scholarly journals Application of Laser-Enhanced Ionization: Atomization Efficiency Determination

1992 ◽  
Vol 46 (9) ◽  
pp. 1370-1375 ◽  
Author(s):  
King-Dow Su ◽  
King-Chuen Lin ◽  
Wei-Tzou Luh
Keyword(s):  
Free Atom ◽  
Number Density ◽  
Atom Number ◽  
Metal Elements ◽  
Atomization Efficiency ◽  
Atom Number Density ◽  
Efficiency Determination

We have demonstrated that the laser-enhanced ionization (LEI) technique can be used to determine the efficiency of atomization of metal elements in an atmospheric acetylene/air flame. We have derived a useful relation between the time-integrated LEI signal and the total free atom number density in a flame. We determine the efficiency of atomization of ∼0.13–0.37 for the lithium element and of ∼1.0 for the sodium element. Our results agree well with AA measurements reported previously.

Experimental and Modeling Studies of B Atom Number Density Distributions in Hot Filament Activated B2H6/H2and B2H6/CH4/H2Gas Mixtures†

2006 ◽  
Vol 110 (9) ◽  
pp. 2868-2875 ◽  
Author(s):  
Dane W. Comerford ◽  
Andrew Cheesman ◽  
Thomas P. F. Carpenter ◽  
David M. E. Davies ◽  
Neil A. Fox ◽  
...  
Keyword(s):  
Number Density ◽  
Atom Number ◽  
Density Distributions ◽  
Modeling Studies ◽  
Atom Number Density ◽  
Hot Filament

scholarly journals Investigation of the on-axis atom number density in the supersonic gas jet under high gas backing pressure by simulation

AIP Advances ◽  
2015 ◽  
Vol 5 (10) ◽  
pp. 107220 ◽  
Author(s):  
Guanglong Chen ◽  
A. S. Boldarev ◽  
Xiaotao Geng ◽  
Yi Xu ◽  
Yunjiu Cao ◽  
...  
Keyword(s):  
Gas Jet ◽  
Number Density ◽  
Atom Number ◽  
Backing Pressure ◽  
Atom Number Density ◽  
Supersonic Gas Jet

Quantification of Gas-Phase H-Atom Number Density by Tungsten Phosphate Glass

2005 ◽  
Vol 44 (1B) ◽  
pp. 732-735 ◽  
Author(s):  
Takashi Morimoto ◽  
Hironobu Umemoto ◽  
Koji Yoneyama ◽  
Atsushi Masuda ◽  
Hideki Matsumura ◽  
...  
Keyword(s):  
Gas Phase ◽  
Phosphate Glass ◽  
Number Density ◽  
Atom Number ◽  
Atom Number Density

scholarly journals Gas-Phase Silicon Atom Densities in the Chemical Vapor Deposition of Silicon from Silane

1993 ◽  
Vol 334 ◽  
Author(s):  
Michael E. Coltrin ◽  
William G. Breiland ◽  
Pauline Ho
Keyword(s):  
Chemical Vapor Deposition ◽  
Gas Phase ◽  
Silicon Atom ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Rotating Disk ◽  
Number Density ◽  
Atom Number ◽  
Density Profiles ◽  
Calculated Density

AbstractSilicon atom number density profiles have been measured using laser-induced fluorescence during the chemical vapor deposition of silicon from silane. Measurements were obtained in a rotating-disk reactor as a function of silane partial pressure and the amount of hydrogen added to the carrier gas. Absolute number densities were obtained using an atomic absorption technique. Results were compared with calculated density profiles from a model of the coupled fluid flow, gas-phase and surface chemistry for an infinite-radius rotating disk. An analysis of the reaction mechanism showed that the unimolecular decomposition of SiH2 is not the dominant source of Si atoms. Profile shapes and positions, and all experimental trends are well matched by the calculations. However, the calculated number density is up to 100 times smaller than measured.

Mass Determination by Direct Measurement of Electron Scattering

1975 ◽  
Vol 33 ◽  
pp. 240-241
Author(s):  
M. K. Lamvik ◽  
A. V. Crewe
Keyword(s):  
Cross Section ◽  
Electron Scattering ◽  
Mass Density ◽  
Variable Mass ◽  
Scattering Cross Section ◽  
Mass Determination ◽  
Number Density ◽  
Cross Sectional ◽  
Thin Slice ◽  
Scattering Cross

If a molecule or atom of material has molecular weight A, the number density of such units is given by n=Nρ/A, where N is Avogadro's number and ρ is the mass density of the material. The amount of scattering from each unit can be written by assigning an imaginary cross-sectional area σ to each unit. If the current I0 is incident on a thin slice of material of thickness z and the current I remains unscattered, then the scattering cross-section σ is defined by I=IOnσz. For a specimen that is not thin, the definition must be applied to each imaginary thin slice and the result I/I0 =exp(-nσz) is obtained by integrating over the whole thickness. It is useful to separate the variable mass-thickness w=ρz from the other factors to yield I/I0 =exp(-sw), where s=Nσ/A is the scattering cross-section per unit mass.

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