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M Zakaullah - One of the best experts on this subject based on the ideXlab platform.
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optical Emission Spectroscopy of ar n2 mixture plasma
Journal of Quantitative Spectroscopy & Radiative Transfer, 2007Co-Authors: Abdul Qayyum, Shaista Zeb, M A Naveed, S A Ghauri, N U Rehman, M ZakaullahAbstract:Abstract Optical Emission Spectroscopy measurements are presented to characterize the different excitation and ionization processes of both atomic and molecular species in Ar–N2 mixture plasma under different discharge conditions. Particularly, the Emission intensities of nitrogen (0–0) band of second positive system at 337.1 nm and (0–0) band of first negative systems at 391.4 nm are used to determine the dependence of their radiative states [ N 2 ( C 3 Π u ) , N 2 + ( B 2 Σ u + ) ] on argon fraction in the mixture. It is observed that the addition of argon gas influences the radiative states differently due to their different populating mechanisms. The results demonstrate that the addition of argon to nitrogen plasma remarkably enhance the population of N 2 ( C 3 Π u ) radiative state through Penning excitation involving argon metastable states. The electron temperature is determined from Ar-I spectral line intensities, using Boltzmann's plot method and is found to depend on argon fraction in the mixture.
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diagnostics of nitrogen plasma by trace rare gas optical Emission Spectroscopy
Journal of Applied Physics, 2005Co-Authors: Abdul Qayyum, Shaista Zeb, M A Naveed, S A Ghauri, M Zakaullah, Abdul WaheedAbstract:Trace rare-gas–optical Emission Spectroscopy is carried out to characterize the nitrogen plasma as a function of discharge parameters. The functional dependence of N2(CΠu3) and N2+(BΣu+2) excited states is monitored by measuring the Emission intensities of the bandheads of second positive and first negative systems. The excited-state population density of N atoms and N2 molecules, extracted from their optical Emission, is related to the ground-state population density after normalizing the changes for excitation cross section and electron energy distribution function by optical actinometry. The electron temperature is determined from the plasma-induced optical Emission of trace rare gas by the line-to-line method. The obtained data may help us to adjust the optimum discharge conditions for the production of active species, which are considered to be important for the desired treatment of the samples.
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optical Emission Spectroscopy of abnormal glow region in nitrogen plasma
Plasma Chemistry and Plasma Processing, 2005Co-Authors: Abdul Qayyum, Shaista Zeb, Abdul Waheed, Shujaat Ali, M ZakaullahAbstract:Optical Emission Spectroscopy of the active species in N2 plasma is carried out to investigate their concentration as a function of discharge parameters such as filling pressure (2.0–7.0 mbar), source power (100–200 W) and gas flow rate (50–300 mg/min). The primary motivation of this work is to obtain reliable information about the concentration of the active species of N2 plasma, which play an important role in plasma surface nitriding processes. Emission intensity from the selected electronic excited states of molecular and atomic species is evaluated as a function of discharge parameters to investigate their concentration. The Emission intensity ratio I(N 2 + )/I(N2) and I(N+)/I(N) of the electronic transitions is also evaluated as a function of discharge parameters to investigate the relative dependence of their concentrations. It is observed that the concentration of the active species of N2 plasma is strongly affected by the filling pressure and source power whereas flow rate has no significant effect. An increased occurrence of N 2 + molecular ions in comparison with N2 molecules, and N+ ions in comparison with N atoms is observed with source power whereas decreased occurrence of N 2 + molecular ions in comparison with N2 molecules, and N+ ions in comparison with N atoms is observed with the rise in filling pressure.
Abdul Qayyum - One of the best experts on this subject based on the ideXlab platform.
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optical Emission Spectroscopy of ar n2 mixture plasma
Journal of Quantitative Spectroscopy & Radiative Transfer, 2007Co-Authors: Abdul Qayyum, Shaista Zeb, M A Naveed, S A Ghauri, N U Rehman, M ZakaullahAbstract:Abstract Optical Emission Spectroscopy measurements are presented to characterize the different excitation and ionization processes of both atomic and molecular species in Ar–N2 mixture plasma under different discharge conditions. Particularly, the Emission intensities of nitrogen (0–0) band of second positive system at 337.1 nm and (0–0) band of first negative systems at 391.4 nm are used to determine the dependence of their radiative states [ N 2 ( C 3 Π u ) , N 2 + ( B 2 Σ u + ) ] on argon fraction in the mixture. It is observed that the addition of argon gas influences the radiative states differently due to their different populating mechanisms. The results demonstrate that the addition of argon to nitrogen plasma remarkably enhance the population of N 2 ( C 3 Π u ) radiative state through Penning excitation involving argon metastable states. The electron temperature is determined from Ar-I spectral line intensities, using Boltzmann's plot method and is found to depend on argon fraction in the mixture.
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diagnostics of nitrogen plasma by trace rare gas optical Emission Spectroscopy
Journal of Applied Physics, 2005Co-Authors: Abdul Qayyum, Shaista Zeb, M A Naveed, S A Ghauri, M Zakaullah, Abdul WaheedAbstract:Trace rare-gas–optical Emission Spectroscopy is carried out to characterize the nitrogen plasma as a function of discharge parameters. The functional dependence of N2(CΠu3) and N2+(BΣu+2) excited states is monitored by measuring the Emission intensities of the bandheads of second positive and first negative systems. The excited-state population density of N atoms and N2 molecules, extracted from their optical Emission, is related to the ground-state population density after normalizing the changes for excitation cross section and electron energy distribution function by optical actinometry. The electron temperature is determined from the plasma-induced optical Emission of trace rare gas by the line-to-line method. The obtained data may help us to adjust the optimum discharge conditions for the production of active species, which are considered to be important for the desired treatment of the samples.
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optical Emission Spectroscopy of abnormal glow region in nitrogen plasma
Plasma Chemistry and Plasma Processing, 2005Co-Authors: Abdul Qayyum, Shaista Zeb, Abdul Waheed, Shujaat Ali, M ZakaullahAbstract:Optical Emission Spectroscopy of the active species in N2 plasma is carried out to investigate their concentration as a function of discharge parameters such as filling pressure (2.0–7.0 mbar), source power (100–200 W) and gas flow rate (50–300 mg/min). The primary motivation of this work is to obtain reliable information about the concentration of the active species of N2 plasma, which play an important role in plasma surface nitriding processes. Emission intensity from the selected electronic excited states of molecular and atomic species is evaluated as a function of discharge parameters to investigate their concentration. The Emission intensity ratio I(N 2 + )/I(N2) and I(N+)/I(N) of the electronic transitions is also evaluated as a function of discharge parameters to investigate the relative dependence of their concentrations. It is observed that the concentration of the active species of N2 plasma is strongly affected by the filling pressure and source power whereas flow rate has no significant effect. An increased occurrence of N 2 + molecular ions in comparison with N2 molecules, and N+ ions in comparison with N atoms is observed with source power whereas decreased occurrence of N 2 + molecular ions in comparison with N2 molecules, and N+ ions in comparison with N atoms is observed with the rise in filling pressure.
Claude Weisbuch - One of the best experts on this subject based on the ideXlab platform.
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evidence for trap assisted auger recombination in mbe grown ingan quantum wells by electron Emission Spectroscopy
arXiv: Mesoscale and Nanoscale Physics, 2020Co-Authors: Daniel J Myers, Andrew C Espenlaub, Kristina Gelzinyte, Erin C Young, Lucio Martinelli, Jacques Peretti, Claude Weisbuch, James S SpeckAbstract:We report on the direct measurement of hot electrons generated in the active region of blue light-emitting diodes grown by ammonia molecular beam epitaxy by electron Emission Spectroscopy. The external quantum efficiency of these devices is <1% and does not droop; thus, the efficiency losses from the intrinsic, interband, electron-electron-hole, or electron-hole-hole Auger should not be a significant source of hot carriers. The detection of hot electrons in this case suggests that an alternate hot electron generating process is occurring within these devices, likely a trap-assisted Auger recombination process.
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evidence for trap assisted auger recombination in mbe grown ingan quantum wells by electron Emission Spectroscopy
Applied Physics Letters, 2020Co-Authors: Daniel J Myers, Andrew C Espenlaub, Kristina Gelzinyte, Erin C Young, Lucio Martinelli, Jacques Peretti, Claude Weisbuch, James S SpeckAbstract:We report on the direct measurement of hot electrons generated in the active region of blue light-emitting diodes grown by ammonia molecular beam epitaxy by electron Emission Spectroscopy. The external quantum efficiency of these devices is <1% and does not droop; thus, the efficiency losses from the intrinsic, interband, electron–electron–hole, or electron–hole–hole Auger should not be a significant source of hot carriers. The detection of hot electrons in this case suggests that an alternate hot electron generating process is occurring within these devices, likely a trap-assisted Auger recombination process.We report on the direct measurement of hot electrons generated in the active region of blue light-emitting diodes grown by ammonia molecular beam epitaxy by electron Emission Spectroscopy. The external quantum efficiency of these devices is <1% and does not droop; thus, the efficiency losses from the intrinsic, interband, electron–electron–hole, or electron–hole–hole Auger should not be a significant source of hot carriers. The detection of hot electrons in this case suggests that an alternate hot electron generating process is occurring within these devices, likely a trap-assisted Auger recombination process.
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Evidence for trap-assisted Auger recombination in MBE grown InGaN quantum wells by electron Emission Spectroscopy
Applied Physics Letters, 2020Co-Authors: Daniel Myers, Andrew C Espenlaub, Kristina Gelzinyte, Lucio Martinelli, Jacques Peretti, Claude Weisbuch, Erin Young, James SpeckAbstract:We report on the direct measurement of hot electrons generated in the active region of blue light-emitting diodes grown by ammonia molecular beam epitaxy by electron Emission Spectroscopy. The external quantum efficiency of these devices is
Ariswan Ariswan - One of the best experts on this subject based on the ideXlab platform.
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KARAKTERISTIK PADA LOGAM BAJA PADUAN DENGAN MENGGUNAKAN METODA X-RAY FLUOROSENCE (XRF) DAN OPTICAL Emission Spectroscopy (OES)
2018Co-Authors: Putra, Risky Hidayat Santoso, Fernandez Fernandez, Ariswan AriswanAbstract:Penelitian ini bertujuan untuk mengetahui komposisi unsur yang terkandung dalam material logam baja Stainless steel, Alloy steel, dan Carbon steel; Menghitung nilai hubungan intensitas dengan persentase unsur logam baja yang diuji (Cr,Ni) yang berpengaruh dalam proses korosi suatu logam; Mengetahui karakteristik dari setiap material baja paduan jenis Zeron 100, SS-310, 17-4PH, dan SS-304; Mengetahui perbandingan hasil uji yang digunakan dari alat Niton XL2 GOLDD yang berbasis X-Rays Fluorosence (XRF) dan ARC Met 8000 dengan prinsip Optical Emission Spectroscopy (OES) untuk lebih cepat dalam melakukan proses pengujian. Data penelitian diperoleh melalui hasil uji persentase kandungan unsur yang terkandung dengan nilai intensitas tertinggi menggunakan XRF XL-2 GOLDD berbasis X-Rays Fluorosence (XRF) dan besar persentase unsur yang tekandung menggunakan Arc Met 8000 berbasis Optical Emission Spectroscopy. Hasil penelitian ini menunjukkan bahwa terdapat berbagai unusr yang terkandung diantaranya Ni, Fe, Mn, Cr ,S, Si, P, Co, Mo dengan komposisi unsur tertinggi ialah unsur Besi (Fe), Kromium (Cr), dan Nickel (Ni). Hasil uji Kromium (Cr) dengan Peak 5,42 KeV dan Nickel (Ni) dengan Peak 7,28 KeV, jenis Zeron 100 memiliki kandungan Kromium sebesar 24,90% dan Nickel 6,80%, jenis SS-310 memiliki kandungan Kromium sebesar 23,90% dan Nickel 19,33%, jenis 17-4PH memiliki kandungan Kromium sebesar 15,4% dan Nickel 4,1%, dan jenis SS-304 memiliki kandungan Kromium sebesar 17,96,9% dan Nickel 7,71%. Dari keempat jenis logam tersebut, Jenis Zeron 100 memiliki ketahanan yang baik terhadap korosi karena tergolong ke dalam jenis Super Duplex Steel. Adapun urutan jenis logam ditinjau dari yang sangat baik tahan terhadap korosi yaitu jenis Zeron 100, SS-310, 17-4PH, dan SS-304. Kata Kunci : Karakteristik Logam, Kandungan Unsur Logam, XRF, OE
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Karakteristik Pada Logam Baja Paduan dengan Menggunakan Metoda X-Rays Fluorosence (XRF) dan Optical Emission Spectroscopy (OES)
2018Co-Authors: Santoso Putra, Risky Hidayat, Fernandez Fernandez, Ariswan AriswanAbstract:Penelitian ini bertujuan untuk mengetahui komposisi unsur yang terkandung dalam material logam baja Stainless steel, Alloy steel, dan Carbon steel; Menghitung nilai hubungan intensitas dengan persentase unsur logam baja yang diuji (Cr,Ni) yang berpengaruh dalam proses korosi suatu logam; Mengetahui karakteristik dari setiap material baja paduan jenis Zeron 100, SS-310, 17-4PH, dan SS-304; Mengetahui perbandingan hasil uji yang digunakan dari alat Niton XL2 GOLDD yang berbasis X-Rays Fluorosence (XRF) dan ARC Met 8000 dengan prinsip Optical Emission Spectroscopy (OES) untuk lebih cepat dalam melakukan proses pengujian. Data penelitian diperoleh melalui hasil uji persentase kandungan unsur yang terkandung dengan nilai intensitas tertinggi menggunakan XRF XL-2 GOLDD berbasis X-Rays Fluorosence (XRF) dan besar persentase unsur yang tekandung menggunakan Arc Met 8000 berbasis Optical Emission Spectroscopy. Hasil penelitian ini menunjukkan bahwa terdapat berbagai unusr yang terkandung diantaranya Ni, Fe, Mn, Cr ,S, Si, P, Co, Mo dengan komposisi unsur tertinggi ialah unsur Besi (Fe), Kromium (Cr), dan Nickel (Ni). Hasil uji Kromium (Cr) dengan Peak 5,42 KeV dan Nickel (Ni) dengan Peak 7,28 KeV, jenis Zeron 100 memiliki kandungan Kromium sebesar 24,90% dan Nickel 6,80%, jenis SS-310 memiliki kandungan Kromium sebesar 23,90% dan Nickel 19,33%, jenis 17-4PH memiliki kandungan Kromium sebesar 15,4% dan Nickel 4,1%, dan jenis SS-304 memiliki kandungan Kromium sebesar 17,96,9% dan Nickel 7,71%. Dari keempat jenis logam tersebut, Jenis Zeron 100 memiliki ketahanan yang baik terhadap korosi karena tergolong ke dalam jenis Super Duplex Steel. Adapun urutan jenis logam ditinjau dari yang sangat baik tahan terhadap korosi yaitu jenis Zeron 100, SS-310, 17-4PH, dan SS-304
R. H. Judge - One of the best experts on this subject based on the ideXlab platform.
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Single vibronic level Emission Spectroscopy of jet-cooled HSiF and DSiF
The Journal of Chemical Physics, 2001Co-Authors: David A. Hostutler, Dennis J Clouthier, R. H. JudgeAbstract:Using the technique of single vibronic level Emission Spectroscopy, the ground state vibrational manifolds of jet-cooled HSiF and DSiF have been studied. The radicals were produced in a pulsed electric discharge jet using trifluorosilane (HSiF3 or DSiF3) as the precursor. The gas phase ground state harmonic vibrational frequencies of both isotopomers have been determined for the first time. A normal coordinate analysis using the vibrational frequencies and literature values for the centrifugal distortion constants allowed the determination of all six ground state force constants. Our previous ground state rotational constants have been combined with the calculated harmonic contributions to the α constants to obtain an average (rz) structure and an estimate of the equilibrium (rez) structure. The reliability of the force constants has been evaluated by Franck–Condon simulations of the Emission spectra and comparisons of the calculated and experimentally determined inertial defects.