Direct-drive implosion experiments on the GEKKO XII laser (9 kJ, 0.5 /xm, 2 ns) with deuterium and tritium (DT) exchanged plastic hollow shell targets demonstrated fuel areal densities (pR) of -0.1 g/cm 2 and fuel densities of -600 times liquid density at fuel temperatures of -0.3 keV. (The density and pR values refer only to DT and do not include carbons in the plastic targets.) These values are to be compared with thermonuclear ignition conditions, i.e., fuel densities of 500-1000 times liquid density, fuel areal densities greater than 0.3 g/cm 2 , and fuel temperatures greater than 5 keV. The irradiation nonuniformity in these experiments was significantly reduced to a level of <5°/o in root mean square by introducing random-phase plates. The target irregularity was controlled to a 1% level. The fuel pR was directly measured with the neutron activation of Si, which was originally compounded in the plastic targets. The fuel densities were estimated from the pR values using the mass conservation relation, where the ablated mass was separately measured using the time-dependent X-ray emission from multilayer targets. Although the observed densities were in agreement with one-dimensional calculation results with convergence ratios of 25-30, the observed neutron yields were significantly lower than those of the calculations. This suggests the implosion uniformity is not sufficient to create a hot spark in which most neutrons should be generated.

Based on the results obtained for C–N and Si–C–N films, a systematic investigation of reactive magnetron sputtering of hard quaternary Si–B–C–N materials has been carried out. The Si–B–C–N films were deposited on p-type Si(100) substrates by dc magnetron co-sputtering using a single C–Si–B target (at a fixed 20% boron fraction in the target erosion area) in nitrogen-argon gas mixtures. Elemental compositions of the films, their surface bonding structure and mechanical properties, together with their oxidation resistance in air, were controlled by the Si fraction (5–75%) in the magnetron target erosion area, the Ar fraction (0–75%) in the gas mixture, the rf induced negative substrate bias voltage (from a floating potential to −500V) and the substrate temperature (180–350°C). The total pressure and the discharge current on the magnetron target were held constant at 0.5Pa and 1A, respectively. The energy and flux of ions bombarding the growing films were determined on the basis of the discharge characteristics measured for the rf discharge dominating in the deposition zone. Mass spectroscopy was used to show composition of the total ion fluxes onto the substrate and to explain differences between sputtering of carbon, silicon and boron from a composed target in nitrogen-argon discharges. The films, typically 1.0–2.4μm thick, possessing a density around 2.4gcm−3, were found to be amorphous in nanostructure with a very smooth surface (Ra⩽0.8nm) and good adhesion to substrates at a low compressive stress (1.0–1.6GPa). They exhibited high hardness (up to 47GPa) and elastic recovery (up to 88%), and extremely high oxidation resistance in air at elevated temperatures (up to a 1350°C substrate limit).

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Formation of ultrathin amorphized Si layer by femtosecond laser irradiation is reported in this letter. Below the fluence of ablation threshold, femtosecond laser irradiation induced an amorphization of crystalline Si. The authors confirmed the thickness of amorphous Si layer by transmission electron microscope. The thickness of the amorphized layer was found to be quite uniform and did not depend on the number of irradiated laser pulses and fluence, which was related to the effective light penetration depth.

We present the effects of the application of a nonthermal plasma jet to a liquid surface on H2O2 and NO2− generation in the liquid. Two distinct plasma irradiation conditions, with plasma contact and with no observable plasma contact with the liquid surface, were precisely compared. When the plasma was made to touch the liquid surface, the H2O2 concentration of the plasma-treated water was much higher than the NO2− concentration. In contrast, when no observable contact of the plasma with the liquid surface occurred, the ratio of the NO2− to H2O2 concentration became over 1 and NO2− became more dominant than H2O2 in the plasma-treated water. Our experiments clearly show that reactive oxygen and nitrogen species can be selectively produced in liquid using appropriate plasma-irradiation conditions of the liquid surface. The ratio of NO2− to H2O2 was controlled within a wide range of 0.02–1.2 simply by changing the plasma-irradiation distance from the liquid surface.