scholarly journals Plasma-Profile Control in an ICP Reactor

2021 ◽  
Vol 2083 (2) ◽  
pp. 022017
Author(s):  
Songyao Wu ◽  
Yinghui Li ◽  
Haojun Xu ◽  
Mao Lin ◽  
Renwei Zuo ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Density ◽  
Electromagnetic Scattering ◽  
Plasma Parameter ◽  
Parameter Distribution ◽  
High Electron ◽  
External Circuit ◽  
Induced Magnetic Field ◽  
Profile Control ◽  
Peak Value

Abstract ICP is widely used in electromagnetic scattering due to its high electron density and simple structure. The distribution of plasma parameters can affect the electromagnetic scattering, so the control of plasma parameter distribution is very important for aircraft stealth. Firstly, the effect of the number of coil turns on the plasma parameter distribution is analyzed. With the increase of the number of coil turns, the peak value of induced magnetic field decrease, the width of magnetic field increase and the homogeneity of plasma increase. Then, the Boltzmann solver is used to calculate the plasma electron energy distribution function at different positions under the four-turn coil. Finally, the influence of external circuit capacitance on plasma parameter distribution is analyzed. In this cavity structure, the electron density first increases and then decreases with the external circuit capacitance increase, and the peak value is on 75 pF. In this study, we propose a method to further regulate the plasma parameter distribution by using terminal capacitance to control the induced magnetic field.

scholarly journals Magnetic Field Dependence of Transition to High Electron Density Phase in a Linear Plasma Device NUMBER

2020 ◽  
Vol 15 (0) ◽  
pp. 2401042-2401042
Author(s):  
Hiroki HACHIKUBO ◽  
Atsushi OKAMOTO ◽  
Takaaki FUJITA ◽  
Hideki ARIMOTO ◽  
Ryosuke OCHIAI ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Density ◽  
Field Dependence ◽  
Magnetic Field Dependence ◽  
High Electron ◽  
High Electron Density ◽  
Plasma Device ◽  
Linear Plasma

Electron microscope study of the secretory activity of epithelial cells in embryonic thymus

1990 ◽  
Vol 48 (3) ◽  
pp. 382-383
Author(s):  
H. Alasam
Keyword(s):  
Cell Differentiation ◽  
T Cell ◽  
Epithelial Cells ◽  
Electron Density ◽  
Secretory Activity ◽  
T Cell Differentiation ◽  
High Electron ◽  
Transmission Electron ◽  
Medullary Epithelial Cells ◽  
Thymic Factor

The possibility that intrathymic T-cell differentiation involves stem cell-lymphoid interactions in embryos led us to study the ultrastructure of epithelial cell in normal embryonic thymus. Studies in adult thymus showed that it produces several peptides that induce T-cell differentiation. Several of them have been chemically characterized, such as thymosin α 1, thymopoietin, thymic humoral factor or the serum thymic factor. It was suggested that most of these factors are secreted by populations of A and B-epithelial cells.Embryonic materials were obtained from inbred matings of Swiss Albino mice. Thymuses were disected from embryos 17 days old and prepared for transmission electron microscopy. Our studies showed that embryonic thymus at this stage contains undifferentiated and differentiated epithelial cells, large lymphoblasts, medium and few small lymphocytes (Fig. 5). No differences were found between cortical and medullary epithelial cells, in contrast to the findings of Van Vliet et al,. Epithelial cells were mostly of the A-type with low electron density in both cytoplasm and nucleus. However few B-type with high electron density were also found (Fig. 7).

A novel analytical calculation of magnetic field in the slotted air gap of spoke-type permanent-magnet machines using conformal mapping

2020 ◽  
pp. 1-15
Author(s):  
Jianqi Li ◽  
Yu Zhou ◽  
Jianying Li
Keyword(s):  
Magnetic Field ◽  
Conformal Mapping ◽  
Permanent Magnet ◽  
Flux Density ◽  
Analytical Method ◽  
Electromotive Force ◽  
Analytical Calculation ◽  
Air Gap ◽  
Permanent Magnet Machines ◽  
Peak Value

This paper presented a novel analytical method for calculating magnetic field in the slotted air gap of spoke-type permanent-magnet machines using conformal mapping. Firstly, flux density without slots and complex relative air-gap permeance of slotted air gap are derived from conformal transformation separately. Secondly, they are combined in order to obtain normalized flux density taking account into the slots effect. The finite element (FE) results confirmed the validity of the analytical method for predicting magnetic field and back electromotive force (BEMF) in the slotted air gap of spoke-type permanent-magnet machines. In comparison with FE result, the analytical solution yields higher peak value of cogging torque.

Effective Dielectric Function of Porous Silicon: the Transverse Component

1994 ◽  
Vol 358 ◽  
Author(s):  
G. Gumbs
Keyword(s):  
Absorption Spectrum ◽  
Absorption Coefficient ◽  
Electron Density ◽  
Quantum Wires ◽  
Interband Transition ◽  
Incident Light ◽  
Transverse Component ◽  
Effect Of Temperature ◽  
High Electron ◽  
Confining Potential

ABSTRACTA self-consistent many-body theory is developed to study the effect of temperature and electron density on the interband absorption coefficient and the frequency-dependent refractive index for an array of isolated quantum wires. The peaks in the absorption coefficient correspond to interband transitions resulting in the resonant absorption of light. The oscillations in the derivative spectrum are due to the quantization of the energy levels related to the in-plane confining potential for such reduced dimensional systems. There are appreciable changes in the absorption spectrum when the electron density or temperature is increased. One interband transition peak is suppressed in the high electron density limit and the thermal depopulation effect on the electron subbands can be easily seen when the temperature is high. We also find that the exciton coupling weakens the shoulder features in the absorption spectrum. This study is relevant to optical characterization of the confining potential and the areal density of electrons using photoreflectance. By using incident light with tunable frequencies in the interband excitation regime, contactless photoreflectance measurements may be carried out and the data compared with our calculations. By fitting the numerical results to the peak positions of the photoreflectance spectrum, the number of electrons in each wire may be extracted.

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