Related papers: On a Positron Channeling in Ionic Crystals
We have recorded channeling patterns produced by 1 to 2 MeV protons aligned with <111> axes in 55 nm thick silicon crystals which exhibit characteristic angular structure for deflection angles up to and beyond the axial critical angle,…
K-shell ionization and characteristic x-ray radiation (CXR) by high-energy electrons and positrons in oriented silicon crystals are studied using computer simulation. A method for this simulation has been developed and is described in…
The influence has been studied of the ionization laser polarization on the effective temperature of an ultracold electron source, which is based on near-threshold photoionization. This source is capable of producing both high-intensity and…
Ionization cooling channels with a wide variety of characteristics and cooling properties are being developed. These channels can produce cooling performances that are largely consistent with the ionization cooling theory developed…
This paper presents a quantitative analysis of the impact of inelastic collisions of ultra-relativistic electrons and positrons, passing through oriented crystalline targets, on the channeling efficiency and on the intensity of the…
We study a molecular lattice Hamiltonian in which polaronic charge carriers interact with non linear potentials provided by local atomic fluctuations between two equilibrium sites. The path integral formalism is applied to select the class…
Alkali halide crystals doped with certain impurity ions show a low temperature behaviour, which differs significantly from that of pure crystals. The origin of these characteristic differences are tunneling centers formed by atomic or…
Silicon nanocrystals (Si NCs) have shown great promise for electroluminescent and photoluminescent applications. In order to optimize the properties of Si NC devices, however, electronic transport in Si NCs films needs to be thoroughly…
The characteristics of the electron-photon showers initiated by 2 to 10 GeV electrons aligned along the <111>-axis of tungsten crystals are compared with those for the amorphous tungsten . In this energy range, as known, the positron yield…
Heavy ions channeling through crystals with multi-GeV kinetic energies can create electron-positron pairs. In the framework of the ion, the energy of virtual photons arising from the periodic crystal potential may exceed the threshold…
Significant temperature effects on the electrokinetic transport in a nanochannel with a slab geometry are demonstrated using a molecular dynamics (MD) model. A system consisting of Na+ and Cl- ions dissolved in water and confined between…
The properties of the superconducting state in calcium under the pressure at 120 GPa were analyzed. By using the imaginary axis Eliashberg equations it has been shown, that the Coulomb pseudopotential reaches the high value equal to 0.215.…
We propose a simple linear scaling expression in reciprocal space for evaluating the ion--electron potential of crystalline solids. The expression replaces the long-range ion--electron potential with an equivalent localized charge…
An essential property of layered systems is the dynamical nature of the screened Coulomb interaction. Low energy collective modes appear as a consequence of the layering and provide for a superconducting-pairing channel in addition to the…
We use energy discrimination of keV ions transmitted through a thin, single-crystalline silicon membrane to correlate specific angular distribution patterns formed in channelling geometry with trajectory-dependent electronic energy loss.…
We study the interaction between a neutral atom or molecule and a conductor-patched dielectric surface. We model this system by a perfectly reflecting disc lying atop of a non-dispersive dielectric half-space, both interacting with the…
The properties of a partially ionized plasma in a long cylindrical tube subject to a uniform axial electric field are investigated. The plasma is maintained by an external ionizing source balanced by bulk and surface recombinations.…
We derive and discuss expressions for the temperature-dependent electrostatic polarizabilities of off-center ions holding good under various experimental conditions. At low temperatures and electric-field strengths, all of them reasonably…
We report on observations of thermal motion of a single, Doppler-cooled ion along the axis of a linear radio-frequency quadrupole trap. We show that for a harmonic potential the thermal occupation of energy levels leads to Gaussian…
The physical processes that control the partition of released magnetic energy between electrons and ions during reconnection is explored through particle-in-cell simulations and analytical techniques. We demonstrate that the development of…