Abstract The wakefield excitation and electron acceleration is investigated in the presence of laser pulse with without frequency-chirp an under-dense plasma via particle cell simulation. For this purpose, first 1D model revisited. analytical expressions for longitudinal wake-potential generated behind are obtained. results show that wake-fields excited by pulses strongly dependent on chirp parameter. These could be very useful as a starting point optimization studies real LWFA experiment.

The model given by Patil et al., for the self-focusing of lowest-order Bessel–Gaussian laser beam, is revisited introducing exponential plasma density ramp in this paper. Plasma changes due to combined effect relativistic and ponderomotive nonlinearities, which arise nonuniform spatial profile beam leading stronger self-focusing. Under paraxial ray approximation, expression evolution laser-beam width parameter obtained solved numerically order achieve We have observed that as Bessel...

Abstract This paper deals with the study of propagation electromagnetic wave in a rectangular waveguide filled an inhomogeneous plasma which electron density varies linearly transverse direction to mode propagation. A transcendental equation ω (microwave frequency) is obtained that governs In addition, attempt made examine effect inhomogeneity on energy gain acquired by (electron bunch) when it injected along On basis angle deflection motion we optimize microwave parameters so does not...

In this article, EH01 field components are evaluated in a cylindrical waveguide filled with plasma the presence of external static magnetic applied along direction mode propagation. The electron acceleration inside plasma-filled is investigated numerically for single-electron model. It found that very sensitive to initial phase mode-field components, field, density, point injection electron, and microwave power density. maximum amplitude mode’s approximately 100 times greater than...

Ultrahigh-gradient acceleration, by a chirped circularly polarized (CP) laser pulse in the presence of planar magnetic wiggler, is investigated numerically. A simple linear profile frequency has been introduced our model. The combined effect chirping and tapered wiggler field on electron acceleration discussed detail. It found that parameter, tapering initial phase laser, spot size intensity all have strong influence acceleration. If an optimal same direction as externally applied during...

The characteristics of obliquely propagating dust acoustic solitary wave in magnetized dusty plasma are analysed by considering the to have electrons, two-temperature ions and massive grains with heavy charge. reductive perturbation technique is used derive relevant Korteweg-deVries (KdV) equation. effect density temperature hot cold ions, angle propagation, mass, charge on soliton characteristic investigated greater detail. situation electron-depleted also uncovered.

Isolated terawatt (TW) attosecond (as) hard X-ray pulse is greatly desired for four-dimensional investigations of natural phenomena with picometer spatial and temporal resolutions. Since the demand such sources continuously increasing, possibility generating by a single current spike without use optical or electron delay units in an undulator line addressed. The conditions (width height) modulation laser (wavelength power) also discussed. We demonstrate that isolated TW-level as can be...

Analytical expressions for the TE10 mode fields and acceleration gradient an electron are obtained in a plasma filled rectangular waveguide under effect of obliquely applied external magnetic field. The lower upper cutoff frequencies propagation evaluated various parameters. is increased with microwave frequency angle It becomes reduced higher density stronger larger achieved when .

The effect of plasma-electron collision and their thermal motion is investigated on the externally injected electron in a warm magnetized plasma-filled cylindrical waveguide cross section 13.68 cm2. numerical results are presented for external electron-energy gain its trajectory nonrelativistic γe=1 stationary v0=0 waveguide. Results shows that an electron-cyclotron frequency ωc greater than electron-plasma ωp, 100 keV acquires 1.74 MeV energy 2.5 cm distance plasma density n0=1.08×1017/m3,...

Abstract Attosecond metrology using laser-based high-order harmonics has been significantly advanced and applied to various studies of electron dynamics in atoms, molecules solids. Laser-based have a limitation low power photon energies. There is, however, great demand for even higher energy. Here, we propose scheme terawatt attosecond (TW-as) X-ray pulse free-electron laser controlled by few cycle IR pulse, where one dominant current spike an bunch is used repeatedly amplify seeded...

A scheme for laser-induced acceleration of an electron injected initially at angle to the direction a short-wavelength laser is investigated, where additional long-wavelength electromagnetic wave introduced achieve high energy gain. Due beating effect waves, can gain energy. Some computational results are presented estimate by proposed scheme, increases increasing difference wavelengths.

The generation of isolated attosecond hard x-ray pulse has been studied under the enhanced self-amplified spontaneous emission (ESASE) scheme with density and energy modulation an electron bunch. It is demonstrated in simulation that a high contrast ratio can be produced by adjusting driver laser wavelength distribution An ~146 full-width half-maximum (FWHM) at 0.1 nm obtained saturation length 34 meter for beam parameters Korean X-ray Free Electron laser.

Abstract For a real, meaningful pump-probe experiment with attosecond temporal resolution, an intense isolated pulse is in demand. that purpose we report the generation of pulse, especially X-ray region using current-enhanced self-amplified spontaneous emission free electron laser (FEL). We use few cycle to manipulate electron-bunch inside two-period planar wiggler. In our study, employ beam parameters Pohang Accelerator Laboratory (PAL)-XFEL. The RF phase effect accelerator columns on...

In the Trojan Horse injection process for plasma-based particle accelerators, we have investigated how longitudinal phase space of witness bunch would be governed by parameters ionization laser and background plasma in limit quasistatic wakefield approximation. The tunneling rate distribution pulse is introduced to describe time interval initial electrons. quasilinear (or equivalently quasistatic) regime charged beam-driven considered make wake potential constant driver beam frame....

The amplitude of wake fields generated by the finite-width laser pulse propagating in an underdense plasma are determined using weakly nonlinear equations (n'e≪n0) for triangular (TR) and two types sawtooth (SD SI, defined section 2) pulses making duration same as electron period. In addition to density perturbations ne', potential ϕ field Ez behind pulses, expression change relativistic factor γ or energy gain is obtained discussed all these under effect frequency f, τ (corresponding n0)...

In this paper, several schemes of soft X-ray and hard free electron lasers (XFEL) their progress are reviewed. Self-amplified spontaneous emission (SASE) schemes, the high gain harmonic generation (HGHG) scheme various enhancement through seeding beam manipulations discussed, especially in view attosecond pulses. Our recent work on pulses is also discussed. our study, enhanced SASE utilized, using parameters an XFEL under construction at Pohang Accelerator Laboratory (PAL). Laser, chicane...

Abstract The significant contribution of greenhouse gas (GHG) emissions to global climate change and stratospheric ozone depletion has been calling the attention assess effect agricultural management on them. Although machine learning (ML) methods have widely used for quantification various inherent dynamic soil properties, accuracy these techniques in prediction GHG remains unclear. Therefore, this study aims at evaluating performance six different ML including simple linear regression,...