[en] In order to apply the terahertz (THz) imaging technique to high-T_C superconductor thick film, the THz imaging system was improved to observe the back-scattered THz radiation pulse. Using the improved system we succeeded in the observation of supercurrent distribution in Bi₂Sr₂CaCu₂O_8+δ thick film in Meissner state

[en] Japan plans to reprocess and reutilise the spent nuclear fuel from nuclear power generation. However, the temporary storage of spent fuel is assuming increasing importance as a means of ensuring flexibility in the nuclear fuel cycle. Our investigations of various methods of storage have shown that casks are the most suitable means of storing small quantities of spent fuel of around 500 t, and research and development are in progress to establish dry storage technology for such casks. The soundness of fuel cladding is being investigated. The most important factor in evaluating soundness in storage under inert gas as currently envisaged is creep deformation and rupture, and a number of investigations have been made of the creep behaviour of cladding. The present study was conducted on the basis of existing in-house results in collaboration with Nippon Kakunenryo Kaihatsu KK (Nippon Nuclear Fuel Department Co.), which has hot lab facilities. Tests were run on the creep deformation behaviour of irradiated cladding, and the maximum allowable temperature during dry storage was investigated. (author)

[en] High-energy ion implantation is very important for SiC power semiconductor devices. To form an implanted aluminum box-profile, continuously variable energy RFQ (CVE-RFQ) linac was newly constructed. The linac is a bottom-settled type RFQ structure with double tunable plates. The resonance frequency range of this cavity is from 11.8 to 29.3 MHz, and Q-value of the cavity is over 5000. Beam acceleration test was carried out using Ar ions. Result showed that the ions were accelerated from 12 to 450 KeV using an RF power of 2.7 kW. (author)

[en] Zircaloy-2 cladding tubes, recrystallized at 853 K, which had been irradiated in the core region of the Fukushima Daiichi No. 3 reactor for up to three years were used for tension, burst, and Vickers hardness testings. The specimens, irradiated at fluences of 1 to 5x10²⁵ n/m² (E.MeV), were tested using identical test machines and procedures, which allowed quite precise fluence dependence data of mechanical properties to be obtained. The yield strength increment Δσsub(y) with irradiation was confirmed to follow the following equation, when the neutron fluence was over 1x10²⁴ n/m²: Δσsub(y)=A(phit)sup(n) where n=0.1. This relation was similarly recognized for tensile strength, hoop yield strength, ultimate hoop strength, and Vickers hardness. The hoop yield strength to yield strength ratio for unirradiated specimens was about 1.7 which demonstrated the material's anisotropy, while for specimens irradiated at more than 1x10²⁵ n/m², the ratio decreased to about 1.2, which corresponded to isotropical behavior. Elongations decreased rapidly in the early stage of irradiation until, at about 1x10²⁴ n/m², saturation was observed. Circumferential elongation showed a similar trend. A spiral fracture mode was observed in the case of tension tests of irradiated specimens, which corresponded to small elongations. Vickers hardness was linearly related to the tensile strength. (author)

[en] The results from the direct measurements of the trilinear gauge boson couplings are reported using the data taken with the D null detector at Fermilab. The limits on the anomalous coupling parameters were obtained at the 95% CL from three processes, WW/WZ production with the subsequent W boson decay to an electron and a neutrino and the second W or Z boson decay to two jets and W_γ and Z_γ productions with the subsequent W and Z boson decays to electron and muon channels

[en] The Fab fragments of antimyosin antibodies, labeled with /sup 99m/Tc, were used in the scintigraphic examination of 30 patients with myocardial infarction. The ability to detect necrosis and determine its extent from the antimyosin scan were compared with the results of quantitative regional wall motion analysis by contrast ventriculography at 10 to 14 days and /sup 99m/Tc-pyrophosphate imaging. Antimyosin images recorded by planar and single photon-emission computed tomography (SPECT) delineated areas of myocardial necrosis in 27 of 30 patients (90%) compared with a 91% sensitivity of pyrophosphate in 21 of 23 patients. Infarct size was determined by both antimyosin and pyrophosphate SPECT images. Results by both techniques showed a significant correlation with computer-derived hypokinetic segment length (r = .79 for both, p = .002) and peak creatine kinase (r = .9 for both, p less than .01). Although sensitivity for and correlations with markers of necrosis were similar with both techniques, infarct size by pyrophosphate SPECT was 1.7 times larger than infarct size by antimyosin SPECT (p less than .01). Certain zones in the infarct area were differentially labeled; the nature and irreversibility of injury wihin these zones remains to be clarified

[en] Since 1980, many experiments with new interesting ideas for the measurement of the electron (anti-) neutrino mass have been and are currently proceeding in the world. And their results are eagerly awaited in the field of the elementary particle physics, astrophysics and cosmonology to confirm that the neutrino has the mass of a few tens of eV. (J.P.N.)

[en] The electrical resistivity and superconducting properties of a newly synthesized superconducting material of the form Pb₃BiSsub(x) (x = 1.5-3.0) composed of all non-transition elements are presented. The sample film is fabricated by quick evaporation of the original sintered material. It is found that temperature dependence of electrical resistivity has anomalous behavior as represented by broad maximum in higher temperature region and minimum in lower temperature region. The critical temperature is about 8 K and the critical field is 35 k0e at 4.2 K for the sample with x = 1.9. The transition width is very broad for the magnetic transition, in contrast to the sharp transition at Tsub(c). The gap structure of a Pb₃BiSsub(x)- I - Sn tunnel junction is also presented. (author)

[en] Diagnosis of rejection after cardiac transplantation is currently made by right ventricular endomyocardial biopsy. To evaluate antimyosin imaging as a noninvasive means of detecting human cardiac rejection, the Fab fragment of murine monoclonal antimyosin antibodies was labeled with indium-111 and given intravenously to 18 patients (age 45 +/- 12 years) in 20 studies 7 days to 9 years after transplantation. Endomyocardial biopsy specimens were obtained at the time of each imaging study. Eight patients had positive scans confirmed by biopsy as rejection, and eight patients had negative scans and no evidence of rejection on biopsy. Discordance was observed in four studies, two with positive scans and no rejection on biopsy and two with negative scans and positive biopsy. The sensitivity, specificity, and overall accuracy of the technique were each 80%. Imaging with radiolabeled antimyosin antibody Fab fragments may be of value in the noninvasive identification of rejection in the cardiac transplant recipient

[en] Ultrafast optical response of carriers in Tl₂Ba₂CaCu₂O_8+δ thin films was, for the first time, investigated by means of time-resolved pump and probe reflectivity measurement using femtosecond optical pulse. The transient reflective data showed a relaxation time of optically excited quasiparticles as long as about 3.6 ps at 4.6 K. This value is intermediate between those for YBa₂Cu₃O_7-δ and Bi₂Sr₂CaCu₂O_8+δ, and well explains the difference in the terahertz radiation properties for these high-T_c superconducting materials