The dynamics of spheromak plasmas in coaxial helicity injection (CHI) systems has been investigated using three-dimensional magnetohydrodynamic (MHD) numerical simulations. It was found that toroidal current is driven by repetitive asymmetric plasmoid injection, which is related to the n = 1 oscillations. In addition, we propose that multiple pulse operation of the helicity injection is effective for improving confinement because it reduces the n = 1 fluctuations.

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The resolution limit of conventional optical lithography is thought to be around 70 nm. EUV lithography using EUV radiation with a wavelength region of 10 to 14 nm can break through this limitation and can achieve a resolution of below 50 nm. EUV employs reflection-type optics involving multilayer mirrors. Wafers are exposed in a vacuum and reflection-type masks are used. Chemically amplified photoresist materials used for KrF lithography can be applied to EUV lithography. The required EUV power from an EUV source for a throughput of over 100 wph is estimated to be about 80 to 120 W.

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An extreme ultraviolet (EUV) radiation source is a critical factor for the success of EUV lithography. Although there are many methods and operating parameters for the generation of EUV light, none of the currently known sources meets the requirements of EUV lithography systems. In addition, the EUV source must be an integral part of a total lithography system, and must satisfy several criteria imposed by other parts of the entire system. For the purpose of examining the prospects for such sources, the emissivity from hot dense plasmas has been estimated with a model including opacity, ion abundance, hydrodynamics, and radiation transport. For quantitative estimation, the similarity of energy structure of Xe⁹⁺ and Xe¹⁰⁺ is considered. Only a small amount of data exists regarding Xe¹⁰⁺ ionization and energies of excited states. Various ideas for improvements are presented.

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The present status of the development of laser-produced plasma EUV sources throughout the world is summarized. The year 2002 will be remembered as a turning point when target material shifts from xenon to tin for high conversion efficiency. Research on the EUVL source taking place at the AIST is also briefly described.

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This paper reviews the research and development of the high average power, extreme ultraviolet light source based on laser produced plasma by EUVA. The technology is based on a liquid Xe micro jet, high repetition rate short pulse Nd:YAG laser, and various diagnostics for plasma optimization are described.

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The present status of the development of light sources based on discharge for EUV lithography is reviewed. The discharges, such as Z-pinch, capillary discharge, plasma focus and hollow cathode discharge, are compared and their significant features are pointed out. The performance of each type of discharge is summarized.The plans and the present state of the development of EUV high sources at Tokyo Institute of Technology and Kumamoto University are briefly described.

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Some important issues for the practical application of a discharge-basedEUV source for lithography are described. Innovative ideas taking into consideration both plasma physics and technological elements such as pulse power, materials, and heat management are required for the solution of key issues. Engineering approaches are described with the development plan of the EUVA. It is necessary to consider the factors relating to the issue as a whole in research and development in order to produce a clean, high power and high quality photon.

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The extreme ultraviolet (EUV) light source development project of the EUVA and the research collaboration between industry and universities are described. The development of EUV light sources using both laser produced plasma and discharge produced plasma is currently under way. The goal of four-year project is to attain 10 W output power at an intermediate focus point which should satisfy all the requirements of the EUV lithography light sources. The collaboration with universities will expand next year under the new research framework of the leading program of laser-based EUV sources.

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Two nobel radiation process are reviewed. One is a DARC (Dc to Ac Radiation Convertor) and the other is a superradiance process. DARC can emit the radiation from a static electric field via the interaction between the field and a laser created ionization front. The frequency of the radiation mainly depends on the geometry of the DARC structure. The superradiance is the stimulated emission from spatially localized ensembles of electrons and is promising method of generating powerful ultrashort electromagnetic pulses. Here, radiation from a thin electron layer is reviewed as a simple model of superradiance.

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Basic interactions between an intense electron beam and a cavity are reviewed. An intense electron beam with strong self-field can be compressed using coaxial cavities with decreasing lengths. An intense electron beam with subnanosecond duration is available by this scheme.

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A one-dimensional particle-in-cell simulation has been conducted in order to improve the physical understanding of the laser-pulse photo-detachment diagnostics of negative ions, and thus to assess the accuracy of the measurements. An emphasis is placed on a short time scale (20 ns after photo-detachment for parameters of a typical glow discharge plasma) behaviour, where the laser Thomson scattering technique combined with the photo-detachment has recently been developed. The plasma consisting of background electrons, positive argon ions (Ar⁺), and negative oxygen ions (O^-) is treated. It is assumed that all of the negative ions in the laser-irradiated region (photo-detachment region) are replaced by the photo-detached electrons in the time scale much faster than in the time characteristic of the electron plasma oscillation. The loss of photo-detached electrons from the photo-detachment region quickly forms a potential structure in 2 ns. The potential traps the remaining photo-detached electrons. Due to the thermal fluctuation of the electrostatic electric field, the slow decay of the photo-detached electrons follows the initial fast decay. Because of these motions of photo-detached electrons, the measured negative ion density was found to underestimate the actual value by 25 %.

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The D-T neutron skyshine experiments have been carried out at the Fusion Neutronics Source (FNS) of JAERI with the neutron yield of ∼1.7×10¹¹n/s. The concrete thickness of the roof and the wall of a FNS target room are 1.15 and 2 m, respectively. The FNS skyshine port with a size of 0.9 × 0.9 m² was open during the experimental period.The radiation dose rate outside the target room was measured as far as about 550 m away from the D-T target point with a spherical rem-counter. The highest neutron dose was about 0.5 μSv/hr at a distance of 30 m from the D-T target point and the dose rate was attenuated to 0.002 μSv/hr at a distance of 550 m. The measured neutron dose distribution was analyzed with Monte Carlo code MCNP-4B and a simple line source model. The MCNP calculation overestimates the neutron dose in the distance range larger than 250 m. The neutron spectra were evaluated with a ³He detector with different thickness of polyethylene neutron moderators. Secondary gamma-rays were measured with high purity Ge detectors and NaI scintillation detectors.

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Fuel processing technology and tritium safe-handling technology have been developed through US/DOE-JAERI collaboration from 1987 till 2001, and the technologies to construct the tritium plant system of ITER have been made currently available. This paper overviews the major achievements of this collaborative researches over fourteen years, which were performed mainly at the Tritium Systems Test Assembly (TSTA) of the Los Alamos National Laboratory (LANL). The tritium plant system consists mainly of a fuel processing system, which includes a fuel cycle system and a blanket tritium recovery system, and a tritium confinement/removal system. The fuel cycle system recovers fuel from plasma exhaust gas and recycles it. In the collaboration, major key components and subsystems were developed, and the performance of the integrated system was successfully demonstrated over its one-month operation in which plasma exhaust model gas was processed at a processing rate of up to 1/6 level of the ITER. The technological basis of the fuel cycle system was thus established. Blanket tritium recovery technology was also successfully demonstrated using the TSTA system. Through the successful safeoperation of the TSTA, reliability of tritium confinement/removal system was verified basically. In addition, much data to confirm or enhance safety were accumulated by experiments such as intentional tritium release in a large room. Furthermore,distribution of tritium contamination in the vacuum vessel of the TFTR, a large tokamak of the Princeton Plasma Physics Laboratory (PPPL), was investigated in this work.

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