Topic
Plasma channel
About: Plasma channel is a research topic. Over the lifetime, 2486 publications have been published within this topic receiving 33719 citations.
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TL;DR: A laser accelerator that produces electron beams with an energy spread of a few per cent, low emittance and increased energy (more than 109 electrons above 80 MeV) and opens the way for compact and tunable high-brightness sources of electrons and radiation.
Abstract: Laser-driven accelerators, in which particles are accelerated by the electric field of a plasma wave (the wakefield) driven by an intense laser, have demonstrated accelerating electric fields of hundreds of GV m-1 (refs 1–3) These fields are thousands of times greater than those achievable in conventional radio-frequency accelerators, spurring interest in laser accelerators4,5 as compact next-generation sources of energetic electrons and radiation To date, however, acceleration distances have been severely limited by the lack of a controllable method for extending the propagation distance of the focused laser pulse The ensuing short acceleration distance results in low-energy beams with 100 per cent electron energy spread1,2,3, which limits potential applications Here we demonstrate a laser accelerator that produces electron beams with an energy spread of a few per cent, low emittance and increased energy (more than 109 electrons above 80 MeV) Our technique involves the use of a preformed plasma density channel to guide a relativistically intense laser, resulting in a longer propagation distance The results open the way for compact and tunable high-brightness sources of electrons and radiation
1,749 citations
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TL;DR: The experimental observation of curved plasma channels generated in air using femtosecond Airy beams, where the tightly confined main intensity feature of the axially nonsymmetric laser beam propagates along a bent trajectory, leaving a curved plasma channel behind.
Abstract: Plasma channel generation (or filamentation) using ultraintense laser pulses in dielectric media has a wide spectrum of applications, ranging from remote sensing to terahertz generation to lightning control. So far, laser filamentation has been triggered with the use of ultrafast pulses with axially symmetric spatial beam profiles, thereby generating straight filaments. We report the experimental observation of curved plasma channels generated in air using femtosecond Airy beams. In this unusual propagation regime, the tightly confined main intensity feature of the axially nonsymmetric laser beam propagates along a bent trajectory, leaving a curved plasma channel behind. Secondary channels bifurcate from the primary bent channel at several locations along the beam path. The broadband radiation emanating from different longitudinal sections of the curved filament propagates along angularly resolved trajectories.
746 citations
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TL;DR: In this paper, simultaneous optical, electrical, and thrust measurements of an aerodynamic plasma actuator are presented, which reveal the temporal and macro-scale spatial structure of the plasma and the electrical characteristics of the discharge to the actuator performance as measured by the thrust produced.
Abstract: We present simultaneous optical, electrical, and thrust measurements of an aerodynamic plasma actuator. These measurements indicate that the plasma actuator is a form of the dielectric barrier discharge, whose behavior is governed primarily by the buildup of charge on the dielectric-encapsulated electrode. Our measurements reveal the temporal and macroscale spatial structure of the plasma. Correlating the morphology of the plasma and the electrical characteristics of the discharge to the actuator performance as measured by the thrust produced indicates a direct coupling between the interelectrode electric field (strongly modified by the presence of the plasma) and the charges in the plasma. Our measurements discount bulk heating or asymmetries in the structure of the discharge as mechanisms for the production of bulk motion of the surrounding neutral air, although such asymmetries clearly exist and impact the effectiveness of the actuator.
644 citations
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TL;DR: In this paper, the energy spectra of ions and fast electrons accelerated by a channeling laser pulse in near-critical plasma are studied using three-dimensional (3D) Particle-In-Cell simulations.
Abstract: Energy spectra of ions and fast electrons accelerated by a channeling laser pulse in near-critical plasma are studied using three-dimensional (3D) Particle-In-Cell simulations. The realistic 3D geometry of the simulations allows us to obtain not only the shape of the spectra, but also the absolute numbers of accelerated particles. It is shown that ions are accelerated by a collisionless radial expansion of the channel and have nonthermal energy spectra. The electron energy spectra instead are Boltzmann-like. The effective temperature Teff scales as I1/2. The form of electron spectra and Teff depends also on the length of the plasma channel. The major mechanism of electron acceleration in relativistic channels is identified. Electrons make transverse betatron oscillations in the self-generated static electric and magnetic fields. When the betatron frequency coincides with the laser frequency as witnessed by the relativistic electron, a resonance occurs, leading to an effective energy exchange between the l...
579 citations
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TL;DR: In this article, the propagation of an atmospheric pressure plasma jet (APPJ) was investigated by using an intensified charge coupled device (ICCD) camera and it was shown that the APPJ is mainly an electrical phenomenon and not a flow related one.
Abstract: The propagation of an atmospheric pressure plasma jet (APPJ) is investigated by use of an intensified charge coupled device (ICCD) camera. It is shown that the APPJ is mainly an electrical phenomenon and not a flow related one. The jet does not consist of a voluminous plasma. Much more, the presented plasma source acts like a "plasma gun" blowing small "plasma bullets" out of its mouth. Furthermore, the interaction of the jet with a surface has been investigated.
541 citations