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Kα line emission from Mo was experimentally and theoretically studied using clean, ultrahigh-intensity femtosecond laser pulses. The absolute yields of Kα x-rays at 17 keV from Mo were measured as a function of the laser pulse contrast ratio and irradiation intensity. Significantly enhanced Kα yields were obtained by employing high contrast ratio at optimum irradiance. Conversion efficiencies of 4.28 × 10−5/sr, the highest values obtained to date, was demonstrated with contrast ratios in the range of 10−10 to 10−11.

The experimental studies on zonal flows and turbulence have been carried out in Compact Helical System [K. Matsuoka, S. Kubo, M. Hosokawa, in Plasma Physics and Controlled Nuclear Fusion Research, Proc. 12th Int. Conf., Nice, 1988 (International Atomic Energy Agency, Vienna, 1989, Vol. 2, p. 411] using twin heavy ion beam probes. The paper presents the experimental observations of stationary zonal flow, nonlinear couplings between zonal flow and turbulence, and the role of zonal flow in the improved confinement, together with the recent discovery of zonal magnetic field. The presented experimental results strongly support the new paradigm that the plasma transport should be considered as a system of drift wave and zonal flows, and provides the first direct evidence for turbulence dynamo that the structured magnetic field can be really generated by turbulence. © 2008 American Institute of Physics.

The present status of experiments on zonal flows in magnetic confinement experiments is examined. The innovative use of traditional and modern diagnostics has revealed unambiguously the existence of zonal flows, their spatio-temporal characteristics, their relationship to turbulence and their effects on confinement. In particular, a number of observations have been accumulated on the oscillatory branch of zonal flows, named geodesic acoustic modes, suggesting the necessity for theories to give their proper description. In addition to these basic properties of zonal flows, several new methods have elucidated the processes of zonal flow generation from turbulence. Further investigation of the relationship between zonal flows and confinement is strongly encouraged as cross-device activity including low temperature, toroidal and linear devices. © 2007 IAEA.

A zonal magnetic field is found in a toroidal plasma. The magnetic field has a symmetric bandlike structure, which is uniform in the toroidal and poloidal directions and varies radially with a finite wavelength of mesoscale, which is analogous to zonal flows. A time-dependent bicoherence analysis reveals that the magnetic field should be generated by the background plasma turbulence. The discovery is classified as a new kind of phenomenon of structured magnetic field generation, giving insight into phenomena such as dipole field generation in rotational planets.

The study describes the Fabrication and characterization of [MgB.sub.2] films with two-dimensional artificial pinning centers (2D-APCs) using ZnO nanowires. The analysis reveals that such a fabrication of ZnO nanowires does not affect the crystallinity of the wires.

The design and fabrication of a 5 GHz superconducting 4-pole miniature bandpass filter by using quasi-spiral resonator (QSR) for international mobile telecommunication (IMT)-advanced base station receiver application is described.

The design of a transmit band pass filter using circular-disk high-temperature superconductor (HTS) bulk resonators with a 5.0 GHz center frequency and 100 MHz bandwidth which could be applied in international mobile telecommunication (IMT) is presented.

Investigating the preparation and microwave properties of Tl-2212 and Tl-1223 thin films on a CeO2, buffered sapphire substrate is discussed. It shows the surface resistance of Tl-1223 film slightly higher than the Tl-2212 film due to an inferior surface morphology.

The relationship between in-plane orientation, grain axis fluctuation and critical current, and surface resistance of YBa2Cu3O7-delta films.

In-plane alignment of C-axis oriented thin films was studied to determine the effect of lattice matching.

Research is presented describing the study and development of an efficient high temperature superconducting cooling system for use with miniaturized antennas.

The designed and measured results on direct-fed right hand circularly polarized microstrip single patch and four element array fabricated from both copper and superconductor are reported. For the theoretical analysis of the antennas, a full-wave microwave circuit simulator based on the method of moments and can handle the microwave surface impedance was used. Results showed that superconducting antennas exhibit a remarkable improvement over their metal counterparts.

A study on how the microwave surface resistance of YBa2u3Oy (YBCO) thin films are affected by the crystallinity and surface roughness of CeO2 buffer on R-plane Al2O3 substrate was conducted. X-ray diffraction method was used to measure the microwave surface resistance from the microstrip line resonator's transmission characteristics. Results show that the quality of the upper layer of the YBCO is affected by the poor crystallinity of thin CeO2.

Superconducting rectangular patch antennas of YBa2C3O7-y thin films and Cu films with an input-impedance of 50 ohms and a resonance frequency of 5 GHz were developed. The antennas' geometric form was determined using the moment method and a transmission line model. Results show that the Cu thin film patch antennas have higher return loss at 19 K than YBa2C3O7-y patch antennas.

This paper describes recent results of the R&D on the 70MW class superconducting generators called model machines in an 11-year period project conducted by Super-GM. Three types of model machines are under manufacturing now. Static excitation tests of two slow response excitation type model machines are performed. The test facility is also under construction.

The development of superconducting generators has been progressing in Japan since 1988 as a part of the New Sunshine Project of the Agency of Industrial Science Technology. Toshiba has been in charge of research and development of the quick response excitation type superconducting generator in the project. We are manufacturing the partial rotor model, which has the same rotor diameter and shorter winding length comparing with the 70 MW class quick response model machine. We assembled completely the inner rotor and carried out its excitation test in a cryostat. In this paper, we report the test results of heater quench, quench current, training, and pulse excitation.

A double-stranded cable for use in the field winding of a 70-MW superconducting generator was characterized. Specifically, measurements of inter-strand resistance and ac losses were carried out on a formvar-insulated cable made of niobium-titanium, copper and copper-nickel wires. The results, which enabled correlations between inter-strand resistance and inter-strand coupling loss, revealed a larger strand deformation at the Z-S contact plane than in the Z-Z level.

The Engineering Research Assn. for Superconductive Generation Equipment and Materials has developed slow-response and quick-response excitation-type rotors and a model stator as part of its 11-year program to develop 70-MW superconducting generators. At present, model machines based on its rotor and stator designs are being built. When finished, they will be tested under actual load conditions using the motor-generator technique.

This paper describes recent results of the R&D on the 70 MW class superconducting generator (hereinafter called model machine) in Super-GM, according to an 11-year period program since 1988.

Investigating the observation distribution and movement of vortices in a Y-123 single crystal, a Bi-2212 single crystal, a Y-123 QMG sample and in Bi-2223 Ag-sheathed tapes using the high-resolution Bitter method is discussed. It is concluded that the differences in the vortex distribution and movement in the samples with and without neutron irradiation.