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Basement rocks below the Athabasca Basin, Saskatchewan, have been intensely altered through paleoweathering and multiple hydrothermal events, including the formation of world-class unconformity-type uranium deposits. Here, we demonstrate the utility of Ti-oxide thermochronology for identifying thermotectonic events in these altered rocks leading to uranium mineralization along basement structures. Rutile grains along the P2 fault, a major fault in the eastern Athabasca Basin, exhibit 207Pb/206Pb ages of ca. 1850-1700 Ma, with a weighted mean of 1757 ± 6 Ma (mean square of weighted deviation [MSWD] = 1.4, n = 116). The older ages (>1770 Ma) record regional metamorphism reaching a temperature of 875 °C during the Trans-Hudson orogeny. Pb diffusion modeling indicates that metamorphic rutile should exhibit cooling ages of 1760-1750 Ma. Rutile grains showing young ages, <1750 Ma, reflect isotopic resetting during regional asthenospheric upwelling between 1770 and 1730 Ma related to the emplacement of the Kivalliq igneous suite to the north. This thermotectonic event (temperature > 550 °C) promoted hydrothermal activity to produce silicified rocks, i.e., "quartzite," along the P2 fault, which later focused mineralizing fluids for unconformity-type uranium deposits. The young rutile ages also indicate that the basement rocks remained hot until 1700 Ma, providing the maximum age for the deposition of the Athabasca sediments. Anatase yields a concordia age of 1569 ± 31 Ma (MSWD = 0.30, n = 5), which is within uncertainty of the oldest ages for uraninite of the McArthur River deposit. This age corresponds to the incursion of basinal fluids in the basement along the P2 fault during uranium mineralization. [ABSTRACT FROM AUTHOR]

Photon imaging technology is applied in various research fields such as quantum information communication and biological imaging. We have been developing photon-counting devices using optical transition edge sensors (TES). We demonstrated a single-photon spectroscopic imaging system comprising an optical TES and a scanning microscope. However, a great number of TES pixels are required to increase the field of view in the imaging system. To read out the TES array, output signals need to be multiplexed. Microwave SQUID multiplexer (MW-Mux) is a kind of frequency multiplexing method with a carrier wave having a frequency of several GHz, and it can be used to widen the frequency band. In this paper, we report the first demonstration on readout of an optical TES with MW-Mux. [ABSTRACT FROM AUTHOR]

Optical transition edge sensor (TES) detectors that can resolve the energy of a single optical photon have proven to be desirable in multicolor fluorescence microscopy. Here, detectors with a higher energy resolution can distinguish dyes having similar or closer emission wavelengths, thus enabling the observation of multiple kinds of dyes simultaneously. To improve energy resolution, it is necessary to know how different the measured energy resolution is from the limit determined by the temperature sensitivity αI and current sensitivity βI, as extracted from the complex impedance. Due to the very fast response of an optical TES (the time constant is shorter than 1 µs), the complex impedance must be measured up to frequencies larger than 10 MHz. However, at high frequencies, the parasitic impedance in the circuit and reflections of electrical signals caused by discontinuities in the characteristic impedance of the readout circuits become significant. To reduce these effects, twisted pair cables are replaced with coaxial ones in this work; thus, a cleaner transfer function of the readout at high frequencies is obtained. The measured impedance of the studied TES is consistent with that given by the single-block model. [ABSTRACT FROM AUTHOR]

A detailed investigation of photocarrier transport and localized states in undoped hydrogenated microcrystalline silicon (μc-Si:H) has been performed using the modulated photocurrent (MPC) technique. The MPC-derived drift mobility shows a systematic variation with crystalline grain size and volume fraction, as well as a distinct anisotropy. The physical implications of these observations are discussed in accordance with models that consider connectivity of crystalline grains and geometry of individual grains. The frequency spectra of MPC mobility and their dependence on excitation intensity are also analyzed in comparison with those observed for hydrogenated amorphous silicon (a-Si:H), leading to a common property of localized states that can explain the experimental results for these materials. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Presents information on a study which aimed to investigate carrier transport in hydrogenated amorphous silicon by applying the modulated photoconductivity (MPC) technique. Fundamental property of amorphous semiconductors; Theory for drift mobility measurements that characterize MPC behavior; Experimental details; Results of the study.

Focuses on the measurement of the electron-spin resonance (ESR) under a modulated photoexcitation in an attempt to investigate the nonequilibrium carriers trapped at band-tail states within hydrogenated amorphous silicon. Why the photomodulation technique is successfully applied; How the access to the recombination kinetics for band-tail carriers obtained.

Optical transition edge sensors (TESs) are characterized by a very fast response, of the order of μs, which is 103 times faster than TESs for X-ray and gamma-ray. To extract important parameters associated with the optical TES, complex impedances at high frequencies (> 1 MHz) need to be measured, where the parasitic impedance in the circuit and reflections of electrical signals due to discontinuities in the characteristic impedance of the readout circuits become significant. This prevents the measurements of the current sensitivity β, which can be extracted from the complex impedance. In usual setups, it is hard to build a circuit model taking into account the parasitic impedances and reflections. In this study, we present an alternative method to estimate a transfer function without investigating the details of the entire circuit. Based on this method, the complex impedance up to 30 MHz was measured. The parameters were extracted from the impedance and were compared with other measurements. Using these parameters, we calculated the theoretical limit on an energy resolution and compared it with the measured energy resolution. In this paper, the reasons for the deviation of the measured value from theoretically predicted values will be discussed. [ABSTRACT FROM AUTHOR]

Presents a study which fabricated gold-n-type gallium arsenide Schottky contacts on a single-crystal part of polycrystalline gallium arsenide. Experiment; Results; Discussion.

Investigates the capacitive response of deep iron acceptors in a semi-insulating n-type iron-doped Schottky barrier. Effects of deep iron acceptors on the impedance of a semi-insulating n-type iron-doped indium phosphide Schottky barrier; Measurement of the capacitance and conductance at various frequencies; Explanation for the impedance characteristics in terms of the delayed response of deep iron acceptors.

Focuses on a study which applied a spectroscopy technique based on modulated photoconductivity measurements with varying illumination level to investigate the capture coefficients and the energy distribution of defect states in undoped amorphous silicon. Theory of modulated photoconductivity spectroscopy; Discussion of the carrier capture process and the defect formation mechanism; Evolution of modulated photoconductivity response with illumination level.

Proposes a method for investigating the diffusion of photocarriers in semiconductors by the analysis of phase shift between a temporally modulated illumination grating and its inducing photocurrent. Theory of the modulated photocarrier grating technique; Diffusion length measurement in amorphous silicon; Comparison with the result of the steady-state photocarrier grating measurement.

Presents information on a study that investigated the conduction type, resistivities, carrier concentrations and mobilities in polycrystalline chalcopyrite AgInS[sub2] films. Methodology of the study; Results and discussion on the study.

Investigates the electrical properties of n-type InP metal-insulator-semiconductor (MIS) structures. Hysteresis in the capacitance-voltage curves of a typical InP MIS structure; Interfacial properties of InP MIS structures; Value of the minimum surface state density.

Presents a study that analyzed the electrical properties of n-type indium antimonide metal-insulator-semiconductor (MIS) structures. Analysis of the capacitance-voltage characteristics of the MIS structures; Evaluation of the surface density of the MIS; Determination of the resistivities of the MIS structures.

Presents information on a study which investigated the localized deep states in undoped α-silicon:hydrogen using current transient spectroscopy. Outline of current transient spectroscopy; Experimental details; Results and discussion; Conclusions.

The readout of transition-edge sensor (TES) bolometers with a large multiplexing factor is key for the next generation cosmic microwave background (CMB) experiment, Polarbear-2 (Suzuki in J Low Temp Phys 176:719, ), having 7588 TES bolometers. To enable the large arrays, we have been developing a readout system with a multiplexing factor of 40 in the frequency domain. Extending that architecture to 40 bolometers requires an increase in the bandwidth of the SQUID electronics, above 4 MHz. This paper focuses on cryogenic readout and shows how it affects cross talk and the responsivity of the TES bolometers. A series resistance, such as equivalent series resistance of capacitors for LC filters, leads to non-linear response of the bolometers. A wiring inductance modulates a voltage across the bolometers and causes cross talk. They should be controlled well to reduce systematic errors in CMB observations. We have been developing a cryogenic readout with a low series impedance and have tuned bolometers in the middle of their transition at a high frequency ( $$>$$ 3 MHz). [ABSTRACT FROM AUTHOR]

Reports the results of in situ measurements of stress and surface morphology for cobalt/palladium multilayer films fabricated by rf sputtering. Experiment conducted; Results; Discussion.

High purity Mg–Al–spinel powders were processed to form slurries for tape casting. The dried green tapes were cut and laminated via thermo-compression under uniaxial and isostatic pressure conditions. Finally the laminates were sintered pressurelessly in air. The influence of the transformation temperature of the green tape׳s binder–plasticizer system and of lamination parameters on density and microstructure of the sintered laminates was analyzed. UV‐VIS transmission spectroscopy was performed to measure the transparency of the fired laminates. The interrelation between the lamination parameters, sintering behavior and properties of the sintered product is discussed. Isostatic thermal lamination resulted in higher sintered densities than uniaxial lamination. For both techniques an increase in lamination pressure or temperature led to higher relative densities after sintering. The laminates exhibited total forward transmission values of up to 67% at a wavelength of 700 nm. [ABSTRACT FROM AUTHOR]

The surface structure of epitaxial β-FeSi2(100) thin film grown on Si(001) was analyzed using the quantitative low-energy electron diffraction intensity-voltage (LEED I-V) method, ab initio density functional theory (DFT) calculations, and scanning tunneling microscopy (STM). LEED patterns measured on the β-FeSi2(100) surface reveal two domains of a p(2 × 2) reconstruction with p2gg diffraction symmetry. The iron-silicide film truncation and atomic surface structure were determined by LEED I-V method: The smallest Pendry's reliability factor Rp = 0.22 ± 0.02 was achieved for the bare β-FeSi2 film truncated by an Si layer, whereas Si and Fe ad-atom structures were excluded. Significant atomic relaxations within the topmost surface layers were revealed by the LEED I-V method and confirmed by DFT. The simulated STM patterns from the best-fit model agree well with the measured STM images on the β-FeSi2(100)/Si(001)-p(2 × 2) surface: Four Si atoms on a surface form one bright protrusion on STM patterns. Electronic band structure analysis of the bulk and epitaxial β-FeSi2(100) was carried out. A bare truncated epitaxial film was found to be metallic. Surface electronic states were identified by a partial k-resolved atomic-orbital based local density-of-state analysis. [ABSTRACT FROM AUTHOR]

We develop a continuous-time quantum Monte Carlo (CTQMC) method for quantum impurities coupled to interacting quantum wires described by a Tomonaga-Luttinger liquid. The method is negative-sign free for any values of the Tomonaga-Luttinger parameter, which is rigorously proved, and, thus, efficient low-temperature calculations are possible. Duality between electrons and bosons in one-dimensional systems allows us to construct a simple formula for the CTQMC algorithm in these systems. We show that the CTQMC for Tomonaga-Luttinger liquids can be implemented with only minor modifications of previous CTQMC codes developed for impurities coupled to noninteracting fermions. We apply this method to the Kane-Fisher model of a potential scatterer in a spin-less quantum wire and to a single spin coupled with the edge state of a two-dimensional topological insulator assuming an anisotropic XXZ coupling. Various dynamical response functions such as the electron Green's function and spin-spin correlation functions are calculated numerically and their scaling properties are discussed. [ABSTRACT FROM AUTHOR]

We demonstrate the highly sensitive terahertz (THz) sensing of a water-glycerol mixture poured on a metamaterial surface using reflection-based THz time domain spectroscopy. The reflectance at the resonant dip frequency changes significantly with glycerol concentration. The detection sensitivity is about 8 times higher than that compared to the case without a metamaterial structure. We also investigate how sensitivity depends on the Q factor of the metamaterial resonance for highly absorptive media, such as a water solution in the THz region. [ABSTRACT FROM AUTHOR]

Abstract: Primordial gravitational waves generated by inflation have produced an odd-parity pattern B-mode in the cosmic microwave background (CMB) polarization. LiteBIRD (Light satellite for the studies of B-mode polarization and Inflation from cosmic background Radiation Detection) aims at detecting this B-mode polarization precisely. It requires about 2000 detectors capable of detecting a frequency range from 50GHz to 250GHz with ultra low noise. Superconducting detectors are suitable for this requirement. We have fabricated and tested microwave kinetic inductance detectors (MKIDs) and developed a new readout system. We have designed antenna-coupled MKIDs. Quasi-particles are created by incident radiation and are detected as a change of the surface impedance of a superconductor strip. This change of the surface impedance is translated into the change of the resonant frequency of a microwave signal transmitted through the resonator. We also have developed a new readout system for MKIDs. The newly developed readout system is not only able to read out the amplitude and the phase data with the homodyne detection for multi-channels, but also provides a unique feature of tracking the resonant frequency of the target resonator. This mechanism enables us to detect signals with a large dynamic range. We report on the recent R&D status of the developing MKIDs and on the read-out system for LiteBIRD. [Copyright &y& Elsevier]

We investigate reentrant superconductivity in an Ising ferromagnetic superconductor URhGe under a transverse magnetic field hx. The superconducting transition temperature for p-wave order parameters Tsc is calculated and shows two domes as a function of hx. We find strong enhancement of Tsc in the high-field dome near a saturation field hs where the spins align in the transverse direction. Soft magnons generate strong attractive interactions there. Spin components of the pairing show a significant change between hx < hs and hx > hs. We also discuss the appearance of superconductivity with zero-spin pair due to cancellation between external and exchange fields. [ABSTRACT FROM AUTHOR]

Abstract Ferritchromite is rarely reported in forearc mantle peridotites. This contribution describes ferritchromite alteration and zoned Cr-spinel in serpentinites from the Rio San Juan Complex in the Dominican Republic. These rocks originated from the forearc mantle and protruded along lithosphere-scale faults in the mid Eocene. The cores of the Cr-spinel grains have Cr# ratios [i.e. atomic Cr/(Cr + Al)] between 0.48 and 0.66; such values are relatively high and are considered to represent primary compositions. Relatively high Zn contents in the grain cores (0.46-0.95 wt.% ZnO) are also thought to be primary; they reflect exceptionally cool conditions in the northern Caribbean forearc mantle. A progressive change in the zoning of Cr-spinel is recorded in the samples. Weakly zoned grains of Cr-spinel have rims with lower Mg# ratios [i.e. atomic Mg/(Mg + Fe2+)] and slightly higher Cr# ratios than the cores. More strongly zoned grains of Cr-spinel, in addition to low Mg# and high Cr# in their rims, have a marked increase in Fe3+# [i.e. Fe3+/(Fe3+ + Al + Cr)] of up to 0.35 in their rims and are partially coated by Mg-rich chlorite. All grains show core-to-rim decreases in their Zn content and increases in Ti, Mn and V. The association with Mg-rich chlorite and the compositional zoning are reminiscent of those reported for ferritchromite. Ferritchromite (with Fe3+# >0.5) is common in ultramafic rocks in amphibolite-grade terranes; however, the serpentinite samples described herein show little evidence of high-grade metamorphism. The lowtemperature serpentine-group mineral lizardite is dominant and high-temperature antigorite is either very rare or absent; other high-temperature minerals, such as talc, tremolite and cummingtonite, are trace constituents. The observed zoning in the Cr-spinel is thought to represent 'immature' ferritchromite, probably formed in response to a short-lived thermal event. This event appears to have been on too short a timescale to produce either proper ferritchromite or significant quantities of high-temperature minerals. It may be related to the emplacement of the nearby Rio Boba Intrusion, or the upward protrusion of the serpentinites along the lithosphere-scale Septentrional fault zone from the base of the mantle wedge through its hotter interior. We suggest that such alteration is rare in forearc serpentinites because they are not commonly heated during exhumation along the plane of subduction. This work demonstrates that Cr-spinel compositions can be modified by relatively low-grade metamorphism. [ABSTRACT FROM AUTHOR]

Abstract: We have developed a prototype time-resolved neutron imaging detector employing the micro-pixel chamber (), a micro-pattern gaseous detector, coupled with a field programmable gate array-based data acquisition system for applications in neutron radiography at high-intensity neutron sources. The prototype system, with an active area of 10×10cm2 and operated at a gas pressure of 2atm, measures both the energy deposition (via time-over-threshold) and three-dimensional track of each neutron-induced event, allowing the reconstruction of the neutron interaction point with improved accuracy. Using a simple position reconstruction algorithm, a spatial resolution of was achieved, with further improvement expected. The detailed tracking allows strong rejection of background gamma-rays, resulting in an effective gamma sensitivity of 10−12 or less, coupled with stable, robust neutron identification. The detector also features a time resolution of . [Copyright &y& Elsevier]

We investigate a four-impurity Anderson model where localized orbitals are located at vertices of a regular tetrahedron and find a novel fixed point in addition to the ordinary Fermi liquid phase. That is characterized by unscreened scalar chirality of a tetrahedron. In this phase, parafermions emerge in the excitation spectrum and quasiparticle mass diverges as l/|Tln³T| at low temperatures (T). The diverging effective mass is a manifestation of singular Fermi liquid states as in the underscreened Kondo problem. Between the two phases, our Monte Carlo results show the existence of a non-Fermi liquid critical point where the Kondo effects and the intersite antiferromagnetic interactions are valanced. Singular behaviors are prominent in the dynamics and we find that the frequency dependence of the self-energy is the marginal Fermi liquid like --Im σ ~ |ɷ|. [ABSTRACT FROM AUTHOR]

The satellite LiteBIRD (Light satellite for the studies of B-mode polarization and Inflation from cosmic background Radiation Detection) is being designed to detect the B-mode polarization of the cosmic microwave background radiation. LiteBIRD will carry about 2,000 detectors for measurements in five bands (60, 80, 100, 150, and 220 GHz). Microwave kinetic inductance detectors (MKIDs) that can be multiplexed in a single readout line are suitable for the large focal plane detector array. We develop an MKID readout system for LiteBIRD to monitor the amplitude, phase, and resonant frequency of each MKID resonator simultaneously and follow movements of the resonant frequency caused by changes in the input radiation intensity. This mechanism enables us to have a larger dynamic range for the MKIDs, compared with a system that monitors the amplitude and phase on the resonant frequency. We also propose an MKID having a half-wavelength resonator. This MKID transmits the resonant microwave signal from one feedline to another. It can offer clear microwaves passing through the resonators, even if the coupling and internal quality factors are mismatched. With this MKID, our readout system can track resonance frequency changes much more easily. We present the status of the readout system development and demonstrate the performance with the half-wavelength MKID. [ABSTRACT FROM AUTHOR]

We analyze non-Fermi liquid (NFL) properties along a line of critical points in a two-channel Anderson model with phonon-assisted hybridizations. We succeed in identifying hidden nonmagnetic SO(5) degrees of freedom for the valence-fluctuation regime, and we analyze the model on the basis of boundary conformai field theory. We find that the NFL spectra along the critical line, which is the same as those in the two-channel Kondo model, can be alternatively derived by a fusion in the nonmagnetic SO(5) sector The leading irrelevant operators near the NFL fixed points vary as a function of Coulomb repulsion U\ operators in the spin sector dominate for large U, while those in the S0(5) sector dominate for small U, and we confirm this variation in our numerical renormalization group calculations. As a result, the thermodynamic singularity for small V differs from that of the conventional two-channel Kondo problem. In particular, the impurity contribution to specific heat is proportional to temperature, and bipolaron fluctuations, which are coupled electron-phonon fluctuations, diverge logarithmically at low temperatures for small U. [ABSTRACT FROM AUTHOR]

Abstract: We have successfully refined the position resolution of a two-dimensional X-ray photon-counting detector based on the micro-pixel gas chamber () by measuring the charge distribution of an X-ray interaction without the use of analog-to-digital converters (ADCs). By updating the logic of the Field Programmable Gate Arrays (FPGAs) included in the data acquisition system, we were able to acquire the pulse widths, or time-above-threshold of the signals, by measuring both the leading and trailing edges of the digital signals. By using the measured widths to estimate the peak of the charge distribution, the position resolution of our detector was improved to from a value of found using the FPGA logic of the previous system. This represents an improvement of nearly 60%. [Copyright &y& Elsevier]

ABSTRACT We present theoretical calculations for the differential distribution of stellar orbital eccentricity for a sample of solar-neighbourhood halo stars. Two types of static, spherical gravitational potentials are adopted to define the eccentricity e for given energy E and angular momentum L, such as an isochrone potential and a Navarro-Frenk-White potential that can serve as two extreme ends covering in between any realistic potential of the Milky Way halo. The solar-neighbourhood eccentricity distribution Δ N( e) is then formulated, based on a static distribution function of the form f( E, L) in which the velocity anisotropy parameter β monotonically increases in the radial direction away from the galaxy centre, such that β is below unity (near-isotropic velocity dispersion) in the central region and asymptotically approaches ∼1 (radially anisotropic velocity dispersion) in the far distant region of the halo. We find that Δ N( e) sensitively depends upon the radial profile of β, and this sensitivity is used to constrain such a profile in comparison with some observational properties of Δ Nobs( e) recently reported by Carollo et al. In particular, the linear e-distribution and the fraction of higher e stars for their sample of solar-neighbourhood inner-halo stars rule out a constant profile of β, contrary to the opposite claim by Bond et al. Our constraint of β≲ 0.5 at the galaxy centre indicates that the violent relaxation that has acted on the inner halo is effective within a scale radius of ∼10 kpc from the galaxy centre. We argue that our result would help to understand the formation and evolution of the Milky Way halo. [ABSTRACT FROM AUTHOR]

We present theoretical calculations for the differential distribution of stellar orbital eccentricity in a galaxy halo, assuming that the stars constitute a spherical, collisionless system in dynamical equilibrium with a dark matter halo. In order to define the eccentricity e of a halo star for given energy E and angular momentum L, we adopt two types of gravitational potential, such as an isochrone potential and a Navarro-Frenk-White potential, which could form two ends covering in-between any realistic potential of dark matter halo. Based on a distribution function of the form that allows constant anisotropy in velocity dispersions characterized by a parameter β, we find that the eccentricity distribution is a monotonically increasing function of e for the case of highly radially anisotropic velocity dispersions (), while showing a hump-like shape for the cases from radial through tangential velocity anisotropy (). We also find that when the velocity anisotropy agrees with that observed for the Milky Way halo stars (), a nearly linear eccentricity distribution of results at , largely independent of the potential adopted. Our theoretical eccentricity distribution would be a vital tool of examining how far out in the halo the dynamical equilibrium has been achieved, through comparison with kinematics of halo stars sampled at greater distances. Given that large surveys of the SEGUE and Gaia projects would be in progress, we discuss how our results would serve as a new guide in exploring the formation and evolution of the Milky Way halo. [ABSTRACT FROM AUTHOR]

Abstract: We studied the structure and magnetism of the bcc-Fe(111) phase to the fine-polycrystal and β-FeSi2 phases in solid phase epitaxial growth of iron silicides on Si(111) surfaces. In the polycrystal phase displaying Debye rings in reflection high-energy electron diffraction, we found randomly-oriented bcc-Fe fine-crystals to be responsible for the phase, and obtained ferromagnetic hysteresis but the magnetization was small. In the polycrystal phase, other irons and silicides were sometimes included: epitaxially-grown bcc-Fe crystals with preferential orientation in different directions, and β-FeSi2(101) or (110) layers. We show a growth scheme with annealing for structure and magnetism of these phases. [Copyright &y& Elsevier]

Abstract: Anomalous ULF geomagnetic field change is considered to be one of the most convincing and promising phenomena among earthquake-related electromagnetic effects, because we expect emissions from the crust of the source region. There has been a great deal of accumulated and convincing evidence of ULF magnetic signatures before large earthquakes as reported in the previous studies. In order to verify these phenomena preceding large earthquakes and to clarify the relationship between electromagnetic phenomena and possible physical mechanism, we have investigated the data of ULF geomagnetic observations at Kototabang and Biak stations associated with the 2004/2005 Sumatra earthquakes. A case study is carried out in this work to investigate the pre-earthquake ULF geomagnetic anomalies during the Sumatra–Andaman earthquake on December 26, 2004 (magnitude Mw=9.0 and depth=30km from USGS catalog), and Sumatra–Nias earthquake on March 28, 2005 (Mw=8.7 and depth=30km). For the aim of finding any precursors, we have adopted the spectral density ratio analysis and transfer functions analysis based on wavelet transform method. Results of the spectral density analysis indicate similar variations to those of amplitude for the induction arrow in transfer function analysis. Both of these variations at Kototabang exhibit strange or anomalous changes from a few weeks before the Sumatra–Andaman earthquake to July 2005, while there are no apparent changes at remote station of Biak. To make these results more convincing, the fractal analysis based on a Higuchi method has been applied to the same observed data, which also show a significant change (or decrease) in mono-fractal dimension a few weeks before the earthquakes. This result would lend a further support to those by the spectral density ratio and transfer function analyses. So, we can conclude that the anomalous change as observed simultaneously by the three methods, might be a possible signature related with the earthquake preparation phase of Sumatra earthquakes. [Copyright &y& Elsevier]

Abstract: The major problem on magnetic alignment of graphite particles is the difficulty to produce graphite particles composed of a single crystal, and suppress their agglomeration. Thus, it is essential to produce graphite particles composed of a single crystal and disperse them using mechanical grinding or shearing with addition of a suitable dispersant. In this study, the suitable dispersant for graphite particle and the optimum condition for mechanical grinding are studied in respect to the crystal alignment of natural graphite in slip casting under a high magnetic field. [Copyright &y& Elsevier]

This paper deals with the diffraction and scattering of a TM plane wave from a binary periodic random surface generated by a stationary binary sequence using the stochastic functional approach. The scattered wave is represented by a product of an exponential phase factor and a periodic stationary process. Such a periodic stationary process is regarded as a stochastic functional of the binary sequence and is expressed by an orthogonal binary functional expansion with band-limited binary kernels. Then, hierarchical equations for the binary kernels are derived from the boundary condition without approximation. We point out that binary kernels obtained by a single scattering approximation diverge unphysically when the periodic random surface is zero on average, thus the effects of multiple scattering should be taken into account. The expressions of such binary kernels are obtained using the multiply renormalizing approximation. Then, statistical properties such as differential scattering cross-section and the optical theorem are numerically calculated with the first two order binary kernels and illustrated in the figures. It is found that the incoherent Wood's anomaly appears in the angular distribution of scattering even when the surface has zero average. [ABSTRACT FROM AUTHOR]

Calculation of magnetization of the ternary single crystal compound NdRh2Ge2 has been carried out by using the wave-like molecular field model to explain the complex magnetic behavior. The field-induced magnetic structures having the propagation vectors, Q2 = (0, 0, 39/40), Q3 = (0, 0, 35/40), Q4 = (0, 0, 31/40), and Q5 = (0, 0, 0/40) (= the field-induced ferromagnetic phase) were proposed. Calculation on the basis of these structures and the antiferromagnetic phase with Q1 = (0, 0, 1) well reproduces the experimental magnetization processes and H-T magnetic phase diagram. [ABSTRACT FROM AUTHOR]

Abstract: We report on the development of a large Compton camera with the full reconstruction of the Compton process based on a prototype. This camera consists of two kinds of detectors. One is a gaseous time projection chamber (micro-TPC) for measuring the energy and the track of a Compton recoil electron. The micro-TPC is based on a -PIC and a GEM, which are micro-pattern gas detectors (MPGDs). The size of the micro-TPC was in the case of the prototype, and we enlarged it to . The other detector part is a NaI (Tl) Anger camera for measuring the scattered gamma-ray. With these informations, we can completely reconstruct a Compton event, and determine the direction of the incident gamma-ray, event by event. We succeeded in reconstructing events of incident 662keV gamma-rays. The measured angular resolutions of the “angular resolution measure” (ARM) and the “scatter plane deviation” (SPD) were and (FWHM), respectively. [Copyright &y& Elsevier]

Abstract: The Time Projection Chamber (TPC) has been recognized as a potentially powerful detector for the search of WIMPs by measuring the directions of nuclear recoils, in which the most convincing signature of WIMPs, caused by the Earth''s motion around the Galaxy, appears. We report on the first results of a performance study of the neutron exposure of our prototype micro-TPC with (90:10) and gas at 150Torr. [Copyright &y& Elsevier]

Abstract: A Micro Pixel Chamber, called “-PIC”, is a gaseous 2D imaging detector with a fine pixel electrode based on the Printed Circuit Board technology, and we developed it for the X/gamma-ray imaging and the tracking of the charged particles [A. Ochi, et al., Nucl. Instr. and Meth. A 478 (2002) 196; T. Nagayoshi, et al., Nucl. Instr. and Meth. A 525 (2004) 20.]. The previous -PIC has a fine position resolution, a high gas gain, a good gas gain uniformity and the stable operation. Although the detection area of the previous -PIC is not large enough for a variety of the application, for example an MeV gamma-ray Compton camera [T. Tanimori, et al., New Astron. Rev. 48 (2004) 263.] and dark matter search [T. Tanimori, et al., Phys. Lett. B 578 (2004) 241.]. Therefore, we developed a new -PIC having a detection area. The structure and the pitch of the electrode are same as those of the previous -PIC. There are pixels in the whole area. This -PIC (TOSHIBA SN041129-1) is operated with a stable gas gain of and a maximum gain of at the center region, and the variety of the gain was 16.7% RMS. An X-ray image of the whole area was also taken by the irradiation of the X-rays from 109Cd (22keV) to the whole detection area. [Copyright &y& Elsevier]

Abstract: We have developed a position-sensitive scintillation camera with a large area as an absorber of an advanced Compton gamma-ray camera. At first we tested GSO(Ce) crystals. We compared light output from the GSO(Ce) crystals under various conditions: the method of surface polishing, the concentration of Ce, and co-doping Zr. As a result, we chose the GSO(Ce) crystals doped only 0.5mol% Ce, surface of which was polished by chemical etching for the scintillator of our camera. We also made a scintillation camera which consisted of nine position-sensitive PMTs (PSPMTs Hamamatsu flat-panel H8500 ), the each of which had anodes with a pitch of 6mm and coupled to arrays of pixelated GSO(Ce) scintillators. For the readout system of 576 anodes of the PMTs, we used chained resistors to reduce the number of readout channels down to 48 for saving power consumption. The camera has the position resolution of less than 6mm and a typical energy resolution of 10.5% (FWHM) at 662keV at each pixel in a large area of . Furthermore, we constructed a array of pixelated GSO(Ce) scintillators, and glued it to a PMT H8500. This camera had the position resolution of less than 3mm in area of , except for some of edge pixels; the energy resolution was typically 13% (FWHM) at 662keV. [Copyright &y& Elsevier]

Abstract: We have studied the performance of two different types of front-end systems for our gamma camera based on Hamamatsu H8500 (flat-panel 64 channels multi-anode PSPMT) with a CsI(Tl) scintillator array. The array consists of 64 pixels of which corresponds to the anode pixels of H8500. One of the system is based on commercial ASIC chips in order to read out every anode. The others are based on resistive charge divider network between anodes to reduce readout channels. In both systems, each pixel (6mm) was clearly resolved by flood field irradiation of 137Cs. We also investigated the energy resolution of these systems and showed the performance of the cascade connection of resistive network between some PMTs for large area detectors. [Copyright &y& Elsevier]

We studied adsorption and reaction of nitric oxide on Si(111)7 × 7, 5 × 2-Au, $\alpha-\sqrt{3},\times \sqrt{3}-{\rm Au}$, $\beta-\sqrt{3} \times \sqrt{3}-{\rm Au}$, and 6 × 6-Au surfaces with low-energy electron diffraction, Auger electron spectroscopy, and scanning tunneling microscopy (STM). We found that NO gas reacts most strongly with the 7 × 7 surface, strongly with the 5 × 2-Au surface, and little with the other Si(111)-Au surfaces. STM results indicated that the NO exposure removes adatoms and erodes the row structure on the 5 × 2-Au surface at room temperature. [ABSTRACT FROM AUTHOR]

Abstract: A prototype of the MeV gamma-ray imaging camera based on the full reconstruction of the Compton process has been developed. This camera consists of a micro-TPC that is a gaseous Time Projection Chamber (TPC) and scintillation cameras. With the information of the recoil electrons and the scattered gamma-rays, this camera detects the energy and incident direction of each incident gamma-ray. We developed a prototype of the MeV gamma-ray camera with a micro-TPC and a NaI(Tl) scintillator, and succeeded in reconstructing the gamma-rays from 0.3 to 1.3MeV. Measured angular resolutions of ARM (Angular Resolution Measure) and SPD (Scatter Plane Deviation) for 356keV gamma-rays were and , respectively. [Copyright &y& Elsevier]

We have studied a Si(111)2×2-Fe surface exposed to nitric oxide at room temperature with Auger electron spectroscopy, low-energy electron diffraction, and scanning tunneling microscopy (STM). The surface local structure of Si(111)2×2-Fe has been modeled to be similar to that of Si(111)7×7; both structures have Si adatom and Si first-layer restatom, but the restatom in the former surface bonds to Fe atoms. It is known that NO molecules dissociatively adsorb on Si(111)7×7 surface, especially atop adatoms. Before the exposure to the Si(111)2×2-Fe surface, STM images showed 2×2 islands on the 2×2 terrace. After the exposure, the 2×2 islands were eroded at the island edge while the 2×2 terrace was stable against nitric oxide. We ascribed the inert property of the 2×2 terrace, and the reactive property of the 2×2 island edges and the 7×7 terrace, primarily to the Si restatom with different neighbor atoms. [Copyright &y& Elsevier]

Previous studies on Spitak, Loma Prieta, and Guam earthquakes indicate that large earthquakes were accompanied by preceding magnetic anomalies. In order to confirm these facts and to investigate ULF phenomena in details, a network of ULF magnetometers has been installed in Japan. Network observations including small arrays have been carried out. Also, the geomagnetic data observed at Matsukawa station associated with Iwateken Nairiku Hokubu earthquake (M6.1, September 3, 1998, depth 10 km) are presented. 4.5 years data have been analyzed and the obtained result is discussed. The variation of spectral density ratio between the horizontal and vertical components (polarization) exhibits an anomalous behavior two weeks before the earthquake. This is a unique change discovered from the rather long-term analysis, which suggests that this anomalous change might be a possible signal associated with the earthquake preparation phase. [Copyright &y& Elsevier]

In order to study earthquake-related ULF geomagnetic field changes, it is important to discriminate the noises such as magnetic pulsations originated from solar–terrestrial interactions and artificial noises from DC-driven trains and factories. For this aim, the interstation transfer functions and wavelet transform method have been proposed and applied to the data obtained at the ULF electromagnetic sensor array at the Boso Peninsula, Japan. It is concluded that this interstation transfer function approach has a capacity for signal discrimination; that is, it shows effectiveness to eliminate noises originated from the external ionospheric sources and its secondary effects. [Copyright &y& Elsevier]

We present evidence that the Hurst exponent of the ultra low frequency component of the geomagnetic field varies similarly to the energy release of the local swarm of earthquakes observed in Japan in 2000. Similarity is demonstrated between the energy release by the shocks and variations of the Hurst exponent derived for the three component records of the geomagnetic field. [Copyright &y& Elsevier]

OBJECTIVE:: To examine the effect of age on the relationship between fat-free mass (FFM) and fat mass (FM), and fat-free mass index (FFMI) and fat mass index (FMI) by applying body composition chart analysis on pre- and postadolescent Japanese subjects. SUBJECTS AND METHOD:: A sample of 516 children (244 boys and 272 girls) ranging in age from 11 to 17?y and 840 adults (288 male and 552 female subjects) ranging in age from 18 to 59?y were studied to determine a body composition by an underwater weighing method. FMI and FM were put on an x- and y-axis in body composition chart 1, and FFMI (FFM/ height2) and FMI (FM/height2) were taken on an x- and y-axis in body composition chart 2. RESULTS:: In body composition chart 1, the plots for male subjects stayed flat from 11 to 14?y and after that a steady growth of FFM concurring with the FM growth was observed. During the adult stage, steady increments of FM and gradual decreases of FFM were observed. In body composition chart 2, steady increases of FFMI and gradual decreases of FMI were indicated in the male preadolescent period. In the adult stage, FFMI decreased year by year, although the FMI continued to increase. In female subjects, a conspicuous increase of FMI was observed throughout all periods of the present subjects. After middle age, the decline of FFMI was characteristically demonstrated in the chart. CONCLUSION:: The relationships between FFM and FM are characteristically delineated on the body composition charts demonstrating clear gender differences. The change of body mass index was not reflecting the change of adiposity level in male subjects, although it was occurring along with the changes of the adiposity level in female subjects.International Journal of Obesity (2004) 28, 520-524. doi:10.1038/sj.ijo.0802593 Published online 10 February 2004 [ABSTRACT FROM AUTHOR]