A5073424228- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Laser-Matter Interactions and Applications
- Gyrotron and Vacuum Electronics Research
- Terahertz technology and applications
- Magnetic confinement fusion research
- Pulsed Power Technology Applications
- Particle Accelerators and Free-Electron Lasers
- Laser Design and Applications
- Atomic and Molecular Physics
- Dust and Plasma Wave Phenomena
- Particle physics theoretical and experimental studies
- High-pressure geophysics and materials
- Nuclear Physics and Applications
- High-Energy Particle Collisions Research
- Fluid Dynamics and Turbulent Flows
- Nuclear physics research studies
- Electromagnetic Simulation and Numerical Methods
- Gamma-ray bursts and supernovae
- Quantum Chromodynamics and Particle Interactions
- Electrohydrodynamics and Fluid Dynamics
- Advanced X-ray Imaging Techniques
- Particle accelerators and beam dynamics
- Solid State Laser Technologies
- Mechanical and Optical Resonators
Weizmann Institute of Science
2023
Institute of Applied Physics
2014-2023
N. I. Lobachevsky State University of Nizhny Novgorod
2016-2023
Heinrich Heine University Düsseldorf
2021
Russian Academy of Sciences
2014
A. N. Kosygin Moscow State Textile University
2001-2005
We demonstrate both theoretically and experimentally the possibility of correlating phase a Cherenkov superradiance (SR) pulse to sharp edge current pulse, when spontaneous emission electron bunch serves as seed for SR processes. By division driving voltage across several parallel channels equipped with independent cathodes we can synchronize sources arrange two-dimensional array. In experiments carried out, coherent summation radiation from four 8-mm wavelength band generators peak power...
This paper presents the first experimental realization of a scheme that allows for tuning velocity peak intensity focal spot with relativistic intensity. By combining tunable pulse-front curvature axial deposition characteristics an axiparabola, aspheric optical element, this system provides control over dynamics laser-wakefield accelerators. We demonstrate ability to modify ultrashort laser pulses be superluminal or subluminal. The results are supported by theoretical calculations and...
We present a self-consistent theory of strongly nonlinear plasma wakefield (bubble or blowout regime the wakefield) based on energy conservation approach. Such wakefields are excited in plasmas by intense laser particle beam drivers and characterized expulsion electrons from propagation axis driver. As result, spherical cavity devoid (called "bubble") surrounded thin sheath made expelled is formed behind In contrast to previous theoretical model [W. Lu et al., Phys. Rev. Lett. 96, 165002...
For the first time, we demonstrate experimentally possibility of Cherenkov superradiant generation with a phase imposed by an ultrashort seed microwave pulse. The phases and initiated Ka-band pulses were correlated accuracy 0.5–0.7 rad for power ratio down to −35 dB. Characteristics such process determined in frame basic theoretical model that describes both spontaneous stimulated emission electron beam moving corrugated waveguides. obtained results open up opportunities reaching extremely...
We introduce a first full analytical bubble and blow-out model for radially inhomogeneous plasma in quasi-static approximation. For both cases we calculate the accelerating focusing fields. In our also assume thin electron layer that surrounds wake field configuration within. Our theory holds arbitrary radial density profiles reduces to known models limit of homogeneous plasma. From previous study hollow channels with smooth boundaries laser-driven acceleration regime know pancake-like laser...
It is shown that electrostatic plasma wakefields can efficiently radiate at harmonics of the frequency when has a positive density gradient along propagation direction driver. The driver propagating subluminal group velocity excites wakefield with same phase velocity. However, due to gradient, wake steadily increases behind As soon as becomes superluminal, couples radiative electromagnetic modes. period time stays above speed light depends on scale length. radiates well-defined in terahertz...
For relativistic Cherenkov devices, we investigate the process of high-power microwave pulse generation with its phase correlating to sharp edge an e-beam current pulse. Our theoretical consideration is referred quasi-stationary and superradiative (SR) regimes when spontaneous emission serves as seed for development further coherent oscillations. Phase correlation excited pulses characteristics front and/or initial external electromagnetic has been additionally confirmed by particle-in-cell...
The phase velocity of a laser-driven wakefield can be efficiently controlled in plasma channel. A beatwave two long laser pulses is used. frequency difference between these equals the local frequency, so that slow resonant excitation wave possible. Because driver energy spread over many periods, interference pattern run with an arbitrary along channel and generate same velocity. This defined by radius structure transverse modes excited wake matched exactly to witness vacuum speed light for...
Modern laser systems are able to generate short and intense pulses ionizing matter in the poorly explored barrier-suppression regime. Field ionization this regime is studied analytically numerically. For analytical studies, both classical quantum approaches used. Two approximations solve time-dependent Schr\"odinger equation proposed: free electron approximation, which atomic potential neglected, motionless only external field term considered. In rate extremely strong fields derived. The...
Based on the already existing analytical theory of strongly-nonlinear wakefield (which is called "bubble") in transversely inhomogeneous plasmas, we study particular behavior non-loaded (empty) bubbles and with accelerated bunches. We obtain an expression for shape a bubble general case verify it particle-in-cell (PIC) simulations. derive method calculation acceleration efficiency arbitrary The influence flat-top electron bunches studied. It also shown that possible to achieve homogeneous...
An analytical model of a plasma bubble (a wake wave in the strongly nonlinear regime) transversely inhomogeneous is generalised to an arbitrary profile electron sheath at its boundary. Within framework this generalisation we have found potential within and shown that envelope described by second-order equation, similar equation less general theory. We also determined domain parameters which considerably simplified no longer depends on sheath.
Based on a model of plasma wakefield in the strongly nonlinear (bubble) regime, we develop lowest-order perturbation theory for components electromagnetic fields inside and outside bubble using assumption small thickness electron sheath boundary bubble. Unlike previous models, derive simple explicit expressions not only vicinity center bubble, but whole volume (including areas driving or accelerated bunches) as well it. Moreover, apply results to case radially non-uniform and, particular,...
We propose a setup for positron acceleration consisting of an electron driver and laser pulse creating twofold plasma column structure. The resulting wakefield is capable accelerating bunches over long distances even when the evolution considered. scheme studied by means particle-in-cell simulations. Further, analytical expression focusing fields are obtained, showing equilibrium lines along which witness bunch accelerated.
We investigate in detail the method of coherent summation multiple sub-gigawatt Ka-band backward-wave oscillators (BWOs) based on their phase-imposed excitation by an incoming short seed electromagnetic pulse. For theoretical analysis, we use particle-in-cell simulations as well a basic model that describes both spontaneous and stimulated Cherenkov emission electron beam moving corrugated waveguides. In scope model, influence front edge length, phase power pulse, other conditions important...
We study electron acceleration in a plasma wakefield under the influence of radiation-reaction force caused by transverse betatron oscillations wakefield. Both classical and strong quantum-electrodynamic (QED) limits radiation reaction are considered. For constant accelerating force, we show that amplitude QED parameter $\chi$ radiation-dominated regime reaches equilibrium value determined only magnitude field, while averaged over saturates at smaller than thus is incapable preventing...
Abstract A formula is proposed for calculating the rate of field ionisation an atom or ion, taking into account both tunnel and barrier suppression ionisation. Compared with previous in 2018, it more accurately describes transition region between ionisations determined mainly by two parameters: potential ion amplitude external electric field. This makes presented suitable use numerical packages simulating interaction high-power laser radiation matter particle-in-cell (PIC) method.
We present the first acceleration of electrons by an axiparabola-focused wake-field. This proof-of-concept experiment strengthens argument for axiparabola-based solution dephasingless LWFA. also show numerical simulations confirming experimental results.
We propose a new method for analytical self-consistent description of the excitation strongly nonlinear wakefield (a bubble) excited by an electron bunch. This makes it possible to calculate shape bubble and distribution electric field in based only on properties driver, without relying any additional parameters. The results are verified particle-in-cell simulations show good correspondence. A complete solution cylindrical drivers scaling laws other plasma accelerator parameters depending...
Considering the popularity of two-dimensional particle-in-cell simulations, a 2D model plasma wakefield in strongly nonlinear (bubble) regime transversely non-uniform is developed. A differential equation for boundary bubble geometry obtained, its analytic solution derived. simulations are used to confirm validity our model. The results compared realistic 3D geometry. For uniform plasma, it shown that elongated and has stronger focusing forces, while structure accelerating field remains...
Available analytical wakefield models for the bubble and blow-out regime of electron-plasma acceleration perfectly describe important features like shape, fields, trapping ratio, achievable energy, energy distribution radial emittance. As we show, wakefields with an extremely small amplitude these fail to accelerating electric field its divergence in rear. Since prominent parameter regimes Trojan horse photocathode injection exhibit this feature, it is great importance work out that fix...