Search

The KOTO ($K^0$ at Tokai) experiment aims to observe the CP-violating rare decay $K_L \rightarrow \pi^0 \nu \bar{\nu}$ by using a long-lived neutral-kaon beam produced by the 30 GeV proton beam at the Japan Proton Accelerator Research Complex. The $K_L$ flux is an essential parameter for the measurement of the branching fraction. Three $K_L$ neutral decay modes, $K_L \rightarrow 3\pi^0$, $K_L \rightarrow 2\pi^0$, and $K_L \rightarrow 2\gamma$ were used to measure the $K_L$ flux in the beam line in the 2013 KOTO engineering run. A Monte Carlo simulation was used to estimate the detector acceptance for these decays. Agreement was found between the simulation model and the experimental data, and the remaining systematic uncertainty was estimated at the 1.4\% level. The $K_L$ flux was measured as $(4.183 \pm 0.017_{\mathrm{stat.}} \pm 0.059_{\mathrm{sys.}}) \times 10^7$ $K_L$ per $2\times 10^{14}$ protons on a 66-mm-long Au target., Comment: 27 pages, 16 figures. To be appeared in Progress of Theoretical and Experimental Physics

The GEKKO⁄HIPER-laser driven shock experiments were characterized in detail for studies on equation-of-state (EOS) in ultra-high pressure regime. High-quality shock waves were produced with optically smoothed laser beams. Key issues on EOS measurement with shock waves, the spatial uniformity and the temporal steadiness of shock, and the preheating problem were investigated by measurements of the self-emission and reflectivity from target rear surface. Our experiments and analysis based on impedance matching method were validated by use of double-step targets consisting of two Hugoniot standard metals. Extreme shock waves previously only achieved in nuclear explosion experiments were generated using the laser direct-drive experimental scheme.

The temporal evolution of the density profile of a directly laser-driven polystyrene target was observed for the first time using an x-ray penumbral imaging technique coupled with side-on x-ray backlighting at the GEKKO XII [C. Yamanaka et al., IEEE J. Quantum Electron. QE-17, 1639 (1981)]–High Intensity Plasma Experimental Research laser facility (IL=0.7×1014 W/cm2, λL=0.35 μm). This density measurement makes it possible to experimentally confirm all physical parameters [γ(k),k,g,ṁ,ρa,Lm] appearing in the modified Takabe formula for the growth rate of the ablative Rayleigh–Taylor instability. The measured density profiles were well reproduced by a one-dimensional hydrodynamic simulation code. The density measurement contributes toward fully understanding the ablative Rayleigh–Taylor instability.

To create a conceptual design of a tracking system of a target injected into a wet-walled, laser-fusion reactor, the influence of residual gas on the target trajectory is discussed based on a kinetic model, assuming all of the impinging molecules are adsorbed on the target surface. The model targets are a high-gain target for central ignition and a fast-ignition target with a cone as an optical guide for an additional heating laser. In the case of a fast-ignition target, tracking in the reactor might be skipped, depending on its condition, because of the heavy cone. Recent activities in fabrication of the fast-ignition target are briefly mentioned.

A design space of the injection velocity of a cryogenic target for the vapor pressure in a future laser fusion reactor with a wet wall is discussed. The discussion includes gain reduction due to X-ray preheat, sphericity degradation, and melting of the cryogenic layer due to adsorption of the metal vapor in the reactor. The preliminary estimation indicates that the injection velocity of a cryogenic target insulated with a 200-μm-thick, 250 mg/cc foam layer should be >130 m/s and the vapor pressure in the reactor must be

We developed and improved high space- and time-resolution x-ray imaging techniques (3–6 μm, 100–200 ps). These techniques were coupled with side-on x-ray backlighting for observing hydrodynamics of directly laser-driven polystyrene plasmas. As a high sensitive x-ray image detector, Imaging Plate was introduced to penumbral imaging technique [S. Fujioka et al., Rev. Sci. Instrum. 73, 2588 (2002)]. Noise in penumbral images was reduced by this improvement, and high quality density profiles of plasmas were obtained. A large-magnification slit camera, whose slit width and magnification were 4 μm and 82.8, was coupled with an x-ray streak camera (XSC). Due to the advantage of the large-magnification, high spatial resolution of 5.8 μm was found even with an XSC, the photocathode of which usually has low spatial resolution. These techniques are useful in understanding of hydrodynamic instability in inertial confinement fusion.

Rayleigh–Taylor (RT) instability is one of the most important physical issues in the inertial confinement fusion research. The reduction of its growth rate due to laser-driven ablation, which is described by the modified Takabe formula, is of great importance for a precise understanding of the target physics. We have developed various diagnostic techniques for the measurement of the parameters appearing in the Takabe formula, such as the growth rate, the acceleration, the mass ablation rate, and the density structure including ablation density and density scalelength. Face-on and side-on x-ray backlighting were coupled with moire interferometry imaging, penumbral imaging, and Fresnel zoneplate imaging. All the physical parameters related to RT instability were measured experimentally, and compared with simulation results.

A uniform laser ablation was observed in a polystyrene film coated with a photovoltaic perylene/phthalocyanine bilayer when an incident took place at an intensity range of 10 9 –10 10 W/cm 2 ( λ =1064 nm, 1.1 ns FWHM). Without the bilayer coating, the laser pulse formed spiky structures in the polystyrene film as self-focusing traces of the laser pulse, while for the coated film, the uniform surface ablation trace without the spiky interior structures was observed. In the case of incident of 532 nm where the coating material exhibits no reflection, such difference depending the coating was not observed. These phenomena were coupled with the reflection and conduction properties via its photovoltaic effect, and agreed with the required ablation to achieve high-density compression of the fuel capsule for inertial fusion energy (IFE).

One-dimensional (1D) penumbral imaging technique with high spatial resolution has been developed, and applied to density profile measurements in laser-driven Rayleigh-Taylor instability experiments at a GEKKO XII-HIPER laser system. A laser-irradiated planar target was observed with side-on x-ray backlighting. A penumbral image of an x-ray radiograph was made by using a knife-edge imager. The x-ray radiograph was, then, reconstructed by differentiating the penumbral image with a proper Wiener filtering. A density profile was deduced from the reconstructed x-ray radiograph. In a proof-of-principle experiment, the density profile of a polystyrene (PS) target before laser irradiation was measured by using this method, and high spatial resolution of 3–4 μm was demonstrated. A laser-irradiated PS target in the acceleration phase was observed. The experimentally observed density profile was found to be consistent with the prediction by a 1D hydrodynamic simulation code. The x-ray penumbral imaging is a very sim...

症例は27歳,男性.脳性麻痺による精神遅滞があり, 17歳時より呑気を認めた. 21歳時より腹部単純X線写真上巨大結腸を認め,イレウス症状を頻回に認めた. 1999年10月23日,横行結腸軸捻転をきたし,大腸内視鏡下に解除を試みたが不可能であり,翌日緊急手術を施行した.横行結腸が中結腸動脈を中心に180度回転し,横行結腸全体に虚血性変化を認めたため横行結腸切除を行い,結腸を端々吻合した.術後は高カロリー輸液,人工呼吸器管理を行い, MRSA肺炎,術後イレウス等合併症を認めたが,保存的治療にて改善し, 1999年12月13日より経口摂取可能となった.呑気症のために巨大結腸を呈し,外科的処置が必要であったという報告は稀で,われわれが調べえた範囲では,本邦過去10年間に2例にすぎない.また巨大結腸症を呈し,イレウス症状を繰り返す例には重症心身障害者とはいえ積極的に待機手術を検討すべきと思われた.

Modern high-power lasers can generate extreme states of matter that are relevant to astrophysics, equation-of-state studies and fusion energy research. Laser-driven implosions of spherical polymer shells have, for example, achieved an increase in density of 1,000 times relative to the solid state. A new laser technology ‘ultra-intense’ laser is now opening a new ground of the laser fusion research, which is called as fast ignition. During the last several years, we have extensively studied elementary physics relevant to the fast ignitor. Based on these results, we have succeeded enforced heating of imploded plasmas with a 100 TW laser as the first demonstration of this new approach. The experimental result implies the future possibility of breakeven and ignition with significantly small laser energies. This new approach provides a route toefficientfusionenergy production.

The initial imprint caused by the spatial non-uniformity of laser intensity which generates a mass perturbation is one of the critical issues for directly driven laser fusion research. To mitigate such laser imprint a foam-hybrid target, which has low-density foam layer and is coated with high-Z material, was proposed. In such targets, the X-ray radiation plays a significant role in the formation of the initial imprint. For short wavelength perturbations, a clear suppression of the perturbation growth is observed in the foam-hybrid target. The perturbation growth is reduced by radiation preheating since the ablation surface is smoothed. Moreover, the emitted X-rays from the coated high-Z material suppresses the hydrodynamic instability at the interface of plastic and foam. However, the ablation structure is sensitive to the opacity model. Thus, it is important to analyze the role different radiation models play in the hydrodynamics. In this work we will compare both CRE and LTE models.

CR-39 film stacks are used to measure the energy and angular distribution of protons emitted from the rear surface of ultra-intense laser illuminated plastic foils. The experiment suggests that the energetic protons are dragged away from the rear surface, where the hot electron formed a virtual cathode. The two-dimensional particle in cell simulation supports this hypothesis. For 5 (100) μm thick target, 1.8×109 protons have a slope temperature of 3 (2) MeV. The ring structure of proton emission leads us to the hypothesis that a toroidal magnetic field associated with the hot electrons works on the fast ions and deflects them. From the logarithmic slope of the ring diameter versus the ion energy, the product of the magnetic field × the length over which it works on the ions is estimated to be up to 1000 MG⋅μm. The simulation shows that a strong toroidal magnetic field was excited at the target rear side with expansion of plasmas. The proton’s angular distribution from the rear surface has the logarithmic ...

A 76-year-old woman was seen at the hospital because of a left anterior neck tumor. Physical examination revealed a 7.5×4.5cm hard mass in the left lobe of her thyroid. Based on the findings of the aspiration biopsy cytology, the tumor was diagnosed as papillary carcinoma of the thyroid. A subtotal thyroidectomy and a modified radical neck dissection were performed (T4, Ex2, Nla). Because the huge tumor and the metastatic lymph nodes invaded the left recurrent laryngeal nerve, the nerve was sacrificed. We could not anastomose the recurrent laryngeal nerve directly because the proximal edge of the nerve could not be identified. Furthermore, we could not use the left ansa cervicalis for the reconstruction because of its condition. So we anastomosed the distal stump of left recurrent laryngeal narve to the right ansa cervicalis which was brought up by passed in front of the trachea. After the operation, hoarseness due to unilateral vocal cord paralysis was observed. But her voice was improved gradually. Five mouths later, the patient was satisfied with her voice. Recurrent laryngeal nerve reconstruction with contralateral ansa cervicalis was effective for the improvement of the phonation of the patient who underwent recurrent nerve severance.

Coordination structures of neodymium(III) complexes with some β-diketones were investigated in terms of their correlations with emission efficiency in deuterated dimethylsulfoxide (DMSO-d6). The analysis of UV-vis spectra, 13C NMR, electrospray mass spectrometry (ES-MS) spectra, XANES and EXAFS analysis of tris(hexafluoroacetylacetonato)neodymium(III) complex, [Nd(hfa-H)3(H2O)2], and tris[bis(perfluorooctanoyl)methanato]neodymium(III), [Nd(pom-H)3], in DMSO indicated that the deuterated tris(hexafluoroacetylacetonato)neodymium(III), Nd(hfa-D)3, and deuterated tris[bis(perfluorooctanoyl)methanato]neodymium(III), Nd(pom-D)3, in DMSO-d6 should have a symmetrical, rigid and bulky shell composed of six inner-coordinating DMSO molecules and three weakly coordinating hfa-D and pom-D molecules. The improvement in the emission efficiency of the neodymium complexes with the low vibrational and weakly coordinating β-diketonates in DMSO-d6 was ascribed to their symmetrical rigid coordination structures, which should ...

A novel Nd3+ complex, Nd(POA-D)3, with asymmetric ligands (POA: perfluorooctanoylacetic acid), was synthesized in order to enhance the transition probability in its f–f transition by reducing symmetry of the ligand field around Nd3+. This complex gives the 2.5 times higher oscillator strength of the hypersensitive transition in methanol-d4 than the corresponding symmetrical complex, Nd(POM-D)3 (POM: bisperfluorooctanoylmethane). The Stark splitting of the emitting level of Nd(POA-D)3 was observed and the Judd-Ofelt analysis gave a large Ω2 value, clearly showing the asymmetric environment around Nd3+. 13C NMR analysis, molecular orbital and molecular mechanics calculations and EXAFS analysis suggest that the asymmetric environment achieved in Nd(POA-D)3 is ascribed mainly to the asymmetric distribution of electrons on the coordinating O atoms. The higher absorption coefficient of Nd(POA-D)3 leads to 1.86 times stronger emission than Nd(POM-D)3 when measured at the common concentration and conditions. It is stressed that introduction of asymmetric ligands is a promising way for promoting emission of Nd3+ in solutions when coupled with replacement of C–H bonds with C–D and C–F in the ligands.

We report here two cases of intestinal Behget disease with perforation. A 42-year-old man was admitted to the hospital because of abdominal distension and abdominal pain. There was a history of undergoing an ileocecal resection for idiopathic colon ulcer 7 years before admission, when he was diagnosed as Behcet disease. We performed a surgery under a diagnosis of ileal perforation. Another patient, a 54-year-old woman was transferred to the hospital because of severe abdominal pain. She had been diagnosed as having Behcet disease a few years before admission. Abdominal XP examination confirmed perforation of the intestine. Emergency operation revealed some perforations in a portion from the ascending to descending colon. Extended right hemicolectomy was performed. It is demonstrated in these cases that intestinal Behcet disease easily causes perforation and often demands emergency operation, with resultant postoperative recurrence or complication in a high frequency. So if the diagnosis of intestinal Behcet disease is made, and if downhill course is observed after periodical medical checks, some prophylactic operation would be necessary.

Perdeuterated hexafluoroacetylacetonato-neodymium [Nd (HFA-D) 3] and -ytterbium [Yb (HFA-D) 3] complexes were synthesized by the keto-enol tautomerism reaction of Nd (HFA-H) 3 and Yb (HFA-H) 3 in methanol-d4 in order to reduce the radiationless transition to the ligands. The luminescence properties of the Nd (HFA-D) 3 complex in organic solvents were analyzed by the Judd-Ofeltheory. The luminescence quantum yield of the Yb (HFA-D) 3 complex increased with the increasing coordination ability of the solvent molecules. The luminescence lifetime of the Yb (HFA-D) 3 complex in dimethylstilfoxide (DMSO-d6) which had the highest coordination ability was 66 μs.

維持透析患者の食道癌手術は侵襲が大きいと考えられるが, 今回我々は縦隔鏡, 腹腔鏡補助下食道抜去術を施行し, 良好な術後経過を得たので報告する.症例は59歳, 男性で, 透析歴は1年10か月, 原疾患は糖尿病. 下血, 嚥下困難を主訴として入院となり, 精査の結果, 食道胸部中部の進行食道癌と診断し, 食道抜去術を施行した. 手術用縦隔鏡を用い頸部から食道の剥離を行い, 腹腔側からは腹腔鏡補助下に剥離を行った.術中出血量は350mlと少なく, 本術式は維持透析患者に安全かつ侵襲の少ない食道癌術式と考えられた.

Tris-(hexafluoroacetylacetonato)neodymium(III), [Nd(HFA-D)3], was prepared by chelation of Nd3+ ion with deuterated hexafluoroacetylacetone in CD3OD. Luminescence of the Nd3+ complex was observed for the first time in organic solvents and the quantum yield was estimated to be of the order of 10−2 in deuterated acetone solution. The absorption spectrum of [Nd(HFA-D)3] dissolved in acetone was comparable with that of Nd3+ ion in Y3Al5O15 matrix (Nd:YAG). Splitting of the 4 F 3 2 level was determined to be 82.3 cm−1 in this system. These spectral characteristics suggest that the physical nature of Nd3+ coordination environments should be uniform and well defined by coordination of HFA in solution.

A field experimental site for laser triggered lightning (LTL) has been prepared targetting the winter thunderstorms in Hokuriku region. This paper discusses the results from laboratory experiments and field observation on winter thunderstorms at Mihama district. A new scheme of determining the laser irradiation timing, the PB (Preliminary Breakdown) trigger, and its preliminary results on LTL are also described.

右側結腸に穿孔性多発潰瘍を認めた腸型ベーチェット病疑診の1手術例を経験したので報告する. 症例は46歳の女性で, 既往歴に口腔内アフタ性潰瘍を認めた. 入院後汎発性腹膜炎の診断で緊急開腹し, 右側結腸に多発性穿孔を認め, 右側結腸広範切除術を施行した. 切除標本では結腸の随所に大小不同の紡錘形を呈する境界明瞭な強い打ち抜き状の潰瘍およびびらんを認め, 少なくとも15か所以上で穿孔していた, 術後外陰部アフタを認め, human leucocyte antigen (HLA) B5, B51が陽性であることより腸型ベーチェットが疑われた. 今回のごとく特徴的な潰瘍形態を呈した結腸型べーチェット多発穿孔例は文献的に非常にまれと考えられた.

The deuterated tris(hexafluoroacetylacetonato)neodymium(III) complex, Nd(HFA-D)3, was obtained by keto−enol tautomerism reaction of Nd(HFA)3 in methanol-d4. The emission of Nd(HFA-D)3 was observed in the following anhydrous deuterated organic solvents: methanol-d4, acetone-d6, THF-d8, DMF-d7, and DMSO-d6. The intensity and lifetime of the emission in DMSO-d6 are much superior to those in other deuterated solvents. The specific interaction of DMSO molecules with Nd(HFA)3 was confirmed by 13C NMR and 19F NMR analysis. The strong coordination ability of DMSO to Nd3+ ion in Nd(HFA-D)3 led to the enhanced emission in DMSO owing to the suppression of radiationless transition via vibrational excitation of D2O molecules in the vicinity of Nd(HFA-D)3.

We are preparing a laser triggered lightning method for the winter thunderstorm. Using a - 150-J electron beam excited CO2 laser, we obtained a laser plasma channel consisting of many plasma beads made of ionized aerosols in the atmosphere. The laser plasma channel initiates an electrical streamer and propagates a leader. We discuss experimental results on the critical conditions for initiating streamer from a laser plasma channel and for leader propagation through a laser plasma channel.

Control of lightning is a dramatic challenge to nature. The lightning attacks to the electric power line make a lot of economical loss in the sophisticated modern society since electric power failure induces a lot of trouble in the computerized systems even if it is very short time. If the lightning could be controlled one will be free from such a trouble and save the cost expensed for electric power failure guard system. The scenarios and issues of laser triggered lightning are reviewed presenting some experimental results as well as the mechanisms and types of lightning, characteristics of the long gap electric discharge and some results of triggered lightning by rockets.

It is a crucial issue to make an intense plasma channel in the atmosphere for laser triggered lightning. The laser characteristics of laser propagation and plasma generation have been studied under various weather conditions. The line density of plasma channel in snowy weather is less than that in fine weather due to the laser energy attenuation and the decrease of aerosols, the cores of plasma beads, by snow. To initiate a leader at the top of lightning tower, the line density of plasma channel is needed to be over one hundred per meter. Some remedies to overcome this effects will be discussed.

A series of experiments were conducted using cryogenic deuterium targets to study fundamental physics and implosion dynamics with the GEKKO XII glass laser system [IEEE J. Quantum Electron. QE‐17, 1639 (1981)]. Preheat sources were found to be due to a shock wave and hot electrons. A new method to measure the fuel ρR using proton spectra was employed. Measured in detail were the implosion dynamics of cryogenic deuterium foam with a plastic ablator and a CH shell with a controlled pressure of deuterium gas targets. Under current experimental conditions sources of nonuniformity were discussed in terms of Rayleigh–Taylor instability.

We report on a measurement of the decay {ital K}{sub {ital L}}{r_arrow}{mu}{sup +}{mu}{sup {minus}}{gamma} from Fermilab experiment E799. We observe 207 candidate signal events with an estimated background of 10.5{plus_minus}4.0 events and establish {ital B}({ital K}{sub {ital L}}{r_arrow}{mu}{sup +}{mu}{sup {minus}}{gamma})=[3.23{plus_minus}0.23(stat){plus_minus}0.19(syst)]{times}10{sup {minus}7}. This provides the first measurement of the {ital K}{gamma}{gamma}{sup *} form factor in the muonic Dalitz decay mode of the {ital K}{sub {ital L}}.

We have measured the polarization of Λ and Λ hyperons produced by 800 GeV protons on a Be target at a fixed targeting angle of 4.8 mrad. Comparison with previous data at 400 GeV production energy and twice the targeting angle shows no significant energy dependence for the Λ polarization. This is in striking contrast to the energy dependence found for σ+ and Ξ− polarizations. We find no evidence for Λ polarization at 800 GeV.

We report the results of a search for the decay [ital K][sub [ital L]][sup 0][r arrow][pi][sup 0][pi][sup 0][gamma] conducted by the E799 Collaboration at Fermilab. The amplitude for this process vanishes to [ital O]([ital p][sup 4]) in chiral perturbation theory, so a measurement of the decay would directly probe [ital O]([ital p][sup 6]) effects. This is the first published search for this decay mode and we set a 90% confidence level upper limit on the branching ratio of [ital B]([ital K][sub [ital L]][sup 0][r arrow][pi][sup 0][pi][sup 0][gamma])[lt]2.3[times]10[sup [minus]4].

We have determined the branching ratio of [ital K][sub [ital L]][r arrow][ital e][sup +][ital e][sup [minus]][ital e][sup +][ital e][sup [minus]] based on the observation of 27 four-electron final state events with 0.36 estimated background event, [ital B]([ital K][sub [ital L]][r arrow][ital e][sup +][ital e][sup [minus]][ital e][sup +][ital e][sup [minus]]) =[3.96[plus minus]0.78(stat)[plus minus]0.32(syst)][times]10[sup [minus]8]. Using the distribution of the angle between the [ital e][sup +][ital e][sup [minus]] pair decay planes, we find that the decay proceeds predominantly through the [ital K][sub 2]([ital CP]=[minus]1) state.

The present report describes the adhesion of metal foils without a conventional glue to provide a precise thickness (~ 20 µm) of an adhered step target for ultrahigh pressure, laser shock experiments. The technique involves two processes: single molecule coating on the metal surface and fastening the two surfaces together. For the two 20 µm aluminum targets of single foil and adhered foils, a negligible difference in laser shock speed was observed in comparison with laser energy and target thickness.

The control of the refractive index of laminated coatings consisting of alternating stacks of nanoscale Al2O3 and TiO2 sublayers grown by atomic layer deposition has been achieved. The refractive index of the coating linearly changed from 1.870 to 2.318 as the thickness of the single TiO2 sublayer was varied from 2.0 to 39 A while that of the single Al2O3 sublayer was kept constant at 5.5 A. The refractive index could be varied by adjusting only the number of growth cycles of each material. This approach will have potential applications to optical multilayer coatings consisting of well-controlled extremely thin layers.

The present report describes ultralow density (2–12 mg/cm3) plastic (CH2) foams whose density is close to the cutoff density of the plasma for visible and near-infrared light beams (0.55–1.3 µm). These foams are prepared from a poly(4-methyl-1-pentene) gel with hexanol derivatives by extraction using supercritical fluid CO2. Their intended use is in laser-plasma experiments and as a laser-plasma X-ray source. Their microstructure (2–10 µm) was finer than that of the previous poly(4-methyl-1-pentene) foam and could be varied using different hexanols.