Presence Of Electron Emission Research Articles

Comment on “Effects of an oblique magnetic field on sheath formation in the presence of electron emission”

AbstractSato et al. have studied the secondary electron emission and the sheath formation in the presence of a magnetic field. The rate of secondary electron inflow has been reported for two angular distributions of the secondary electrons: cosine and isotropic. While the cosine distribution has been correctly implemented, the isotropic one has been misdefined, leading to defective results. The present comment discusses the difference between the isotropic and false isotropic distributions and compares the subsequent results.

Study of the reverse current range in a knudsen diode with surface ionization under overneutralized conditions in the presence of electron emission from the collector: Part II. Small electrode spacing

study of the reverse current range in a knudsen diode with surface ionization under overneutralized conditions in the presence of electron emission from the collector: Part II. Small electrode spacing

Study of the reverse current range in a knudsen diode with surface ionization under overneutralized conditions in the presence of electron emission from the collector: Part I. Large electrode spacing

A Knudsen diode with surface ionization under overneutralized conditions is studied in the range of reverse current. The electrode spacing is assumed to be small, which causes the potential jumps near the electrodes to overlap. The asymptotic behavior of the current under high negative voltage is investigated.

Conditions for the existence of a positively charged structure in a Penning discharge

An analytical model is developed for the high-current form of a low-pressure glow discharge in a magnetic field. Expressions are derived for the critical magnetic induction and critical pressure, below which it becomes impossible for this form of discharge to exist. It is shown that the transition from the high-voltage form to the high-current form of discharge with increasing pressure is not attributable to an increase in the ionization rate, but to an increase in the drift velocity of plasma electrons across the magnetic field. Estimates based on the expressions derived in the article agree in order of magnitude with the experimental data. It is shown that the region in which discharge exists can change considerably in the presence of electron emission.

The influence of electron emission from the collector on the potential distribution within a Knudsen diode with surface ionization in the underneutralized regime

This paper gives a theoretical treatment of the distribution of potentials within a Knudsen diode with surface ionization in the underneutralized regime in the presence of electron emission from the collector surface. A method is derived to calculate the potential distribution. It is shown that if the emission from the collector is sufficiently strong, spatially oscillatory (“wavelike”) potential distributions do not form; instead, a continuous transition occurs from a distribution with a virtual anode to one with a virtual cathode. Particular attention is focused on the neighborhood of the transition point from one of these distributions to the other.

Effects of an Oblique Magnetic Field on Sheath Formation in the Presence of Electron Emission

AbstractIt is found from kinetic analyses that an oblique magnetic field provides two presheath mechanisms. One is due to the ion polarization drift and another is due to the finite ion‐gyroradius effect. The secondary‐electron inflow is effectively diminished due to reflection by the Lorentz force and the emission coefficient is limited to a value less than 0. 8 by the space‐charge effect when the magnetic angle approaches to 90°.

Sheath and Heat Flow of a Two-Electron-Temperature Plasma in the Presence of Electron Emission

The electrostatic sheath and the heat flow of a two-electron-temperature plasma in the presence of electron emission are investigated analytically. It is shown that the energy flux is markedly enhanced to a value near the electron free-flow energy flux as a result of considerable reduction of the sheath potential due to electron emission if the fraction of hot electrons at the sheath edge is much smaller than one. If the hot- to cold-electron temperature ratio is of the order of ten and the hot electron density is comparable to the cold electron density, the action of the sheath as a thermal insulator is improved as a result of suppression of electron emission due to the space-charge effect of hot electrons.

Heat flow through a Langmuir sheath in the presence of electron emission

Heat flow through a Langmuir sheath in the presence of electron emission