Possibility of a Large Helical Device equilibrium having a zero rotational transform surface is examined by using the three-dimensional MHD equilibrium code, HINT. We find the existence of the equilibrium but with the formation of two or three n = 0 islands composing the homoclinic-type structure near the center, where n is a toroidal mode number.

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Ion temperature and flow velocity in the MAP-II divertor simulator plasmas were measured using a high-resolution spectrometer combined with image expander optics which can also correct the astigmatism in spherical mirrors. The fine structure of the hydrogenic helium line was taken into consideration in the fitting procedures. This enables the comparison of the absolute flow velocity measurements between spectroscopy and the Mach probe.

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Electron Cyclotron Heating (ECH) and Electron Cyclotron Current Drive (ECCD) are attractive options for improving the performance of fusion reactor plasmas. Oblique launch of the electromagnetic wave to magnetized plasma demands specified elliptical polarization for high mode purity of ordinary or extraordinary waves. Polarizers for high power millimeter waves have been developed using corrugated all-metal mirrors. Structure analysis of polarizers will be important for high power, high frequency, and long pulse ECCD system in the next generation of fusion devices.

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We review recent progress in theoretical and observational cosmology. Recent observations of cosmic microwave background anisotropy and high-redshift supernova search have suggested that the universal expansion seems accelerating for dark energy ρ_Λ/ρ_C ≈ 0.69, and needs cold dark matter ρ_DM/ρ_C ≈ 0.27 for explaining the universal flatness. Only a small fraction Ω_b = ρ_b/ρ_C = 0.044 ± 0.004 is the baryonic mass. This Ω_b value is at least 1 - 2σ above the optimum value which is determined from the cosmological theory for primordial (Big-Bang) nucleosynthesis. We propose a primordial nucleosynthesis model with asymmetric neutrino-lepton number and inhomogeneous baryon-number density distribution, while still satisfying the observational constraints on light-mass elemental abundances. We also discuss the brane world cosmology and propose a new model of disappearing cold dark matter. We discuss quintessential inflation in order to explain the dark energy.

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We review recent progress in theoretical studies of r-process nucleosynthesis in supernova (SN) explosions. We found suitable physical conditions for a successful r-process and that particle and nuclear reactions on light neutron-rich nuclei as well as heavy nuclei play the significant roles in primary r-process. We also review astronomical observations of the neutron-capture elements detected in extremely metal-deficient halo stars. These stars are presumed to be the second generation, and their chemical composition consists of freshly synthesized heavy elements in the first generation exploding SNe in the Galaxy. We discuss cosmochronology by the use of long-lived radioactive nuclei like ²³²Th (half life τ_1/2 = 14.05 Gyr) and ²³⁸U (half life τ_1/2 = 4.468 Gyr). We found theoretical reason for the universality of r-process abundance pattern for 56 ≤ Z ≤ 70, but that it is not simply extended to 70 < Z including actinides. We propose that the U/Th cosmochronometer is a roburst cosmic clock although Th/Eu is not reliable.

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Recent spectroscopic studies of metal-deficient stars have revealed individual nucleosynthesis processes in the early Galaxy. As a base of these studies, detailed understanding of stellar evolution and nucleosynthesis in low-mass stars is indispensable. Our studies using the Japanese large telescope Subaru have contributed especially to the understanding of nucleosynthesis of intermediate-mass stars and their evolution.

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Light elements lighter than to iron are synthesized by nuclear reactions in plasma formed in the cores of fixed stars. These reactions have created large amount of energy resulting in the evolution of stars. Therefore, laboratory experiments for individual astrophysical nuclear-reactions provide one of the keys to understanding the evolution of the universe and nucleosynthesis. The recent development of radio-isotope (RI) beams extends the research field to reactions involving unstable nuclei, which play important roles in explosive events as novae, supernovae, shell burning of neutron stars, primordial nuclear synthesis, and so on.

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Heavier elements than iron are synthesized by neutron capture reactions in stars, either by the slow neutron capture process or the rapid neutron capture process. Due to the recent observational and theoretical progress in the study of stellar nucleosynthesis and Big-Bang nulceosynthesis, much interest has arisen regarding experimental study of the neutron capture reaction of a nucleus. This report briefly describes the recent progress mentioned above, the experimental study aimed at measuring the neutron capture cross sections of a nucleus, and future plans to further extend the activity of nuclear astrophysics using neutrons.

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Nuclear reactions in stars are known to be affected by the surrounding plasma. The reaction rates between various light nuclei measured in recent laboratory experiments show an increasing enhancement with decreasing collision energy compared with the extrapolation from higher energies. This phenomenon has been analysed in terms of the screening effects by bound target electrons. Surprisingly in all systems experimentally studied so far the extracted screening energy is significantly larger than the value in the adiabatic limit, which is expected to be the maximum value. Comparison with the recent indirect mothod named the Trojan Horse method also suggests a large screening effect to exist in direct measurements. We review the present status of the theoretical and experimental studies of this problem, and touch a recent study which has pointed out the importance of the explicit treatment of the behaviour of electrons in the tunneling region based on a semiclassical mean field theory of quantum tunneling.

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Methods for transport analyses of plasma flow and electric field in toroidal plasmas are summarized showing some samples of the experiments. The analyzing methods are mainly based on the neoclassical transport theory. The measurement methods are also mentioned. In the analysis of the flow and the radial electric fields, it is important that they are analyzed together.

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A series of lecture notes on bases for transport analysis of toroidal plasmas are summarized. A part of insufficiency is compensated. Unresolved and emerging issues on transport are described. Concluding remarks by each author are presented.

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Microwave reflectometry is a plasma diagnostic that launches microwaves to a plasma and measures the wave reflected at a cutoff layer in the plasma. It is used mainly for density profile and density fluctuation measurements. This lecture note is written for those who want to make a reflectometer and apply it to a target plasma. Various types of microwave reflectometers and a simple numerical tool useful for designing a system and for analyzing data are described. Details of a virtual system are also explained.

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This paper describes the design and experimental results regarding a solid breeder blanket for a tokamak-based fusion power plant, which is cooled with supercritical pressure water. The analysis of the system shows that a thermal efficiency of 41% can be achievable with cooling conditions of 25 MPa, 510°C. Thermo mechanical analysis of the first wall shows that the present design can withstand supercritical pressure and a high heat load from plasma. The 3D neutronics analyses show that a local TBR of more than 1.4 can be obtained. Elementary R&D concerning manufacturing techniques for the blanket structure and breeder/neutron multiplier pebbles have also been developed in parallel with the blanket design.

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A key issue in attaining high plasma performance in the Tokamaks is the optimization of current profile, involving such functions as stabilizing the neo-classical tearing mode (NTM) and control of the internal transport barrier (ITB). In the JT-60U, a high power electron cyclotron heating (ECH) system at 110 GHz has been developed for local plasma heating and current drive. We have demonstrated the technical feasibility of an antenna which can scan EC beam in both the toroidal and poloidal directions. The toroidal scan enabled co- and counter- current drive and also pure plasma heating. Automatic stabilization of the NTM was demonstrated by means of current drive at the magnetic island employing feedback control of the poloidal beam angle. The total injected power has been extended to 2.8 MW for 3.6 sec and each gyrotron delivers ˜ 1 MW for 5 sec. This world record regarding the injection energy was attained by an upgrade of the gyrotron using an RF absorber in the beam tunnel to suppress the parasitic oscillation and to improve the transmission efficiency of the waveguide system.

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