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An extended MHD study of the 16 October 2015 MMS diffusion region crossingMar 15 2019The Magnetospheric Multiscale (MMS) mission has given us unprecedented access to high cadence particle and field data of magnetic reconnection at Earth's magnetopause. MMS first passed very near an X-line on 16 October 2015, the Burch event, and has since ... More

Spectral Control via Multi-Species Effects in PW-Class Laser-Ion AccelerationMar 15 2019Laser-ion acceleration with ultra-short pulse, PW-class lasers is dominated by non-thermal, intra-pulse plasma dynamics. The presence of multiple ion species or multiple charge states in targets leads to characteristic modulations and even mono-energetic ... More

Extreme high field plasmonics: electron acceleration and XUV harmonic generation from ultrashort surface plasmonsMar 15 2019Experiments on the excitation of propagating surface plasmons (SPs) by ultrashort, high intensity laser interaction with "grating" targets are reviewed. At intensities exceeding $10^{19}~\mbox{W cm}^{-2}$ on target, i.e. in the strongly relativistic regime ... More

Density shocks in the relativistic expansion of highly charged one component plasmasMar 14 2019In a previous paper we showed that dynamical density shocks occur in the non-relativistic expansion of dense single component plasmas relevant to ultrafast electron microscopy; and we showed that fluid models capture these effects accurately. We show ... More

Scattering of electron holes in the context of ion-acoustic regimeMar 14 2019Mutual collisions between ion-acoustic (IA) solitary waves are studied based on a fully kinetic simulation approach. Two cases, small and large relative velocity, are studied and the effect of trapped electron population on the collision process are focused ... More

[Plasma 2020 Decadal] Multipoint Measurements of the Solar Wind: A Proposed Advance for Studying Magnetized TurbulenceMar 13 2019A multi-institutional, multi-national science team will soon submit a NASA proposal to build a constellation of spacecraft to fly into the near-Earth solar wind in a swarm spanning a multitude of scales in order to obtain critically needed measurements ... More

[Plasma 2020 Decadal] Disentangling the Spatiotemporal Structure of Turbulence Using Multi-Spacecraft DataMar 13 2019This white paper submitted for 2020 Decadal Assessment of Plasma Science concerns the importance of multi-spacecraft missions to address fundamental questions concerning plasma turbulence. Plasma turbulence is ubiquitous in the universe, and it is responsible ... More

Radiation in equilibrium with plasma and plasma effects on cosmic microwave backgroundMar 13 2019The spectrum of the radiation of a body in equilibrium is given by Planck's law. In plasma, however, waves below the plasma frequency cannot propagate, consequently, the equilibrium radiation inside plasma is necessary different from the Planck spectrum. ... More

Extreme Plasma AstrophysicsMar 13 2019This is a science white paper submitted to the Astro-2020 and Plasma-2020 Decadal Surveys. The paper describes the present status and emerging opportunities in Extreme Plasma Astrophysics -- a study of astrophysically-relevant plasma processes taking ... More

Interpretation of quasi-periodic frequency sweeping in electron cyclotron emission of nonequilibrium mirror-confined plasma sustained by high-power microwavesMar 12 2019In [Viktorov M. E. et al., Eur. Phys. Lett., V.116, P.55001, 2016] we reported on chirping frequency patterns that have been observed in the electron cyclotron emission from strongly nonequilibrium plasma confined in a table-top mirror magnetic trap. ... More

Machine learning characterisation of Alfvénic and sub-Alfvénic chirping and correlation with fast ion loss at NSTXMar 12 2019Abrupt large events in the Alfv\'{e}nic and sub-Alfv\'{e}nic frequency bands in tokamaks are typically correlated with increased fast ion loss. Here, machine learning is used to speed up the laborious process of characterizing the behaviour of magnetic ... More

Implementation of energy transfer technique in ORB5 to study collisionless wave-particle interactions in phase-spaceMar 12 2019A new diagnostic has been developed to investigate the wave-particle interaction in the phase-space in gyrokinetic particle-in-cell codes. Based on the projection of energy transfer terms onto the velocity space, the technique has been implemented and ... More

On certain aspects of the THERMOS toolkit for modeling experimentsMar 12 2019The THERMOS toolkit has been developed to calculate radiative properties of plasmas. This article contains a brief survey of some of its key features used by calculation of opacities and emissivities and by analysis of specific experiments. The code has ... More

The role of second-order radial density gradient for helicon power absorptionMar 12 2019To reveal the mysterious and still controversial mechanism of high ionization efficiency during helicon discharges, this work focuses particularly on the role of second-order derivative in radial density profile, both analytical and numerically. It is ... More

The filamented electron bunch of the bubble regimeMar 12 2019We present a theory for describing the inner structure of the electron bunch in the bubble regime starting from a random distribution of electrons inside the bubble and subsequently minimizing the system's energy. Consequently, we find a filament-like ... More

A conservative phase-space moving-grid strategy for a 1D-2V Vlasov-Fokker-Planck EquationMar 11 2019We develop a conservative phase-space grid-adaptivity strategy for the Vlasov-Fokker-Planck equation in a planar geometry. The velocity-space grid is normalized to the thermal speed and shifted by the bulk-fluid velocity. The configuration-space grid ... More

Revisiting the Fe XVII line emission problem: High-resolution laboratory measurements of the 3s-2p and 3d-2p line-formation channelsMar 11 2019We determined relative X-ray photon emission cross sections in Fe XVII ions that were mono-energetically excited in an electron beam ion trap. Line formation for the 3s-2p and 3d-2p transitions of interest proceeds through dielectronic recombination (DR), ... More

Numerical Simulations of Magnetized Astrophysical Jets and Comparison with Laboratory Laser ExperimentsMar 11 2019The results of MHD numerical simulations of the formation and development of magnetized jets are presented. Similarity criteria for comparisons of the results of laboratory laser experiments and numerical simulations of astrophysical jets are discussed. ... More

[Plasma 2020 Decadal] The Material Properties of Weakly Collisional, High-Beta PlasmasMar 11 2019This white paper, submitted for the Plasma 2020 Decadal Survey, concerns the physics of weakly collisional, high-beta plasmas -- plasmas in which the thermal pressure dominates over the magnetic pressure and in which the inter-particle collision time ... More

Simulated Refraction-Enhanced X-Ray Radiography of Laser-Driven ShocksMar 10 2019Refraction-enhanced x-ray radiography (REXR) is used to infer shock-wave positions of more than one shock wave, launched by a multiple-picket pulse in a planar plastic foil. This includes locating shock waves before the shocks merge, during the early ... More

Proton-proton collisions in the turbulent solar wind: Hybrid Boltzmann-Maxwell simulationsMar 08 2019The mechanism of heating for hot, dilute and turbulent plasmas represents a long-standing problem in space physics, whose implications concern both near-Earth environments and astrophysical systems. Here, in order to explore the possible role of inter-particle ... More

Electron-positron pair production in oscillating electric fields with double-pulse structureMar 07 2019Electron-positron pair production from vacuum in a strong electric field oscillating in time is studied. The field is assumed to consist of two consecutive pulses, with variable time delay in between. Pair production probabilities are obtained by numerical ... More

Effects of excitation voltage pulse shape on the characteristics of atmospheric-pressure nanosecond dischargesMar 07 2019The characteristics of atmospheric-pressure microdischarges excited by nanosecond high-voltage pulses are investigated in helium-nitrogen mixtures, as a function of the parameters of the excitation voltage pulses. In particular, cases of single-pulse ... More

Feasibility of optical probing of relativistic plasma singularitiesMar 07 2019Singularities in multi-stream flows of relativistic plasmas can efficiently produce coherent high-frequency radiation, as exemplified in the concepts of Relativistic Flying Mirror [S. V. Bulanov, et al., Phys. Rev. Lett. 91, 085001 (2003)] and Burst Intensification ... More

Feasibility of optical probing of relativistic plasma singularitiesMar 07 2019Mar 08 2019Singularities in multi-stream flows of relativistic plasmas can efficiently produce coherent high-frequency radiation, as exemplified in the concepts of Relativistic Flying Mirror [S. V. Bulanov, et al., Phys. Rev. Lett. 91, 085001 (2003)] and Burst Intensification ... More

Three-wave interactions in magnetized warm-fluid plasmas: general theory with evaluable coupling coefficientMar 07 2019Resonant three-wave coupling is an important mechanism via which waves interact in a nonlinear medium. When the medium is a magnetized warm-fluid plasma, a previously-unknown formula for the coupling coefficients is derived by solving the fluid-Maxwell's ... More

Direct Gyrokinetic Comparison of Pedestal Transport in JET with Carbon and ITER-Like WallsMar 06 2019This paper compares the gyrokinetic instabilities and transport in two representative JET pedestals, one (pulse 78697) from the JET configuration with a carbon wall (C) and another (pulse 92432) from after the installation of JET's ITER-like Wall (ILW). ... More

Theory of Stochastic Shock Drift Acceleration for Electrons in the Shock Transition RegionMar 06 2019We propose a novel electron acceleration mechanism, which we call stochastic shock drift acceleration (SSDA), that extends the standard shock drift acceleration (SDA) for low-energy electrons at a quasi-perpendicular shock to include the effect of stochastic ... More

Micro-Faraday cup matrix detector for ion beam measurements in fusion plasmasMar 06 2019Atomic Beam Probe (ABP) is an extension of the routinely used Beam Emission Spectroscopy (BES) diagnostic for plasma edge current fluctuation measurement at magnetically confined plasmas. Beam atoms ionized by the plasma are directed to a curved trajectory ... More

Drift waves with dust acoustic wave couplingMar 06 2019Drift wave is a prominent mode of a magnetized plasma of inhomogeneous density. It plays an important role in the transport of particles, energy and momentum perpendicular to the ambient magnetic field. The frequency of this mode is governed by the inhomogeneity ... More

In situ spacecraft observations of a structured electron diffusion region during magnetopause reconnectionMar 05 2019The Electron Diffusion Region (EDR) is the region where magnetic reconnection is initiated and electrons are energized. Because of experimental difficulties, the structure of the EDR is still poorly understood. A key question is whether the EDR has a ... More

Hodograph solutions of the wave equation of nonlinear electrodynamics in the quantum vacuumMar 05 2019The process of photon-photon scattering in vacuum is investigated analytically in the long-wavelength limit within the framework of the Euler-Heisenberg Lagrangian. In order to solve the nonlinear partial differential equations (PDEs) obtained from this ... More

Superintense Laser-driven Ion Beam AnalysisMar 05 2019Ion beam analysis techniques are among the most powerful tools for advanced material characterization. Despite their growing relevance in a widening number of fields, most ion beam analysis facilities still rely on the oldest accelerator technologies, ... More

Adaptive Hybridizable Discontinuous Galerkin discretization of the Grad-Shafranov equation by extension from polygonal subdomainsMar 05 2019We propose a high-order adaptive numerical solver for the semilinear elliptic boundary value problem modelling magnetic plasma equilibrium in axisymmetric confinement devices. In the fixed boundary case, the equation is posed on curved domains with piecewise ... More

Boundary-induced effect on the spoke-like activity in ExB plasmaMar 04 2019The spoke instability in an $E\times B$ Penning discharge is shown to be strongly affected by the boundary that is perpendicular to $B$ field lines. The instability is the strongest when bounded by dielectric walls. With a conducting wall, biased to collect ... More

Quasioptical modeling of wave beams with and without mode conversion: III. Numerical simulations of mode-converting beamsMar 04 2019This work continues a series of papers where we propose an algorithm for quasioptical modeling of electromagnetic beams with and without mode conversion. The general theory was reported in the first paper of this series, where a parabolic partial differential ... More

Quasioptical modeling of wave beams with and without mode conversion: II. Numerical simulations of single-mode beamsMar 04 2019This work continues a series of papers where we propose an algorithm for quasioptical modeling of electromagnetic beams with and without mode conversion. The general theory was reported in the first paper of this series, where a parabolic partial differential ... More

Gravitational electromotive force in magnetic reconnection around Schwarzschild black holesMar 04 2019We analytically explore the effects of the gravitational electromotive force on magnetic reconnection around Schwarzschild black holes through a generalized general-relativistic magnetohydrodynamic model that retains two-fluid effects. It is shown that ... More

Do pulsars rotate clockwise or counterclockwise?Mar 04 2019Pulsars are rotating neutron stars which emit lighthouse-like beams. Owing to their unique properties, pulsars are a unique astrophysical tool to test general relativity, inform on matter at extreme densities, and probe galactic magnetic fields. Understanding ... More

Resonant micro-instabilities at quasi-parallel collisionless shocks: cause or consequence of shock (re)formationMar 04 2019A case of two interpenetrating, cold and quasi-neutral ion-electron plasmas is investigated with the multi-fluid approach. We consider that one plasma flows quasi-parallel to the lines of a background magnetic field embedded in another static plasma. ... More

First heat flux estimation in the lower divertor of WEST with embedded thermal measurementsFeb 28 2019The present paper deals with the surface heat flux estimation with thermocouples (TC) and fiber Bragg grating (FBG) embedded in the plasma facing components (PFC) of the WEST tokamak. A 2D heat transfer model combined with the conjugate gradient method ... More

Fast magnetic reconnection and particle accelerationFeb 28 2019Mathematics demonstrates that an ideally evolving magnetic field has an exponentially increasing sensitivity to non-ideal effects for all but truly exceptional evolutions. The implication is that the theory of magnetic reconnection requires reconsideration ... More

Optimizing Laser Pulses for Narrowband Inverse Compton Sources in the High-Intensity RegimeFeb 27 2019Scattering of ultraintense short laser pulses off relativistic electrons allows one to generate a large number of X- or $\gamma$-ray photons with the expense of the spectral width---temporal pulsing of the laser inevitable leads to considerable spectral ... More

Implementing and constraining higher fidelity kinetics for DPAL modelsFeb 27 2019Ionization, hydrocarbon breakdown, and other exotic processes can harm diode-pumped alkali laser (DPAL) performance and components. We develop a physical picture of these processes, including those that drive a non-Maxwell-Boltzmann distribution of electrons, ... More

Measurement of wave-particle interaction and metastable lifetime using laser-induced fluorescenceFeb 27 2019Extensive information, such as ion temperature and wave-particle interactions, can be obtained by direct measurement of ion distribution functions using laser-induced fluorescence (LIF). This nonintrusive plasma diagnostic provides an important window ... More

A fully implicit, scalable, nonlinear, conservative, relativistic Fokker-Planck solver for runaway electronsFeb 26 2019Upon application of a sufficiently strong electric field, electrons break away from thermal equilibrium and approach relativistic speeds. These highly energetic 'runaway' electrons (~MeV) play a crucial role in understanding tokamak disruption events, ... More

Validated Modeling of Atmospheric-Pressure Anodic ArcFeb 26 2019We performed self-consistent modeling of the atmospheric-pressure plasmas produced by arc discharges. Special numerical procedure for coupling of the plasma current, emission current, ion current, sheath voltage drop, heat fluxes at plasma-electrode interfaces ... More

Onset of transverse (shear) waves in strongly-coupled Yukawa fluidsFeb 26 2019A simple practical approach to describe transverse (shear) waves in strongly-coupled Yukawa fluids is presented. Theoretical dispersion curves, based on hydrodynamic consideration, are shown to compare favorably with existing numerical results for plasma-related ... More

Propagation of ultra-short, resonant, ionizing laser pulses in rubidium vaporFeb 25 2019We investigate the propagation of ultra-short laser pulses in atomic rubidium vapor. The pulses are intensive enough to ionize the atoms and are directly resonant with the 780 nm $D_2$ line. We derive a relatively simple theory for computing the nonlinear ... More

Robust surface plasmon polaritons on gyrotropic interfacesFeb 24 2019Unidirectional surface plasmon polaritons (SPPs) at the interface between a gyrotropic medium and a simple medium are studied in a newly-recognized frequency regime wherein the SPPs form narrow, beam-like patterns due to hyperbolic dispersion. The SPP ... More

Temperature-dependent Saturation of Weibel-type Instabilities in Counter-streaming PlasmasFeb 22 2019We present the first 2X2V continuum Vlasov-Maxwell simulations of interpenetrating, unmagnetized plasmas to study the competition between two-stream, Oblique, and filamentation modes in the weakly relativistic regime. We find that after nonlinear saturation ... More

ETG Turbulence Induced Energy flux in the Large Laboratory PlasmaFeb 22 2019The Large Volume Plasma Device (LVPD) has successfully demonstrated excitation of Electron Temperature Gradient (ETG) driven turbulence in finite plasma beta condition , where the threshold condition for ETG turbulence is satisfied. The observed mode ... More

Cross helicity sign reversals in the dissipative scales of magnetohydrodynamic turbulenceFeb 21 2019We perform direct numerical simulations of magnetohydrodynamic (MHD) turbulence with kinetic energy and cross helicity injections at large scales. We observe that the cross helicity changes sign as we go from large and intermediate scales to small scales. ... More

Statistical theory of photon gas in plasmaFeb 21 2019The thermodynamical properties of the photon-plasma system had been studied using statistical physics approach. It is demonstrated that the presence of the plasma medium enables the photon gas to undergo a Bose-Einstein condensation by adjusting the relevant ... More

Interpreting magnetic helicity flux in solar flux emergenceFeb 21 2019Magnetic helicity flux gives information about the topology of a magnetic field passing through a boundary. In solar physics applications, this boundary is the photosphere and magnetic helicity flux has become an important quantity in analysing magnetic ... More

A Thin Foil-foil Proton Recoil Spectrometer for DT neutrons using annular silicon detectorsFeb 20 2019The use of Thin-foil proton recoil (TPR) spectrometers to measure neutrons from Deuterium-Tritium (DT) fusion plasma has been studied previously and is a well established technique for neutron spectrometry. The study presented here focuses on the optimisation ... More

Rotating magnetohydrodynamic turbulenceFeb 20 2019Turbulence in rotating Magneto-hydrodynamic systems is studied theoretically and numerically. In the linear limit, when the velocity and magnetic perturbations are small, the system supports two types of waves. When the rotation effects are stronger than ... More

Head-on collision of nonlinear solitary solutions to Vlasov-Poisson equationsFeb 20 2019Nonlinear solitary solutions to the Vlasov-Poisson set of equations are studied in order to investigate their stability by employing a fully-kinetic simulation approach. The study is carried out in the ion-acoustic regime for a collisionless, electrostatic ... More

The impact of free electron degeneracy on collisional rates in plasmasFeb 19 2019Degenerate plasmas, in which quantum effects dictate the behavior of free electrons, are ubiquitous on earth and throughout space. Transitions between bound and free electron states determine basic plasma properties, yet degeneracy effects on these transitions ... More

Air plasma key parameters for electromagnetic wave propagation at and out of thermal equilibrium: applications to electromagnetic compatibilityFeb 19 2019This article addresses the importance of accurate characterization of plasma parameters for electromagnetic compatibility (EMC) purposes. Most of EMC issues involving plasma materials are obviously multi-physics problems (linking chemical, mechanical, ... More

Formation of solitary zonal structures via the modulational instability of drift wavesFeb 19 2019The dynamics of the radial envelope of a weak coherent drift wave can be approximately described by a nonlinear Schr\"odinger equation, which emerges as a limit of the modified Hasegawa-Mima equation. The nonlinear Schr\"odinger equation has well-known ... More

A Six-moment Multi-fluid Plasma ModelFeb 18 2019We present a six-moment multi-fluid model, which solves the governing equations for both ions and electrons, with pressure anisotropy along and perpendicular to the magnetic field direction, as well as the complete set of Maxwell equations. This set of ... More

Energy transfers in MHD turbulence and its applications to dynamoFeb 18 2019In this paper we describe the mode-to-mode energy transfers and energy fluxes of MHD turbulence. These energy transfers are very useful for understanding the turbulence dynamics, as well as for applications such as dynamo. We illustrate how the energy ... More

Universality of the Abraham-Minkowski dilemma for photon momenta beyond dielectric materialsFeb 18 2019The authors) Whenever light is slowed down, for any cause, two different formulas give its momentum. For dielectrics, the coexistence of those momenta was the heart of the century-old Abraham-Minkowski dilemma, recently resolved. We demonstrate that this ... More

The Efficiency of Coherent Radiation from Relativistic ShocksFeb 17 2019We discuss a mechanism for intense electromagnetic wave emission at an astrophysical relativistic shock in a magnetized collisionless plasma. At the magnetized shock, the particle reflection by a compressed magnetic field of the shock produces a ring-like ... More

Burn regimes in the hydrodynamic scaling of perturbed inertial confinement fusion hotspotsFeb 15 2019We present simulations of ignition and burn based on the Highfoot and High-Density Carbon indirect drive designs of the National Ignition Facility for three regimes of alpha-heating - self-heating, robust ignition and propagating burn - exploring hotspot ... More

Evidence for Electron Landau Damping in Space Plasma TurbulenceFeb 15 2019How turbulent energy is dissipated in weakly collisional space and astrophysical plasmas is a major open question. Here, we present the application of a field-particle correlation technique to directly measure the transfer of energy between the turbulent ... More

A magnetic spectrometer to measure electron bunches accelerated at AWAKEFeb 15 2019A magnetic spectrometer has been developed for the AWAKE experiment at CERN in order to measure the energy distribution of bunches of electrons accelerated in wakefields generated by proton bunches in plasma. AWAKE is a proof-of-principle experiment for ... More

Suitability and robustness of triangular nanostructured targets for proton accelerationFeb 14 2019Ion acceleration in the MeV range can be routinely achieved with table-top laser technology. One of the current challenges is to improve the energy coupling from the laser to the proton beam without increasing the laser peak power. Introducing nanostructures ... More

Low-Density Hydrodynamic Optical-Field-Ionized Plasma Channels Generated With An Axicon LensFeb 14 2019We demonstrate optical guiding of high-intensity laser pulses in long, low density hydrodynamic optical-field-ionized (HOFI) plasma channels. An axicon lens is used to generate HOFI plasma channels with on-axis electron densities as low as $n_e(0) = 1.5\times ... More

Laser wakefield driven generation of isolated CEP-tunable intense sub-cycle pulsesFeb 13 2019Sources of intense, ultra-short electromagnetic pulses are enabling applications such as attosecond pulse generation, control of electron motion in solids and the observation of reaction dynamics at the electronic level. For such applications both high-intensity ... More

Nonlinear saturation and oscillations of collisionless zonal flowsFeb 13 2019In homogeneous drift-wave (DW) turbulence, zonal flows (ZFs) can be generated via a modulational instability (MI) that either saturates monotonically or leads to oscillations of the ZF energy at the nonlinear stage. This dynamics is often attributed as ... More

Properties of Finite Amplitude Electromagnetic Waves propagating in the Quantum VacuumFeb 13 2019We study two counter-propagating electromagnetic waves in the vacuum within the framework of the Heisenberg-Euler formalism in quantum electrodynamics. We solve the non--linear field equations assuming the solution in a form of a Riemann wave. We show ... More

Results from the SuperModel Analysis of the X-COP Galaxy Clusters SampleFeb 13 2019In this work, the analysis of the stacked projected temperature profile of twelve galaxy clusters of the X-COP sample is performed via the SuperModel, a tool for investigating the intracluster medium thermodynamic properties already tested on many clusters ... More

Controlling injection using a magnetic field to produce sub-femtosecond bunches in the laser wakefield acceleratorFeb 13 2019Mar 04 2019It is shown that electron injection into a laser-driven plasma bubble can be manipulated by applying an external magnetic field in the presence of a plasma density gradient. The down-ramp of the density-tailored plasma locally reduces the plasma wave ... More

High current sub-femtosecond electron bunches via magnetic field induced injection braking in laser wakefield accelerationFeb 13 2019It is found that the three-dimensional laser-driven plasma bubble and the electron injection process can be manipulated by incorporating an external magnetic field and a plasma density gradient both along the longitudinal direction. The down-ramp of a ... More

I-mode investigation on the Experimental Advanced Superconducting TokamakFeb 13 2019By analyzing large quantities of discharges in the unfavorable ion $ \vec B\times \nabla B $ drift direction, the I-mode operation has been confirmed in EAST tokamak. During the L-mode to I-mode transition, the energy confinement has a prominent improvement ... More

Minimalist shear-driven large scale dynamoFeb 13 2019We show that non-axisymmetric, non-helical perturbations in an unstratified shear flow produce a shear-plane averaged electromotive force (EMF) rigorously proportional to a spatially dependent kinetic helicity. This new "shear-driven $\alpha$-effect" ... More

Coherent Transition Radiation from Relativistic Beam-Foil Interaction in the Terahertz and Optical RangeFeb 13 2019Coherent transition radiation (CTR) from relativistic electron beam interaction with an overdense plasma foil is investigated by making use of two-dimensional particle-in-cell simulations. Well-defined single electron beam either of uniform profile or ... More

High repetition rate (>= kHz) targets and optics from liquid microjets for the study and application of high intensity laser-plasma interactionsFeb 12 2019High intensity laser-plasma interactions produce a wide array of energetic particles and beams with promising applications. Unfortunately, high repetition rate and high average power requirements for many applications are not satisfied by the lasers, ... More

High repetition rate (>= kHz) targets and optics from liquid microjets for the study and application of high intensity laser-plasma interactionsFeb 12 2019Feb 20 2019High intensity laser-plasma interactions produce a wide array of energetic particles and beams with promising applications. Unfortunately, high repetition rate and high average power requirements for many applications are not satisfied by the lasers, ... More

The effect of plasma-core induced self-guiding on phase matching of high-order harmonic generation in gasesFeb 12 2019In this work we numerically study a self-guiding process in which ionization plays a dominant role and analyze its effect on high-order harmonic generation (HHG) in gases. Although this type of self-guiding --- termed as plasma-core induced self-guiding ... More

Deterministic and stochastic properties of self-similar Rayleigh-Taylor mixing induced by space-varying accelerationFeb 12 2019Rayleigh-Taylor interfacial mixing has critical importance in a broad range of processes in nature and technology. In most instances Rayleigh-Taylor dynamics is induced by variable acceleration, whereas the bulk of existing studies is focused on the cases ... More

Extremely intense laser-based electron acceleration in a plasma channelFeb 12 2019Laser pulses of extreme intensities ($I>10^{22}~ \mathrm{W/cm^2}$) are about to become available in the laboratory. The prepulse of such a laser can induce a plasma expansion that generates a low-density channel in near-critical gas jets. We present a ... More

Are we ready to transfer optical light to gamma-rays?Feb 12 2019Scattering relativistic electrons with optical lasers can result in a significant frequency upshift for the photons, potentially producing $\gamma$-rays. This is what linear Compton scattering taught us. Ultra-intense lasers offer nowadays a new paradigm ... More

The emission of energetic electrons from the complex streamer corona adjacent to leader steppingFeb 12 2019We here propose a model to capture the complexity of the streamer corona adjacent to leader stepping and relate it to the production of energetic electrons serving as a source of X-rays and $\gamma$-rays, manifesting in terrestrial gamma-ray flashes (TGFs). ... More

Imbalanced kinetic Alfvén wave turbulence: from weak turbulence theory to nonlinear diffusion models for the strong regimeFeb 12 2019A two-field Hamiltonian gyrofluid model for kinetic Alfv\'en waves retaining ion finite Larmor radius corrections, parallel magnetic field fluctuations and electron inertia, is used to study turbulent cascades from the MHD to the sub-ion scales. Special ... More

Plasma-grains interaction mediated by streaming non-Maxwellian ionsFeb 11 2019A comprehensive parametric study of plasma-grain interaction for non-Maxwellian streaming ions in steady-state employing particle-in-cell simulation is delineated. Instead of considering the inter-grain interaction potential to be the linear sum of isolated ... More

Scaling laws for harmonically trapped two-species mixtures at thermal equilibriumFeb 11 2019We discuss the scaling of the interaction energy with particle numbers for a harmonically trapped two-species mixture at thermal equilibrium experiencing interactions of arbitrary strength and range. In the limit of long-range interactions and weak coupling, ... More

Field theory and structure-preserving geometric particle-in-cell algorithm for drift wave instability and turbulenceFeb 11 2019A field theory and the associated structure-preserving geometric Particle-In-Cell (PIC) algorithm are developed to study low frequency electrostatic perturbations with fully kinetic ions and adiabatic electrons in magnetized plasmas. The algorithm is ... More

Penetration depth of an electric field in a semi-infinite plasmaFeb 11 2019It is shown that the penetration of an oscillating electric field in a semi-infinite classical plasma obeys the standard exponential attenuation law $e^{-x/\lambda_{e}}$ (besides oscillations), where $x$ is the distance from the wall and $\lambda_{e}$ ... More

Elastic Alfven waves in elastic turbulenceFeb 11 2019Speed of sound waves in gases and liquids is governed by medium compressibility. There exists another type of non-dispersive waves which speed depends on stress instead of medium elasticity. A well-known example is the Alfven wave propagating, with a ... More

Stellar energetic particles in the magnetically turbulent habitable zones of TRAPPIST-1-like planetary systemsFeb 11 2019Planets in close proximity to their parent star, such as those in the habitable zones around M dwarfs, could be subject to particularly high doses of particle radiation. We have carried out test-particle simulations of ~GeV protons to investigate the ... More

The multi-scale nature of the solar windFeb 09 2019The solar wind is a magnetized plasma and as such exhibits collective plasma behavior associated with its characteristic spatial and temporal scales. The characteristic length scales include the size of the heliosphere, the collisional mean free paths ... More

Full particle-in-cell simulation of the interaction between two plasmas for laboratory experiments on the generation of magnetized collisionless shocks with high-power lasersFeb 09 2019A preliminary numerical experiment is conducted for laboratory experiments on the generation of magnetized collisionless shocks with high-power lasers by using one-dimensional particle-in-cell simulation. The present study deals with the interaction between ... More

Low RF power plasma ignition and detection for in-situ cleaning of 1.3 GHz 9-cell cavitiesFeb 08 2019Superconducting Radio Frequency (SRF) cavities performance preservation is crucial, from vertical test to accelerator operation. Field Emission (FE) is still one of the performance limiting factors to overcome and plasma cleaning has been proven successful ... More

The Barkas Effect in Plasma TransportFeb 08 2019Molecular dynamics simulations reveal that a fundamental symmetry of plasma kinetic theory is broken at moderate to strong Coulomb coupling: the collision rate depends on the signs of the colliding charges. This symmetry breaking is analogous to the Barkas ... More

A new HLLD Riemann solver with Boris correction for reducing Alfvén speedFeb 07 2019Mar 03 2019A new Riemann solver is presented for the ideal magnetohydrodynamics (MHD) equations with the so-called Boris correction. The Boris correction is applied to reduce wave speeds, avoiding an extremely small timestep in MHD simulations. The proposed Riemann ... More

A new HLLD Riemann solver with Boris correction for reducing Alfvén speedFeb 07 2019A new Riemann solver is presented for the ideal magnetohydrodynamics (MHD) equations with the so-called Boris correction. The Boris correction is applied to reduce wave speeds, avoiding an extremely small timestep in MHD simulations. The proposed Riemann ... More

Kinetic Entropy as a Diagnostic in Particle-in-Cell Simulations of Astrophysical, Heliospheric, and Planetary PlasmasFeb 07 2019We describe a systematic development of kinetic entropy as a diagnostic in fully kinetic electromagnetic particle-in-cell (PIC) simulations and investigate some of its uses to interpret plasma physics processes in astrophysical, heliospheric, and planetary ... More