Experimental results on measurement of dd-reaction cross sections in the energy range of 0.1–1.5 keV using the Z-pinch technique are presented. The experiment was fulfilled at the high current generator of the High-Current Electronics Institute, city of Tomsk, Russia. The dd-fusion neutrons were registered by time-of-flight scintillator detectors and BF3 detectors of thermal neutrons. The estimates were obtained at 90% of the confidence level for the upper limits of the neutron-producing dd-reaction cross sections for average deuteron collision energies of 0.11, 0.34, 0.37, and 1.46 keV. These results substantiate feasibility to get a cross section magnitude for dd-reaction in the range of the collision energy of 0.8–3 keV using similar technology at the pulse current level of 2–3 MA.

Rare gas or lead clusters of several hundreds to many thousands of atoms per cluster were irradiated by intense laser pulses producing peak intensities up to 1017W/cm2. Fast, highly charged fragment ions were observed by means of standard TOF mass spectrometry as well as a magnetic deflection TOF device (MDTOF). Charge states of up to Xe30+ or Pb18+ were detected with maximum kinetic energies reaching far beyond 100 keV for Xe. A strong dependence of the charging and heating process on the laser pulse duration was found. While the resulting ionic fragment spectra are qualitatively similar for rare gas and lead clusters, the kinetic energies for the metal clusters seem to be significantly lower.

We present the results of the theoretical studies of the plasma heating in the flows which converge toward the axis of cylindrical cavity. We show that as a result of the shock wave reflection from the axis, the narrow hot filament is formed. This phenomenon is important for the interpretation of the dynamic processes in the electric discharges used for X-ray generation. We notice that the plasma parameters which can be of interest for inertial confinement fusion (ICF) can be reached in such the processes.

Recently, there has been great interest growing in ultrahigh field particle acceleration driven by ultraintense laser interactions with beams and plasmas. Although numerous concepts of particle acceleration by laser fields have been proposed almost since the beginning of the laser evolution, there has been tremendous progress in recent years on their theoretical and experimental aspects owing to advances in the generation of ultraintense short laser pulses. The laser–plasma accelerator concepts are reviewed on the laser wakefield acceleration mechanism. In particular, the electron acceleration by the laser wakefield in plasmas is illustrated by our recent experimental results, including the propagation of the ultrashort intense laser pulses in plasmas.

On the basis of the Lorentz equation the analytical solution of the equations of motion of a charged particle in the electromagnetic (EM) waves combined with constant electric or magnetic fields has been found. The possibility of controlling of the parameters of motion in velocity and spatial spaces is discussed as follows.

During the diffraction of a femtosecond pulse with a grating, apart spectral filtering, there occurs a time stretching due to the difference in the path length among the rays diffracted, even of equal wavelength. The reason resides in the action of the grating: to depart from the behavior of the mirror, that is, α = β, and to direct the rays in directions whose paths are groove-by-groove different of mλ. The compensation of this broadening is studied in the following by using a pair of grating in a particular mounting. The configuration is studied for the application in the selection of one single laser harmonics in the framework of high order harmonic generation processes.

A kinetic theory for quantum many-particle systems in time-dependent electromagnetic fields is developed based on a gauge-invariant formulation. The resulting kinetic equation generalizes previous results to quantum systems and includes many-body effects. It is, in particular, applicable to the interaction of strong laser fields with dense correlated plasmas. Numerical results are obtained for the cycle-averaged electron–ion collision frequency in a high-frequency field.

The main purpose of this work is to describe the construction and operation of the low energy accelerator with energy in the range from (zero to 100 KeV). This accelerator includes an ion source of the cold cathode Penning type (with pierce geometry for ion beam extraction), an accelerating tube (with 8 electrodes) and Faraday cup (FC) for measuring ion current. A vacuum system which gives vacuum of the order 3.0 × 10−8 Torr is used. A palladium tube is used to supply the source with pure hydrogen atoms. It was possible to operate this accelerator with an energy 50 KeV at minimum hydrogen pressure, 6.3 × 10−6 Torr. The total resistance applied between the accelerating electrodes RT = 31.5 MΩ. These data include the influence of the pressure in the accelerating tube, the magnetic field of the ion source, the extraction potential and the accelerating potential on the collector ion current. It was possible to accelerate protons with an energy 50 KeV with current about 100 μA at pressure 6.3 × 10−6 Torr, the source magnetic field = 110 G (IB = 2 A), the arc current = 0.4 A and the extraction potential = 10 KV.

The role of collisional absorption is supposed to be important in the beginning of the interaction between a laser pulse and matter. Later on, collective absorption phenomenons take place. The scope of this paper is to present first results about the so-called AC-run-away effect, defined as a “sudden transition from collisional absorption regime to a collective one.” For this purpose, we use a simple model based on ballistic theory. The delicate point concerning the Coulomb logarithm is also studied: we propose for it a convenient cutoff and an ensemble averaged Coulomb logarithm fit formula. Another application of the model presented here is the normal skin effect. We show some sensible differences between the present approach and those based on more common and rough collision frequency formulas.

The effect of the relative phase between the components of a bichromatic field of frequencies ω and 3ω is discussed in the case of free–free transitions in laser-assisted electron-hydrogen scattering. For fast projectile and low field intensities, the role of target dressing is pointed out.

We report time-dependent simulations of the evolution of atoms, molecules, and solids in the presence of intense electromagnetic radiation using the density functional theory. In the case of the ionic degrees of freedom we find that selective breaking of strong bonds may be possible at off-resonant infrared frequencies by a novel “concerted kick” mechanism. In the case of the electron response we find the following: free atoms and ions under intense infrared light respond with high harmonics in the X-ray regime; for a free molecule (Si2), we predict an unusual third harmonic response to a UV pulse centered at a frequency equal to the primary electronic excitation of the molecule; for a semiconductor (Si), we find several odd harmonics in response to a continuous wave of subgap infrared radiation. Prospects for future calculations are discussed.

Intense continua of electromagnetic radiation of very brief duration are formed in the interaction of focused ultra-short terawatt laser pulses with matter. Two different kinds of experiments, which have been performed utilizing the Lund 10 Hz titanium-doped sapphire terawatt laser system are being described, where visible radiation and X-rays, respectively, have been generated. Focusing into water leads to the generation of a light continuum through self-phase modulation. The propagation of the light through tissue was studied addressing questions related to optical mammography and specific chromophore absorption. When terawatt laser pulses are focused onto a solid target with high nuclear charge Z, intense X-ray radiation of few ps duration and with energies exceeding hundreds of keV is emitted. Biomedical applications of this radiation are described, including differential absorption and gated-viewing imaging.

Equations (10)–(12) and (14)–(16) of this paper, as well as the paragraph following (16), contain errors and should be corrected as follows (primes indicate corrected equations). The corrections do not alter the analyses and conclusions in the remainder of the paper.

Article appeared in Laser and Particle Beams (1998), 16, 295–316