Total energy losses due to the radiation in an acoustically based undulator: the undulator and the channeling radiation included

This paper is devoted to the investigation of the radiation energy losses of an ultra-relativistic charged particle channeling along a crystal plane which is periodically bent by a transverse acoustic wave. In such a system there are two essential mechanisms leading to the photon emission. The first one is the ordinary channeling radiation. This radiation is generated as a result of the transverse oscillatory motion of the particle in the channel. The second one is the acoustically induced radiation. This radiation is emitted because of the periodic bending of the particle's trajectory created by the acoustic wave. The general formalism described in our work is applicable for the calculation of the total radiative losses accounting for the contributions of both radiation mechanisms. We analyze the relative importance of the two mechanisms at various amplitudes and lengths of the acoustic wave and the energy of the projectile particle. We establish the ranges of projectile particle energies, in which total energy loss is small for the LiH, C, Si, Ge, Fe and W crystals. This result is important for the determination of the projectile particle energy region, in which acoustically induced radiation of the undulator type and also the stimulated photon emission can be effectively generated. The latter effects have been described in our previous works

Parameters of the crystalline undulator and its radiation for particular experimental conditions

We report the results of theoretical and numerical analysis of the crystalline undulators planned to be used in the experiments which are the part of the ongoing PECU project [1]. The goal of such an analysis was to define the parameters (different from those pre-set by the experimental setup) of the undulators which ensure the highest yield of photons of specified energies. The calculations were performed for 0.6 and 10 GeV positrons channeling through periodically bent Si and Si$_{1-x}$Ge$_x$ crystals.Comment: 13 pages, 8 figures, submitted to SPI

Dynamical Screening of Atom Confined by Finite-Width Fullerene

This is an investigation on the dynamical screening of an atom confined within a fullerene of finite width. The two surfaces of the fullerene lead to the presence of two surface plasmon eigenmodes. It is shown that, in the vicinity of these two eigenfrequencies, there is a large enhancement of the confined atom's photoabsorption rate.Comment: 10 pages, 4 figures correction of figure 2 and equation 1

Electron-based crystalline undulator

We discuss the features of a crystalline undulator of the novel type based on the effect of a planar channeling of ultra-relativistic electrons in a periodically bent crystals. It is demonstrated that an electron-based undulator is feasible in the tens of GeV range of the beam energies, which is noticeably higher than the energy interval allowed in a positron-based undulator. Numerical analysis of the main parameters of the undulator as well as the characteristics of the emitted undulator radiation is carried out for 20 and 50 GeV electrons channeling in diamond and silicon crystals along the (111) crystallographic planes.Comment: 16 pages, 8 figures, Latex, IOP styl