[en] Hefei Tokamak HT-7 Upgrade (HT-7U) will be designed for advanced tokamak operating modes. All of the coils will use NbTi/Cu cable-in-conduit conductor (CICC) cooled with forced-flow supercritical helium (SHe). The poloidal field (PF) system comprises a central solenoid and six ring coils. The PF coils provide 10.0 V-s to ohmically start and control a long pulse of a 1.0 MA plasma current. The coils will be stable during all modes of normal operation and from all disturbances, including plasma disruptions. The conductor design and the coils manufacture are discussed, the major parameters and performances of the coils are presented

[en] Selenium-75-labelled dinonyl-diselenide, C₉H₁₉⁷⁵SeSeC₉H₁₉, was synthesized and identified. It was injected into white rats in order to observe the selenium distribution in the tissues using inorganic ⁷⁵SeO₂ as the control agent. The sequence order of the ⁷⁵Se-dinonyl-diselenide uptake by tissues was: pancreas, muscles, stomach, liver, kidneys, spleen, blood, lungs, heart, brain, eyes. A very high accumulation of ⁷⁵Se-dinonyl-diselenide in the pancreas was observed, similar to that of the pancreatic imaging agent ⁷⁵Se-methionine. Furthermore, the enzymatic activity of glutathione peroxidase in the case of organic diselenide injection was higher than that measured for selenite. Selenium of dinonyl-diselenide was more effective and retainable in the process of converting itself to selenium-containing enzyme via the metabolic reactions. It may be advisable to replace inorganic sodium selenite by organic selenium compounds. Sodium selenite has been widely used in the prevention of the Keshan disease in China. (author)

[en] Hefei Tokamak HT-7 Upgrade (HT-7U) is a nuclear fusion experimental device with advanced tokamak operating modes. All of the coils will use NbTi/Cu Cable-in-Conduit Conductor (CICC) cooled with forced-flow supercritical helium (SHe). Up to date, the conductor fabrication for the central solenoid (CS) model coil has been completed. The length of the conductor is 370 m. The CICC consists of cabled 108 NbTi strands and 54 Cu strands in 316 L jacket by TIG welding. The outer dimensions of the conduit are 17.4 mm x 17.4 mm with an outer-corner radius of 3.5 mm. The void fraction of the conductor is 38 %. In this paper, we present a detailed description of the conductor manufacture for the CS model coil. (author)

[en] Rapid formation of ultra-thin dielectrics by Si surface modification (oxidation/renitridation/reoxidized nitrided oxides) using a low energy (<3.0 keV, dose range 0.75-3.0 C cm^-2) large area e-beam, which is based on cold cathode glow discharge of secondary emission, has been performed. Ultra-thin dielectric films over a range up to 200 A were grown rapidly. Higher oxidation rate (∼ 625 A² s^-1) and renitridation for shorter irradiation time (≤ 120 s) were obtained at lower substrate temperature (∼ 740⁰C) in N₂, O₂-He gas. AES and XPS demonstrated an electron-stimulated process on Si. Identifications of AES and C-V measurement for renitrided/reoxidized nitrided oxide films have shown that during a short processing of the e-beam (60-120 s) in N₂-He gas, nitrogen atoms can be incorporated in SiO₂ bulk besides nitrogen being piled up at SiO₂-Si interface, the shifts of C-V curves for the grown films have been also discussed. This e-beam as an alternative for rapid modification may be used to grow ultra-thin dielectric films on Si surfaces. (author)

[en] The HT-7U superconducting tokamak is an advanced steady-state plasma physics experimental device to be built at the Institute of Plasma Physics, the Chinese Academy of Sciences (CASIPP). The preliminary engineering design incorporates the superconducting toroidal field (TF) and poloidal field (PF) magnets, the vacuum vessel, the radiation shields, the cryostat and the current leads. The general mechanical structure of the HT-7U tokamak device with the detail structure of main parts is in design phase. The stability calculation and analysis of superconductors and coils have been done initially. The maximum field on the TF and PF coils and the maximum stress on the cases of coils, vacuum vessel and cryostat are evaluated. The R and D programs on the HT-7U tokamak device have been planned and in progress, which are focused on the design and development of conductors and model coils both in bath-cooling and force-cooling, test facility, winding machine, prototype of one 1/16 segment of vacuum vessel, and some key technologies. (author)

[en] To reveal the influence of erbium interlayer on the formation of nickel silicide and its contact properties on Si substrate, Er(0.5-3.0 nm) and Ni(20 nm) are successively deposited onto Si(1 0 0) substrate and are treated by rapid thermal annealing in pure N₂ ambient. The NiSi formation temperature is found to increase depending on the Er interlayer thickness. The formation temperature of NiSi₂ (700 deg. C) is not influenced by Er addition. But with 2 nm Er interlayer, the formed NiSi₂ is observed textured with preferred orientation of (1 0 0). During the formation of NiSi, Er segregates to the surface and little Er remains at the NiSi/Si(1 0 0) interface. Therefore, the Schottky barrier height of the formed NiSi/n-Si(1 0 0) contact is measured to be 0.635 ∼ 0.665 eV which is nearly invariable with different Er addition

[en] The R and D program of the superconducting model coil of HT-7U is in progress. A central solenoid model coil (CSMC) and a double-pancake toroidal field dummy coil (TFDC) have been designed and under fabrication in the Institute of Plasma Physics, the Chinese Academy of Sciences (ASIPP). CSMC has inner and outer diameters of 574 mm and 1140 mm respectively, height of about 485 mm and 216 turns in total. The peak field of it is 6.3 T with operating current of 18 kA. CSMC will be tested in ASIPP in the next year. TFDC is a 2/3 scale of toroidal field coil of HT-7U using a full size dummy conductor. A winding machine for cable-in-conduit conductor (CICC) coils has been constructed in ASIPP. (author)

[en] In this combined film thickness, scanning electron microscopy (SEM), X-ray diffraction and optical properties study, we explore the effects of different stirring speeds on the growth and optical properties of ZnS film deposited by CBD method. From the disclosed changes of thickness of ZnS film, we conclude that film thickness is independent of the stirring speeds in the heterogeneous process (deposition time less than 40 min), but increases with the stirring speeds and/or deposition time increasing in the homogeneous process. Grazing incident X-ray diffraction (GIXRD) and the study of optical properties disclosed that the ZnS films grown with different stirring speeds show partially crystallized film and exhibit good transmittance (70-88% in the visible region), but the stirring speeds cannot give much effects on the structure and optical properties in the homogeneous process.