No abstract available

[en] What performance can be expected for dedicated detectors was the main theme of discussion in this subgroup. In the case of dedicated detectors, it is possible to consider the requirement for a specific physics issue and neglect others. Therefore, single purpose detectors can be designed so that they have an ability to take clear data with good resolution, good S/N ratio and considerably low systematic error. In the TRISTAN energy range, the event rate of interesting process is estimated to be low, and the background level may be high. In order to obtain the significant signals of a rare process, excellent dedicated detectors are required. A brief survey of typical detectors was carried out. For example, toponium and Higgs physics require the good resolution of gamma detection. In the case of low energy gamma measurement, bismuth germanate seems to be a best shower material for electromagnetic calorimeters. Lead glass is often used for high energy gamma measurement because of the good energy resolution, and scintillation glass may be a detector for medium energy gamma. For accurate decay vertex measurement, solid state detector hodoscopes will be available. Compact BGO balls, huge water balls, magnetized iron boxes and modified MAC detectors are proposed for their special purposes. (Kako, I.)

[en] We study the possible occurrence of finite pion mean field in finite nuclei in the relativistic mean field (RMF) theory. We calculate explicitly various N = Z closed shell nuclei with finite pion mean field in the RMF theory with the standard parameter set and the pion-nucleon coupling in free space. The finite pion mean field is introduced by breaking the parity symmetry of the intrinsic single-particle states. We demonstrate the actual occurrence and the property of the finite pion mean field

[en] A low- to medium-level radioactive waste sealing container is constructed by depositing a foundation coating consisting essentially of zinc, cadmium or a zinc-aluminum alloy over a steel base, then coating an organic synthetic resin paint containing a metal phosphate over the foundation coating, and thereafter coating an acryl resin, epoxy resin, and/or polyurethane paint. The sealing container can consist of a main container body, a lid placed over the main body, and fixing members for clamping and fixing the lid to the main body. Each fixing member may consist of a material obtained by depositing a coating consisting essentially of cadmium or a zinc-aluminum alloy over a steel base

[en] Self-assembled nanostructure fabrication technology holds much potential to further the interests of nanoscience and nanotechnology. Using a low-energy mass-selected ion beam deposition system, we fabricated self-assembled silicon carbide (SiC) nanotiles. Methylsilicenium ions (SiCH₃⁺) used as single precursors were generated from dimethylsilane (SiH₂(CH₃)₂). Low-energy SiCH₃⁺ ions (100 eV) were deposited on a Si(100) substrate at 500-600 deg. C. The characteristics of the self-assembled SiC nanotiles were analyzed by reflection high-energy electron diffraction (RHEED), a scanning electron microscope (SEM) and an atomic force microscope (AFM). The self-assembled SiC nanostructure displayed the properties of a zinc-blende structure (3C-SiC) and heteroepitaxial growth. The shape of the self-assembled SiC nanotiles was rectangular with an edge length of 150-200 nm and a height of 10-30 nm. Optimum temperature was found to be 600 deg. C due to the sensitivity of crystal quality and shape of the self-assembled SiC nanotiles to growth temperature

[en] Silicon carbide (SiC) films were grown on Si(111) substrates by low-energy ion beam deposition for the purpose of investigating momentum effects on crystal growth. Dimethylsilane (SiH₂(CH₃)₂) was ionized to obtain methylsilicenium ions (SiCH₃⁺) with Si-C bonding for use as precursors. The ion beam was extracted at 25 m keV for efficient transport from the ion source to the deposition chamber, and SiCH₃⁺ ions were mass-selected by a sector magnet. Ions transported at high energy were decelerated in front of the substrate to desired energies of 20-100 eV. Ion beam current at the substrate was 0.1-0.2 μA. Temperature at the Si(111) substrate was held at 750 deg. C during ion beam deposition and pressure in the deposition chamber atmosphere was kept below 3.9x10^-7 Pa. Incident SiCH₃⁺ ions measured with an energy analyzer were found to have monochromatic energy distributions, e.g. the FWHM was only 1 eV in the case of 100 eV. Crystal structures of the SiC thin films were analyzed in situ by reflection high-energy electron diffraction (RHEED). Under conditions of incident SiCH₃⁺ ions energies of 60-100 eV, 3C-SiC(111) was grown on Si(111) substrate. On the other hand, under conditions of incident ion energies of 20-50 eV, 2H-SiC was grown on Si(111) substrate. In conclusion, the momentum of low-energy ions was found to exert an effect on the determination of SiC crystal structures

[en] Field reconstruction has been performed for the KEK large-aperture-magnet ''TOKIWA''. The magnetic field components are determined point-by-point by an iteration method in which the output voltage from the Hall probes placed in three dimensional directions are used simultaneously. The field components are thus reconstructed accurately within 32 G everywhere in the magnet volume. (author)

[en] We study the possible occurrence of finite pion mean field in finite nuclei in the relativistic mean field (RMF) theory. We calculate explicitly various N = Z closed-shell nuclei with finite pion mean field in the RMF theory with the standard parameter set and the pion-nucleon coupling in free space. The finite pion mean field is introduced by breaking the parity symmetry of intrinsic single-particle states. We demonstrate the actual occurrence and the property of the finite pion mean field

[en] A two-dimensional (2D) measurement system for FRC plasmas based on spectroscopy and computed tomography has been developed. The features of this system are as follows: (1) fifty chord signals of plasma emission are collected using five ten-channel fiber optic arrays; (2) 2D emission intensity profiles can be reconstructed as a function of time with up to a 0.25 μs resolution; (3) the result has explicit physical meaning with the help of five grating monochromators; (4) the measurement wavelength is tunable over visible and ultraviolet regions, and the bandwidth is also variable (0.2-2nm). The authors first measured a translated plasma at the outlet of the source region in the FIX machine. Typical plasma parameters of the source plasma produced on the FIX machine were total temperature ∼ 200eV, electron density ∼6.4 x 10¹⁵ cm^-3, and a lifetime ∼80μs. The separatrix radius and the length of the plasma were about 4.5 and 70cm, respectively. Five photocollector arrays were placed azimuthally around the z-axis at interval angles of 55 ∼ 65 degree. The result of reconstructing a set of 2D and time-resolved profiles is given. Since the major aim of this measurement, however, is observation of equilibrium profiles, formation, gross instability, plasma end profiles, they are now trying to measure the 2D bremsstrahlung profile at the midplane in the source region. At the same time, they are improving the optical system to increase the sensitivity for future measurements in the confinement region where the plasma density will be at least 100 times lower than in the source. Additionally, a reconstruction technique for a 2D H_β emission profile is being developed

[en] Recently, a prototype soft x-ray pinhole camera was fielded on FRX-C/LSM at Los Alamos and TRX at Spectra Technology. The soft x-ray FRC images obtained using this camera stand out in high contrast to their surroundings. It was particularly useful for studying the FRC during and shortly after formation when, at certain operating conditions, flute-like structures at the edge and internal structures of the FRC were observed which other diagnostics could not resolve. Building on this early experience, a new soft x-ray pinhole camera has been installed on FRX-C/LSM, which permits more rapid data acquisition and briefer exposures. It will be used to continue studying FRC formation and to look for internal structure later in time which could be a signature of instability. This paper summarizes the initial operation of this camera. As of this writing, the camera has been used primarily in conjunction with measurements of external magnetic field asymmetries of FRCs. Some of the images obtained during the bias and pressure scans of this series of measurements are included to indicate the effect of varying source conditions on formation