Radiative and Electrical Properties of a Center-Post Cathode Magnetron Glow Discharge Device

1988 ◽  
Vol 42 (4) ◽  
pp. 576-583 ◽  
Author(s):  
Suzanne Tanguay ◽  
Richard Sacks
Keyword(s):  
Magnetic Field ◽  
Electrical Properties ◽  
Glow Discharge ◽  
Field Strength ◽  
Constant Current ◽  
Glow Discharge Plasma ◽  
Basic Operation ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
The Magnetic Field

Current-voltage characteristics and spatially resolved atomic emission data are used to describe the basic operation of a magnetron glow discharge plasma device. The low-pressure glow discharge lamp uses a center-post cathode and a concentric ring-shaped anode. A coaxial magnetic field of a few hundred Gauss is used to achieve magnetron operation where plasma electrons are trapped in closed paths which are concentric with the electrode structure. This results in dramatic changes in the radiative and electrical properties of the device. With constant current, lamp operating voltage may be reduced by more than a factor of two when the magnetic field is present. The effects of filler gas pressure and magnetic field strength on the current-voltage characteristics are presented. The presence of the magnetic field results in a radial contraction of the plasma. This contraction increases with increasing field strength and with decreasing pressure. Ion lines from the Ar filler gas are more affected by the field than are neutral-atom lines from the cathode material.

scholarly journals DC Glow Discharge in Axial Magnetic Field at Low Pressures

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Shen Gao ◽  
Shixiu Chen ◽  
Zengchao Ji ◽  
Wei Tian ◽  
Jun Chen
Keyword(s):  
Magnetic Field ◽  
Glow Discharge ◽  
Differential Equations ◽  
Axial Magnetic Field ◽  
Glow Discharge Plasma ◽  
Dc Glow Discharge ◽  
Fluid Approximation ◽  
Low Pressures ◽  
Physical Quantities ◽  
The Magnetic Field

On the basis of fluid approximation, an improved version of the model for the description of dc glow discharge plasma in the axial magnetic field was successfully developed. The model has yielded a set of analytic formulas for the physical quantities concerned from the electron and ion fluids equations and Poisson equation. The calculated results satisfy the practical boundary conditions. Results obtained from the model reveal that although the differential equations under the condition of axial magnetic field are consistent with the differential equations without considering the magnetic field, the solution of the equations is not completely consistent. The results show that the stronger the magnetic field, the greater the plasma density.

SUPERCONDUCTIVITY ASSOCIATED WITH THE GRANULAR STRUCTURE IN Ba2YCu3O7−δ

1988 ◽  
Vol 02 (08) ◽  
pp. 1011-1015
Author(s):  
YONG ZHAO ◽  
QIRUI ZHANG ◽  
WEIYAN GUAN ◽  
JIANSHENG XIA ◽  
ZHENHUI HE ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Transport Properties ◽  
Single Phase ◽  
Granular Structure ◽  
Current Voltage ◽  
Granular Superconductivity ◽  
Current Voltage Characteristics ◽  
The Magnetic Field ◽  
Nonmonotonic Behavior

The dependence of the resistance on the magnetic field and the current-voltage characteristics of the single phase Ba 2 YCu 3 O 7−δ have been measured. The nonmonotonic behavior and a hysteresis of R(H) and the current-voltage characteristics suggest that the granular superconductivity exist in this material, and it plays an important role in transport properties.

scholarly journals Влияние электронного и дырочного допирования на транспортные характеристики халькогенидных систем

2021 ◽  
Vol 63 (5) ◽  
pp. 606
Author(s):  
О.Б. Романова ◽  
C.C. Аплеснин ◽  
Л.В. Удод
Keyword(s):  
Magnetic Field ◽  
Electrical Properties ◽  
Hall Effect ◽  
Charge Carriers ◽  
Hall Constant ◽  
Temperature Range ◽  
Current Voltage ◽  
Semiconductor Compounds ◽  
Current Voltage Characteristics ◽  
Ohmic Conductivity

The electrical properties and the Hall effect in semiconductor compounds Ag0.01Mn0.99S and Tm0.01Mn0.99S have been studied in the temperature range 80–400 K in a magnetic field of 12 kOe. The mechanism of conduction is established, which depends on the type of doping and concentration from the current - voltage characteristics. At the replacement of manganese by silver, the Mott type was found, and the replacement by thulium causes ohmic conductivity. The mobility and type of charge carriers are found from the Hall constant.

scholarly journals DESIGN AND APPLICATION OF GLOW DISCHARGE CLEANING AT URAGAN-2M STELLARATOR

2021 ◽  
pp. 19-24
Author(s):  
Yu.V. Kovtun ◽  
V.E. Moiseenko ◽  
S.M. Maznichenko ◽  
A.V. Lozin ◽  
V.B. Korovin ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Glow Discharge ◽  
System Design ◽  
Breakdown Voltage ◽  
Experimental Studies ◽  
Gas Discharge ◽  
Argon Atmosphere ◽  
Gas Pressure ◽  
Current Voltage ◽  
Current Voltage Characteristics

For the Uragan-2M stellarator, a glow discharge cleaning (GDC) system is developed. An overview of the GDC system design is presented. The first experimental studies of GDC in an argon atmosphere have been carried out. The dependence of the breakdown voltage on the argon pressure is determined. The current-voltage characteristics of the gas discharge were measured as a function of the working gas pressure also in presence of a magnetic field.

On the Configuration of the Magnetic Field of β CrB

1976 ◽  
Vol 32 ◽  
pp. 613-622
Author(s):  
I.A. Aslanov ◽  
Yu.S. Rustamov
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Radial Velocity ◽  
Magnetic Field Strength ◽  
Complex Shape ◽  
Rotation Period ◽  
Field Variation ◽  
Magnetic Field Variation ◽  
Secular Variations ◽  
The Magnetic Field

SummaryMeasurements of the radial velocities and magnetic field strength of β CrB were carried out. It is shown that there is a variability with the rotation period different for various elements. The curve of the magnetic field variation measured from lines of 5 different elements: FeI, CrI, CrII, TiII, ScII and CaI has a complex shape specific for each element. This may be due to the presence of magnetic spots on the stellar surface. A comparison with the radial velocity curves suggests the presence of a least 4 spots of Ti and Cr coinciding with magnetic spots. A change of the magnetic field with optical depth is shown. The curve of the Heffvariation with the rotation period is given. A possibility of secular variations of the magnetic field is shown.

scholarly journals Effect of Magnetic Field on the Forced Convective Heat Transfer of Water–Ethylene Glycol-Based Fe3O4 and Fe3O4–MWCNT Nanofluids

2021 ◽  
Vol 11 (10) ◽  
pp. 4683
Author(s):  
Areum Lee ◽  
Chinnasamy Veerakumar ◽  
Honghyun Cho
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Field Strength ◽  
Ethylene Glycol ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Hybrid Nanofluid ◽  
Forced Convective Heat Transfer ◽  
The Magnetic Field

This paper discusses the forced convective heat transfer characteristics of water–ethylene glycol (EG)-based Fe3O4 nanofluid and Fe3O4–MWCNT hybrid nanofluid under the effect of a magnetic field. The results indicated that the convective heat transfer coefficient of magnetic nanofluids increased with an increase in the strength of the magnetic field. When the magnetic field strength was varied from 0 to 750 G, the maximum convective heat transfer coefficients were observed for the 0.2 wt% Fe3O4 and 0.1 wt% Fe3O4–MWNCT nanofluids, and the improvements were approximately 2.78% and 3.23%, respectively. The average pressure drops for 0.2 wt% Fe3O4 and 0.2 wt% Fe3O4–MWNCT nanofluids increased by about 4.73% and 5.23%, respectively. Owing to the extensive aggregation of nanoparticles by the external magnetic field, the heat transfer coefficient of the 0.1 wt% Fe3O4–MWNCT hybrid nanofluid was 5% higher than that of the 0.2 wt% Fe3O4 nanofluid. Therefore, the convective heat transfer can be enhanced by the dispersion stability of the nanoparticles and optimization of the magnetic field strength.

scholarly journals The effects of magnetic field strength on the properties of wind generated from hot accretion flow

2018 ◽  
Vol 615 ◽  
pp. A35 ◽  
Author(s):  
De-Fu Bu ◽  
Amin Mosallanezhad
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Pressure Gradient ◽  
Magnetic Field Strength ◽  
Magnetic Pressure ◽  
Gas Pressure ◽  
Accretion Flow ◽  
Accretion Flows ◽  
Black Hole Accretion ◽  
The Magnetic Field

Context. Observations indicate that wind can be generated in hot accretion flow. Wind generated from weakly magnetized accretion flow has been studied. However, the properties of wind generated from strongly magnetized hot accretion flow have not been studied. Aims. In this paper, we study the properties of wind generated from both weakly and strongly magnetized accretion flow. We focus on how the magnetic field strength affects the wind properties. Methods. We solve steady-state two-dimensional magnetohydrodynamic equations of black hole accretion in the presence of a largescale magnetic field. We assume self-similarity in radial direction. The magnetic field is assumed to be evenly symmetric with the equatorial plane. Results. We find that wind exists in both weakly and strongly magnetized accretion flows. When the magnetic field is weak (magnetic pressure is more than two orders of magnitude smaller than gas pressure), wind is driven by gas pressure gradient and centrifugal forces. When the magnetic field is strong (magnetic pressure is slightly smaller than gas pressure), wind is driven by gas pressure gradient and magnetic pressure gradient forces. The power of wind in the strongly magnetized case is just slightly larger than that in the weakly magnetized case. The power of wind lies in a range PW ~ 10−4–10−3 Ṁinc2, with Ṁin and c being mass inflow rate and speed of light, respectively. The possible role of wind in active galactic nuclei feedback is briefly discussed.

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