Free electron model

About: Free electron model is a research topic. Over the lifetime, 4678 publications have been published within this topic receiving 103535 citations.

The colour of gold and its alloys

Abstract: The optical properties of metals, and particularly their high reflectivity, are related to the effect on their free electrons of the energy of the incident light, but a satisfactory explanation of the characteristic colours of gold and its alloys and intermetallic phases has become possible only since calculations could be made of energy band structures.

Electron Collision Cross-Sections Determined from Beam and Swarm Data by Boltzmann Analysis

Abstract: Whenever free electrons collide with atoms and molecules, a wide variety of kinetic processes may take place. Electron collision cross-sections, of interest in plasma processing of VLSI production, carbonization of surfaces and so on, modeling of gas lasers, physics of gaseous dielectrics, analysis of high current discharge switches, applications for space science and radiation physics and chemistry, have been determined from available electron beam and electron swarm data utilizing the Boltzmann analysis. The goal of electron collision studies is to provide absolute values of cross-sections for all processes involved, from elastic to inelastic scattering, as a function of incident electron energy and scattering angle. In spite of many experimental and theoretical studies, electron impact cross-sections for atoms and molecules have not been systematically quantified.

Free-electron lasers with electromagnetic standing wave wigglers

Abstract: A detailed analysis of the electromagnetic standing wave wiggler for free-electron lasers (FEL's) is conducted for both circular and linear wiggler polarizations, following a single-particle approach. After determination of the unperturbed electron orbits in the wiggler field, the single-particle spontaneous emission spectrum and subsequently the gain in the low gain Compton regime (using the Einstein coefficient method) are explicitly calculated. This analysis results in a clear understanding of the resonance conditions and the coupling strength associated with each resonance of this type of FEL. In particular, a striking feature obtained from this investigation is that the electromagnetic standing wave wiggler FEL, under certain circumstances, exhibits a rich harmonic content. This harmonic content is caused by the presence of both the forward and backward wave components of the standing wave wiggler field. In addition, the nonlinear self-consistent equations for this type of FEL are also presented, permitting further investigation of it by the theoretical techniques and numerical codes developed for conventional FEL's.

Smith–Purcell Radiation from Low-Energy Electrons

Abstract: Recent advances in the fabrication of nanostructures and nanoscale features in metasurfaces offer new prospects for generating visible light emission from low-energy electrons. Here we present the experimental observation of visible light emission from low-energy free electrons interacting with nanoscale periodic surfaces through the Smith–Purcell (SP) effect. We demonstrate SP light emission from nanoscale gratings with periodicity as small as 50 nm, enabling the observation of tunable visible radiation from low-energy electrons (1.5 to 6 keV), an order of magnitude lower in energy than previously reported. We study the emission wavelength and intensity dependence on the grating pitch and electron energy, showing agreement between experiment and theory. Our results open the way to the production of SP-based nanophotonics integrated devices. Built inside electron microscopes, SP sources could enable the development of novel electron–optical correlated spectroscopic techniques and facilitate the observatio...