Diagnostic information obtained from x-ray emission accompanying the laser-matter interaction represents a primary tool for identification and exploitation of phenomena occurring in hot dense plasmas. To fully utilize the potential contained in the shapes and shifts of the spectral lines, sophisticated high-resolution instruments have been developed. The basic spectroscopic conceptions for K-shell plasma diagnosis are outlined. The main characteristics of toroidally bent crystal spectrometers and vertical-dispersion instruments are briefly reviewed. The applications of high-precision x-ray spectrometers in investigation of strongly correlated plasmas are demonstrated on a detailed analysis of the spectral line emission from two types of laser-produced plasmas. The redults of experiments performed at 0.4 ns laser system ASTERIX and 150 fs system ATLAS are presented, the diverse character of the observed line profiles and the dense-plasma line shifts to red is discussed. The conclusions for the line shift-based plasma diagnosis are drawn.

High-density plasma created near a solid surface by an intense femtosecond laser pulse emits ultrashort x-ray pulses that are synchronized with the laser pulse. We show the spectral and temporal properties of broadband soft x-rays emitted from a femtosecond laser-produced plasma on a metal surface. The soft x-ray emission was increased about 20-fold by fabricating an array of nanocylinders on a gold surface. We demonstrate the cross-correlation measurement of soft x-ray pulse duration in the femtosecond region by using an optical field-induced ionization process in Kr gas. We used a 10-ps soft x-ray pulse to demonstrate the time-resolved absorption measurement of optically excited silicon near its L_II,III edge. We alo employed a picosecond soft x-ray to measure the spatiotemporal evolution of ablated particles in femtosecond-laser-produced aluminum plasma.

Interaction of a cluster jet with a very intense laser pulse generates x-rays in the keV domain. Many features of this type of source are well characterized and understood but their temporal structure is still being discussed. We performed experiments on photoelectron emission of a pure copper metallic sample irradiated by such a source of x-rays. We determined the best laser and gas jet parameters in order to enhance the photoemission yield. The maximum signal was obtained with 30 bars of xenon irradiated by 250 fs 75 mJ pulse at 800 nm, corresponding to an intensity of 2.10¹⁶ W/cm². We were able to observe a peak of Auger electrons at 62 eV in the photoelectron spectrum. This suggests that pulse duration measurements based on the Laser Assisted Auger Decay (LAAD) technique are possible.

The plasma emission of tin, aluminum and cupper targets irradiated with laser intensities ranging from 10¹¹ to 10¹⁶ W/cm² has been measured beween 7nm and 18 nm. A chirped pulse amplified Ti:Sapphire laser oscillating at 790- nm with either 100 fs or 300 ps pulse duration and a Nd:YAG laser oscillating at 1064 nm with 10 ns pulse duration (fwhm) have been used. The observed plasma emission was strongest for the 300 ps laser pulse irradiation, which might be due to the additional laser plasma heating during plasma formation.

It was demonstrated experimentally that liquid with low pressure of saturated vapor can be used as target for femtosecond laser plasma formation. Plasma formed at free liquid surface (vacuum oil) in vacuum by femtosecond laser pulse with intensity above 10¹⁶ W/cm² is similar to high-temperature plasma formed at solid target surface. So, from x-ray and ionic time-of-flight measurements the temperature of hot electrons for oil target is 6 ± 3 keV and for crystalline silicon target is 4 ± 1 keV. The optics diagnostic of liquid surface relaxation has shown that upper repetition rate of laser pulses for interaction with non-perturbed liquid surface is 10 Hz.

We propose to use an intense short pulse laser of the TEM(1,0)+TEM(0,1) mode in vacuum in order to trap and accelerate an electron bunch. The laser intensity distribution serves a confinement effect for electrons in the transverse direction by a transverse ponderomotive force. The electrons are accelerated longitudinally by a longitudinal ponderomotive force. In our computations, we employ a three-dimensional laser field and the relativistic equation of motion including a relativistic radiation damping effect. The maximum electron energy is about 195 [MeV] with an acceleration gradient of 5.25 [GeV/m] at the laser intensity of 1.23 x 10¹⁸ [W/cm²]. An emittance of the electron bunch accelerated is small and the spatial size in the radial and longitudinal directions are about 1000 [μm] and [μm], respectively. Such the electron bunch may have potentials for nano-technology applications, cancer treatment, a new point light source and so on.

Results of fast light ion yield measurements are presented. Laser-plasma experiments were carried out on picosecond laser PROGRESS-P at laser intensities on a target to be 1 ÷ 4•10¹⁸ W/cm². Ring image and extremely small angular divergence of fast ion beam were found. Hard ions with energy more than 8 MeV were recorded. Model of fast ion generation is discussed and typical energy and spatial distribution of fast ion extension are estimated.

We investigate the harmonics generation from a pure dielectric target when submitted to laser intensities in the 10¹⁸W/cm². We demonstrate the negative influence of the prepulses and ASE by addressing the direct comparison of the harmonic spectra with and without the introduction of a perfectly controlled plasma mirror system. Harmonics up to the 20th of the fundamental of the Ti-Sa laser are clearly visible in a situation free of any plasma expansion.

A combination of a high-power CO₂ laser synchronized to a 70 MeV high-brightness electron linear accelerator operated at the Brookhaven Accelerator Test Facility (ATF) provides a platform for exploring novel methods of particle acceleration, x-ray generation and other advanced areas of beam physics and applications. We review the latest results from the ATF laser/e-beam interaction and plasma experiments including: staged electron laser acceleration (STELLA), Thomson scattering, laser channeling in a capillary discharge, and plasma wake study.

An experimental study has been carried out on the dynamical process taking place in the plasma generated by a Q-switched Nd:YAG laser (1.064 nm, 8 ns, 175 mJ) on a water surface at atmospheric air pressure. Accurate dynamical characterization of the resulting plasma has been carried out using gated intensified optical multichannel analyzer. The occurrence of the hydrogen emission lines of H I 656.2 nm (H_α), H I 486.1 nm (H_β), H I 434.0 nm (H_γ) and H I 410.1 nm (H_δ) was observed. Line broadening of hydrogen emission lines was studied in term of its emission time profile. In addition to reaffirming the role of the shock wave mechanism in the generation of atmospheric plasma, an analysis of the time-resolved spatial integrated of emission intensities and the time-resolved averaged temperature was made using the emission lines of Cu I 510.5 nm and Cu I 521.8 nm. As a result, the occurrence of two-stage emission processes, the shock excitation stage and cooling stage has been proved. The experimental result considering the characteristics of the atmospheric plasma can be well understood by considering the shock wave model instead of breakdown mechanism. Further application for quantitative analysis of calcium and sodium in water was also performed. A linear calibration curve was obtained without using any internal standardization and the detection limit in this stage of the experiment was estimated to be less than 1 ppm for calcium and sodium in water.

The analysis of the methods increasing line emission from plasma produced by subpicosecond laser pulses is given. An interaction of subpicosecond laser pulse with foil (1) and a pair of laser pulses with a bulk solid target (2) is considered. It is shown that maximal line intensity corresponds to certain width of foil (1) and time separation betwwen laser pulses (2).

Hot electrons may significantly influence interaction of ultra short laser pulses with solids. Accurate consideration of resonant absorption of laser energy and hot electrons generation at a critical surface was achieved through the developed physical and mathematical models. 2D ray tracing algorithm has been developed to simulate laser beam refraction and Bremsstrahlung absorption with allowance for non-linear influence of a strong electromagnetic field. Hot electrons transport was considered as a straight-line flows weakening by a friction force calculated in the approximation of the average state of ionization. Developed models were coupled with 2D Lagrangian gas dynamic code "ATLANT" that takes into account non-linear heat transport. The developed program has been applied to simulate irradiations of Al foils by picosecond laser double pulses. Hot electrons transport and heating resulted in thin foil explosions. The transition from exploding foil regime to the ablative one with foil thickening has been simulated and analyzed at various values of laser light intensity. In second series of calculations we have modeled the interaction of nanosecond iodine laser with two-layered target.

The self-similar solution of one dimensional non-stationary system of hydrodynamic equations together with Poisson equation was obtained for fast electrons and ions of laser plasma. Final energy of accelerated ions was obtained for initial energy, temperature and density of fast electrons. Ion distribution function was found at the different regimes of acceleration.

New nonthermal mechanism of sound photoexcitation in semiconductors having transition into ferromagnetic phase is proposed. The efficiency of this mechanism is compared with the efficiency of electron-deformation mechanism. Simple situation of a drift with constant velocity is described. The duration of generated acoustic pulse depends on the velocity of the drift and the thickness of transition area.

Making use of time-of-flight and mass-spectroscopic methods we investigated influence of the film on the target surface at vacuum of 10^-5 Torr onto ions emission from plasma created by femtosecond laser pulse with itensity of 2 • 10¹⁶ W/cm². It was shown that the highest energy per charge (8.5 keV) acquire protons, while basic target ions (Si, Ti) gain less energy. Heating by laser nanosecond pulse advancing femtosecond pulse by 0.1 - 100 ms with energy density up to 20 J/cm² allows for effective surface cleaning due to removal of molecules containing hydrogen, carbon and oxygen. By the contrast to the instantaneous resistive heating the pulsed laser cleaning provides for higher heating temperatures and can be used for any solid targets in the regimes of thermal and plasma cleaning.

In the process of creation of multi-layered coating through evaporation of the dielectric occurs considerable smoothing of an initial grating relief. The smoothing results in reduce of the diffraction efficiency and damage threshold of the grating at the working wavelength. The value of the smoothing is measured. Calculation of the structure parameters of the grating by real smoothing is made to improve the diffraction efficiency and damage threshold.

We report here the characteristics of noncollinear sum frequency generation in nonlinear KDP crystals by ultrashort (80 fsec) IR pulses irradiated by the intense Ti:Sapphire laser and their behavior in single shot auto-crosscorrelator (ACC) configuration. In particular we study the case where one of the beams is very weak. Our aim is to develop a procedure to provide delay time signal between light pulses for time resolved pump probe experiments based on the extraction of the phase-matched SHG spatial distribution by means of pulse shape analysis technique. We intend to apply these results to synchronize a weak short-pulse source and an intense Ti:Sapphire laser and to measure the pulse time jitter between them.

We analyzed analytically and numerically the possibility of high intensity laser pulse compression at stimulated scattering from plasma noise and at the non-linear interaction of a short seed pulse with a contra-propagated main long pulse on the inhomogeneous plasma slab. Optimal conditions for highest compression ratio are obtained. Conversion efficiency in these conditions can reach a high level.

The illumination system presented in the paper consists of an elliptical mirror collecting light in the solid angle over 103 and two plane mirrors (one of them is a grazing incidence mirror). The projection lens consists of two 4^th-order aspherical mirrors with the diminished obscuration 0.36. The simultaneous exposure wafer area is 0.82 x 0.82 mm² and NA = 0.36. The obscuration of the projection lens and obscured aperture of the illumination system influence the contrast of nanometer features of image. Mathematical simulation of imaging by the partially coherent theory is performed for target bars with L&S 15, 30, and 45 nanometers. The results of computer simulation give the reliable values of contrast 0.50, 0.58 and 0.6 correspondingly.

The scheme of fast ignition by super-intense laser of DT target placed at a cavity of the radiate plasma liner, created in a "dynamic-hohlraum" system is considered. It is shown that this scheme can supply effective TN fusion. The process of compression and preheating of DT fuel of shell target by X-ray radiation of Dynamic Hohlraum is simulated by the code TRITON with parameters of Z-generator of Sandia National Laboratory. The optimum parameters of target are obtained. The mechanism of ignitor creation by protons, accelerated by ultra-shot laser radiation is considered and corresponding laser parameters are evaluated. The mathematical simulation of the following thermonuclear (TN) burn wave propagation in DT target is carried out with the use of TERA code based upon the direct statistical simulation of kinetics of fast charged particles and quantum of thermal radiation on each time step of hydrodynamics. The released TN energy is obtained as a function of ignition energy. The theoretical explanations of obtained dependencies are presented. The laser parameters necessary to produce G>>1 are determined.

The report presents the theoretical and experimental results obtained during the first year of the ISTC project No. 1926. The energy and temporal characteristics of the laser radiation necessary to ignite the working components mixture in a rocket engine combustion chamber have been predicted. Two approaches have been studied: the optical gas fuel laser-induced breakdown; the laser-initiated plasma torch on target surface. The possibilities and conditions of the rocket fuel components ignition by a laser beam in the differently designed combustion chambers have been estimated and studied. The comparative analysis shows that both the optical spark and light focusing on target techniques can ignite the mixture.

The report presents principal theoretical and experimental results obtained during the first year of the ISTC project # 2155 realization. The mechanisms of high-energy electrons formation in high intensity and short laser pulse interaction with solid targets has been suggested and investigated. Neutron generation (reaction D + D → ³He + n) from laser-produced plasma at 10¹⁷ W/cm² intensity has been investigated. Neutron yield more than 10⁴ per pulse was received.

Nuclei-candidates fit for γ-lasers of the SPTEN class which were selected firstly at 2001 are screened again. SPTEN (Soft Prompt Transplantation of Excited Nuclei, Karyagin, 1983, 1995) is the unique class in which the knot of contradictions between pumping, lasing, and active medium's cooling could be extricated. The amplification growth's and seed photon wait's stages are two phases of the stage before generation (SBG) which comes before the mirrorless lasing. Main features of SBG booked in present screening are: (1) The time-life of spontaneous photon could be raised via the prolongator (Karyagin, 1997, 2001). (2) The evolution of SBG and generation stages are governed via the amount of the prolonged amplified modes which could be controlled via the prolongator's length and size of blind. The last two things in SBG weigh on the qualification rank of nuclei-candidates through a force on the γ-lasing's quality. Particularly that rank depends on confinement in which γ-laser is working: in close space of land laboratory or in cosmic space. Such detailed examination of the mirrorless γ-mode selection principles (Karyagin, 1997 - 2003) is issued firstly.

Recently in lapse of γ-laser (GL) research, a row of so-called width path effects (WPE) were predicted (Karyagin, 1998-2003) in the stage before generation (SBG). A rarity of resonant photons and relatively short effective time of their resultant action on work nuclei is a necessary condition for WPE existence. So the SBG is a suitable arena for a total WPE exhibition. WPE notedly change the generation conditions and need to be accounted at screening of nuclei-candidates for GL of SPTEN class. Aside from GL some other ways for the WPE exhibition exist. One such way is the search of a transparency of resonant media. Possible experiments in γ-diapason recently suggested (Karyagin, 2002, 2003) for the WPE exhibition could be transferred to the optical diapason. Some advantages to check WPE in the optical diapason are pointed here.