Messung der Druckerhöhung in einem Wasserstoff-Lichtbogen bei überlagertem axialem Magnetfeld

1966 ◽  
Vol 21 (4) ◽  
pp. 390-398 ◽  
Author(s):  
H. F. Döbele ◽  
R. Wienecke ◽  
S. Witkowski
Keyword(s):  
Magnetic Field ◽  
Pressure Distribution ◽  
Axial Magnetic Field ◽  
Arc Discharge ◽  
Radial Pressure ◽  
Experimental Results ◽  
Small Opening ◽  
Saha Equation ◽  
Cylindrically Symmetric ◽  
Inner Region

In a cylindrically symmetric hydrogen arc discharge located in an axial magnetic field, pressure is increased in the inner region, where ionization occurs. Measurements were made with initial pressures of 7.5 and 15 torr, with temperatures between 8000 and 12 000 °K, and with magnetic inductions of 8.5 and 12.5 kGauss. A mercury gauge was connected to a small opening in the anode to measure the radial pressure distribution in the plasma. Temperatures and electron densities were determined spectroscopically. The SAHA equation was found to be applicable in this case. Therefore, experimental results can be compared with theory based on the SAHA equation.

Effects of repeated interactions and correlational disintegration on kinetic and transport properties of a non-neutral plasma in strong fields

1990 ◽  
Vol 44 (1) ◽  
pp. 167-190 ◽  
Author(s):  
Alf H. Øien
Keyword(s):  
Magnetic Field ◽  
Particle Transport ◽  
Axial Magnetic Field ◽  
Debye Length ◽  
Electron Plasma ◽  
Larmor Radius ◽  
Equilibration Time ◽  
Cylindrically Symmetric ◽  
Electric Potentials ◽  
Good Agreement

Collisions in a cylindrically symmetric non-neutral (electron) plasma, where the Larmor radius is much smaller than the Debye length, and the consequent particle transport, are studied. The plasma is confined radially by a strong axial magnetic field and axially by electric potentials. Hence two particles may interact repeatedly. Eventually they drift too far away from each other poloidally to interact any more, owing to shear in the E × B drift. The consequent build-up of correlation is limited by correlational disintegration due to collisions with ‘third particles’ between the repeated interactions. A kinetic equation including these effects is derived, and the cross-field particle transport along the density gradient is found. An associated equilibration time is shown to scale as B and to be in good agreement with the experimentally obtained values of Briscoli, Malmberg and Fine.

scholarly journals Can Resistive Kink Instabilities Drive Simple Loop Flares?

1989 ◽  
Vol 104 (2) ◽  
pp. 305-308
Author(s):  
M. Velli ◽  
G. Emaudi ◽  
A.W. Hood
Keyword(s):  
Magnetic Field ◽  
Boundary Conditions ◽  
Growth Rates ◽  
Axial Magnetic Field ◽  
Small Region ◽  
Coronal Loops ◽  
Simple Loop ◽  
Cylindrically Symmetric ◽  
Line Tying ◽  
Kink Instability

SummaryA detailed analysis of the kink instability in finite length (inertially line-tied), cylindrically symmetric coronal loops is presented. The correct line-tying boundary conditions within the framework of ideal and resistive magnctohydrodynamics are discussed, and the growth rates of unstable modes and corresponding eigenfunctions are calculated. Resistive kink modes are found to be unstable in configurations where the axial magnetic field undergoes an inversion, resistive effects being confined to a small region around the loop vertex.

Numerische Berechnung der gekoppelten Verteilungen von Potential und Temperatur für Wasserstoff-Lichtbögen endlicher Länge in axialen Magnetfeldern

1970 ◽  
Vol 25 (4) ◽  
pp. 459-472
Author(s):  
J. Raeder ◽  
S. Wirtz
Keyword(s):  
Magnetic Field ◽  
Heat Flux ◽  
Energy Balance ◽  
Mass Flow ◽  
Finite Length ◽  
Electric Potential ◽  
Radial Flow ◽  
Axial Magnetic Field ◽  
Arc Discharge ◽  
Partial Differential

Abstract The energy balance is used to derive a partial differential eqution for the heat flux potential in a rotational symmetric arc column of finite length. This equation is combined with a corresponding equation for the electric potential in order to calculate the distributions of temperature and electric potential for an arc discharge in a strong axial magnetic field. Because the coupling of the two equations is very complicated, all investigations have to be made numerically. The influence of mass flow is studied by taking into account drastically simplified distributions of the azimuthal and radial flow velocities.

A Study of a Weakly Ionized Rotating Plasma

1979 ◽  
Vol 34 (6) ◽  
pp. 672-690 ◽  
Author(s):  
M. M. B. Wijnakker ◽  
E. H. A. Granneman ◽  
J. Kistemaker
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Pressure Distribution ◽  
Rotational Velocity ◽  
Symmetry Plane ◽  
Radial Pressure ◽  
Plasma Potential ◽  
Theoretical Treatment ◽  
Ion Temperature ◽  
Weakly Ionized

Abstract Measurements are reported on a weakly ionized rotating argon plasma generated by two identical gas discharges facing each other. In each discharge a current up to 100 A is drawn between a point-like cathode and a ring-shaped anode. Axial magnetic fields up to 0.26 T are applied. All measurements have been done at 1 torr.For magnetic field strengths below 0.17 T the plasma has a more or less uniform radial distribution; above 0.17 T a contracted plasma column is present along the axis of the cylinder. In the symmetry plane between the two discharges measurements have been done on the rotational velocity of neutrals and ions, the electron density and temperature, the ion temperature, the plasma potential and the radial pressure distribution. The rotational velocity, the plasma potential and the pressure distribution are also calculated. The theoretical treatment is based on the theory developed by Klüber and Wilhelm and Hong.In the low magnetic field case velocities of 700 m/sec are found for ions as well as neutrals. The agreement between theory and experiment is good in this case. At high magnetic fields, the ions and neutrals are found to have azimuthal velocities of 1900 and 700 m/sec, respectively.The radial pressure enhancement due to the centrifugal forces is found to be approximately a factor of two whereas the theory predicts only a factor of 1.2. In a discharge in which a mixture of argon and xenon is used a relative separation factor of 2.15 is found.

Spontaneous generation of magnetic field in an imploding plasma

1984 ◽  
Vol 32 (3) ◽  
pp. 349-357 ◽  
Author(s):  
S. K. H. Auluck
Keyword(s):  
Magnetic Field ◽  
Axial Magnetic Field ◽  
Equations Of Motion ◽  
Field Configuration ◽  
Spontaneous Generation ◽  
Centripetal Acceleration ◽  
Cylindrically Symmetric ◽  
Order Of Magnitude ◽  
Reversed Field ◽  
Metallic Liner

Spontaneous generation of an axial magnetic field is predicted when the usually neglected centripetal acceleration term is properly taken into account in the two-fluid equations of motion for a cylindrically symmetric imploding plasma. An order-of-magnitude calculation is presented to illustrate spontaneous generation of a reversed-field configuration in a plasma imploded by a metallic liner.

Experimental Investigation of the Flow Between Corotating Disks

1970 ◽  
Vol 37 (3) ◽  
pp. 844-849 ◽  
Author(s):  
R. Adams ◽  
W. Rice
Keyword(s):  
Experimental Investigation ◽  
Laminar Flow ◽  
Uncertainty Analysis ◽  
Pressure Distribution ◽  
Analytical Model ◽  
Newtonian Fluid ◽  
Radial Pressure ◽  
Experimental Results ◽  
Wide Range ◽  
Incompressible Newtonian Fluid

Experimental results are presented for the flow of an incompressible Newtonian fluid, with full admission, between closely spaced corotating disks. The radial pressure distribution is shown to coincide very closely with analytical results for laminar flow earlier presented by other investigators, over a wide range of the parameters pertinent to the flow description. A referenced analytical model for laminar flow between corotating disks is thus given credence. The experimental arrangement and procedure are described and a supporting uncertainty analysis is presented.

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