We present the general linear transfer matrix of FEL in the collective regime in terms of a single-mode radiation field amplitude and e-beam current and velocity modulation parameters. The formulation is useful to account for composite configurations of the FEL, including non-radiating sections, and is employed to demonstrate the possibility to control the SASE radiation power (including its su...

High-order harmonic generation from atomic systems is considered in the crossed fields of a relativistically strong infrared laser and a weak attosecond pulse train of soft x rays. Due to one-photon ionization by the x-ray pulse, the ionized electron obtains a starting momentum that compensates the relativistic drift, which is induced by the laser magnetic field, and allows the electron to effi...

Coherent nonlinear structures in the form of vortical motions are frequently observed in laboratory devices and in auroral plasmas. Our objective here is to suggest that any realistic description of plasma vortices must involve three-dimensional nonlinear wave models, which account for the nonlinear coupling between finite amplitude electrostatic and/or electromagnetic disturbances. Specificall...

High-resolution analyses of lake sediment from southwestern Alaska reveal cyclic variations in climate and ecosystems during the Holocene. These variations occurred with periodicities similar to those of solar activity and appear to be coherent with time series of the cosmogenic nuclides 14C and 10Be as well as North Atlantic drift ice. Our results imply that small variations in solar irradianc...

A novel technique for microfabricating alkali atom vapor cells is described in which alkali atoms are evaporated into a micromachined cell cavity through a glass nozzle. A cell of interior volume 1 mm3, containing 87Rb and a buffer gas, was made in this way and integrated into an atomic clock based on coherent population trapping. A fractional frequency instability of 6 x 10(-12) at 1000 s of i...

We show that the sender and the receiver each require coherent devices in order to achieve unconditional continuous variable quantum teleportation (CVQT), and this requirement cannot be achieved with conventional laser sources, linear optics, ideal photon detectors, and perfect Fock state sources. The appearance of successful CVQT in recent experiments is due to interpreting the measurement rec...

Ultrahigh speed images of E B discharges are collected during electrostatic probing of magnetized microdischarges. Two azimuthally separated floating micro-Langmuir probes inserted into an axisymmetric microscale magnetically confined plasma are used to characterize azimuthal drift waves. The images reveal features associated with probe intrusion, showing how the electrostatic probes may disrup...

A free-floating plate is introduced in a Benard convection cell with an open surface. It partially covers the cell and distorts the local heat flux, inducing a coherent flow that in turn moves the plate. Remarkably, the plate can be driven to a periodic motion even under the action of a turbulent fluid. The period of the oscillation depends on the coverage ratio, and on the Rayleigh number of t...

The incident angle of ground motion is one of the sources of uncertainty in the seismic response of buildings. Moreover, understanding the structural response to the impose ground motion may cause significant changes in the maximum response of buildings. In order to investigate the effect of the spatial distribution of orthogonal components of earthquake strong motion on the structural response...

this paper has studied motahari's point of view  on the divine revelation as a methodological problem. in islamic philosophers' point of view, divine revelation is result of :union: of prophet and active intellect. they consider the divine revelation as knowledge and emphasize its cognitive identity. on the other hand, some scholars reduce the divine revelation to tendencies and empha...