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This paper proposes a new design of an impact mode piezoelectric power generator that is able to operate in a wide frequency bandwidth by using a round piezoelectric ceramic as the energy converter. The evaluation results show that the output of the power generator can be optimized by implementing a so-called indirect impact configuration. To realize this type of configuration, a shim plate is placed between the piezoelectric ceramic and the hitting structure. At a certain base excitation frequency, the output efficiency of this configuration increases to about 4.3 times that of the direct impact configuration. Furthermore, it is demonstrated that the designated power generator is able to generate electric energy up to approximately 1.57 mJ within 120 s from the vibration of a moving vehicle.

This paper presents an analytical and experimental study on the effect of mechanical impact parameters on impact-mode piezoelectric ceramic power generators. The parameters are the velocity and mass. The method of analysis is based on a weight drop experiment. The results show that the peak of the instantaneous output voltage is proportional to the impact velocity, and for the output power, it is in a straight line relationship with the same parameter. For the same velocity of impact, the advantage of using heavy objects is clear because its momentum and the impact force are higher. However, an adjustment in the velocity of impact is found to be more effective for higher instantaneous output power than the mass. This finding is supported by the output power that is generated by a 4-g steel ball with a momentum of 4.34 g/s, which is almost 300% higher than that of an 8-g steel ball for the same momentum. The frequency responses of a vibration-based impact-mode piezoelectric ceramic power generator also support the same conclusion.

This study reports the effects of the parameters of a vibration-based impact mode piezoelectric power generator. First, an evaluation of the effects of the impact parameters, the mass, and the impact velocity is presented. It is found that the output voltage of the piezoelectric device in impact mode is directly proportional to the velocity, whereas the output power is equal to a quadratic function of the same variable. For the same impact momentum, the effect of the velocity in generating a higher peak output is dominant compared with the mass. Second, the vibration-based impact mode piezoelectric power generator is discussed. The experimental results show that a wider operating frequency bandwidth of the output power can be achieved with the preloading configuration. However, regarding magnitude, due to the high velocity of impact, the configuration with a gap between the tip and the piezoelectric device produces a higher output.

We demonstrate a novel structure of a flapping-based piezoelectric power generator for bicycle pedals. The flapping structure and the circuit configuration have been proposed, and the effectiveness of the proposed structure is experimentally evaluated by the bicycle trainer. In the proposed structure, the number of lights can be freely selected by changing the number of flapping poles, and the light colors of the front and rear LEDs can be automatically switched by using the pedaling force. In addition, the flapping-based piezoelectric power generator can be easily applied to the commonly-used bicycle pedals.

Vibration energy harvesting is widely recognized as the useful technology for saving energy. The piezoelectric energy harvesting device is one of energy harvester and is used to operate certain types of MEMS devices. Various factors influence the energy regeneration efficiency of the lead zirconate titanate piezoelectric (PZT) devices in converting the mechanical vibration energy to the electrical energy. This paper presents the analytical and experimental evaluation of energy regeneration efficiency of PZT devices through impedance matching method and drop-weight experiments to different shape of PZT devices. The results show that the impedance matching method has increased the energy regeneration efficiency while triangular shape of PZT device produce a stable efficiency in the energy regeneration. Besides that, it becomes clear that the power, energy and subsequently efficiency of the triangular plate are higher than those of the rectangular plate under the condition of the matching impedance and the same PZT area.

A large-acceptance multiparticle spectrometer SAMURAI has been constructed at the RIKEN RI Beam Factory (RIBF) for RI beam experiments. It was designed primarily for kinematically complete experiments such as the invariant-mass spectroscopy of particle-unbound states in exotic nuclei, by detecting heavy fragments and projectile-rapidity nucleons in coincidence. The system consists of a superconducting dipole magnet, beam line detectors, heavy fragment detectors, neutron detectors, and proton detectors. The SAMURAI spectrometer was commissioned in March 2012, and a rigidity resolution of about 1/1500 was obtained for RI beams up to 2.4 GeV/c.

A new injector linac “RILAC2”, has recently been constructed at the RIKEN RI Beam Factory. The main part of the RILAC2 is a drift tube linac that consists of three newly designed cavities. These cavities operate in continuous wave (CW) mode at a fixed frequency of 36.5 MHz. Their structure is based on a quarter-wavelength resonator because this is the smallest resonator available in this frequency range among the available structures. We adopted the direct coupling method in the construction of these cavities. A power amplifier was directly coupled to the cavity without a long transmission line to reduce the installation area and simultaneously reduce construction cost. A detailed cavity and coupler design was carried out via simulation. Our work also describes the design process using three-dimensional electromagnetic simulation software. Construction and operation tests are also shown.

This paper proposes a new method of output optimization for a wideband vibration-based impact mode piezoelectric power generator. The method utilizes indirect impact configuration so that the impact forces will be optimally transferred to the device. As a result, at certain frequency, the peak voltage increases by 4.3 times that of the direct impact configuration.

The charge-state distributions of 238 U and 136 Xe ions at 11 MeV/nucleon were measured using a gas charge stripper to test whether the charge states in gaseous media were acceptable for acceleration at the RIKEN RI-Beam Factory (RIBF). A differential pumping system facilitated the increase of the N 2 gas thickness to 1.3 mg/cm 2 ; this is sufficient for the most probable charge state to attain equilibrium. The charge states of 238 U attain equilibrium at 56.0, 56.6, and 55.7 in N 2 , Ar, and CO 2 media with thicknesses of 125, 79, and 126 μ g / cm 2 , respectively, whereas those of 136 Xe attain equilibrium at 40.5, 40.1, and 40.3 in N 2 , Ar, CO 2 media with thicknesses of 163, 95, and 139 μ g / cm 2 , respectively. The equilibrium charge states of 136 Xe are acceptable for acceleration by the subsequent cyclotron, whereas those of 238 U are not acceptable for acceleration without a major remodeling of the accelerator.

This paper presents a study on effect of two mechanical impact parameters on impact mode piezoelectric power generation. The parameters are velocity and mass. Free fall experiment is used as the evaluation method. It turns out that peak of instantaneous output voltage is proportional to the impact velocity and for output power it is in a straight line relationship with the same parameter. For the same impact velocity, advantage in the usage of heavy object becomes clearer as its momentum and impact force are higher. However, adjustment in the velocity of impact is found to be more effective for higher instantaneous output power than the mass. This is proven by the output power which has been generated by 4g steel ball with momentum of 4.34gm/s is nearly 300% higher than that of 8g steel ball for the same momentum. Further analysis with forced vibration-based impact mode piezoelectric power generation experiment shows that the same conclusion can be made.

We have developed carbon stripper foils, liquid Li strippers, and gas strippers to find the most suitable stripper for high intensity uranium ion beams at the RIKEN RI beam factory (RIBF). The lifetime of newly developed polymer coated carbon foils has been measured online with a beam. A water stripper has been developed offline as a test for a liquid lithium stripper. A windowless gas target has been used as a nitrogen gas stripper and tested offline with the gas injected into the target cell. The maximum pressure of the target cell was 9.25 kPa, which corresponds to a thickness of 1.04 mg/cm 2 .

In order to study the S11(1535) resonance in the nuclear medium, total cross sections of the (γ, η) reactions on C, Al and Cu have been measured for photon energies between 680 and 1000 MeV. A broad resonance due to the excitation and decay of the S11 resonance in the nucleus has been clearly observed for the first time. The apparent energy and width of the resonance are 900 and 300 MeV, respectively. Model calculations based on the quantum molecular dynamics have been performed. A comparison of the calculations with the data indicates that the S11 resonance in nuclei should have a larger width; the width of about 250 MeV is required while the elementary one is about 150 MeV.

Recently, a design of model matching and adaptive control systems under the presence of measurement noise is reported by employing a nonminimal order state observer. But this method can be only used for the case where the plant is stably invertible. In this paper, it will be shown that the idea is also applicable to the case of pole placement. The proposed method can be Implemented by simple calculation comparing with the design of Kalman filter or H ∞ control. So the proposed method is adequate for an adaptive control in which the controllers must be calculated on line.

An ultralow-background fluorescence-photon detection system has been successfully developed for the collinear laser spectroscopy of highly charged ion beams having a relativistic velocity. We applied the technology of a cryopump to a photon-detection system. A charcoal panel, optical filters and four movable collimators strongly reduced the background due to scattered photons of the incident laser beam. The background due to collisions between the ion beam and residual gas was also suppressed by improving the vacuum using a cryopump technique. With this system, we clearly observed the laser-induced fluorescence spectra of the 2S 1/2 -2P 1/2,3/2 transitions in an Li-like 11 B 2+ ion beam with a signal-to-noise ratio of 200. The ion-beam energy was 11.25A MeV and the intensity was 10 4 ions/bunch. We also demonstrated that the system has the capability of measuring the lifetimes of excited states.

The efficiency of positron production by a 1.2-GeV electron beam incident on a tungsten single crystal oriented in an axially channeling condition has been experimentally studied. Positron yields from a 1.2-mm-thick crystal have been measured to be ,2.5 3.0 times larger than those from amorphous targets with the same thickness. A simple model simulation of the positron production process shows that coherent bremsstrahlung, as well as channeling radiation, contributes to the enhancement of the positron yields. [S0031-9007(98)05357-5]

The experimental study of the reaction 3He(γ, pp)n is being carried out in the photon energy range Eγ = 200–500 MeV at the Tokyo 1.3 GeV electron synchrotron. By use of the tagged and linearly polarized photon beam, and the π-sr magnetic spectrometer TAGX, a kinematically complete measurement of the reaction 3He(γ, pp)n will be made. The high statistics measurements of dσdΩ and Σ of the reaction 3He(γ, pp)n will clarify the photon absorption mechanism.

The neutron spectroscopy of the $\ensuremath{\beta}$-delayed neutron decay of ${}^{14}$Be has been investigated. A strong neutron group, which accounts for much of the $\ensuremath{\beta}$-decay yield and could explain the discrepancy in total neutron branching ratio found in a previous experiment, was observed. We found that the total width of the final state for this transition is $60\ifmmode\pm\else\textpm\fi{}5\ifmmode\pm\else\textpm\fi{}6$ keV, and the measured half-life of the ${}^{14}$Be $\ensuremath{\beta}$ decay was $4.29\ifmmode\pm\else\textpm\fi{}0.18$ ms. The limits on the branching ratio and log$\mathrm{ft}$ value determined for this group are compared with the earlier work and the results of a shell-model calculation.

The response of a scintillation detector array consisting of 7 pure CsI crystals with a thickness of 13.5 radiation lenghths has been measured to electrons, positrons and charged pions with momenta ranging from 250 to 1000 MeV/ c . For electrons and positrons the detector provides a very linear response to the incident energy. High energy charged pions make a peak at around 150 MeV corresponding to the ionization energy loss. In addition to the peak, comparable yields which are caused by nuclear reactions are distributed up to the maximum available enegy and form a broad bump. The shape of the broad bump for positive pions is different from that for negative pions with the same momentum. A simulation with a GEANT program cannot reproduce the shape of the broad bump.

The experimental study of nuclear moments of several neutron-rich nuclei, using the phenomenon of ejectile spin polarization in the projectile fragmentation reaction, is reported. The spin-polarized fragments14B and15B were produced in the fragmentation of18O projectiles on a Nb target at 64.7 MeV/u. They were implanted into a Mg single crystal, and the quadrupole momentsQ were determined by theβ-NMR method. The results, ¦Q(14B)¦ =29.84 ±0.75 mb and ¦Q(15B)¦=38.01 ±1.08 mb, are compared with theoretical models. Shell model calculations in a 0ħω model space, using effective charges commonly accepted in this mass region, predict values about 40% larger than the experimentalQ(15B). Agreement is obtained when a much smaller effective charge for neutrons is employed. The method was also applied to the measurement of the magnetic moments of17N and17B. The result reveals an important contribution of configurations with excess neutrons coupled to formJ π=2+.

A new gamma-ray telescope using scintillation fiber together with an image intensifier is presented. The image intensifier we used has been improved in the sensitive range of the wavelength (beyond 300 nm) and the quantum efficiency (maximum 20%). The results of the beam test using the accelerator and the Monte Carlo simulation for the prototype telescope show that the device has the angular resolution of 0.5° at 900 MeV. On the basis of results of the prototype telescope, we propose a new SCIFI (SCIntillation FIber) telescope for future gamma-ray astronomy. The new telescope has achieved a large solid angle. With this merit, the new telescope can investigate very dark gamma-ray sources and monitor transient events such as gamma-ray burst. In addition, the cost of devices used in the telescope is not expensive so that an extension of the area of the telescope is easily realized in comparison with telescopes using silicon detector such as GLAST.

The magnetic moments of $^{17}\mathrm{N}$ and $^{17}\mathrm{B}$ were measured by using spin-polarized radioactive nuclear beams which were obtained from the projectile fragmentation reaction. The observed magnetic moment of $^{17}\mathrm{N}$, \ensuremath{\Vert}\ensuremath{\mu}${(}^{17}$N)\ensuremath{\Vert}=(0.352\ifmmode\pm\else\textpm\fi{}0.002)${\mathrm{\ensuremath{\mu}}}_{\mathit{N}}$, where ${\mathrm{\ensuremath{\mu}}}_{\mathit{N}}$ is the nuclear magneton, falls outside the Schmidt lines. By virtue of a simplifying feature of nuclear structure inherent in a ${\mathit{p}}_{1/2}$ valence nucleus, the deviation from the Schmidt value is attributed on firm ground to admixing of the configurations in which two neutrons in the sd shell are coupled to ${\mathit{J}}^{\mathrm{\ensuremath{\pi}}}$=${2}^{+}$. This interpretation is confirmed in standard shell-model calculations. The calculations reproduce fairly well the experimentally inferred amount of ${2}^{+}$ admixture, as well as the experimental magnetic moment itself. The magnetic moment for $^{17}\mathrm{B}$ was determined as \ensuremath{\Vert}\ensuremath{\mu}${(}^{17}$B)\ensuremath{\Vert}=(2.545\ifmmode\pm\else\textpm\fi{}0.020)${\mathrm{\ensuremath{\mu}}}_{\mathit{N}}$. The result is substantially smaller than the \ensuremath{\pi}${\mathit{p}}_{1/2}$ single-particle value, and the shell-model calculations indicate that the quenching of \ensuremath{\mu} largely stems from ${\mathit{J}}^{\mathrm{\ensuremath{\pi}}}$=${2}^{+}$ configurations of the sd neutrons. The observed amount of quenching, however, is larger than the shell-model predictions, suggesting an enhanced contribution of the ${2}^{+}$ neutron configurations. This result is explained if the pairing energy for neutrons in the sd shell of a neutron-rich nucleus is assumed to diminish by about 30%. We also find that the use of the reduced pairing energy improves agreements in the magnetic moment and low-lying energy levels of $^{17}\mathrm{N}$ as well. \textcopyright{} 1996 The American Physical Society.

A set of CsI(pure) crystals have been tested for use as an electromagnetic calorimeter for π0 detection in photonuclear reactions at photon energies below 1.2 GeV. Performances of the calorimeter including energy and position resolution are studied by using the electron and tagged-photon beams at the INS-Tokyo electron synchrotron. In the first experiment for the nuclear coherent π0 photoproduction carried out at INS, a π0 mass resolution of 7 MeV (rms) has been obtained in the π0 energy region between 0.5 and 1.0 GeV.

Phenomenon of ejectile spin polarization in the projectile fragmentation reaction was exploited as a tool to produce polarized radioactive nuclei. The polarized unstable nuclei were subjected to the β-detected NMR meaurements, and the magnetic moments and electric quadrupole moments were determined for several neutron-rich light nuclei. The comparison of the experimental results with theoretical predictions shows that the nuclear moments provide useful test of models for nuclear structure and interaction in the region of light-mass unstable nuclei.

We have made a kinematically complete measurement of the Coulomb dissociation of 11Be on Pb target at 72A MeV. The low-lying dipole strength distribution indicated the importance of the direct breakup mechanism, which was also supported by the observed effect of the Coulomb post acceleration. The E1 dominance of the reaction was confirmed by the angular distribution of 10Be in the rest frame of 11Be.

The Coulomb excitation of a very neutron-rich nucleus 32Mg to its 2+ state was studied using an unstable nuclear beam of 32Mg at 49.2 MeV/u with a 208Pb target. The B(E2) value of 454±78 e2fm4 was extracted by a coupled channel analysis. The value is in good agreement with recent predictions. It confirms a large deformation for 32Mg suggested by the low excitation energy of the 2+ state, and points to the vanishing of the N = 20 shell gap.

We have measured the excitation energy spectrum of the 10 Be+n system in the Coulomb dissociation of the one-neutron-halo nucleus 11Be on a Pb target at 72A MeV. We have determined the dipole strength distribution dB (E1) /dEx which shows a strong peak at about 800 keV excitation energy. The spectral shape is consistent with a direct breakup model. The Coulomb post accelaration effect has been observed also to support the direct breakup mechanism. The E1 dominance of the Coulomb dissociation is confirmed by observed angular distributions of 10Be in the 11Be rest frame.

SAMURAI project aims to open a new research field in nuclear physics by the use of a large acceptance spectrometer for kinematically complete measurements of multiple particles emitted in RI-beam induced reactions. The SAMURAI spectrometer consists of a large gap superconducting dipole magnet, heavy ion detectors, neutron detectors, and proton detectors. What is special about the SAMURAI system is that projectile-rapidity protons or neutrons are detected with large angular and momentum acceptance in coincidence with heavy projectile fragments. With an effective combination of these equipments, the SAMURAI system allows us to perform various experiments: electromagnetic dissociation, various direct reactions, polarized deuteron induced reactions, and EOS studies. SAMURAI project is currently underway at RIBF. The construction of the superconducting dipole magnet will start in autumn 2010 and finish in spring 2011. The detectors are also being constructed in parallel. The first commissioning run will be performed in early 2012.

A new beam pipe with an optimally designed mask system has been incorporated into the TOPAZ detector at the TRISTAN e + e − collider. It has allowed successful operation of a high-precision vertex chamber installed at a distance of 55 mm from the beam line and of a hermetic calorimetry covering 99.8% of the solid angle. We report on the design of the mask system and our running experience.

Measurements of the forward-backward asymmetry of e + e − → cc events were carried out at a mean √s energy of 57.95 GeV at TRISTAN, KEK. The cc events were tagged either by the full-reconstruction of D ∗± or the inclusive P T spectrum of π s ± from D ∗± → D 0 ( D 0 )π s ± . The forward-backward asymmetry was measured to be A FB c = −0.49 −0.13 +0.14 (stat.) ± 0.06 (syst.), consistent with the standard model.

We have investigated the properties of jet production in almost real γγ collisions at √s=58 GeV with the TOPAZ detector at the TRISTAN e+e− collider. The data were analyzed with a jet-clustering method based on a cone algorithm. The jet rate shows evidence for a hard scattering effect of the hadronic constituents of a photon (resolved photon processes). We have also observed a substantial energy flow in the small-angle region, which is additional evidence for resolved photon processes. We present the transverse momentum dependence of the inclusive jet and two-jet cross sections and compare them with different model predictions.

Differential cross sections and vector and tensor analyzing powers for the 11 B(d, 2 He) 11 Be reaction at 70 MeV have been measured and Gamow-Teller and spinflip dipole transitions are identified. Observed mean excitation energy and strength for the spinflip dipole transition in which possible neutron halo effect manifests itself are consistent with the shell model prediction which takes the neutron halo into account.

The total photoproduction cross section is determined from a measurement of electroproduction with the ZEUS detector at HERA. The Q2 values of the virtual photons are in the range 10−7

A high-statistics experiment on the reaction π − p→ π + π − π 0 n at 8.06 GeV/ c has been performed using a spectrometer detecting both charged particles and gamma rays. A partial-wave analysis based on the isobar model has been carried out for π + π − π 0 data in the mass range between 0.86 and 1.50 GeV for four t ′ regions: 0.0–0.1, 0.1–0.25, 0.25–0.45 and 0.45–0.95 (GeV/ c 2 ). Two axial-vector resonances, a 1 (1260) and h 1 (1170), were observed in the analysis. The masses and widths of a 1 and h 1 were determined to be M (a 1 = 1121 ± 8 MeV, Λ (a 1 = 239± 11 MeV, M (h 1 = 1168±4 MeV and Λ (h 1 = 345±6 MeV, respectively, by fitting the Breit-Wigner formula to the partial wave amplitude. A fit including the Deck type background was also tried in each t ′ region. The results showed a small effect on these resonance parameters and were consistent with those obtained by the simple Breit-Wigner fitting.

The process e+e−→μ+μ−and e+e− have been studied in the energy range s=52−61.4 GeV, using the TOPAZ detector at TRISTAN. From an integrated luminosity of L = 74.0 pb−1, lowest-order cross sections and forward-backward asymmetries are measured to be 〈σμμ〈 = 25.4±0.9±1.2 pb, 〈Aμμ〉 = (−32.2±3.1±1.1)%, 〈σττ〉 = 27.1±1.1±1.2 pb, 〈Aττ〉 = (−33.9±4.9±1.0)% , at an average energy of s〉=57.87 GeV. From the measured assymetry we derive axial vector couplings of acaμ=0.96±0.09±0.01,and acaτ=1.01±0.14±0.01±. These results are consistent with standard model expectations. Lower limits in the range 2–5 TeV (95%CL)are placed on compositeness scale parameters for leptons.

The decay property of {sup 20}Na was studied using a {sup 20}Mg beam to learn better the onset mechanism of the rapid-proton process. The delayed protons were successfully measured, which correspond to one of the possible 1{sup +} states in {sup 20}Na. There is no clear beta decay to the first excited 1{sup +} state above the proton threshold, suggesting that this state would not be the {ital s}-wave resonance in the thermal reaction of {sup 19}Ne+{ital p} as was expected before. The half-life time of {sup 20}Mg is determined to be 114{plus minus}17 ms. The stellar reaction rate of {sup 19}Ne({ital p},{gamma}){sup 20}Na is also discussed based on the present experimental result.

We have measured the cross section for γγ production with the TOPAZ detector in the energy region √ s =50.0–61.4 GeV. The observed cross section for γγ production integrated over |cos θ | ⩽ 0.77 is 50.2±0.8±2.2 pb at 〈√ s 〉=57.6 GeV and the ratio of this value to the QED prediction is 1.01±0.02±0.04. The angular distribution is in good agreement with the QED predictions, thereby setting limits on the compositeness scales, Λ L+R + =168 GeV, Λ L+R − =97 GeV, Λ L,R =141 GeV, Λ L,R − =81 GeV, and Λ L−R ± =68 GeV, at the 95% confidence level. The reaction e + e − → γγγ was also studied and was found consistent with the QED prediction.

An experimental study of b-quark jets using high-pT electrons was carried out at √s=58 GeV with the TOPAZ detector at the e+e− collider TRISTAN at KEK. The forward-backward charge asymmetry of the b-quark was obtained to be A b b =−0.55±0.27( stat. )±0.07( syst. ) , consistent with the standard model prediction. Also, such jet properties of the b-quark as the average charged multiplicity and the rapidity of charged particles were analyzed. In order to purify the b-quark event samples in this analysis, only events with backward-going electrons or forward-going positrons were used. The energy dependence of these jet properties was studied by making comparisons with the results of the DELCO experiment at the PEP collider (√s=29 GeV) at SLAC.

The TOPAZ group working at the e + e − storage ring TRISTAN has installed a vertex chamber using slow gas based on a mini jet-cell design. A major feature of the chamber is the simplicity of its mechanical structure accomplished by using monolithic ceramic endplates. Ceramic has proved to be an excellent material for the precision construction necessary to obtain a high resolution vertex chamber. The mechanical structure of the chamber, the method used for the precise positioning of the wires and the properties of the ceramic endplates are presented.

A new type of liquid- 3 He target has been developed for photoabsorption experiments at intermediate energies. Using the cooling power of liquid 4 He at reduced vapour pressure, 3 He gas is liquefied into a cylindrical target cell of 180 ml and is maintained at 2.0 K during the experiment. Evaporated 4 He gas is evacuated by a rotary pump and returned into the 4 He bath in the cryostat, where two small mechanical refrigerators with cooling capacities of 3 W at 4.3 K and 10 W at 20 K are operated for the purpose of 4 He recondensation. A maintenance-free operation of more than 1000 hours has become possible by adopting the 4 He circulation system.

A partial-wave analysis based on the isobar model has been carried out for a high statistics π + π − π 0 data in the π − p charge exchange reaction in the mass range between 0.88 and 1.44 GeV. Two axial-vector resonances, a 1 (1260) and h 1 (1170), were observed in the analysis. The masses and widths of a 1 and h 1 were determined by fitting the partial-wave amplitude to the Breit Wigner formula at four t' regions.