Papers by Sergei Krasheninnikov
arXiv: Plasma Physics, 2019
The electron dynamics in counter-propagating laser waves is investigated by employing a novel app... more The electron dynamics in counter-propagating laser waves is investigated by employing a novel approach, where the new Hamiltonian is time-independent when the perturbative laser wave is absent. The physical picture of stochastic electron dynamics is clearly revealed and the threshold values of the amplitude of the perturbative laser field for triggering stochastic electron acceleration are derived for different laser polarization directions and initial electron momentum. It demonstrates that the dephasing rate (new Hamiltonian) between the electron and the dominant laser can be randomly reduced if the amplitude of the perturbative laser is above the threshold such that the electron could be accelerated by the dominant laser well beyond the ponderomotive energy scaling. The impact of a superluminal phase velocity is examined, which slightly changes the stochastic region in Hamiltonian space if the superluminal phase velocity is under a threshold value but significantly decreases the ...
Physics of Plasmas, 2019
The mechanism of stochastic electron acceleration in colliding laser waves is investigated by emp... more The mechanism of stochastic electron acceleration in colliding laser waves is investigated by employing proper canonical variables and effective time, such that the new Hamiltonian becomes time independent when the perturbative laser wave is absent. The performed analytical analysis clearly reveals the physical picture of stochastic electron dynamics. It shows that when the amplitude of the perturbative laser field exceeds some critical value, stochastic electron acceleration occurs within some electron energy range. The conditions, at which the maximum electron energy gained under stochastic acceleration greatly exceeds the ponderomotive energy scaling based on the amplitude of the dominant laser, are derived.
Plasma Physics and Controlled Fusion, 2019
The goal of the Lithium Tokamak eXperiment (LTX) is to produce tokamak discharges with near-zero ... more The goal of the Lithium Tokamak eXperiment (LTX) is to produce tokamak discharges with near-zero recycling, and investigate the consequences of operating under this extreme condition for plasma transport and stability. A major component of LTX is a conducting copper shell with a dynamically-bonded stainless steel liner as the plasma facing component (PFC). Fabrication of a prototype shell section has demonstrated that the tolerances required for conformity to the plasma shape can be maintained. A lithium coating will provide the low recycling PFC on LTX. The goal of depositing 100 nm lithium layers within the five minute interval between discharges has been achieved. Details of the progress in these areas and the status of other LTX tasks will be reported.
Physical Review Letters, 1998
Journal of Nuclear Materials, 1999
Journal of Nuclear Materials, 2013
Springer Series in Plasma Science and Technology, 2020
Springer Series in Plasma Science and Technology, 2020
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Papers by Sergei Krasheninnikov