A5109146112- Probabilistic and Robust Engineering Design
- Laser-Plasma Interactions and Diagnostics
- Groundwater flow and contamination studies
- Numerical methods in engineering
- Structural Health Monitoring Techniques
- Magnetic confinement fusion research
- Advanced Mathematical Modeling in Engineering
- Electron and X-Ray Spectroscopy Techniques
- Ion-surface interactions and analysis
- Scientific Research and Discoveries
- Wind and Air Flow Studies
- Soil and Unsaturated Flow
- Soil Geostatistics and Mapping
- Electromagnetic Scattering and Analysis
- Solar and Space Plasma Dynamics
- Integrated Circuits and Semiconductor Failure Analysis
- Laser-Matter Interactions and Applications
- Advanced Numerical Methods in Computational Mathematics
- Statistical and numerical algorithms
- Laser-induced spectroscopy and plasma
- Model Reduction and Neural Networks
- Atmospheric and Environmental Gas Dynamics
- Nonlinear Dynamics and Pattern Formation
- Mathematical functions and polynomials
- Hydrology and Drought Analysis
Novosibirsk State University
2017-2025
Institute of Computational Mathematics and Mathematical Geophysics
2012-2025
Russian Academy of Sciences
2009-2014
Institute for Systems Analysis
2014
Computing Center
1998
High energy particle accelerators have been crucial in providing a deeper understanding of fundamental particles and the forces that govern their interactions. In order to increase or reduce size accelerator, new acceleration schemes need be developed. Plasma wakefield acceleration, which electrons plasma are excited, leading strong electric fields, is one such promising novel technique. Pioneering experiments shown an intense laser pulse electron bunch traversing plasma, drives fields 10s...
We give direct experimental evidence for the observation of full transverse self-modulation a long, relativistic proton bunch propagating through dense plasma. The exits plasma with periodic density modulation resulting from radial wakefield effects. show that is seeded by ionization front created using an intense laser pulse copropagating bunch. extends over length following seed point. By varying one order magnitude, we frequency scales expected dependence on density, i.e., it equal to...
The seeded self-modulation of a relativistic, charged particle bunch in plasma is shown to grow both along the and plasma, resulting transverse wakefield amplitudes that far exceed initial seed values.
AWAKE is a proton-driven plasma wakefield acceleration experiment. % We show that the experimental setup briefly described here ready for systematic study of seeded self-modulation 400\,GeV proton bunch in 10\,m-long rubidium with density adjustable from 1 to 10$\times10^{14}$\,cm$^{-3}$. short laser pulse used ionization vapor propagates all way along column, suggesting full vapor. occurs bunch, at time and follows affects bunch.
A recently developed three-dimensional version of the quasistatic code LCODE has a novel feature that enables high-accuracy simulations long-term evolution waves in plasma wakefield accelerators. Equations particle motion are modified to suppress clustering and numerical heating macroparticles, which otherwise occur because Debye length is not resolved by grid. The previously observed effects premature wake chaotization wavebreaking disappear with equations.
Abstract A hybrid continuous Random Walk on Boundary algorithm and iterative refinement method is constructed. In this method, the density of double layer boundary integral equation for Laplace resolved by an isotropic calculated a set grid points chosen boundary. Then, residual deterministically, same solved where right-hand side changed with function. This process repeated several times until desired accuracy achieved. compared against standard in terms their labor intensity. Simulation...
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Abstract In this paper, we address a long-standing open problem in stochastic simulation: construction of random walk on spheres (RWS) algorithm for solving system elasticity equations, known as the Lamé equation. Many attempts to generalize classic probabilistic representations like Kac formula parabolic and scalar elliptic equations failed. A different approach based branching (BRWS) introduced our paper 1995 [K. K. Sabelfeld D. Talay, Integral formulation boundary value problems method...
Abstract A meshless stochastic algorithm for solving anisotropic transient diffusion problems based on an extension of the classical Random Walk Spheres method is developed. Direct generalization to equations not possible, therefore, we have derived approximations probability densities first passage time and exit point a small sphere. The can be conveniently applied solve with spatially varying coefficients simply implemented complicated three-dimensional domains. Particle tracking highly...
Abstract A generalization of a polynomial chaos-based algorithm for solving PDEs with random input data is suggested. The field assumed to be defined by its mean and correlation function. method uses the Karhunen–Loève expansion, in analytical form, field. Potentially, however, if desired, expansion can also constructed randomized singular value decomposition function recently suggested our paper [Math. Comput. Simulation 82 (2011), 295–317]. chaos then resolving probabilistic...
The Random Walk on Fixed Spheres (RWFS) introduced in our paper [25], and further developed [26], is presented details for Laplace Lamé equations governing static elasticity problems. approach based the Poisson type integral formulae written each disc of a domain consisting family overlapping discs. original differential boundary value problem equivalently reformulated form system defined intersection surfaces (arches, 2D, caps, if generalized to 3D spheres). To solve obtained equations,...
Abstract We suggest a random walk on spheres based stochastic simulation algorithm for solving drift-diffusion-reaction problems with anisotropic diffusion. The diffusion coefficients and the velocity vector vary in space, size of walking is adapted to local variation these functions. method mesh free extremely efficient calculation fluxes boundaries concentration absorbed particles inside domain. Applications cathodoluminescence (CL) electron beam induced current (EBIC) methods analysis...
Abstract A Random Walk on Ellipsoids (RWE) algorithm is developed for solving a general class of elliptic equations involving second- and zero-order derivatives. Starting with constant coefficients, we derive an integral equation which relates the solution in center ellipsoid over defined by structure coefficients original differential equation. This relation extended to parabolic where first passage time distribution survival probability are given explicit forms. We suggest efficient...
A recently developed three-dimensional version of the quasistatic code LCODE has a novel feature that enables high-accuracy simulations long-term evolution waves in plasma wakefield accelerators. Equations particle motion are modified to suppress clustering and numerical heating macroparticles, which otherwise occur because Debye length is not resolved by grid. The previously observed effects premature wake chaotization wavebreaking disappear with equations.
Abstract A probabilistic collocation based polynomial chaos expansion method is developed to solve stochastic boundary value problems with random coefficients and randomly distributed initial data. In this paper we deal two different data: the Darcy equation lognormally hydraulic conductivity, a diffusion absorption, distribution of concentration under periodic conditions. Special attention paid extension input data arbitrary correlation functions defined both analytically through...
Article Forward and Backward Stochastic Lagrangian Models for turbulent transport the well-mixed condition was published on January 1, 2001 in journal Monte Carlo Methods Applications (volume 7, issue 3-4).
A new general stochastic-deterministic approach for a numerical solution of boundary value problems potential and elasticity theories is suggested. It based on the use Poisson-like integral formulae overlapping spheres. An equivalent system equations derived then approximated by linear algebraic equations. We develop two classes special Monte Carlo iterative methods solving these systems which are kind stochastic versions Chebyshev iteration method successive overrelaxation (SOR). In case...