نتایج جستجو برای: electron gas
تعداد نتایج: 539187 فیلتر نتایج به سال:
A theoretical model is developed for electron velocity saturation in high power GaN transistors. It is shown that electron velocity at high electric fields is reduced due to heating of electron gas since the high density of nonequilibrium LO phonons cannot efficiently transfer heat to the lattice. However, the resulting degradation of electron velocity is found to be weaker than previously repo...
We discuss the model of a D-dimensional confined electron gas in which the particles are trapped by a harmonic potential. In particular, we study the non-interacting kinetic and exchange energies of finite-size inhomogeneous systems, and compare the resulting Thomas–Fermi and Dirac coefficients with various uniform electron gas paradigms. We show that, in the thermodynamic limit, the properties...
In an electron beam sustained discharge Xenon laser the discharge energy deposition has been varied in order to investigate the saturation effect on the Xenon laser. The current density of the electron beam is varied separately in the range of 0.1-2.7 A/cmz to obtain optimized discharge excitation conditions as a function of electron beam current density and gas pressure. An optimal fractional ...
Preliminary studies performed with the cold bore superconducting undulator installed in the ANKA (Angstrom source Karlsruhe) storage ring suggest that the beam heat load is mainly due to the electron wall bombardment. Electron bombardment can both heat the cold vacuum chamber and induce an increase in the pressure because of gas desorption. In this contribution we compare the measurements of th...
A linear response theory is provided for the dynamic interaction effects of an electron soliton confined in semiconductor quantum well with a conducting surface or a two-dimensional electron gas. It is shown that the soliton-electron-gas effective potential contains a dissipative component resisting against changes of the soliton charge density. Due to the energy dissipation moving solitons are...
According to the theory of relativity, the relativistic Coulomb’s force between an electron pair is composed of two parts, the main part is repulsive, while the rest part can be attractive in certain situations. Thus the relativistic attraction of an electron pair provides an insight into the mechanism of superconductivity. In superconductor, there are, probably at least, two kinds of collectiv...
Low-temperature photoluminescence-excitation spectra are studied in an n-type modulation-doped T-shaped single quantum wire with a gate to tune electron densities. With a nondegenerate one-dimensional (1D) electron gas, the band-edge absorption exhibits a sharp peak structure induced by the 1D density of states. When the dense 1D electron gas is degenerate at a low temperature, we observe a Fer...
We give an alternate derivation of Weldon's formula for combining products of factors with non identical analytic behavior. While such a formula would appear to be useful in finite temperature calculations, we give an example of a zero temperature calculation, namely, the degenerate electron gas, to justify the result.
We describe a feedback mechanism in the gas cascade amplification process used in magnetic immersion lens environmental scanning electron microcopy (ESEM). Feedback dominates gas gain under the conditions typically used for ultra-high-resolution ESEM and gives rise to novel dependencies of the imaging signal and noise on microscope operating parameters. It is ascribed tentatively to the generat...
We calculate the free energy of the quantum uniform electron gas for temperatures from near 0 to 100 times the Fermi energy, approaching the classical limit. An extension of the Vashista-Singwi theory to finite temperatures and a self-consistent compressibility sum rule is presented. Comparisons are made to other local-field correction methods, as well as recent quantum Monte Carlo simulation a...
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