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An instrumented depth-sensitive microindentation technique was applied to evaluate mechanical properties of thin corroded layers of some ceramics which were immersed in boiling, highly condensed sulfuric acid up to 1000 h. Indentation load–depth curves were analyzed using a finite element model to systematically investigate the effect on the ceramics of film or corroded layer. The mechanical properties of both the oxide films and the corroded layers were evaluated through the combination between analytical and experimental results on the indentation curves. It was found that the relationship between thickness T of oxide films or corroded layers and the depth d determined by the slope change on the indentation load/depth–depth curve is described as T ≈10 d . The bending strengths of Si 3 N 4 and Al 2 O 3 after immersion were evaluated using the d associated with the corroded layer thickness and the K IC obtained before immersion. It was confirmed that the strength degradation of Si 3 N 4 and Al 2 O 3 due to the boiling sulfuric acid corrosion can be estimated using K IC and d -value.

A permanent magnet rotating type induction pump (PM pump) was developed to provide mercury to a liquid mercury target system in Japan Spallation Neutron Source (JSNS). Mechanical pumps, such as a gear pump and a centrifugal pump, have risk of leakage of mercury from the seal parts. Induction pumps can avoid mercury leakage because they have no seal parts. The PM pump could be compact compared with a conventional induction pump; however, power loss must be reduced to avoid overheating of the system. Then optimizations for the thickness of mercury duct wall and width of the duct were carried out to reduce heat loss due to the eddy current in the duct generated by the induction, and to reduce flow-induced loss. As for the flow-induced loss, backflow would occur at the outside of the duct because of the difference in the Lorentz force between inside and outside of the duct. Consequently, the developed PM pump could have sufficient performance for the target system in JSNS and operate with low vibration.

A new approach to study the high momentum component of deuteron D-state wave function by measuring the polarization correlation coefficient, C// [ =1+ 1 4 A yy +A xx + 3 4 C y,y +C x,x ], for the 3 He → ( d → ,p )4He reaction is proposed. The first measurement of C// has been carried out at Ed=270 MeV by using a newly constructed spin-exchange-type polarized 3He target. The obtained value is 0.223±0.044(statistical)±0.037(systematic). DWBA calculations are unable to reproduce the present results. Each component of C// is compared with data for the d+p backward scattering and the deuteron inclusive breakup. A similarity in polarization observables is found among these reactions.

The high-spin isomer in 151Er ( Ex = 10.3 MeV, T1/2 = 420 ns) has been studied by the 116Sn ( 40Ar , 5n) 151Er reaction at 197MeV. From the \( \gamma \gamma\) coincidence relations, a new transition with an energy of 1514keV was found. This finding requires the revision of the spin-parity assignment from previous 67/2- to 61/2+ or 65/2- . The 61/2+ assignment is the one which was predicted by the deformed independent particle model as an isomer with a large oblate deformation ( \( \beta\) = - 0.17) of the \(\ensuremath[\nu(f_{7/2}h_{9/2} i_{13/2}) \pi(h^4_{11/2})]_{61/2^+}\) configuration. The isomerism may be attributed to the sudden shape change of the isomer from the nearly spherical shape of the lower-spin yrast states to the oblate shape.

High-resolution laser spectroscopy in Sm I has been performed by using a tunable diode laser together with a highly collimated atomic beam. Hyperfine structures and isotope shifts of Sm isotopes have been measured for four transitions in the wavelength region of 636–687 nm; the largest isotope shift has been observed. Hyperfine constants A and B of 147 Sm and 149 Sm have been determined for six levels. By using the purest s 2 - s p transition with the largest isotope shift, nuclear parameters λ, changes in mean-square nuclear charge radii δ , and nuclear deformation parameters δ have been derived and discussed.

Microindentation tests on ceramics (Si-SiC, SiC, Al2O3 and Si3N4) immersed in boiling 95 wt% sulfuric acid for 100 or 1000 hours were performed to evaluate the mechanical properties of their corroded layers. The thickness (T) of corroded layer on ceramics was evaluated in terms of characteristic depth (d) which was determined from the point of inflection on the Depth-Load/Depth curve by the microindentation test. The relationship between T and d was found to be given as T ≒ 10d. Finite element analyses were performed to validate the relationship and to clarify the effects of mechanical properties of corroded layer and the indenter tip radius on the relationship as well. The mechanical properties [Young's modulus (Ef) and yield stress (σyf)] of corroded layers of Al2O3 and Si3N4 were identified by fitting the predicted Depth-Load/Depth curve to the experimental data.

This paper deals with the characterization of mechanical properties of impacted morsellized cancellous allograft (IMCA) produced by dynamic compaction of allograft femoral heads ground by commercially available bone mills, i.e. rotating rasp and reciprocating type bone mills. Various ranges and profiles of particle size in the graft aggregates were obtained using these bone mills, and the effect of number of compaction as well as the distribution of particle sizes on the mechanical properties of IMCA under quasistatic compression and shear loading conditions was discussed. The morsellized cancellous allograft prepared by the reciprocating type bone mill showed a broad distribution of particle sizes, and gave IMCA superior mechanical properties to the graft with a more uniform size distribution, or prepared by the rotating rasp type bone mills. The increase of number of compaction also improved the mechanical properties of IMCA in compression.

A new approach to study the high momentum component of deuteron D-state wave function by measuring the polarization correlation coefficient, C∥, for the 3 H e( d , p)4He reaction has been proposed. In order to carry out the experiment, a spin exchange type polarized 3He target was constructed at RIKEN Accelerator Research Facility (RARF). The density of the target was 2.2 × 1020 cm−3 (8.2 amagats), and the polarization was about 10%. The spin flip system worked well. The experiment has been carried out in November, 1996, at RARF, using a polarized deuteron beam of 270 MeV.

We have made high-resolution laser spectroscopy of the hyperfine structure of a radioactive isotope $^{179}\mathrm{Ta}$ (${T}_{\frac{1}{2}}=1.8$ y) using an argon-ion sputtering atomic-beam source. From hyperfine constants $A$ and $B$ of the atomic ground state ($^{4}F_{\frac{3}{2}}5{d}^{3}6{s}^{2}$), the magnetic dipole and electric quadrupole moments of the nuclear ground state of $^{179}\mathrm{Ta}(I=\frac{7}{2})$ have been determined for the first time: ${\ensuremath{\mu}}_{I}^{179}=2.289(9){\ensuremath{\mu}}_{N}$ and ${Q}_{s}^{179}=3.37(4)$ b. It is pointed out that magnetic moments of the ground and isomeric states in the region $N=102\ensuremath{-}112$ can be systematically described in terms of the presently available theory while the revealed systematic behavior of electric quadrupole moments is hardly reproduced by the theory.

Vector analyzing powers for proton elastic scattering from 8He at 71 MeV/nucleon have been measured using a solid polarized proton target operated in a low magnetic field of 0.1 T. The spin-orbit potential obtained from a phenomenological optical model analysis is found to be significantly shallower and more diffuse than the global systematics of stable nuclei, which is an indication that the spin-orbit potential is modified for scattering involving neutron-rich nuclei. A close similarity between the matter radius and the root-mean-square radius of the spin-orbit potential is also identified., Comment: 6 pages, 4 figures, accepted for publication in Physical Review C Rapid Communication

The atomic-beam laser-rf double-resonance technique has been used to make precision measurements of the hyperfine structure (hfs) splittings in the 5${\mathit{d}}^{2}$6${\mathit{s}}^{2}$ $^{3}$${\mathit{F}}_{\mathit{J}}$ (J=2\char21{}4) states in $^{177,179}\mathrm{Hf}$ i. By making corrections to the second-order hfs effects, magnetic dipole (A), electric quadrupole (B), and magnetic octupole (C) hfs constants are obtained for the $^{3}$${\mathit{F}}_{\mathit{J}}$ states in $^{177,179}\mathrm{Hf}$: The constant C has a strong J dependence as well as does A and B; the isotopic ratio of the constant A between $^{177}\mathrm{Hf}$ and $^{179}\mathrm{Hf}$ has a significant J dependence, indicating J-dependent hyperfine anomalies, while that of the constant C is independent of J within experimental uncertainties, which is taken to be the ratio of the nuclear-ground-state magnetic octupole moments \ensuremath{\Omega}, i.e., \ensuremath{\Omega}${(}^{177}$Hf)/\ensuremath{\Omega}${(}^{179}$Hf)=-0.41(9). It is also pointed out that there is a clear indication of nuclear-spin dependence of the isotopic ratios of C. The single-electron hfs parameters of the 5d electron for the 5${\mathit{d}}^{2}$6${\mathit{s}}^{2}$ configuration in Hf i are obtained, and the Sternheimer shielding factor ${\mathit{R}}_{5\mathit{d}}$=-0.397(8) is derived.

A new laser ion source configuration based on resonant photoionization in a gas cell has been developed at RIBF RIKEN. This system is intended for the future PArasitic RI-beam production by Laser Ion-Source (PALIS) project which will be installed at RIKEN’s fragment separator, BigRIPS. A novel implementation of differential pumping, in combination with a sextupole ion beam guide (SPIG), has been developed. A few small scroll pumps create a pressure difference from 1000 hPa–10−3 Pa within a geometry drastically miniaturized compared to conventional systems. This system can utilize a large exit hole for fast evacuation times, minimizing the decay loss for short-lived nuclei during extraction from a buffer gas cell, while sufficient gas cell pressure is maintained for stopping high energy RI-beams. In spite of the motion in a dense pressure gradient, the photo-ionized ions inside the gas cell are ejected with an assisting force gas jet and successfully transported to a high-vacuum region via SPIG followed by a quadrupole mass separator. Observed behaviors agree with the results of gas flow and Monte Carlo simulations.

Hyperfine structure of the 5${\mathit{d}}^{3}$6${\mathit{s}}^{2}$ $^{4}$${\mathit{F}}_{3/2}$ ground state in $^{180\mathit{m}}\mathrm{Ta}$ i was precisely measured by means of atomic-beam laser-rf double-resonance spectroscopy. Hyperfine-interaction constants A and B for the ground state $^{4}$${\mathit{F}}_{3/2}$ were determined with accuracies of 3 and 10 ppm, respectively. The nuclear electric quadrupole moment was derived, as well as a precise value of the magnetic moment for $^{180\mathit{m}}\mathrm{Ta}$ (${\mathit{I}}^{\mathrm{\ensuremath{\pi}}}$=${9}^{\mathrm{\ensuremath{-}}}$): the magnetic dipole moment is ${\mathrm{\ensuremath{\mu}}}_{\mathit{I}}^{180\mathit{m}}$=+4.825(11)${\mathrm{\ensuremath{\mu}}}_{\mathit{N}}$ and the spectroscopic quadrupole moment is ${\mathit{Q}}_{\mathit{s}}^{180\mathit{m}}$=+4.946(20)b.

Ar-ion sputtering is successfully used to produce intense atomic beams of refractory elements. The population in the ground and low metastable states of Ta 1 is investigated for the sputtered atoms. Isotope shifts and hyperfine structures of seven transitions have been measured for the stable isotopes of Hf, Ta and W. The hyperfine coupling constantsA andB are determined for eight atomic levels of177,179Hf,181Ta and183W.

The vector analyzing power has been measured for the elastic scattering of neutron-rich 6He from polarized protons at 71 MeV/nucleon making use of a newly constructed solid polarized proton target operated in a low magnetic field and at high temperature. Two approaches based on local one-body potentials were applied to investigate the spin-orbit interaction between a proton and a 6He nucleus. An optical model analysis revealed that the spin-orbit potential for 6He is characterized by a shallow and long-ranged shape compared with the global systematics of stable nuclei. A semimicroscopic analysis with a alpha+n+n cluster folding model suggests that the interaction between a proton and the alpha core is essentially important in describing the p+6He elastic scattering. The data are also compared with fully microscopic analyses using non-local optical potentials based on nucleon-nucleon g-matrices., 20 pages, 20 figures, accepted by Physical Review C

A high‐resolution laser spectroscopy system for refractory elements with an argon‐ion‐ sputtering atomic beam source was constructed, and it has been demonstrated that the sputtering method is extremely useful as an atomic beam source for high‐resolution laser spectroscopy to measure hyperfine structures and isotope shifts for refractory elements, such as Hf, Ta, and W. This source produced intense neutral atomic beams of more than 1010 atoms/s for these elements, and the yield was easily controlled by adjusting the argon‐ion current and the acceleration voltage. Resonance linewidths were 32, 66, and 48 MHz for Hf, Ta, and W, respectively, which are sufficient to measure the hyperfine structures and the isotope shifts in optical transitions. With this system, the signal‐to‐noise ratio reached more than 106. In addition, the temperature of the sputtered atoms found was rather low compared to the kinetic energy given to the atoms.

Vector analyzing power for the proton-{sup 6}He elastic scattering at 71 MeV/nucleon has been measured for the first time, with a newly developed polarized proton solid target, which works at a low magnetic field of 0.09 T. The results are found to be incompatible with a t-matrix folding model prediction. Comparisons of the data with g-matrix folding analyses clearly show that the vector analyzing power is sensitive to the nuclear structure model used in the reaction analysis. The {alpha}-core distribution in {sup 6}He is suggested to be a possible key for understanding the nuclear structure sensitivity.

The half-life and the magnetic moment were measured for the first excited state in $^{132}\mathrm{I}$, of which the inconsistent results on the half-life have been reported by several other groups. This time, measurements were performed on $^{132}\mathrm{I}$ obtained as a decay product of a $^{132}\mathrm{Te}$ radioactive beam from the ion guide at Tohoku University. The half-life of this level was determined to be ${T}_{1/2}=1.120\ifmmode\pm\else\textpm\fi{}0.015$ ns using a conventional coincidence technique with a pair of BaF${}_{2}$ detectors. The time-differential perturbed angular correlation technique was successfully applied to the first excited state in $^{132}\mathrm{I}$ implanted into nickel foils. The magnetic moment of this state was determined to be $\ensuremath{\mu}=+(2.06\ifmmode\pm\else\textpm\fi{}0.18){\ensuremath{\mu}}_{N}$. The present results are consistent with values reported by Gorodetzky et al. and Singh et al.

MW-class spallation neutron sources are being developed in the world. High intensive and energy protons are injected into heavy liquid metals; mercury, lead or lead bismuth, to induce the spallation reaction that produces neutrons. At the moment the proton beams are injected, thermal shock is occurred in the liquid metal and cases pressure waves that excite rapidly the solid container wall. As a result, cavitation bubbles are formed along the interface between the liquid metal and the solid wall. The micro-jet collides against the solid wall at the bubble collapse and damages on the surface. The stainless steel with the multi-layered surface consisting of stainless steel and gold films with 100 mm in thickness was newly developed to mitigate the damage by liquid-metal microjet impact. The damage and dynamic response were compared between homogeneous and multilayered surfaces experimentally and numerically. The stress waves propagation was evaluated along the interface between layers. The dynamic deformation of multi-layered surface is dependent on the thickness of layers and the stress propagation might be dispersed by the interface of multi-layered surface. It can be said that the multi-layered surface improvement is effective to reduce the localized impact deformation.

Roles of spin-dependent interactions in unstable nuclei have been investigated via the direct reaction of radioactive ions with a solid spin-polarized proton target. The target has a unique advantage of a high polarization of 20–30% under low magnetic field of 0.1 T and at a high temperature of 100 K, which allow us to detect recoil protons with good angular resolution. Present status of on-going experimental studies at intermediate energies, such as proton elastic scattering and ([Formula: see text]) knockout reaction, and new physics opportunities expected with low-energy RI beams are overviewed.

We measured the differential cross section and the spin correlation parameter C{sub yy} of the p-vector+{sup 3}He-vector elastic backward scattering at 200, 300, and 400 MeV at {theta}=180 deg. in the center-of-mass frame to study the mechanism of the reaction and to examine the validity of the {sup 3}He wave functions based on two different realistic two-body forces. This is the first measurement of the spin correlation parameter C{sub yy} of the p-vector+{sup 3}He-vector EBS at intermediate energies. The experimental results were compared with few-body calculations, including three reaction mechanisms: two-nucleon-pair exchange, pion exchange, and direct pp scattering. It was found that few-body calculations describe the differential cross-section data reasonably well. The spin correlation parameter C{sub yy} shows clear evidence for the two-nucleon-pair exchange processes in the reaction, demonstrating that the spin observables are helpful for deeper understanding of the reaction mechanism.

Vector analyzing power was measured for the proton elastic scattering on 6He at 71 MeV/u. We applied a solid polarized proton target, which was operated in a low magnetic field of 88 mT and at high temperature of 100 K, to a radioactive‐isotope beam experiment. Low energy recoil protons were successfully detected due to the modest operation conditions of the target. Selection of p+6He elastic scattering events was clearly carried out with detected protons. Absolute values of the analyzing power were determined for the first time.

Application of polarization proton scatterings to radioactive nuclear beam experiments is proposed. A polarized proton solid target which works at a high temperature of several tens of Kelvin and in a low magnetic field of ∼ 0.1 T is needed for the purpose. The proton polarization can be produced by transferring an electron population difference in photo‐excited triplet states of an aromatic molecule by means of a cross polarization technique. By using this method, we have constructed a polarized proton solid target specifically designed for use in radioactive nuclear beam experiments. The target has been used in the measurement of vector analyzing power for the p − 6He elastic scattering at 71 MeV/A.

The hyperfine structure of the radioactive isotope {sup 175}Hf has been measured by means of laser spectroscopy. The magnetic dipole and electric quadrupole moments of {sup 175}Hf are determined: {ital {mu}{sub I}={minus}0.62(3){mu}{sub N}} and {ital Q{sub s}}=+2.6(2) b; the sign of {mu}{ital {sub I}} has been shown to be negative. It has been shown that {sup 175}Hf has almost the same nuclear charge radius as {sup 174}Hf. {copyright} {ital 1997} {ital The American Physical Society}

Authors have ever developed the spherical thermograph system and clarified the realities of the thermal environment of the urban built space. In this paper, we propose the method that enables us to obtain surface temperature with this system from the thermal image including reflections and shows the result of applying the method to the actual space.

Thermal barrier coatings (TBCs) of plasma sprayed yttria stabilised zirconia (YSZ) are increasingly utilised for heat exposed components of advanced gas turbines1,2. An important reason for the application of zirconia coatings is the low thermal conductivity of this ceramic material which is further diminished in a TBC by the high concentration of spraying induced microstructural defects, e.g. crack-shaped defects between and within the spraying splats. Thus with TBCs on gas cooled turbine components stiff temperature gradients can be realised as an important prerequisite for an increased thermal efficiency of the energy conversion process.

A proton polarizing system have been designed and constructed in order to develop a polarized proton solid target applicable to an experiment with a radioactive isotope beam. Protons are polarized by a method called microwave-induced optical nuclear polarization. Our goal is to attain a polarization of more than 30% in the target sample with a diameter of 20 mm and a length of 5 mm.

A non-linear ultrasonic method was applied for evaluating the cavitation damage, so-called pitting damage, in the mercury target of the Japan Spallation Neutron Source (JSNS). First, pitting damage was imposed on disk specimens in mercury using the magnetic impact testing machine (MIMTM) with various numbers of impacts (0, 104, 105, 106, 107 and 108). The pitting damage was imaged with resonance and non-resonance modes, respectively, by employing a non-linear acoustic imaging system. Waveform attenuation and generation of higher harmonics, which have high relevance to the degree of pitting damage, were useful for the imaging. Combined with the attenuation phenomenon, the resonance mode imaged the micropits with higher harmonics more effectively with higher harmonics, compared with the non-resonance mode.

Isotope shifts and hyperfine structures of four transitions in W i have been measured as well as isotope shifts in Lu i by means of atomic-beam laser spectroscopy. Magnetic-dipole hyperfine constants A of $^{183}\mathrm{W}$ are determined for the atomic states $^{7}$${\mathit{D}}_{1}$, $^{7}$${\mathit{F}}_{1}$, and $^{7}$${\mathit{F}}_{3}$ of the 5${\mathit{d}}^{4}$6s6p configuration. The nuclear parameters \ensuremath{\lambda} and \ensuremath{\delta}〈${\mathit{r}}^{2}$〉 are derived for W stable isotopes. J dependences of the isotope shifts are observed for the $^{2}$D term of the 5d6${\mathit{s}}^{2}$ configuration in Lu i and the $^{5}$D term of the 5${\mathit{d}}^{4}$6${\mathit{s}}^{2}$ configuration in W i. Parameters ${\mathit{z}}_{5\mathit{d}}$ of the crossed-second-order effects are derived for the Lu i 5d6${\mathit{s}}^{2}$ and W i 5${\mathit{d}}^{4}$6${\mathit{s}}^{2}$ configurations, and ${\mathit{z}}_{5\mathit{d}}$/\ensuremath{\lambda} is found to be 411(26) MHz/${\mathrm{fm}}^{2}$ for W. A systematic behavior of the normalized parameter ${\mathit{z}}_{\mathit{n}\mathit{l}}$/\ensuremath{\lambda}${\mathrm{\ensuremath{\zeta}}}_{\mathit{n}\mathit{l}}$ is discussed.

The vector analyzing power has been measured for the elastic scattering of neutron-rich 6He and 8He from polarized protons at 71 MeV/A making use of a newly constructed solid polarized proton target operated in a low magnetic field of 0.1 T and at a relatively high temperature of 100 K. An optical model analysis revealed that the spin-orbit potentials for 6He and 8He are characterized by shallow and long-ranged shape compared with the global systematics of stable nuclei. Such a characteristics reflect a diffused density distribution of the neutron-rich isotopes.

Combined with a collimated atomic beam source, diode laser without external cavity has been used as a spectroscopic light source to study atomic hyperfine structures and isotope shifts of Ba i. Spectroscopic measurements of the 6s 2 1 S 0 – 6s6p 3 P 1 transition of Ba i have been carried out. All hyperfine peaks of 135,137Ba have been clearly seen and resolution of 50 MHz has been attained. Hyperfine constants A and B of the 3 P 1 state of 135,137Ba have been determined. Isotope shifts of stable Ba isotopes have also been measured. From the measured isotope shifts, the 6s electron density at the nucleus has been deduced to be 76.4(53) a.u. and discussed in terms of the Hartree-Fock approximation.

Structural components of advanced gas turbines utilize ceramic thermal barrier coatings (TBCs) with low thermal conductivity. The thermal barrier function is further increased by the large number of processing defects typically originating from the deposition process of the ceramic coating. In particular, plasma sprayed TBCs are known to reduce the thermal conductivity by inter-lamellar defects (cracks). However, these defects also have to be considered as sources of delamination which ultimately yields failure of the TBC. To study the initial stages of delamination, e.g. the extension of the inter-lamellar cracks, a novel mechanical testing method was applied. With a geometry similar to the double cantilever beam compressive loading was transferred into tensile stress normal to the interfaces of the thermal barrier composite. Thus a mode I opening is given to the inter-lamellar cracks in the TBC and to the flaws along the interface with the bond coat (BC). As sprayed and annealed TBCs were tested. Fracture relevant microstructural changes in the TBC and at the interface between BC and TBC were monitored with the resolution of optical and scanning electron microscopy. The growth of favorably oriented cracks was measured as a function of applied load. Also the local strain situation was determined via the analysis of the image contrast. The obtained strain and crack growth results are analyzed and discussed with respect to failure mechanism, critical strain and strength.