. Although most of results and conclusions of this analysis are related to the application of silicon lines for LIBS characterization they are of general importance and may be applied to other elements and different low-temperature plasma sources. The analysis of experimental procedures used for LIBS diagnostics from emission profiles of non-hydrogenic spectral lines is carried out in the following order: the influence of laser ablation and crater formation, spatial and temporal plasma observation, line selfabsorption and experimental profile deconvolution, the contribution of ion broadening in comparison with electron impacts contributions to the line width in case of neutral atom line and some other aspects of line shape analysis are considered. The application of Stark shift for LIBS diagnostics is demonstrated and discussed. Finally, the recommendations for an improvement of experimental procedures for LIBS electron number density plasma characterization are offered.

AIP Conference Proceedings, 2004

A short review of experiments dealing with excessive Doppler broadening of hydrogen and deuterium... more A short review of experiments dealing with excessive Doppler broadening of hydrogen and deuterium Balmer lines in various gas discharges is presented. Both old and new experimental data of excessive line broadening are discussed from the point of view of the collision model and the resonance transfer model. The results of several new experiments reported here, like the earlier ones, clearly support the collision model of excessive broadening.

Publications De L Observatoire Astronomique De Beograd, Nov 1, 1999

J.Phys.Chem.Ref.Data , 1982

Spectral Line Shapes: 16th …, 2002

We have extended our critical review of the available experimental data on Stark widths and shift... more We have extended our critical review of the available experimental data on Stark widths and shifts for spectral lines of non-hydrogenic neutral atoms and positive ions by one year, including the year 2000, so that we now cover the period from 1989 through the end of 2000. Our recently completed new review represents a continuation of earlier critical reviews up to 1988. Data tables containing the selected experimental Stark broadening parameters are presented with estimated accuracies. Guidelines for the accuracy estimates, developed during the previous reviews, are summarized. The data are arranged according to elements and spectra, and these are presented in alphabetical and numerical order, respectively. A total of 77 spectra are covered, and the material on multiply charged ions has significantly increased. Comparisons with comprehensive calculations based on semi-classical theory are made whenever possible, since the comparison with theory has often been a principal motivation for the experiments.

Journal of Physical and Chemical Reference Data, 2002

We have extended our critical review of the available experimental data on Stark widths and shift... more We have extended our critical review of the available experimental data on Stark widths and shifts for spectral lines of non-hydrogenic neutral atoms and positive ions by one year, including the year 2000, so that we now cover the period from 1989 through the end of 2000. Our recently completed new review represents a continuation of earlier critical reviews up to 1988. Data tables containing the selected experimental Stark broadening parameters are presented with estimated accuracies. Guidelines for the accuracy estimates, developed during the previous reviews, are summarized. The data are arranged according to elements and spectra, and these are presented in alphabetical and numerical order, respectively. A total of 77 spectra are covered, and the material on multiply charged ions has significantly increased. Comparisons with comprehensive calculations based on semi-classical theory are made whenever possible, since the comparison with theory has often been a principal motivation for the experiments.

Spectrochimica Acta Part B: Atomic Spectroscopy, 2010

Spectrochimica Acta Part B: Atomic Spectroscopy, 2012

We present an analysis of the procedure for plasma electron number density, N e , diagnostics bas... more We present an analysis of the procedure for plasma electron number density, N e , diagnostics based on the comparison of theoretical and experimental shape or width of hydrogen Balmer lines. Low N e diagnostics, requiring an extension of available theoretical Stark broadening data tables was examined first. The difficulties encountered during experimental line profile analysis at low N e are discussed and appropriate procedures suggested. The widely adopted deconvolution of experimental profile by fitting with a Voigt function is examined and it is shown that this deconvolution introduces large systematic error in Stark width determination. This uncertainty can be decreased but never completely avoided by fixing the Gaussian part of the Voigt function. Simple formulas of satisfactory accuracy for deconvolution at the half width of experimental profile were investigated and their application recommended. The contribution of Van der Waals broadening to the experimental profile is examined and the correction for its contribution discussed. Approximate and reliable formulas for the evaluation of N e from the Stark width were critically evaluated. To estimate the applicability of different sets of theoretical data for N e diagnostics, a comparison of theory versus experiments was carried out and best data tables were recommended. For low N e diagnostics the application of higher members of Balmer series is advised whenever possible.

Physics Reports, 1999

... Although the theory was used only as a consistency check, an important conclusion is derived ... more ... Although the theory was used only as a consistency check, an important conclusion is derived from ... effect due to the quasistatic field of ions shifts the energy of the upper and lower ... By taking into account the linear dependence of the Stark broadening parameters upon N e for ...