Yutaka Itou

Titanium carbide coating on inconel 625 liner for JT-60 BY HCD-ARE

Abstract The HCD-ARE (activated reactive evaporation using a hollow cathode discharge) method was applied to coat the TiC layer, being a low Z material, on the full-size Inconel 625 liner for JT-60 with the aim of ascertaining its capability of mass-productive coating and further of supplying suitable products which satisfy the properties required from fusion devices. The film was deposited at the substrate temperature of 500°C using an in-line evaporation system consisting of four vacuum chambers. The characteristics of the films are nearly equal to each other over the whole area of the sample liner. The deposited films of about 20 μm thick and a nearly stoichiometric composition show a preferred orientation in the (220) direction and the value of their line half-width is 0.23 ~ 0.26 deg. The lattice constants are nearly equal to those of the bulk crystal. By XPS observation the chemical shifts in C1s and Ti 2p sol3 2 binding of the TiC film were about −3 and +1 eV which are nearly equal to those of the single crystal, respectively. As a result of convenient valuation of the durability of coatings, TiC film exhibiting a strong adhesion and an adequate durability was obtained by the HCD-ARE method.

Manufacture and assembly of the 6-meter-long cryomodules for superconducting RF Test Facility (STF) at KEK

A superconducting RF test facility (STF) is being constructed at KEK for R&D oriented toward the International Linear Collider (ILC). Under KEKs guidance, Hitachi, Ltd. has manufactured cryostat components at its factory and completed final assembly in the STF Linac Building at KEK. The STF cryomodule consists of two cryostats, each about six meters long based on the TESLA-TTF-type III design. Each cryostat can house four 9-cell cavities, each one meter in length. This report outlines the flow of manufacturing from the factory to final assembly, and describes the manufacturing of equipment, assembly precision, and other matters.

Recent activities in accelerator construction and STF cryomodule

Since being founded in 1910, Hitachi, Ltd. has been providing a wide lineup of products and services in fields ranging from consumer home electronics to social infrastructure. The corporation has conducted a wide range of activities in the field of particle accelerators as well. This paper describes Hitachis contributions to the history of accelerator construction, major devices recently handled by Hitachi, and its efforts in developing STF cryomodules as part of recent R&D oriented toward the International Linear Collider (ILC).

Fabrication of a double-wall vacuum vessel model of H type steel beam for ITER

A new fabrication method of a vacuum vessel for the fusion experimental reactor (ITER) has been developed. This method is to obtain more desirable fabrication accuracy and easier nondestructive inspections. H type steel beams of 310 mm height and 20 mm thickness have been used as material of a vacuum vessel because of its structural advantages to form a double wall. To make sure of the method and characteristics on fabrication, a full scale half model of a sector was manufactured, and nondestructive examinations and dimension measurements were performed. This paper describes a discussion on the fundamental way to form a double wall vacuum vessel, the procedure of the H type steel vacuum vessel by electron beam welding and the results of experimental model fabrication.

REDUCTION OF ERROR FIELD IN CHS

One of the most important things to design a helical system is an accuracy of the coil windings. To get the meaningful experimental results, we designed carefully and, as a result, the expected error field was reduced less than 1–2 gauss at the plasma surface when the field strength on the magnetic axis is 1.5 Tesla. The influence of this error field is negligible, because this value is very small and has no dangerous resonance. To ensure this, we measured the magnetic field components by the Hall device and the magnetic surfaces by the fluorescent mesh.