Instabilities for a relativistic electron beam interacting with a laser irradiated plasma

The effects of a radiation field (RF) on the unstable modes developed in relativistic electron beam--plasma interaction are investigated assuming that $\omega_{0} >\omega_{p}$, where $\omega_{0}$ is the frequency of the RF and $\omega_{p}$ is the plasma frequency. These unstable modes are parametrically coupled to each other due to the RF and are a mix between two--stream and parametric instabilities. The dispersion equations are derived by the linearization of the kinetic equations for a beam--plasma system as well as the Maxwell equations. In order to highlight the effect of the radiation field we present a comparison of our analytical and numerical results obtained for nonzero RF with those for vanishing RF. Assuming that the drift velocity $\mathbf{u}_{b}$ of the beam is parallel to the wave vector $\mathbf{k}$ of the excitations two particular transversal and parallel configurations of the polarization vector $\mathbf{E}_{0}$ of the RF with respect to $\mathbf{k}$ are considered in detail. It is shown that in both geometries resonant and nonresonant couplings between different modes are possible. The largest growth rates are expected at the transversal configuration when $\mathbf{E}_{0}$ is perpendicular to $\mathbf{k}$. In this case it is demonstrated that in general the spectrum of the unstable modes in $\omega$--$k$ plane is split into two distinct domains with long and short wavelengths, where the unstable modes are mainly sensitive to the beam or the RF parameters, respectively. In parallel configuration, $\mathbf{E}_{0} \parallel \mathbf{k}$, and at short wavelengths the growth rates of the unstable modes are sensitive to both beam and RF parameters remaining insensitive to the RF at long wavelengths.Comment: 23 pages, 5 figure

Domain patterning by focused electron beam in wide temperature range in lithium niobate crystal with surface dielectric layer

The equipment of the Ural Center for Shared Use “Modern nanotechnology” Ural Federal University was used. The research was made possible by the Russian Science Foundation (grant № 17-72-10152)

Термовакуумно-напыленные пленки 1Н-индол-3К-(фенил)-альдонитрона - сухопроявляемый материал для лазерной микролитографии

It was experimentally showed that high quality high-gloss films of amorphous type are formed at vacuum deposition of 1H-indole-3N-(phenyl)-aldonitrone. At laser exposure (λ = 351 nm) of films latent image of the mask is formed, which is manifested by vacuum radiation of quartz halogen lamp. The films with the thickness of 1,3±0,2 μm mask phosphorus and boron ions with the energy up to 1 000 eV (at implantation dozes 0,10-0,12 μK1/cm2) in silicon technology of obtaining of BIS.Экспериментально показано, что при вакуумном испарении 1Н-индол-3N-(фенил)-альдонитрона образуются высококачественные глянцевые пленки аморфного типа. При лазерном экспонировании (λ = 351 нм) полученных пленок образуется скрытое изображение маски, которое проявляется вакуумным излучением кварце-во-галогенных ламп КГМ-1. Пленки толщиной 1,3±0,2 мкм маскируют ионы фосфора и бора с энергией до 1 000 эВ (при дозах 0,10-0,12 мКл/см2) в кремниевой технологии получения БИС

On the Possibility of Development of the Explosion Instability in a Two-Component Gravitating System

We obtain an expression for the energy of the density wave propagating in a multicomponent gravitating medium in the form well known from electrodynamics. Using the above, the possibility of "triple production" of the quasi-particles, or waves, with their energies summing up to zero, in a non-equilibrium medium is demonstrated. That kind of resonance wave interaction is shown to result in the development of an explosion instability. By the method developed in plasma physics, the characteristic time of the instability is evaluated.Comment: 15 pages, 3 figures, accepted for publication (JETP

Copper-Stabilized Si/Au Nanowhiskers for Advanced Nanoelectronic Applications

International audienceWe report here the growth and functional properties of silicon-based nanowhisker (NW) diodes produced by the vapor-liquid-solid process using a pulsed laser deposition technique. For the first time, we demonstrate that this method could be employed to control the size and shape of silicon NWs by using a two-component catalyst material (Au/Cu approximate to 601). During the NW growth, copper is distributed on the outer surface of the NW, whereas gold sticks as a droplet to its top. The length of NWs is defined by the total amount of copper in the catalyst alloy droplet. The measurements of the electrical transport properties revealed that in contact with the substrate, individual NWs demonstrate typical I-V diode characteristics. Our approach can become an important new tool in the design of novel electronic components