Resonanzverschiebungen in HF-Entladungen bei axialem Magnetfeld/Resonance Shifts in High Frequency Discharges in Axial Magnetic Field Configurations

1976 ◽  
Vol 31 (9) ◽  
pp. 1122-1130 ◽  
Author(s):  
B. Lammers ◽  
U. Oberlack ◽  
H. Schlüter
Keyword(s):  
Magnetic Field ◽  
High Frequency ◽  
Axial Magnetic Field ◽  
Hydrogen Plasma ◽  
Electron Density Profile ◽  
Field Configuration ◽  
Lower Hybrid ◽  
Neutral Gas ◽  
Apparent Shift ◽  
Lower Hybrid Resonance

AbstractThe pressure dependence of the lower hybrid resonance is investigated in a hydrogen plasma generated by a high frequency discharge. Appreciable shifts of the absorption peak with the neutral gas pressure are observed only in a mirror like magnetic field configuration. The measurements show that this shift cannot be explained by a change of the ion composition of the plasma, but must be attributed to two other mechanisms: The composition of the spectrum of the kn-components is influenced by the axial electron density profile so that at low pressure the higher modes of the spectrum are dominant.With higher pressure the formation of radial modes is favoured which leads to an additional apparent shift of the resonance.

The behavior of TIG welding arc in a high-frequency axial magnetic field

2020 ◽  
Vol 65 (1) ◽  
pp. 95-104
Author(s):  
H. Wu ◽  
Y. L. Chang ◽  
Alexandr Babkin ◽  
Boyoung Lee
Keyword(s):  
Magnetic Field ◽  
High Frequency ◽  
Axial Magnetic Field ◽  
Tig Welding ◽  
Welding Arc

Numerical Investigation of Laser Oscillation in a Recombining Hydrogen Plasma Interacting with Helium Gas in TPD-I

1985 ◽  
Vol 40 (5) ◽  
pp. 485-489 ◽  
Author(s):  
Toshiatsu Oda ◽  
Utaro Furukane
Keyword(s):  
Magnetic Field ◽  
Numerical Investigation ◽  
Axial Magnetic Field ◽  
Hydrogen Plasma ◽  
Plasma Source ◽  
Threshold Level ◽  
Laser Oscillation ◽  
Quantum Numbers ◽  
Magnetically Confined ◽  
Helium Gas

A numerical investigation on the basis of a collisional-radiative (CR) model has shown that laser oscillation between the levels with the principal quantum numbers i = 2 and 3 can be generated in a recombining hydrogen plasma interacting with a dense helium gas as a cooling medium in TPD-I, which is a magnetically confined quiescent high-density plasma source consisting basically of two parts, namely, the discharge region with the cathode at the center of the cusped magnetic field and the plasma column region with the axial magnetic field. The population inversion is found to exceed significantly a threshold level for the laser oscillation even in the quasi-steady state when the hydrogen plasma with ne = 1013 ~ 1014 cm−3 interacts with the helium gas with a pressure of about 50 Torr.

scholarly journals Cosmic ray driven dynamo in barred and ringed galaxies

2010 ◽  
Vol 6 (S274) ◽  
pp. 398-400
Author(s):  
K. Kulpa-Dybeł ◽  
K. Otmianowska-Mazur ◽  
B. Kulesza-Żydzik ◽  
G. Kowal ◽  
D. Wóltański ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Radio Emission ◽  
High Frequency ◽  
Galactic Disk ◽  
Cosmic Ray ◽  
Field Configuration ◽  
Magnetic Field Configuration ◽  
Global Evolution ◽  
Weak Magnetic Fields ◽  
The Magnetic Field

AbstractWe study the global evolution of the magnetic field and interstellar medium (ISM) of the barred and ringed galaxies in the presence of non-axisymmetric components of the potential, i.e. the bar and/or the oval perturbations. The magnetohydrodynamical dynamo is driven by cosmic rays (CR), which are continuously supplied to the disk by supernova (SN) remnants. Additionally, weak, dipolar and randomly oriented magnetic field is injected to the galactic disk during SN explosions. To compare our results directly with the observed properties of galaxies we construct realistic maps of high-frequency polarized radio emission. The main result is that CR driven dynamo can amplify weak magnetic fields up to few μG within few Gyr in barred and ringed galaxies. What is more, the modelled magnetic field configuration resembles maps of the polarized intensity observed in barred and ringed galaxies.

scholarly journals Nichtlineare Welleneinkopplung in ein Plasma erhöhter Elektronentemperatur / Nonlinear Wave Coupling to a Plasma of Enhanced Electron Temperature

1976 ◽  
Vol 31 (12) ◽  
pp. 1566-1571 ◽  
Author(s):  
G. Glomski ◽  
B. Heinrich ◽  
H. Schlüter
Keyword(s):  
Electron Temperature ◽  
Electron Density ◽  
Nonlinear Wave ◽  
Lower Hybrid ◽  
Radio Waves ◽  
Wave Coupling ◽  
Neutral Gas ◽  
At Resonance ◽  
Parametric Effects ◽  
Lower Hybrid Resonance

Abstract Nonlinear Wave Coupling to a Plasma of Enhanced Electron Temperature In continuation of former investigations radio waves of different amplitude in the domain of lower hybrid resonance were coupled to a plasma of enhanced electron temperature. Under linear conditions no dependence of resonance behaviour on the wave amplitude was observed. Exceeding a treshhold maximum of absorption and electron density decreased significantly; both observations may be explained by onset of nonlinear and parametric effects. Increasing the amplitude the discharge only could be maintained by increasing the neutral gas pressure. In the power range of 15 to 20 kW electron density grew rapidly at resonance.

Measurement of the growth of a turbulent mercury jet in a coaxial magnetic field

1967 ◽  
Vol 27 (1) ◽  
pp. 81-96 ◽  
Author(s):  
Miklos Sajben ◽  
James A. Fay
Keyword(s):  
Magnetic Field ◽  
High Frequency ◽  
Axial Magnetic Field ◽  
Magnetic Interaction ◽  
Low Frequencies ◽  
Frequency Components ◽  
Profile Changes ◽  
The Mean ◽  
Wire System ◽  
Made In

Using a hot-wire system developed for this purpose, measurements of the velocity were made in a circular liquid-mercury jet issuing into a low-speed secondary flow and subject to a uniform axial magnetic field. The Reynolds number of the jet was about 10,000 while the magnetic interaction parameter varied from zero to slightly over one. The jet was strongly turbulent under all conditions investigated. The radial distribution of the mean and fluctuating component of the meridional velocity was measured at four axial stations located between 2 and 34 diameters from the nozzle exit. The results indicate that the rate of spreading of the jet is decreased, that the shape of the velocity profile changes and that the turbulent intensity decreases with increasing magnetic-field strength. The high-frequency components of the fluctuations in the second flow seem to be damped more strongly than fluctuations at low frequencies, while the reverse is observed within the core of the jet.

Effect of neutral gas motion on the rotation of dust clusters in an axial magnetic field

2009 ◽  
Vol 16 (1) ◽  
pp. 013702 ◽  
Author(s):  
Jan Carstensen ◽  
Franko Greiner ◽  
Lu-Jing Hou ◽  
Horst Maurer ◽  
Alexander Piel
Keyword(s):  
Magnetic Field ◽  
Axial Magnetic Field ◽  
Neutral Gas

Druckerhöhung und Wärmeleitfähigkeit in einem zylindersymmetrischen Wasserstoffplasma im axialen Magnetfeld unter Berücksichtigung von Thermokräften

1968 ◽  
Vol 23 (11) ◽  
pp. 1695-1706
Author(s):  
J. Raeder ◽  
S. Wirtz
Keyword(s):  
Magnetic Field ◽  
Thermal Conductivity ◽  
Plasma Column ◽  
Thermal Equilibrium ◽  
Axial Magnetic Field ◽  
Hydrogen Plasma ◽  
Local Thermal Equilibrium ◽  
Total Thermal Conductivity ◽  
Boltzmann Equations ◽  
External Pressures

The pressure increase and total thermal conductivity are calculated for an infinitely long hydrogen plasma column in an axial magnetic field. The calculations, which are based on the first and third moments of the Boltzmann equations for atoms, ions and electrons, are carried out under the assumption of local thermal equilibrium. Numerical results are given for magnetic fields up to 150 kG, temperatures to 106°K and external pressures ranging from 103 to 105 dyne/cm2. Comparison of these results with previous calculations, which neglect thermal forces, shows that they cause an increase of pressure also in the completely ionized plasma and therefore modify the thermal conductivity indirectly.

Experimentelle Untersuchungen an einem Wasserstoff-Lichtbogen im achsenparallelen Magnetfeld. I.

1968 ◽  
Vol 23 (6) ◽  
pp. 867-873 ◽  
Author(s):  
C. Mahn ◽  
H. Ringler ◽  
G. Zankl
Keyword(s):  
Magnetic Field ◽  
Heat Conduction ◽  
Field Strength ◽  
Radial Direction ◽  
Axial Magnetic Field ◽  
Hydrogen Plasma ◽  
Power Input ◽  
Measured Temperature ◽  
Radial Temperature ◽  
Theoretical Predictions

In a stationary high density d. c. arc, the electric power input is balanced essentially by heat conduction losses in radial direction. These losses increase greatly with temperature and thus they limit the axial temperatures attainable with reasonable power input.An experiment is described in which considerably higher plasma temperatures have been obtained by reducing the coefficient of heat conduction with a superimposed axial magnetic field. At arc currents of about 2 kA and a magnetic field of 10 kG temperatures in the middle of the arc of the order of 10 eV were reached.The measured temperature, pressure and power input of the hydrogen plasma are compared with calculated values. In particular, the coefficient of heat conduction perpendicular to a magnetic field has been determined by measuring the radial temperature profile and the electric field strength. The results agree with theoretical predictions.

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