Determination of electron affinity of electron accepting molecules

The unoccupied π ^* states of the solid film of electron accepting organic molecules, 7,7,8,8-tetracyanoquinodimethane (TCNQ), fluorinated TCNQ derivatives, 11,11,12,12-tetracyanonaphtho-2,6-quinodimethane (TNAP), C₆₀, and 6,6-phenyl-C₆₁-butyric acid methyl ester (PCBM) have been studied by inverse photoemission spectroscopy. The assignment of the π ^* affinity levels of these typical electron accepting molecules provides the basic information for the organic electronics and the new electronic functional molecular design. The comparison with density functional theory calculations enables understanding how the electron affinity evolves in terms of molecular orbitals. The correlation between the film morphology and the irradiation damage on the TCNQ derivative samples by electron impact during the inverse photoemission measurements is also discussed.     

One-body electron dynamics in a free electron laser

The free electron laser is analyzed by solving the one-body classical Lorentz force equation in the presence of periodic magnetic field and a plane electromagnetic wave. Phase space paths for electrons are related to those of a simple pendulum and describe laser gain, saturation, and coherent electron beam modulation.     

Effective electron–electron and electron–phonon interactions in the Hubbard–Holstein model

We investigate the interplay between the electron–electron and the electron–phonon interaction in the Hubbard–Holstein model. We implement the flow-equation method to investigate within this model the effect of correlation on the electron–phonon effective coupling and, conversely, the effect of phonons in the effective electron–electron interaction. Using this technique we obtain analytical momentum-dependent expressions for the effective couplings and we study their behavior for different physical regimes. In agreement with other works on this subject, we find that the electron–electron attraction mediated by phonons in the presence of Hubbard repulsion is peaked at low transferred momenta. The role of the characteristic energies involved is also analyzed.     

Averaging the electron velocity in three-dimensional models of microwave electron devices in electron gap synthesis

Possible ways of averaging the electron velocity in three-dimensional high-perveance electron gaps are compared. The method proposed for averaging the electron velocity is the most suitable for electron gap synthesis. An estimate is made of the error that occurs in the velocity averaging by this method as a result of the finite value of the beam-focusing magnetic field.St. Petersburg Electrical Engineering Institute of Communications. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, No. 10, pp. 1303–1310, October, 1994.     

Chaotic electron trajectories in a circular free electron laser

The motion of a relativistic electron is analyzed in the field configuration consisting of a circular wiggler magnetic field, an axial magnetic field, and the equilibrium self-electric and self-magnetic fields produced by the non-neutral electron ring. By generating Poincare surface-of-section maps, it is shown that when the equilibrium self-fields is strong enough, the electron motions become chaotic. Although the realistic circular wiggler magnetic field destroys the integrability of the electron motion as the equilibrium self-fields do, the role the latter plays to make the motions become chaotic is stronger than the former. In addition, the axial magnetic field can restrain the occurrence of the chaoticity.     

Study of elastic electron collisions by plasma electron spectroscopy

In this work we study elastic electron collisions by using the plasma electron spectroscopy method, which is based on the study of the electron energy distribution function in a plasma afterglow. We give the results of this method for the electron-electron collision frequency, and the frequency and cross section of the elastic collision of electrons with helium atoms.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 7–11, February, 1987.In conclusion, the authors express their gratitude to Professor N. P. Penkin for useful discussions concerning this work.     

Quantum discord of electron spins of noninteracting electron gases

In this paper, we analyze the quantum discord of electron spins of noninteracting electron gases. Our results imply that the quantum discord depends on the relative distance between the two electrons and the temperature. By a comparison between the quantum discord and the entanglement of formation, we find that the quantum discord is more robust than the entanglement of formation in the sense that the quantum discord takes a zero value only at discrete points of the range of the relative distance whereas the entanglement of formation can disappear for a finite relative distance.     

Sum rules and electron correlations in two-dimensional electron liquid

The low order frequency moment sum rules of the density response function for quantum 2-dimensional electron liquid are given. These are used to obtain an integral equation for the static structure factor. This integral equation is solved self-consistently for different electron densities. Results obtained for the pair-correlation function are positive for all inter-electron separations even at physical densities.     

Ultrahot electron formation under excess electron drift through solid Xe

The formation of "hot" (8 eV) electrons under excess electron drift in a moderate electrostatic field through solid xenon has been experimentally proved by observation of secondary electrons emitted from the photocathode. At T=77 K and U=1000 V one drifting electron produces about 20 (172 nm) photons, the efficiency of electric field-to-vacuum ultraviolet emission conversion is 15% tending to grow with temperature. A self-sustained electric discharge has been generated in solid Xe using a three-electrode cell with a zinc cathode.     

用于真空电子太赫兹器件的微型热阴极电子束源研究

太赫兹波辐射源是太赫兹(THz)波技术的关键.真空电子太赫兹器件在高频、大功率太赫兹源发展中较其他技术有明显的优势,微米尺度高电流密度微型电子束源则是研制真空电子太赫兹器件的核心之一.本文在研制低温、大电流纳米粒子氧化钪掺杂含钪扩散阴极(nanosized-scandia doped dispenser cathode)的基础上,采用发射抑制膜沉积与聚焦离子束(FIB)刻蚀技术,研制无需压缩直接提供高电流密度的微型电子束的电子源.所研究的电子束源直径400μm,在工作温度950fiC,提供空间电荷限制电流密度50 A/cm2时,已稳定工作1000 h以上,并且层流性良好.本文阐述了阴极制备工艺、电子发射特性、微米尺度电子束源的获得和特性,介绍了发射抑制膜的结构和抑制特性的评估.并探讨了镀膜和刻蚀对发射的影响机理.这一电子束源在常规毫米尺度电子源的基础上产生微米尺度的微区高电流密度的电子束,为真空电子太赫兹辐射源的研制提供了新的途径.     

Kilovolt electron backscattering

We present here the results of experiments measuring the energy spectra of electrons backscattered from massive homogeneous Al, Cu, Pd and W targets, with the probing beam primary energyE ₀ varying from 4–32 keV. We have developed the electron backscattering theory based on solving the Boltzmann equation boundary problem by the invariant imbedding method and calculation of inelastic energy loss with the modified Landau function. Comparison of the calculated with experimental data shows that this expanded theory adequately describes the electron reflection processes.     

Holistic electron theory

A relativistic, non-quantum theory of electrons is constructed in which the electron is not considered to be composed of any type of distribution of charge. The electron's structurelessness is defined by several assumptions which, together with Maxwell's equations outside the electron, yield the general fields produced by such an arbitrarily movingholistic electron. Several equations of motion for the holistic electron are found to result from the formulation, the Lorentz-Dirac equation being among them. The formulation, by its very nature, avoids the problems of the electron self-energy and the need for normalization.     

Glow discharge lamps as electron sources for electron impact excitation

It has been found possible to utilize the plasma in the discharge lamp of a conventional ultraviolet photoelectron spectrometer as an electron source f     

Inelastic electron tunneling

Inelastic Electron Tunneling Spectroscopy (IETS) is a new technique for measuring the vibrational spectrum of minute quantities of organic compounds. Sensitivity is its key advantage over the conventional techniques of infrared and Raman spectroscopy. This article will first discuss the technique itself: its theoretical basis, selection rules, sensitivity, vibrational mode shifts due to surface interactions and superconductivity, and sample preparation. Then it will discuss applications of the technique to problems in biology, radiation physics, surface physics, and catalysis.     

Conduction electron optics

Present manufacturing techniques of semiconductor heterostructures offer a possibility to steer the motion of single electrons. Here we suggest semiconductor devices which change the electron wave packet in ways analogous to the systems used in conventional optics. These electron optics devices are demonstrated with several examples.     

Flat electron beams

Electrons from a source in a solenoidal magnetic field emerge from that field with a characteristic angular momentum. This behavior can be used to produce a flat ribbon-like electron beam with zero thickness (to first order). We show that this can be done using a quadrupole triplet and provide analytical expressions for the focal length of each lens. Solutions can be found over a wide range of practical values of the parameters.     

The composite electron

In this paper, the electron is considered a bound state of a neutrino and a negative pion. A model Lagrangian density that combines weak and electromagnetic interactions gives rise to equations of motion that define such a state. In this model, the muon is a bound state of an antineutrino and a negative pion, which explains why it cannot decay into an electron and a photon. The decay of unstable particles is reduced to pair creation plus particle recombination. The neutral pion is described by an interference between the charged-pion states. Several variations of the model are also presented.     

Attosecond electron bunches

Electron bunches of attosecond duration may coherently interact with laser beams. We show how p-polarized ultraintense laser pulses interacting with sharp boundaries of overdense plasmas can produce such bunches. Particle-in-cell simulations demonstrate attosecond bunch generation during pulse propagation through a thin channel or in the course of grazing incidence on a plasma layer. In the plasma, due to the self-intersection of electron trajectories, electron concentration is abruptly peaked. A group of counterstream electrons is pushed away from the plasma through nulls in the electromagnetic field, having inherited a peaked electron density distribution and forming relativistic ultrashort bunches in vacuum.     

Plasma-emitter electron accelerators

This paper considers the physical processes associated with the extraction of electrons from the gas discharge plasma in plasma emitters where the emission boundary is stabilized with a fine grid. The ways of improving the uniformity of the emission current density distribution are discussed. Accelerators designed on the basis of plasma emitters are capable of producing pulsed beams of current 10–10³ A, current density 0.1–1.0 A/cm², pulse duration 10⁻⁷–10⁻³ s, and cross-sectional area up to 10⁴ cm². Institute of High-Current Electronics, Siberian Division of the Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 92–96, April, 2000.