Temporal laser pulse shape effects in nonlinear Thomson scattering

The influence of the laser pulse temporal shape on the Nonlinear Thomson Scattering on-axis photon spectrum is analyzed in detail. Using the classical description, analytical expressions for the temporal and spectral structure of the scattered radiation are obtained for the case of symmetric laser pulse shapes. The possibility of reconstructing the incident laser pulse from the scattered spectrum averaged over interference fringes in the case of high peak intensity and symmetric laser pulse shape is discussed.Comment: 18 pages, 8 figure

Interaction of intense laser pulses with overdense plasmas.

This thesis is devoted to theoretical studies of the interaction of intense laser pulses with solid-state targets. This area of laser physics is very active and fast growing as it might possess a number of useful applications in material science, physics, biology and medicine. The main part of the thesis is devoted to the generation of high-order harmonics on the vacuum-plasma interface due to the longitudinal oscillatory motion of the reflecting surface. This has a prospect of generation of trains or even single attosecond pulses that have much more intensity than those generated in atomic media. Before making this source an instrument for studying electron dynamics in condensed matter or for laser-vacuum interactions, one has to know how to control the important properties of the harmonic beam, namely its temporal and spatial structure. To pursue the answering of the question of control, analytical and numerical studies were performed. Most of the ideas are based on the shaping of the laser pulse (both in temporal and spatial domains) and of the target. The second part of the thesis is devoted to the studies of the generation of energetic ion beams. These beams can be used, for example, in cancer therapy, plasma radiography and isotope production. The studies of the influence of laser pulse ellipticity and target thickness on ion beam monoenergetic features and energy allows one to use the results of this thesis for optimization of future experiments

The Use of Unmanned Aerial Vehicle for Geothermal Exploitation Monitoring: Khankala Field Example

The article is devoted to the use of unmanned aerial vehicle for geothermal waters exploitation monitoring. Development of a geothermal reservoir usually requires a system of wells, pipelines and pumping equipment and control of such a system is quite complicated. In this regard, use of unmanned aerial vehicle is relevant. Two test unmanned aerial vehicle based infrared surveys have been conducted at the Khankala field (Chechen Republic) with the Khankala geothermal plant operating at different regimes: during the first survey – with, and the second – without reinjection of used geothermal fluid. Unmanned aerial vehicle Geoscan 201 equipped with digital (Sony DSX-RX1) and thermal imaging (Thermoframe-MX-TTX) cameras was used. Besides different images of the geothermal plant obtained by the surveys, 13 thermal anomalies have been identified. Analysis of the shape and temperature facilitated determination of their different sources: fire, heating systems, etc., which was confirmed by a ground reconnaissance. Results of the study demonstrate a high potential of unmanned aerial vehicle based thermal imagery use for environmental and technological monitoring of geothermal fields under operation

Low transverse emittance electron bunches from two-color laser-ionization injection

A method is proposed to generate low emittance electron bunches from two color laser pulses in a laser-plasma accelerator. A two-region gas structure is used, containing a short region of a high-Z gas (e.g., krypton) for ionization injection, followed by a longer region of a low-Z gas for post-acceleration. A long-laser-wavelength (e.g., 5 micron) pump pulse excites plasma wake without triggering the inner-shell electron ionization of the high-Z gas due to low electric fields. A short-laser-wavelength (e.g., 0.4 micron) injection pulse, located at a trapping phase of the wake, ionizes the inner-shell electrons of the high-Z gas, resulting in ionization-induced trapping. Compared with a single-pulse ionization injection, this scheme offers an order of magnitude smaller residual transverse momentum of the electron bunch, which is a result of the smaller vector potential amplitude of the injection pulse

Detecting radiation reaction at moderate laser intensities.

We propose a new method of detecting radiation reaction effects in the motion of particles subjected to laser pulses of moderate intensity and long duration. The effect becomes sizable for particles that gain almost no energy through the interaction with the laser pulse. Hence, there are regions of parameter space in which radiation reaction is actually the dominant influence on charged particle motion