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Terahertz (THz) radiation from a plasma cylinder with embedded radial electric and axial magnetic fields is investigated. The plasma density and the electric and magnetic fields are such that the electron plasma frequency is near the electron cyclotron frequency and in the THz regime. Two-dimensional particle-in-cell simulations show that the plasma electrons oscillate not only in the azimuthal direction but also in the radial direction. Spectral analysis shows that the resulting oscillating current pattern has a clearly defined characteristic frequency near the electron cyclotron frequency, suggesting resonance between the cyclotron and plasma oscillations. The resulting far-field THz radiation in the axial direction is also discussed.

A simple model including the effects of initial velocity, air drag, gravity, and electrostatics on the dynamics of airborne droplets emitted from humans is presented. It is found that relatively large droplets can also travel far if their charge and/or the atmospheric electric field is sufficiently large.

In experiments on the effect of magnetic field on electron transportation in laser–plasma interaction, the magnetic field is often produced by two coils and is mirror-like. In this paper, the transport and the reflection of fast electron beam generated in laser–plasma interaction in solid-density plasma immersed in a mirror magnetic field are studied using particle-in-cell simulation. The helicoidal motion of fast electrons in the field and the convergence of magnetic induction lines leads to the collimated transport and focusing of the fast electrons. The reflection of the fast electrons can lead to the decrease in the transmission ratio, and this reflection increases with the magnetic mirror ratio, but saturates at a certain level.

We present a scheme to entangle two magnon modes in two macroscopic yttrium-iron-garnet spheres. The two spheres are placed inside two microwave cavities, which are driven by a two-mode squeezed microwave field. By using the linear state-swap interaction between the cavity and the magnon mode in each cavity, the quantum correlation of the two driving fields is with high efficiency transferred to the two magnon modes. Considerable entanglement could be achieved under experimentally achievable conditions $g \gg \kappa_a \gg \kappa_m$, where $g$ is the cavity-magnon coupling rate and $\kappa_a$, $\kappa_m$ are the decay rates of the cavity and magnon modes, respectively. The entanglement is in the steady state and robust against temperature, surviving up to hundreds of milliKelvin with experimentally accessible two-mode squeezed source., Comment: Comments are welcome

We present a scheme to entangle two microwave fields by using the nonlinear magnetostrictive interaction in a ferrimagnet. The magnetostrictive interaction enables the coupling between a magnon mode (spin wave) and a mechanical mode in the ferrimagnet, and the magnon mode simultaneously couples to two microwave cavity fields via the magnetic dipole interaction. The magnon-phonon coupling is enhanced by directly driving the ferrimagnet with a strong red-detuned microwave field, and the driving photons are scattered onto two sidebands induced by the mechanical motion. We show that two cavity fields can be prepared in a stationary entangled state if they are respectively resonant with two mechanical sidebands. The present scheme illustrates a new mechanism for creating entangled states of optical fields, and enables potential applications in quantum information science and quantum tasks that require entangled microwave fields., Comment: A new mechanism is introduced to produce entangled microwave fields. To appear in PRL

We propose to use intense optical vortex to control laser-based ion acceleration for obtaining high-quality ion beams. An acceleration field favorable for generating well-collimated energetic proton beams results from the interaction of a tailored vortex laser pulse with thin solid-density foil in a blowout regime. Three-dimensional particle-in-cell simulations show that the foil protons can be efficiently accelerated to the GeV level in the form of a beam with small radius (μm), narrow divergence (π mm mrad). The proton beam is of high energy density (>1018 J m−3) and high brightness (>1022 A m−2 rad−2), exceeding that of the Gaussian laser case by four orders of magnitude, and the energy conversion efficiency is about 12 times that under the same laser intensity. The scheme can also be used to accelerate heavier, such as carbon, ions. The resulting ion beams should be useful as compact neutron source, for creation of warm dense matters, as well as ion-beam direct and indirect drive inertial confinement fusion, ultrafast diagnostics of the implosion dynamics in the latter, etc.

Multistream instabilities in the one-dimensional Vlasov−Poisson system are studied numerically by using plasmas with multi-humped electron distributions. The evolution of the total wave energy of the plasma oscillations excited by (numerical) noise consists of transient, growth, and nonlinear saturation stages. It is found that, in the growth stage, the total wave energy oscillates for odd number of streams, but it does not oscillate for even number of streams. It is also found that different spectral (Fourier) modes can dominate different stages of the “linear” growth and nonlinear saturation stages.

Target-normal sheath acceleration (TNSA) of ions by >100-fs relativistic laser pulses irradiating a multichannel target consisting of a row of parallel long wires and a plane back foil is studied. Two-dimensional particle-in-cell simulations show that the laser light pulls out from the wires a large number of dense hot attosecond electron bunches, which are synergetically accelerated forward by the relativistic ponderomotive force of the laser as well as the longitudinal electric field of a transverse magnetic mode that is excited in the vacuum channels between the wires. These electrons are characterized by a distinct two-temperature energy spectrum, with the temperature of the more energetic electrons close to twice the ponderomotive potential energy. After penetrating through the foil, they induce behind its rear surface a sheath electric field that is both stronger and frontally more extended than that without the channels. As a result, the TNSA ions have much higher maximum energy and the laser-to-ion energy conversion efficiency is also much higher. It is found that a laser of intensity 1.37 × 1020 W/cm2, duration 165 fs, and energy 25.6 J can produce 85 MeV protons and 31 MeV/u carbon ions, at 30% laser-to-ion energy conversion efficiency. The effects of the channel size and laser polarization on the TNSA ions are also investigated.

Effects of the system temperature on dust aggregation in plasmas are investigated using two-dimensional molecular dynamics simulations. It is shown that as the system temperature increases, the boundary of the clusters becomes gradually irregular (i.e., deviating from sphere-like), and the cluster system gradually changes from solid to liquid and finally to gas state. The mean square displacement, mean nearest-neighbor distance in the clusters, cluster size and coupling parameter of the system are obtained and the properties of the system structure and dynamics are investigated. The time τ needed for reaching equilibrium for different temperatures is obtained. It is shown that τ firstly decreases and then increases with the temperature, indicating that there is an optimum temperature allowing a dust aggregation to reach an equilibrium state most rapidly. The simulation results agree qualitatively with the experimental observations. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Transport of moderate relativistic micro electron beam in overdense plasma is investigated using numerical simulation and analytical modeling. It is found that if the product of the initial beam current density jb and radius R0 is above a lower limit, which scales like , where ne is the plasma density, the beam will periodically self pinch and relax as it propagates. Otherwise the beam diverges. But if is too large, the pinching behavior becomes quite different. Such micro-beam transport behavior can be attributed to the nonlinear dynamics of the beam electrons in overdense plasma.

The acceleration of protons from the interaction of two intersecting laser pulses in a double-layer target, consisting of a carbon slab with a thin hydrogen layer behind it, is investigated. It is found that a bunch of well-collimated, up to 270 MeV, quasi-monoenergetic protons can be generated. The affected target electrons are heated and accelerated forward by the laser pulses so that the target gradually becomes transparent as the lasers bore into it. Eventually, the thin target becomes fully transparent. The converging laser pulses can then pass through it and the hot backside electron cloud, together with the electrons trapped in them. As a result, behind the target, an inhomogeneous sheath electric field is formed, which not only accelerates the protons but also merges them into a quasi-monoenergetic bunch with low divergence. The energy and spatial spread of the bunch, as well as the peak energy, can be controlled by manipulating the locations of the two lasers.The acceleration of protons from the interaction of two intersecting laser pulses in a double-layer target, consisting of a carbon slab with a thin hydrogen layer behind it, is investigated. It is found that a bunch of well-collimated, up to 270 MeV, quasi-monoenergetic protons can be generated. The affected target electrons are heated and accelerated forward by the laser pulses so that the target gradually becomes transparent as the lasers bore into it. Eventually, the thin target becomes fully transparent. The converging laser pulses can then pass through it and the hot backside electron cloud, together with the electrons trapped in them. As a result, behind the target, an inhomogeneous sheath electric field is formed, which not only accelerates the protons but also merges them into a quasi-monoenergetic bunch with low divergence. The energy and spatial spread of the bunch, as well as the peak energy, can be controlled by manipulating the locations of the two lasers.

When an intense right-hand circularly polarized laser pulse propagates through a highly magnetized (in the direction of laser propagation) foil into the vacuum region between this foil and an unmagnetized foil, it can be multiply reflected and thus quasitrapped between the two foils until its energy is depleted. During the multiple reflections at the magnetized foil, foil electrons are accelerated by the laser light. Electrons that have gained sufficient energy can escape and appear as periodic energetic electron bunches at a time interval determined precisely by the trapping time or the distance between the two foils.

Long distance propagation of an energetic laser pulse with intensity slightly below that for multi-photon ionization in air is considered analytically, by noting that in the process, it is mainly the peak region of the pulse that interacts with the air molecules. Similar to that of much shorter femtosecond laser pulses of similar intensity, the affected air becomes slightly ionized and self-consistently forms a co-propagating thin and low-density plasma filament along the axis. It is found that a hundred-Joule-level laser pulse with a relatively large spot radius and pulse duration can propagate (also in the form of a self-consistent filament) tens of kilometers through the atmosphere. Such laser propagation properties should have applications in many areas.

Electron plasma waves excited and/or modified by finite objects such as laser and charged particle pulses are investigated nonperturbatively using a simple model where the driver is unaffected by the interaction. It is shown that smooth as well as sharply peaked electron plasma wake waves of large amplitude can exist. In particular, two charged pulses moving in tandem can excite a highly localized electron plasma wave without producing the expected long wake wave, a configuration that should be particularly useful for efficient trapping and acceleration of electrons to high energies.

Intense Compton-scattering γ-ray radiation driven by laser wakefield acceleration (LWFA) and generation of ultrashort positron beams are investigated by Monte Carlo simulation. Using an LWFA driven GeV electron bunch and a 45 femtosecond, 90 mJ/pulse, and 10 Hz Ti:Sapphire laser for driving the Compton scattering, fs γ-ray pulses were generated. The latter have a flux of ≥108/s, peak brightness of ≥1020 photons/(s mm2 mrad2 0.1% bandwidth), and photon energy of 5.9 to 23.2 MeV. The γ-ray pulses then impinge on a thin high-Z target. More than 107 positrons/s in the form of sub-100 fs pulses at several MeV can be produced. Such ultrashort positron pulses can be useful as the pump-probe type positron annihilation spectroscopy as well as in other applications.

A new class of exact electrostatic solutions of the Vlasov-Maxwell equations based on the Jeans's theorem is proposed for studying the evolution and properties of two-dimensional anisotropic plasmas that are far from thermodynamic equilibrium. In particular, the free expansion of a slab of electron-ion plasma into vacuum is investigated., 13 pages, 1 figure

An advanced cone-nanolayer target with nanolayers on both inside and outside of the hollow-cone tip is proposed. Two-dimensional particle-in-cell simulations show that laser interaction with such cone-nanolayer targets can efficiently produce fast electron beams with manageable spotsize, and the beams can propagate for a relatively long distance in the vacuum beyond the cone tip.

The magnetic reconnection (MR) configuration was constructed by using two approaching laser-produced plasma bubbles. The characteristics of the MR current sheet were investigated. The driving energy of the laser pulse affects the type of the current sheet. The experiments present “Y-type” and “X-type” current sheets for larger and smaller driving energy, respectively. The energetic electrons were found to be well-collimated. The formation and ejection of plasmoid from the “Y-type” current sheet was expected to enhance the number of accelerated electrons.

A two-dimensional theoretical model for the evolution of solid-density plasma irradiated by short, intense laser pulse is introduced. The electrons near the target surface are pushed inward by the radiation pressure, leading to a receding electron density jump where the laser is reflected. The electrostatic field of the resulting charge separation eventually balances the radiation pressure at the laser peak. After that the charge separation field becomes dominant. It accelerates and compresses the ions that are left behind until they merge with the compressed electrons, resulting in a high-density plasma peak. The laser pulse reflected from the receding electron density jump loses energy in plasma and suffers Doppler frequency red-shift, which can provide valuable information on the laser absorption rate and the speed of the receding electrons. Electron oscillations, including the u × B oscillations across the density jump at twice the laser frequency during the laser action, as well as the low-frequency oscillations appearing after laser action, are identified.

Time evolution of ionospheric D-region plasmas including the perturbations of electrons and charged aerosol particles is investigated under the conditions of polar mesosphere summer echoes (PMSE). It is shown that the time scale of decay of the electron density is in the order of an hour under typical PMSE conditions, in the majority of cases, the electron density is anticor-related to the ion density, except that the radius of aerosol particles is greater than 50 nm. Also, the evolutions under varied parameters, such as the amplitude and width of perturbation, the aerosol particle radius, and the altitude of the PMSE occurrence are investigated. The obtained results are useful for interpreting the experimental observations.

The effect of perpendicular (to the direction of shock propagation) magnetic fields on electron shock-surfing acceleration (ESSA) is investigated. Two-dimensional particle-in-cell simulations show that the strength of background magnetic fields can significantly affect the shock formation process and the electrostatic field structure near the leading edge of the shock. It is found that ESSA is most efficient when the ratio of electron cyclotron frequency to plasma frequency is about 0.1. In this case, there are two types of electrostatic field structures near the shock edge, namely, small-scale filamentary and large-scale dipole electric fields, induced by the Buneman instability and fluid compression, respectively. In such a mixed field structure, the affected electrons can undergo multiple accelerations and gain much higher energies than that under weaker or stronger background magnetic fields.

Quasistationary electron plasma waves of arbitrary amplitude and speed that are exact solutions of the isothermal electron fluid equations are shown to exist.

Collimated proton beams from laser interaction with a slab having a hole on its backside are investigated using particle-in-cell simulation. The hot target electrons driven by the laser expand rapidly into the hole. However, at the hole's corners the electrons are strongly compressed and an intense electron jet is emitted from each corner, tightly followed by the ions. The plasma jets focus and collimate along the axis of the hole and can propagate without divergence within the hole. The effect of the hole diameter on the collimated proton beam is considered.

It is shown that an intense laser pulse can be focused by a conical channel. This anomalous light focusing can be attributedto a hitherto ignored effect in nonlinear optics, namely that the boundary response depends on the light intensity: the innercone surface is ionized and the laser pulse is in turn modified by the resulting boundary plasma. The interaction creates anew self-consistently evolving light-plasma boundary, which greatly reduces reflection and enhances forward propagationof the light pulse. The hollow cone can thus be used for attaining extremely high light intensities for applications in strong-field and high energy-density physics and other areas.Keywords: Laser-cone interaction; Laser focusing; Particle-in-cell simulation Strong-field or high-energy-density physics relies much on thevery high concentration of laser energy in an extremely smalltime/space interval. Chirped pulse amplification technologyhas opened a new era in strong-field physics. By compressingthe laser pulse to the femtosecond regime, terawatt, or evenpetawatt lasers have become available (Perry & Mourou,1994; Perry et al., 1999; Mourou et al., 1998). Furthermore,considerable effort has been made in concentrating laserenergy to a small or tightly focused spot. Recently, powerfullasers have been focused to the 10-wavelength level (Fritzleretal., 2003; Cowan etal.,2004),withpeakintensities reaching10

Dimensional effects in particle-in-cell (PIC) simulation of target normal sheath acceleration (TNSA) of protons are considered. As the spatial divergence of the laser-accelerated hot sheath electrons and the resulting space-charge electric field on the target backside depend on the spatial dimension, the maximum energy of the accelerated protons obtained from three-dimensional (3D) simulations is usually much less that from two-dimensional (2D) simulations. By closely examining the TNSA of protons in 2D and 3D PIC simulations, we deduce an empirical ratio between the maximum proton energies obtained from the 2D and 3D simulations. This ratio may be useful for estimating the maximum proton energy in realistic (3D) TNSA from the results of the corresponding 2D simulation. It is also shown that the scaling law also applies to TNSA from structured targets., Comment: 20 pages, 7 figures, 3 tables, 45 references

Nonlinear coupling of the motion in the three spatial degrees of freedom of a cold fluid electron-positron plasma is investigated. Exact, solutions describing expanding flows with oscillations are obtained. It is found that the energy in the irrotational flow component is in general transferred to the rotational components, but not in the reversed direction. Furthermore, since the density evolution need not be related to all the three flow components, oscillations in one or two of the flow fields can be purely electromagnetic and are not accompanied by density oscillations. Original Publication:Wenmin Zhang, M Y Yu, A R Karimov and Lennart Stenflo, Energy coupling among the degrees of freedom in an electron-positron plasma, 2010, JOURNAL OF PLASMA PHYSICS, (76), 329-335.http://dx.doi.org/10.1017/S0022377809990523Copyright: Cambridge University Presshttp://www.cambridge.org/uk/Postprint available at: Linköping University Electronic Presshttp://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-57398

A practical approach to achieve strong coherent synchrotron emissions (CSE) in relativistic laser-plasma interaction is proposed, where a plane target with its electron density satisfying the self-similar parameter S ≃ n e 0 / a 0 n c = 1 is obliquely irradiated by a P-polarized laser pulse. In this case, electrons at the target surface are periodically dragged out into the vacuum by the laser field component perpendicular to the target surface, resulting in the formation of a series of dense electron bunches propagating along the target surface. Intense CSE is generated by these electron bunches under acceleration by the laser field component parallel to the target surface. Two-dimensional particle-in-cell simulations show that an intense attosecond light pulse at intensity 9.1 × 1020 W/cm2 (electric field strength ∼41% as that of the drive laser) can be obtained through such CSE. In the high-order harmonics with 15 ω 0 < ω n < 500 ω 0 (ω0 is the laser frequency), the power spectrum of the emission scale...

The acceleration of a micrometer-sized plasma pellet at 100 critical densities (1023 cm−3) by consecutive application of ultra-short ultra-intense laser pulses is studied using two-dimensional particle-in-cell simulation. It is shown that due to the repeated actions of the laser ponderomotive force, a small dense plasma pellet can be efficiently accelerated, with a considerable fraction of the plasma ions accelerated to high speeds. The proposed scheme can provide a high-density flux of energetic ions, which should be valuable in many practical applications.

The formation of collisionless electrostatic shock (CES) and ion acceleration in thin foils irradiated by intense laser pulse is investigated using particle-in-cell simulation. The CES can appear in the expanding plasma behind the foil when self-induced transparency occurs. The transmitting laser pulse can expel target-interior electrons, in addition to the electrons from the front target surface. The additional hot electrons lead to an enhanced and spatially-extended sheath field behind the foil. As the CES propagates in the plasma, it also continuously forward-reflects many of the upstream ions to higher energies. The latter ions are further accelerated by the enhanced sheath field and can overtake and shield the target-normal sheath accelerated ions. The energy gain of the CES accelerated ions can thus be considerably higher than that of the latter.

Channeling by a train of laser pulses into homogeneous and inhomogeneous plasmas is studied using particle-in-cell simulation. When the pulse duration and the interval between the successive pulses are appropriate, the laser pulse train can channel into the plasma deeper than a single long-pulse laser of similar peak intensity and total energy. The increased penetration distance can be attributed to the repeated actions of the ponderomotive force, the continuous between-pulse channel lengthening by the inertially evacuating ions, and the suppression of laser-driven plasma instabilities by the intermittent laser-energy cut-offs.

Electron acceleration by a short high-current relativistic electron bunch (EB) in plasmas at three characteristic densities is studied by particle-in-cell simulation. It is found that if the EB is appropriately matched to the background plasma, the blowout space-charge field of the EB can accelerate the trailing bunch electrons at very high energy gain rate. This high energy gain, as well as the large-amplitude wakefield, the turbulent small-scale electron plasma waves, and the formation of large current peaks, are studied. The evolution of the EB, its blowout field, and other related parameters are shown to be self-similar.

During the observation of Perseid, Leonid, Gemenid, and Orionid meteor showers, stable low-frequency lines in the frequency range of 20–60 Hz were recorded against the radio-frequency noise background. A physical mechanism for this effect is proposed, and it is established that the effect itself is related to the modulational interaction between electromagnetic and dust acoustic waves. The dynamics of the components of a complex (dusty) ionospheric plasma with dust produced from the evolution of meteoric material is described. The conditions for the existence of dust acoustic waves in the ionosphere are considered, and the waves are shown to dissipate energy mainly in collisions of neutral particles with charged dust grains. The modulational instability of electromagnetic waves in a complex (dusty) ionospheric plasma is analyzed and is found to be driven by the nonlinear Joule heating, the ponderomotive force, and the processes governing dust charging and dynamics. The conditions for the onset of the modulational instability of electromagnetic waves, as well as its growth rate and threshold, are determined for both daytime and nighttime. It is shown that low-frequency perturbations generated in the modulational interaction are related to dust acoustic waves.

The acceleration of electrons by the self-generated quasi-static magnetic field in the interaction of n laser pulses with a plasma is investigated. The relativistic dynamics of a single electron is followed numerically. It is found that the electron can be much more effectively accelerated by n laser pulses, each with amplitude a0 and having a fixed frequency difference from the preceding one, than by a single pulse with amplitude na0. The large enhancement of acceleration can be attributed to stochastic-like resonance between the electron motion at the beat-frequencies of lasers and at the cyclotron motion frequency.

Speciation of copper in a contaminated soil during electrokinetic remediation (EKR) assisted by H 3PO4 was studied by in situ X-ray absorption near edge structural (XANES) spectroscopy. The least-square fit of the XANES spectrum showed that CuCO 3 (68%) and CuCl2 (32%) were the major copper species in the contaminated soil. In the presence of H3PO4 (40%), most of CuCl2 and about 24% of CuCO3 were dissolved into the aqueous phase. After 90 min of EKR, at least 30% of Cu(II) ions were transported towards the cathode by electric field. A similar dissolution behavior of copper from the soil with 40% H 3PO4 and 2% H2O2 was also observed. Nevertheless, migration of Cu(II) ions to the cathode was highly enhanced in the presence of H3PO4 and H2O2 by EKR for the first 90 min. © 2005 Elsevier B.V. All rights reserved.

The effect of density and size of dust grains on the electron energy distribution function (EEDF) in low-temperature complex plasmas is studied. It is found that the EEDF depends strongly on the dust density and size. The behavior of the electron temperature can differ significantly from that of a pristine plasma. For low-pressure argon glow discharge, the Druyvesteyn-like EEDF often found in pristine plasmas can become nearly Maxwellian if the dust density and/or sizes are large. One can thus control the plasma parameters by the dust grains.

Stratified structures that are observed at heights of 80–95 km in the lower part of the Earth’s ionosphere are known as noctilucent clouds and polar mesosphere summer echoes. These structures are thought to be associated with the presence of vast amounts of charged dust or aerosols. The layers in the lower ionosphere where there are substantial amounts of dust are called the dusty ionosphere. The dust grains can carry a positive or a negative charge, depending on their constituent materials. As a rule, the grains are ice crystals, which may contain metallic inclusions. A grain with a sufficiently large metallic content can acquire a positive charge. Crystals of pure ice are charged negatively. The distribution of the dust grains over their charges has a profound impact on the ionizational and other properties of dust structures in the dusty ionosphere. In the present paper, a study is made of the effect of the sign of the dust charge on the properties of dust acoustic solitons propagating in the dusty ionosphere. It is shown that, when the dust charge is positive, dust acoustic solitons correspond to a hill in the electron density and a well in the ion density. When the dust is charged negatively, the situation is opposite. These differences in the properties of dust acoustic solitons can be used to diagnose the plasmas of noctilucent clouds and polar mesosphere summer echoes.

The effect of plasma nonuniformity on the electron energy distribution function (EEDF) and plasma parameters such as the ion density, electron temperature and dust charge in a dusty plasma are studied using a Boltzmann equation for the electrons and the fluid equations for the ions. The EEDF and the plasma parameters are obtained taking into account electron diffusion. The effect of the dusts on the electron energy-relaxation length is shown to be significant. The latter decreases as the dust density and/or size increase. Only at relatively high dust densities/sizes do the results of the homogeneous Boltzmann equation approach that of the more accurate kinetic equation.

Management of nanopowder and reactive plasma parameters in a low-pressure RF glow discharge in silane is studied. It is shown that the discharge control parameters and reactor volume can be adjusted to ensure lower abundance of nanopowders, which is one of the requirements of the plasma-assisted fabrication of low-dimensional quantum nanostructures. The results are relevant to micro- and nanomanufacturing technologies employing low-pressure glow discharge plasmas of silane-based gas mixtures.

Long-distance propagation of intense laser pulse in air is reconsidered analytically by generalizing the analogy between the laser spotsize and the orbit of a classical particle. It is shown that multiphoton ionization introduces unique features to the laser-air interaction, thereby enabling the long-distance behavior. Several interesting characteristics of the latter are pointed out.

A complex low-pressure argon discharge plasma containing dust grains is studied using a Boltzmann equation for the electrons and fluid equations for the ions. Local effects, such as the spatial distribution of the dust density and external electric field, are included, and their effect on the electron energy distribution, the electron and ion number densities, the electron temperature, and the dust charge are investigated. It is found that dust particles can strongly affect the plasma parameters by modifying the electron energy distribution, the electron temperature, the creation and loss of plasma particles, as well as the spatial distributions of the electrons and ions. In particular, for sufficiently high grain density and/or size, in a low-pressure argon glow discharge, the Druyvesteyn-like electron distribution in pristine plasmas can become nearly Maxwellian. Electron collection by the dust grains is the main cause for the change in the electron distribution function.

Lagrangian variables are used to describe linear and nonlinear oscillations of a magnetized non-neutral plasma slab in a harmonic trap, for slab width larger or comparable to the Debye length. The plasma particles move along the magnetic field lines, so that the oscillations are one-dimensional. The oscillation spectrum is found analytically, and the thermal corrections to the frequencies are calculated in a nonperturbative manner. Simple exact nonlinear solutions for the low-order modes are also obtained.

The optical behavior of a four-level system in a ring cavity driven by two coherent laser fields is studied. One laser field is treated as the incident field and the other the control field, respectively. It is found that there is optical transparency when the difference between the two frequency detunings of the incident and control fields from the corresponding atomic transition frequencies is zero. Optical bistability can be produced and controlled by increasing the magnitude of the frequency difference. The bistable hysteresis becomes larger when the frequency difference is increased. Further increase of the latter can lead to onset of multistability.

A classical model for high-harmonic generation from the interaction of a laser pulse and an atomic gas is introduced. The effects of finite pulse width and laser magnetic field are included. The optimum intensity-pulse width relation for high-harmonic emission and the corresponding power spectrum are presented. The existing high-harmonic cutoff law is found to remain valid.