As the finalization of the hydrogen experiment towards the deuterium phase, the exploration of the best performance of the hydrogen plasma was intensively performed in the Large Helical Device (LHD). High ion and electron temperatures, Ti, Te, of more than 6 keV were simultaneously achieved by superimposing the high power electron cyclotron resonance heating (ECH) on the neutral beam injection (NBI) heated plasma. Although flattening of the ion temperature profile in the core region was observed during the discharges, one could avoid the degradation by increasing the electron density. Another key parameter to present plasma performance is an averaged beta value . The high regime around 4 % was extended to an order of magnitude lower than the earlier collisional regime. Impurity behaviour in hydrogen discharges with NBI heating was also classified with the wide range of edge plasma parameters. Existence of no impurity accumulation regime where the high performance plasma is maintained with high power heating > 10 MW was identified. Wide parameter scan experiments suggest that the toroidal rotation and the turbulence are the candidates for expelling impurities from the core region.

Equation-of-state data, not only pressure and density but also temperature, for polystyrene (CH) are obtained up to 510 GPa. The region investigated in this work corresponds to an intermediate region, bridging a large gap between available gas-gun data below 60 GPa and laser shock data above 500 GPa. The Hugoniot parameters and shock temperature were simultaneously determined by using optical velocimeters and pyrometers as the diagnostic tools and the α-quartz as a new standard material. The CH Hugoniot obtained tends to become stiffer than a semiempirical chemical theoretical model predictions at ultrahigh pressures but is consistent with other models and available experimental data.

Since the approval of the first phase of Fast Ignition Realization Experiment (FIREX-I), we have devoted our efforts on designing advanced targets and constructing the world highest-energy Peta Watt laser. The new target design has the following features. The coupling efficiency from the heating laser to the thermal energy of the compressed core plasma can be increased by the two ways:1) Low-Z foam layer on the inner surface of the cone for optimum absorption. 2) Double cone. Electrons generated in the inner surface of the double cone will return by sheathe potential generated between two cones. The implosion performance can be improved by three ways: 3) Low-Z plastic layer on the outer surface of the cone may suppress the expansion of the Au cone that flows into the interior of the compressed core. 4) Br doped plastic ablator may significantly moderate the Rayleigh-Taylor instability, making implosion more stable. 5) Evacuation of the target center to prevent gas jets from destroying the cone tip. For project robustness, we also explore 6) impact ignition scheme that eliminates complexity of laser-plasma interaction while keeping the compactness advantage of fast ignition. The fully integrated fast ignition experiment is scheduled on 2009. If subsequent FIREX-II will start as proposed, the ignition and burn will be demonstrated shortly after the ignition at NIF and LMJ, providing a scientific database of both central and fast ignition.

The principal Hugoniot for liquid hydrogen was obtained up to 55 GPa under laser-driven shock loading. Pressure and density of compressed hydrogen were determined by impedance-matching to a quartz standard. The shock temperature was independently measured from the brightness of the shock front. Hugoniot data of hydrogen provide a good benchmark to modern theories of condensed matter. The initial number density of liquid hydrogen is lower than that for liquid deuterium, and this results in shock compressed hydrogen having a higher compression and higher temperature than deuterium at the same shock pressure.

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