scholarly journals An investigation of internal ion number density and electron temperature profiles in a laboratory-model Hall thruster

2000 ◽  
Author(s):  
James Haas ◽  
Alec Gallimore
Keyword(s):  
Electron Temperature ◽  
Hall Thruster ◽  
Laboratory Model ◽  
Temperature Profiles ◽  
Number Density

scholarly journals Magnetic field effect on laser-induced breakdown spectroscopy and surface modifications of germanium at various fluences

2017 ◽  
Vol 35 (1) ◽  
pp. 159-169 ◽  
Author(s):  
H. Iftikhar ◽  
S. Bashir ◽  
A. Dawood ◽  
M. Akram ◽  
A. Hayat ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Temperature ◽  
Surface Modifications ◽  
Laser Induced Breakdown Spectroscopy ◽  
Excitation Temperature ◽  
Number Density ◽  
Plasma Parameters ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
The Magnetic Field

AbstractThe effect of the transverse magnetic field on laser-induced breakdown spectroscopy and surface modifications of germanium (Ge) has been investigated at various fluences. Ge targets were exposed to Nd: YAG laser pulses (1064 nm, 10 ns, 1 Hz) at different fluences ranging from 3 to 25.6 J/cm2 to generate Ge plasma under argon environment at a pressure of 50 Torr. The magnetic field of strength 0.45 Tesla perpendicular to the direction of plasma expansion was employed by using two permanent magnets. The emission spectra of laser-induced Ge plasma was detected by the laser-induced breakdown spectroscopy system. The electron temperature and number density of Ge plasma are evaluated by using the Boltzmann plot and stark broadening methods, respectively. The variations in emission intensity, electron temperature (Te), and number density (ne) of Germanium plasma are explored at various fluences, with and without employment of the magnetic field. It is observed that the magnetic field is responsible for significant enhancement of both excitation temperature and number density at all fluences. It is revealed that an excitation temperature increases from Te,max,without B = 16,190 to Te,max,with B = 20,123 K. Similarly, the two times enhancement in the electron density is observed from ne,max,without B = 2 × 1018 to ne,max,with B = 4 × 1018 cm−3. The overall enhancement in Ge plasma parameters in the presence of the magnetic field is attributed to the Joule heating effect and adiabatic compression. With increasing fluence both plasma parameters increase and achieve their maxima at a fluence of 12.8 J/cm2 and then decrease. In order to correlate the plasma parameters with surface modification, scanning electron microscope analysis of irradiated Ge was performed. Droplets and cones are formed for both cases. However, the growth of ridges and distinctness of features is more pronounced in case of the absence of the magnetic field; whereas surface structures become more diffusive in the presence of the magnetic field.

Simulation of Thermal Transport in Nanowire Composites for Macro-Electronics Applications

2004 ◽  
Author(s):  
Satish Kumar ◽  
Jayathi Y. Murthy ◽  
M. A. Alam
Keyword(s):  
Thin Film ◽  
Biot Number ◽  
Thermal Transport ◽  
Thin Film Transistors ◽  
Finite Volume Scheme ◽  
Temperature Profiles ◽  
Number Density ◽  
Plastic Substrates ◽  
Self Heating ◽  
Fourier Theory

Thermal transport in thin film transistors (TFTs) composed of nanowires embedded in plastic substrates is considered. Random ensembles of intersecting and contacting wires embedded in a substrate are analyzed using Fourier theory. Heat generation due to self-heating is included. A finite volume scheme is used to obtain the temperature solutions in the wires and substrate. Temperature profiles in the ensemble are investigated as a function of wire number density, wire-contact Biot number as well as the Biot number for heat transfer to the substrate.

scholarly journals Reduced model prediction of electron temperature profiles in microtearing-dominated National Spherical Torus eXperiment plasmas

2014 ◽  
Vol 21 (8) ◽  
pp. 082510 ◽  
Author(s):  
S. M. Kaye ◽  
W. Guttenfelder ◽  
R. E. Bell ◽  
S. P. Gerhardt ◽  
B. P. LeBlanc ◽  
...  
Keyword(s):  
Electron Temperature ◽  
Model Prediction ◽  
Reduced Model ◽  
Temperature Profiles ◽  
Spherical Torus

Marginal-Stability Calculation of Electron Temperature Profiles in Tokamaks

1976 ◽  
Vol 37 (5) ◽  
pp. 286-289 ◽  
Author(s):  
Wallace M. Manheimer ◽  
K. R. Chu ◽  
Edward Ott ◽  
Jay P. Boris
Keyword(s):  
Electron Temperature ◽  
Marginal Stability ◽  
Temperature Profiles ◽  
Stability Calculation
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