Emission spectra and intrinsic optical bistability in a two-level medium

Scattering of resonant radiation in a dense two-level medium is studied theoretically with account for local field effects and renormalization of the resonance frequency. Intrinsic optical bistability is viewed as switching between different spectral patterns of fluorescent light controlled by the incident field strength. Response spectra are calculated analytically for the entire hysteresis loop of atomic excitation. The equations to describe the non-linear interaction of an atomic ensemble with light are derived from the Bogolubov-Born-Green-Kirkwood-Yvon hierarchy for reduced single particle density matrices of atoms and quantized field modes and their correlation operators. The spectral power of scattered light with separated coherent and incoherent constituents is obtained straightforwardly within the hierarchy. The formula obtained for emission spectra can be used to distinguish between possible mechanisms suggested to produce intrinsic bistability.Comment: 18 pages, 5 figure

Spatial distribution of a plasma vortex obtained under gyromagnetic resonance in the mirror magnetic trap

The spatial configuration of a plasma vortex with the middle relativistic electron component produced under the gyromagnetic autoresonance and confined in the mirror magnetic trap have been studied experimentally and by numerical modeling using a particle in the cell method. Characteristics of bremsstrahlung generated by the plasma vortex on gas and chamber walls were investigated by the X-ray spectrometry and radiometry methods. Obtained results and their analysis have allowed to define the vortex localization and dynamics. The sizes of the bunch: the radius is 2 cm; the size along the axis is about 0.5 cm. The number of electrons trapped in gyromagnetic autoresonance mode is 50-70 percent of the number of electrons in the initial plasma

Nanoparticle Motion in an Ideal Liquid under the Action of Light Pressure in the Field of a Standing Light Wave

We have solved the problem of transparent nanoparticle motion under the action of a gradient component of light pressure force in a field of periodically modulated intensity of continuous laser radiation. For different initial values of particle coordinate and speed, we have found and numerically analyzed the exact solutions of the equation of motion described by the elliptic integrals of the first kind. The simple approximate expressions for the nanoparticle trajectory are obtained as a result of series expansion of the integrand in elliptic integrals. It is shown that depending on initial conditions, two different regimes are possible – harmonic motion and translatory motion with nanoparticle localization in one of the maxima of radiation interference pattern

Spatial distribution of a plasma vortex obtained under gyromagnetic resonance in the mirror magnetic trap

The spatial configuration of a plasma vortex with the middle relativistic electron component produced under the gyromagnetic autoresonance and confined in the mirror magnetic trap have been studied experimentally and by numerical modeling using a particle in the cell method. Characteristics of bremsstrahlung generated by the plasma vortex on gas and chamber walls were investigated by the X-ray spectrometry and radiometry methods. Obtained results and their analysis have allowed to define the vortex localization and dynamics. The sizes of the bunch: the radius is 2 cm; the size along the axis is about 0.5 cm. The number of electrons trapped in gyromagnetic autoresonance mode is 50-70 percent of the number of electrons in the initial plasma

Gyromagnetic autoresonance plasma bunches in a magnetic mirror

Experiments with relativistic plasmas obtained and confined in a magnetic mirror under gyromagnetic autoresonance and their computer simulations are described. Plasma bunches with relativistic electrons are generated. The averaged energy of the electrons in the bunch is about few hundreds keV depending on the parameters of seed plasma, microwave electric field strength, and the rate of the pulse magnetic field increase. Varying the values of these parameters, it is possible to control the bunches. © 2017 Author(s)

Gyromagnetic autoresonance plasma bunches in a magnetic mirror

Experiments with relativistic plasmas obtained and confined in a magnetic mirror under gyromagnetic autoresonance and their computer simulations are described. Plasma bunches with relativistic electrons are generated. The averaged energy of the electrons in the bunch is about few hundreds keV depending on the parameters of seed plasma, microwave electric field strength, and the rate of the pulse magnetic field increase. Varying the values of these parameters, it is possible to control the bunches. © 2017 Author(s)