Electron bunch acceleration in the wake wave breaking regime

Results are presented from theoretical analysis and 2D PIC simulations of electron acceleration in a breaking wake plasma wave generated by a short intense laser pulse during its interaction with a finite-length underdense plasma layer. The high energy electron energy spectrum and transverse emittance are obtained. It is shown that, for laser pulse lengths above the plasma wake wavelength, the wakefield-accelerated electrons are further accelerated by the electromagnetic wave. Published in Russian in Fizika Plazmy, 2006, Vol. 32, No. 4, pp. 291–310. The text was submitted by the authors in English.     

Interaction of electromagnetic waves with plasma in the radiation-dominated regime

A study is made of the main regimes of interaction of relativistically strong electromagnetic waves with plasma under conditions in which the radiation from particles plays a dominant role. The discussion is focused on such issues as the generation of short electromagnetic pulses in the interaction of laser light with clusters and highly efficient ion acceleration in a thin plasma slab under the action of the ponderomotive pressure of the wave. An approach is developed for generating superintense electromagnetic pulses by means of up-to-date laser devices.     

On the design of experiments for the study of relativistic nonlinear optics in the limit of single-cycle pulse duration and single-wavelength spot size

We propose a set of experiments with the aim of studying for the first time relativistic nonlinear optics in the fundamental limits of single-cycle pulse duration and single-wavelength spot size. The laser system that makes this work possible is now operating at the Center for Ultrafast Optical Science at the University of Michigan. Its high repetition rate (1 kHz) will make it possible to perform a detailed investigation of relativistic effects in this novel regime. This study has the potential to make the field of relativistic optics accessible to a wider community and to open the door for real-world applications of relativistic optics, such as electron/ion acceleration and neutron and positron production.     

Formation of current sheets in structurally stable and structurally unstable magnetic configurations with two null lines

The nonlinear dynamics of magnetoacoustic and Alfvén MHD perturbations in structurally unstable magnetic configurations with two null lines (X-lines) is studied both analytically and numerically. It is shown that these perturbations cause the electric current to evolve nonlinearly in such a manner that a structurally unstable configuration of the magnetic field transforms into a structurally stable configuration. Such a transformation is forbidden in ideal magnetohydrodynamics but can occur in the process of magnetic field line reconnection. The final magnetic configuration to which the system evolves is shown to contain no separatrices connecting the null lines.     

Effect of the magnetic field on the resonant particle acceleration

The acceleration of charged particles trapped by a potential wave in a magnetic field is investigated as applied to the problem of the generation of fast particles in a laser plasma. The conditions for unlimited particle acceleration are determined, and the spectra of fast particles are found.     

Generation of high-quality charged particle beams during the acceleration of ions by high-power laser radiation

Numerous applications of protons and ions accelerated by laser radiation require charged particle beams of high quality (i.e., such that the ratio of the energy width of the beam to its mean energy is small). In order to produce beams with controlled quality, it is proposed to use two-layer targets in which the first layer consists of heavy multicharged ions and the second layer (thin and narrow in the transverse direction) consists of protons. The possibility of generating a high-quality proton beam in the interaction of ultraintense laser radiation with such a two-layer target is demonstrated by two-and three-dimensional particle-in-cell computer simulations.     

Concerning the maximum energy of ions accelerated at the front of a relativistic electron cloud expanding into vacuum

Plasma Physics Reports - Results of particle-in-cell simulations are presented that demonstrate characteristic interaction regimes of high-power laser radiation with plasma. It is shown that the...     

Biodegradation of 125I-Labeled monoclonal antibodies after intravenous administration to rats with experimental C6 glioma

Employment of radiolabeled antibodies in biological studies, allows their specific accumulation in organs and tissues to be accurately detected. However, stability of such radiolabeled antibodies depends on both the method of labeling and particular experimental conditions. Therefore, stability of labeled antibodies should be determined in every particular experiment. In this study we have investigated stability of the ¹²⁵I-labeled monoclonal antibodies to gliofibrillary acidic protein (GFAP), endothelial antigen AMVB1, and non-specific mouse IgG at the stage of their synthesis and after their intravenous administration to rats with experimental C6 glioma. Stability of labeled antibodies was determined in blood samples and homogenates of organs by the method of their precipitation with trichloroacetic acid. The ¹²⁵I-radiolabeled antibodies were characterized by high radiochemical putiry, immunochemical activity and stability of the resultant preparations in blood and tissues, and the brain after administration in vivo. Electrophoretic analysis, thin-layer chromatography, and immunohistochemical tests have demonstrated the radiochemical purity, immunochemical competence, and stability of the labeled antibodies in vivo.