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In order to measure the amounts of fluorine (F) atoms in the off-gas drain from polymer electrolyte fuel cells (PEFCs) using proton Rutherford Backscattering Spectroscopy (p-RBS), we used an impinger where potassium hydroxide (KOH) solution (0.1 mol/L) was filled and prepared the targets for p-RBS using these samples. In the measured RBS spectrum, however, the peak of fluorine (F) atoms of the decomposition products could not be clearly observed due to the interference by the low energy tail of the potassium (K) atom's peak. We confirmed using SEM, EPMA and XRD that the origin of the low energy tail of the potassium (K) atom's peak was the absorption of carbon dioxide (CO2) in the air by potassium hydroxide (KOH) solution during drying. We also found that the target prepared by vacuum drying was more suitable for measuring the spectra of light elements in p-RBS than that by natural drying. [ABSTRACT FROM AUTHOR]

Heavy ion fusion sciences and heavy-ion-driven high energy density physics experiments require evaluations of the stopping power with dependences on target density and temperature. We are interested in effects of dissociation of the target molecules which have not been experimentally investigated. The electro-magnetically driven shock wave has been proposed to produce well-defined dissociated target which is required to measure the stopping power with the dissociated effect. We have velocity measurements in the electro-magnetic shock tube to understand the target physical condition. The velocity measurement by laser refraction gives reliable experimental results, which shows that the shock velocity is not enough to dissociate hydrogen completely. The experiments indicate that input energy does not convert to the piston plasma in electro-magnetic shock tube efficiently. [ABSTRACT FROM AUTHOR]

We designed and constructed a proton-induced quasimonochromatic micro-XRF system for wet biological samples. A horizontal beam of MeV protons delivered by a 1.6 MV tandem accelerator was bent downward by 45° using a dipole magnet. A copper (Cu) foil target was placed perpendicular to the incident proton beam. The thickness of the foil was 30 μm, which is slightly larger the proton range. This Cu foil was used also as a vacuum window for the X-rays. The proton-induced quasimonochromatic X-rays (QMXRs) emitted to the atmosphere through the foil were focused by a polycapillary X-ray half lens. The monochromaticity and intensity of the QMXR microbeam as a function of the incident proton energy were investigated. The QMXR microbeam impinged on the horizontal sample surface with an incident angle of 45°, and emitted fluorescent X-rays from the sample were collected by a Si-PIN X-ray detector positioned at 90° with respect to the incident microbeam. The size of the Xray beam was 250 ×m × 350 ×m. To demonstrate the capability of the micro-XRF setup for in-vivo measurement of trace elements in biological samples, we measured cobalt (Co) accumulated in leaves of duckweed floating on a Co solution surface. By using standard samples which simulated the duckweed leaf, the Co concentration in the leaf in the order of 100 ppm could be quantitatively determined. [ABSTRACT FROM AUTHOR]

The equation of state (EOS) of fissile materials under extreme thermodynamic conditions is of great importance to assess the safety of nuclear energy systems related to extremely severe nuclear accidents and intentional nuclear terrorism. In this study, for a simple, safe, and precise measurement of these properties, we propose an experimental setup in which a small amount of fissile material sample is homogeneously heated by an intense short-pulsed heavy-ion beam, and subsequent hydrodynamic motion is examined. As an example, we investigated the response of a slab of uranium foam (density = 5% of solid density) to a pulsed 23Na+ beam with a duration of 2 ns and peak irradiation flux of 5 GW/mm2. The target thickness and incident beam energy were adjusted to 80 μm and 1.5 MeV/u, respectively, for the beam-energy deposition to occur almost at the top of the Bragg peak and inhomogeneity in the stopping power to be ±2.5%. The hydrodynamic motion of the target during and after irradiation was calculated with a one-dimensional radiation hydrodynamic code. To calculate beam-energy deposition in the target, we used density- and temperature-dependent projectile stopping data obtained with a finite-temperature Thomas-Fermi target atomic model and degeneracy-dependent dielectric response functions. The numerical results showed that the target was almost isometrically heated up to ≈105 K well before the rarefaction wave reached the center of the target, and fairly homogeneous temperature and density distributions were obtained at the end of the pulse duration. We discuss the feasibility of experimental EOS studies, such as the evaluation of pressures at off-Hugoniot conditions as a function of internal energy from the measurements of the target expansion velocity. [ABSTRACT FROM AUTHOR]

The equation of state (EOS) of fissile materials under extreme thermodynamic conditions is of great importance to assess the safety of nuclear energy systems related to extremely severe nuclear accidents and intentional nuclear terrorism. In this study, for a simple, safe, and precise measurement of these properties, we propose an experimental setup in which a small amount of fissile material sample is homogeneously heated by an intense short-pulsed heavy-ion beam, and subsequent hydrodynamic motion is examined. As an example, we investigated the response of a slab of uranium foam (density = 5% of solid density) to a pulsed 23 Na + beam with a duration of 2 ns and peak irradiation flux of 5 GW/mm 2 . The target thickness and incident beam energy were adjusted to 80 μm and 1.5 MeV/u, respectively, for the beam-energy deposition to occur almost at the top of the Bragg peak and inhomogeneity in the stopping power to be ±2.5%. The hydrodynamic motion of the target during and after irradiation was calculated with a one-dimensional radiation hydrodynamic code. To calculate beam-energy deposition in the target, we used density- and temperature-dependent projectile stopping data obtained with a finite-temperature Thomas-Fermi target atomic model and degeneracy-dependent dielectric response functions. The numerical results showed that the target was almost isometrically heated up to ≈ 10 5 K well before the rarefaction wave reached the center of the target, and fairly homogeneous temperature and density distributions were obtained at the end of the pulse duration. We discuss the feasibility of experimental EOS studies, such as the evaluation of pressures at off-Hugoniot conditions as a function of internal energy from the measurements of the target expansion velocity. [ABSTRACT FROM AUTHOR]

Heavy ion fusion sciences and heavy-ion-driven high energy density physics experiments require evaluations of the stopping power with dependences on target density and temperature. We are interested in effects of dissociation of the target molecules which have not been experimentally investigated. The electro-magnetically driven shock wave has been proposed to produce well-defined dissociated target which is required to measure the stopping power with the dissociated effect. We have velocity measurements in the electro-magnetic shock tube to understand the target physical condition. The velocity measurement by laser refraction gives reliable experimental results, which shows that the shock velocity is not enough to dissociate hydrogen completely. The experiments indicate that input energy does not convert to the piston plasma in electro-magnetic shock tube efficiently. [ABSTRACT FROM AUTHOR]

We designed and constructed a proton-induced quasimonochromatic micro-XRF system for wet biological samples. A horizontal beam of MeV protons delivered by a 1.6 MV tandem accelerator was bent downward by 45° using a dipole magnet. A copper (Cu) foil target was placed perpendicular to the incident proton beam. The thickness of the foil was 30 μm, which is slightly larger the proton range. This Cu foil was used also as a vacuum window for the X-rays. The proton-induced quasimonochromatic X-rays (QMXRs) emitted to the atmosphere through the foil were focused by a polycapillary X-ray half lens. The monochromaticity and intensity of the QMXR microbeam as a function of the incident proton energy were investigated. The QMXR microbeam impinged on the horizontal sample surface with an incident angle of 45°, and emitted fluorescent X-rays from the sample were collected by a Si-PIN X-ray detector positioned at 90° with respect to the incident microbeam. The size of the X-ray beam was 250 μm × 350 μm. To demonstrate the capability of the micro-XRF setup for in-vivo measurement of trace elements in biological samples, we measured cobalt (Co) accumulated in leaves of duckweed floating on a Co solution surface. By using standard samples which simulated the duckweed leaf, the Co concentration in the leaf in the order of 100 ppm could be quantitatively determined. [ABSTRACT FROM AUTHOR]

In order to measure the amounts of fluorine (F) atoms in the off-gas drain from polymer electrolyte fuel cells (PEFCs) using proton Rutherford Backscattering Spectroscopy (p-RBS), we used an impinger where potassium hydroxide (KOH) solution (0.1 mol/L) was filled and prepared the targets for p-RBS using these samples. In the measured RBS spectrum, however, the peak of fluorine (F) atoms of the decomposition products could not be clearly observed due to the interference by the low energy tail of the potassium (K) atom's peak. We confirmed using SEM, EPMA and XRD that the origin of the low energy tail of the potassium (K) atom's peak was the absorption of carbon dioxide (CO 2 ) in the air by potassium hydroxide (KOH) solution during drying. We also found that the target prepared by vacuum drying was more suitable for measuring the spectra of light elements in p-RBS than that by natural drying. [ABSTRACT FROM AUTHOR]