Abstract
We extend the quantum theory of Time Refraction for a generic spatial and temporal modulation of the optical properties of a medium, such as a dielectric or a gravitational field. The derivation of the local Bogoliubov transformations relating the global electromagnetic modes (valid over the entire span of space and time) with the local modes (valid for the vicinity of each spatial and temporal position) is presented and used in the evaluation of vacuum photon creation by the optical modulations of the medium. We use this approach to relate and review the results of different quantum effects such as the dynamical Casimir effect, space and Time Refraction, the Unruh effect and radiation from superluminal non-accelerated optical boundaries.

Abstract
X-ray emission spectra in the 5-22 nm range were recorded from planar and structured (meshlike groove surface) gold targets at 45 degrees and 90 degrees to the laser axis. A laser beam of 10-ns duration with E-L less than or equal to 700 mJ and 1.06-mum wavelength was used for the experiment. Experimental results indicate an enhanced X-ray yield from a structured target as compared to a planar target under identical experimental conditions. Increased X-ray emission is attributed to plasma confinement and the possibility of conversion of kinetic energy into localized thermal energy of the plasma. Results are analyzed explicitly on the incident laser energy.

Abstract
The quantization procedure for low-frequency modes in a plasma has been generalized to include dust-Coulomb waves (DCWs) which are driven by the grain charge oscillations in a dusty plasma. We thus introduce the concept of "chargeon", the elementary excitation of the ultra low-frequency electrostatic fields in a dusty plasma, which are mainly supported by the grain charge oscillations. Their characteristic features are similar to the usual phonons, but they correspond to very different physical properties of the medium.

Abstract
The effect of photon beam splitting in a time-varying medium is described by classical and quantum theoretical models. It generalizes the concept of time refraction, introduced recently by the authors as a natural extrapolation of the usual concepts of refraction and reflection into the time domain. Total time reflection is shown to exist. A sequence of time refraction processes is shown to lead to temporal interference effects. The concept of temporal beam splitter is introduced. Bogoliubov transformations for the temporal beam splitter are derived. Resonant amplification of light by change in time in the optical medium is shown to exist.

Abstract
We present the classical and quantum theory of time refraction in a generic nonstationary medium. The classical approach leads to expressions for the temporal refraction coefficient, and the temporal Fresnel laws are given. The quantum formulation leads to the derivation of instantaneous Bogoliubov transformations and the evaluation of the number of photon pairs created from vacuum by the temporal changes in the medium. The influence of boundary conditions, the connection of this model with the dynamical Casimir effect, and radiation from superluminal nonaccelerated optical boundaries is also discussed.

Abstract
We describe the effects of the electron trapping due to the background ions in a Rydberg plasma. In the early stages, the ions are not thermalized and obey a Gaussian spatial profile, trapping the coldest electrons. In the present work, we provide expressions for both the electrostatic potential and the electron spatial profiles in two different regimes. We show that in the strong confinement regime F » T/e, a Rydberg plasma can be described by a Thomas-Fermi potential, similar to that obtained for heavy atomic species.