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It has been known that the ultrasonic elliptical vibration cutting (UEVC) is the effective method for ultra-precision machining with diamond tools for ferrous materials. In these cutting methods, the formation of protective films by the adsorption of atmospheric gas to the contact surface suppress the wear of diamond tools. In addition, the ultrasonic vibration cutting has the effect of reducing the rise in the tool temperature during processing, which is also the reason for suppressing tool wear. In this study, to discuss the wear reduction mechanism described above in more details, we investigated the influence of tool wear exerted by the presence or absence of atmospheric gas and by the difference of worked materials. Consequently, it was found that the production of carbide is the controlling factor that determines the wear process of the diamond tool during the ultrasonic vibration cutting. Thus, it was suggested that in atmospheric conditions, the adsorption films from atmospheric gas suppresses the production of carbide, leading to decrease wear of diamond tools.

The purpose of our study was to select the most effective ionic liquid extraction solvents for dysprosium (III) fluoride using a theoretical approach. Conductor-like Screening Model for Real Solvents (COSMO-RS), based on quantum chemistry and the statistical thermodynamics of predefined DyF3-ionic liquid systems, was applied to reach the target. Chemical potentials of the salt were predicted in 4,400 different ionic liquids. On the base of these predictions set of ionic liquids’ ions, manifesting significant decrease of the chemical potentials, were selected. Considering the calculated physicochemical properties (hydrophobicity, viscosity) of the ionic liquids containing these specific ions, the most effective extraction solvents for liquid-liquid extraction of DyF3 were proposed. The obtained results indicate that the COSMO-RS approach can be applied to quickly screen the affinity of any rare earth element for a large number of ionic liquid systems, before extensive experimental tests.

Recent numerical simulations suggest that the typical mass of a Population III (Pop III) star become ∼ 40M⊙. We investigate if a Pop III star can raise a gamma ray burst (GRB) by considering the jet propagation in the stellar envelope for a 40M⊙ Pop III model. We find that a relativistic jet launched from the central black hole pierces the stellar envelope, although a Pop III star has a large envelope since the mass loss is not expected for zero metallicity stars. Thus, a Pop III star can be the progenitor of a GRB. We predict that GRBs from 40M⊙ Pop III progenitors have much longer duration ∼ 105 sec, slightly lower luminosity ∼6×1050 erg/sec and much softer spectrum peak energy ∼ 5 keV than the local long GRBs. Therefore, observationally, we regard a Pop III GRB as a long duration X-ray flash. We can observe such Pop III GRBs using the future detector Lobster.

We developed a two-dimensional gratings-based X-ray interferometer that requires only a single exposure for clinical radiography. The interferometer consisted of a checkerboard phase grating for π phase modulation and a latticed amplitude grating. Using a synchrotron radiation source, the phase grating modulates the X-rays and generates a self-image, transformed to a moire fringe by the amplitude grating. To allow use of a conventional X-ray tube, the latticed source grating was installed downstream from the X-ray tube. Differential phase-contrast and scattering images in two orthogonal directions were obtained by Fourier analysis of the single moire fringe image and an absorption image. Results show that characteristic features of soft tissue in two orthogonal directions were clearly shown in the differential phase-contrast images.

We have studied the morphology of the prompt emission of 36 long gamma-ray bursts with redshifts, well determined spectra by the Band model and 64 msec resolution light curves whose peak counts are 10 times larger than background fluctuations. We parametrize the morphology by the absolute deviation from their constant luminosity (ADCL) and find a clear gap in the distribution, which divides LGRBs into two subclasses: small-ADCL events ( 0.17). We find that two subclasses are apparently separated in the spectral peak energy (Ep) - the peak luminosity (Lp) diagram. The Ep - Lp correlations both for small and large ADCL events are much tighter than the one for the whole events.

We formed a GRB cosmology project in Japan, and promote the observational cosmology with Gamma‐ray bursts (GRBs). In this paper, we introduce recent result of our project with the spectral Epeak‐Luminosity relations. We show the Hubble diagram up to the redshift of z = 8.2, and the confidence contour of the dark energy (ΩΛ) and the dark matter (Ωm) beyond z>2 beyond the current range measured by the Type Ia supernovae. After that, we investigate the origin of data dispersion of the Epeak‐brightness relations, and suggest a possible improvement of their accuracy.

We showed the independence of the Epeak‐Lp from Epeak‐Eiso relations, and using Epeak, Lp, and Eiso as independent parameters, we found the fundamental plane of Gamma‐ray bursts (GRBs). The fundamental plane of GRBs is the tightest correlation only using parameters of prompt emission of GRBs. Thus this correlation have the greatest potential for cosmology among other correlations obtained from GRBs. We calibrated by distances measured by supernovae Ia (SNe Ia). Then we estimated the distance toward high redshift GRBs (z>1.8) with about 30% errors. In this talk, we present cosmological constraints from high redshift GRBs which is as strong as from type Ia supernovae (SNe Ia). Then we show the current status of GRB cosmology and compare them with SNe Ia, clusters of galaxy, and CMB cosmologies. The constraint from high redshift GRBs are consistent with others. This might indicate that the time evolution of dark energy density is not large. Finally, we discuss the future prospect of GRB cosmology.

Effects of atomic oxygen (AO) on mechanical properties of polyimide films were investigated using surface topography observations and tensile tests. The ITO‐coated polyimide films, which are expected to have a high durability against AO attacks, were also evaluated. Surfaces of polyimide films irradiated by AO were deeply eroded, exhibiting a rough texture. The roughness developed as the AO fluence increased. Tensile strength and elongation of the polyimide films degraded after AO irradiation tests. In addition, that degradation became marked concomitantly with increased AO fluence. These results indicate that development of surface roughness can degrade mechanical properties of polyimide films. In contrast, surfaces of ITO‐coated polyimide films remained flat and were hardly affected by AO irradiation. Nevertheless, the tensile strength and elongation of ITO‐coated polyimide films were decreased by AO irradiation. Such degradation resulted from undercut cavities formed by AO erosion at the defects sites of ITO coating.

Estimation of cosmic‐ray spectra in the atmosphere has been an essential issue in the evaluation of the aircrew doses. We therefore developed an analytical model that can predict the terrestrial neutron, proton, He nucleus, muon, electron, positron and photon spectra at altitudes below 20 km, based on the Monte Carlo simulation results of cosmic‐ray propagation in the atmosphere performed by the PHITS code. The model was designated PARMA. In order to examine the accuracy of PARMA in terms of the neutron dose estimation, we measured the neutron dose rates at the altitudes between 20 to 10400 m, using our developed dose monitor DARWIN mounted on an aircraft. Excellent agreement was observed between the measured dose rates and the corresponding data calculated by PARMA coupled with the fluence‐to‐dose conversion coefficients, indicating the applicability of the model to be utilized in the route‐dose calculation.

In spite of extensive efforts of the spectral and lightcurve observations, the emission mechanism of γ‐ray bursts (GRBs) is still unclear. Recently the observational techniques of X‐ray and γ‐ray polarizations have been developed rapidly, and several satellites with high sensitivity for such high energy polarizations have been planned. They will provide us the first definitive detections of GRB polarizations and enable us to discuss their statistical properties. We calculate the distribution of GRB polarizations in the synchrotron models (with globally ordered magnetic field and with small‐scale random magnetic field) and Compton drag model. The results show that the distribution of the polarization degrees of ∼100 bursts detected by a realistic polarimeter satellite, such as POET, may distinguish the three models, and provide direct diagnostics of the emission mechanism, the magnetic field configuration, and the geometry of GRB outflows.

We propose an emission mechanism of prompt gamma‐ray bursts (GRBs) that can reproduce the observed nonthermal spectra with high radiative efficiencies, >50%. We show that, if e± pairs outnumber protons, a radiation‐dominated photosphere becomes unstable to the phase separation between pairs and proton clumps. Pairs are continuously shock heated by proton clumps, scattering the thermal photons into the observed broken power‐law shape. If GRBs come from pair photospheres, pair annihilation lines are predicted above continua. A closure relation exists between the pair annihilation line and the pair creation cutoff, which enables GLAST to test the model and also constrain physical quantities such as the Lorentz factor, optical depth and pair‐to‐baryon ratio, only from observables, even without either line or cutoff. We also discuss the Suzaku/WAM results of the time‐resolved Ep‐L (Yonetoku) relation and the Ep‐L relation for short GRBs. We suggest that the short GRBs could arise from the self‐created photosph...

The late‐time optical/radio afterglows of γ‐ray bursts (GRBs) are believed to be synchrotron emission of electrons accelerated in relativistic collisionless shocks propagating in the ambient medium of the sources. However, the fraction f of electrons that are coupled to protons and accelerated remains unclear and a large number of thermal electrons that are not coupled to protons may be left behind. If f

We propose an emission mechanism of prompt gamma‐ray bursts (GRBs) that can reproduce the observed non‐thermal spectra with high radiative efficiencies, >50%. Internal dissipation below a photosphere can create a radiation‐dominated thermal fireball. If e± pairs outnumber protons, radiative acceleration of e± pairs drives the two‐stream instabilities between pairs and protons, leading to the “proton sedimentation” in the accelerating pair frame. Pairs are continuously shock heated by proton clumps, scattering the thermal photons into the broken power‐law shape, with the non‐thermal energy that is comparable to the proton kinetic energy, consistent with observations. Pair photospheres become unstable around the radius of the progenitor star where strong thermalization occurs, if parameters satisfy the observed spectral (Yonetoku) relation. Pair annihilation lines are predicted above continua. A closure relation exists between pair annihilation lines and cutoffs, which could be verified by GLAST.

This paper discusses the development of a solar thermal power system for oxygen production from lunar regolith. In this solar thermal system, solar radiation is collected by the concentrator array which transfers the concentrated solar radiation to the optical waveguide (OW) transmission line made of low loss optical fibers. The OW transmission line directs the solar radiation to the thermal receiver for thermochemical processing of lunar regolith for oxygen production on the lunar surface. We report the results pertaining to: (1) component development status; (2) regolith melting capability; (3) system efficiency; and (4) system weight. Conceptual designs of the solar thermal system for two lunar oxygen production processes are presented.

Excited states in the neutron‐rich nucleus 12Be were experimentally investigated via α‐inelastic scattering. The excited states in the 12Be nucleus were populated by a 12Be(α,α′) reaction at 60 A MeV in the inverse kinematics, and identified by measuring a 6He+6He breakup channel in coincidence. The differential cross section and the angular correlations between the decay particles were obtained for each excitation energy from 10 MeV to 20 MeV, reconstructed by the measured momentum vectors of the two 6He’s.A multipole decomposition analysis based on the distorted‐wave Born approximation was applied for the angular distribution of the inelastic scattering together with the angular correlation between the decay particles with respect to the directions of the incident beam and to the momentum transfer simultaneously. From the decomposed excitation energy spectra for L=0, 2, and 4, new excited states with Jπ=0+ and Jπ=2+ were identified, which were candidates of the band‐head of a largely deformed rotational...

We show that simple kinematic arguments can give limits on variabilities in gamma‐ray burst (GRB) afterglows. These limits are violated by X‐ray flares in the early afterglows recently identified by the Swift satellite. We discuss that a probable solution is that the central engine continues to eject an intermittent outflow for a very long timescale up to 1 day. This long‐lived engine model may also explain the flat decay of early X‐ray afterglows, while the gamma‐ray efficiency of GRBs should be incredibly high (>75–90%) in this model. We suggest new possible models to evade this efficiency crisis and discuss implications for future observations.

Characterisic features of the invariant mass spectroscopy, a suitable tool for the study of drip‐line nuclei, are described. To demonstrate the powefulness of this spectroscopic method, we show here the results of the recent measurement of E1 strength down to Ere1 ∼ 0 MeV for the two‐neutron halo nucleus 11Li. We have successfully observed strong E1 transitions peaking around Ere1=0.3 MeV in the energy spectrum of 11Li breakup on a Pb target, which were missing in the previous measurements. The deduced B(E1) distribution is in excellent agreement with a three‐body model incorporating the two‐neutron correlations.

Continuous energy neutron‐incident neutron‐production double differential cross sections were measured at the Weapons Neutron Research (WNR) facility of the Los Alamos Neutron Science Center. The energy of emitted neutrons was derived from the energy deposition in a detector. The incident‐neutron energy was obtained by the time‐of‐flight method between the spallation target of WNR and the emitted neutron detector. Two types of detectors were adopted to measure the wide energy range of neutrons. The liquid organic scintillators covered up to 100 MeV. The recoil proton detectors that constitute the recoil proton radiator and phoswich type NaI (Tl) scintillators were used for neutrons above several tens of MeV. Iron and lead were used as sample materials. The experimental data were compared with the evaluated nuclear data, the results of GNASH, JQMD, and PHITS codes.

Lunar In‐Situ Resource Utilization (ISRU) processes require thermal energy at various temperatures. Chemical recovery process (pyrolysis, gas‐solid reactions, gas‐liquid or three‐phase reactions and desorption) requires thermal energy at temperatures from 1000 K to 2500 K. Manufacturing processes (hot liquid processing, sinter forming, composite forming, welding, etc.) can be accomplished with thermal energy at temperatures 1200 K ∼ 1800 K. For these materials process applications, solar thermal power can be effectively utilized. Physical Sciences Inc. has been developing a innovative solar power system in which solar radiation is collected by the concentrator which transfers the concentrated solar radiation to the optical waveguide transmission line made of low loss optical fiber. In this paper we will present the recent progress of the solar thermal power source being developed at PSI, and discuss potential applications of the system to Lunar ISRU processes.

The neutron‐production double‐differential cross sections for the neutron‐induced reaction were measured on iron and lead samples up to 100 MeV. Neutrons produced by a 800 MeV proton‐bombarded spallation target were used as incident particles. The energies of incident neutrons were determined by their flight times on the path between the neutron source and the detectors. A fission ionization detector was utilized to determine the incident‐neutron flux. NE213 liquid organic scintillators were employed to detect outgoing neutrons which were emitted from the sample. As a part of this experiment, the response functions of NE213 detectors for neutrons were also measured by using the spallation neutrons. The energy spectra for outgoing neutrons were derived from their deposition‐energy spectra and the measured response functions of the detectors with unfolding technique. The results were presented at incident energies around 100 MeV, and were compared with GNASH calculations.

We propose a method for examining the cosmic reionization history by using near‐infrared (NIR) colors of afterglows of high redshift (5 < z < 25) gamma‐ray bursts (GRBs) that will be detected by the Swift satellite. The broad‐band photometry has a much higher sensitivity than that of the spectroscopy. A prompt NIR photometric follow‐up of the high‐z GRB afterglows will reveal how many times the reionization occurred in the universe.

The width of the Giant Dipole Resonance in Sn was studied by means of inelastic scattering. This study allowed for the first measurement of the GDR width at a temperature of 1 MeV. The width was found to be 4±1 MeV, and is consistent with the ground state measurement. This result is in disagreement with adiabatic thermal shape fluctuation calculations, indicating an overestimation of the influence of thermal shape fluctuations at low temperature.

In the past 10 years, Physical Sciences Inc. (PSI) has been developing the Optical Waveguide (OW) system for solar energy utilization. In this system, solar radiation is collected by the concentrator which transfers the concentrated solar radiation to the OW transmission line. The OW transmission line transports the solar radiation to the location of solar energy utilization. Applications of this system include: material processing, plant lighting and power generation in space. In this paper, a review of our work conducted during the last 10 years pertinent to in‐situ resource utilization in space is presented.

We have developed the phoswich neutron detector consisting of the NE115 and NE213 scintillators which can distinguish neutron and photon events from charged-particle events. The performance of distinguishing photon and neutron events from charged-particle events was investigated in two neutron and charged-particle mixed fields in NIRS, which gave satisfactory results. In these radiation environments, photon and neutron energy spectra were obtained by the unfolding technique and the evaluated response functions. The proton energy spectra were simultaneously obtained by using the relation between the proton light yield and the incident proton energy.

We describe the early optical observations of the GRB 990806 error box by the Japan/New Zealand Microlensing Observations in Astrophysics (MOA) collaboration. We discuss the telescope system, its operation and suitability for rapid observations for gamma-ray burst optical afterglows.

We consider a close binary system with separation ≂0.2 R⊙ which consists of a (C+O) star of mass ≂4 M⊙ and a neutron star as a progenitor of soft gamma‐ray repeater (SGR) and a high velocity pulsar. After the event of the supernova explosion, both new and old neutron stars have high relative velocity of ≂1000 km s−1 to the center of mass of the ejecta. SGR activities can be induced by the episodic accretion of the supernova ejecta onto the old neutron star or the strange high rotating pulsar of the new neutron star. Future observations with fine positional resolution can clarify the position ambiguity between the gamma ray and X‐ray sources.