[en] An ECR ion source for an AVF-ring cyclotron complex has been constructed at RIKEN. The source is used to produce highly-charged ions for relatively light heavy elements (up to Ca). The first beam from the source was obtained on April 13, 1988. The source has been operated with gaseous elements since then. Through further half a year development, the beam from the source will be axially injected into the AVF cyclotron. The design and the construction of the ion source and the preliminary results are described

[en] Nuclear power plants in Japan have been holding excellent capacity factors of more than 70 percent for the last five years. Their scram frequency has been as low as 0.4 time per reactor year in average. As is obvious from these results, the nuclear power plants in Japan are among the top levels in reliability in the world. The excellence is mainly attributed to: system improvements through recent advanced technology and operating experiences, elaborate preventive maintenance, and intensive training for operators and maintenance personnel. This paper presents the current status and issues of the operation and maintenance of nuclear power plants in Japan, and of the training for station personnel

[en] In order to develop a new compact cluster ion source as a low damage sputtering source for SIMS to analyze ultra-shallow dopant state we have studied the possibility of using a metal cluster complex as an ion beam source. Metal cluster complexes such as Os₃(CO)₁₂ and Ir₄(CO)₁₂ have been studied from the view point of their stability in high vacuum and how to ionize them by using the electron ionization QMS and the XeCl laser ionization TOF. In the case of electron ionization QMS, peaks of Os₃(CO)_n⁺ (n=0-12) and Ir₄(CO)_n⁺ (n=0-12) were observed without the fragment ions such as a monomer, a dimer, etc. In the case of laser ionization TOF, peaks of the fragment and the parent ions without a carbonyl ligand were observed from Os₃(CO)₁₂, and Ir₄(CO)₁₂. The temperature dependence of fragmentation has also been discussed

[en] This paper reports on an ECR ion source for an AVF-Ring Cyclotron complex constructed at Riken. The source is used to produce highly-charged relatively light heavy ions (up to Ar). The first beam from the source was obtained on April 13, 1988. Through further one-year development, the beam from this source will be axially injected-into the AVF cyclotron. The design of the ion source and the beam injection line and the preliminary results are described

[en] Superconducting NdBa₂Cu₃O_7-δ thin films have been prepared in ultrahigh vacuum by the molecular beam epitaxy (MBE) method using a supersonic molecular beam of nitrogen dioxide as an oxidizing agent. A new type of supersonic molecular beam source has been developed, which has a liquid nitrogen trap for cryogenic pumping and is small enough in size to be installed in a conventional MBE system. Films with a transition temperature of about 30 K have been obtained in situ without post-deposition annealing. Throughout deposition epitaxial growth of the films was observed in situ by reflection high-energy electron diffraction

[en] X-ray photoelectron spectroscopy was used to study the oxidation of Cu by oxygen plasma generated from a Kaufman ion gun. It was found that Cu was much less oxidized in co-evaporation with Ba or Nd compared to Cu-only evaporation when the total flux density of supplied metals and the oxygen plasma conditions were similar. It was also found that elemental Ba or Nd deposited on a CuO film at room temperature deoxidized the CuO. (Author)

[en] A scheduling support method for plant construction tasks has been developed by combining PERT, a conventional mathematical programming technique for scheduling, with AI techniques. On the basis of this method, a scheduling support system was implemented and experimentally applied to a practical scheduling problem in power plant construction

[en] Thin films of YBa₂Cu₃O_7-δ(YBCO) were prepared in MBE with two types of oxidizing gases. One is a NO₂ supersonic molecular beam which is well collimated NO₂ beam with a high flux density. The other is a high purity ozone gas with good controllability in flux density. Using RHEED during deposition we observed growth behaviors of YBCO with each oxidizing gas. The RHEED intensity oscillations under coevaporation conditions suggest unit by unit growth of YBCO. The overal RHEED oscillation with period of c-axis unit was observed during sequential deposition with O₃. (orig.)

[en] A scheduling support system through knowledge-based man-machine cooperation has been developed for nuclear power plant construction. The proposed system, named NPCS, has three characteristic functions: (1) Automatic dissolution of constraint violations using a constraint-oriented programming technique; (2) Automatic resource leveling based on a combinatorial-optimization technique using heuristic rules on task ordering; (3) Display of a scheduling chart which facilitates interactive schedule modification performed by expert engineers. A scheduling process of NPCS consists of two steps. At the first steps, an initial schedule with leveled resource is built, and at the second step, the initial schedule is improved interactively, where constraint violations are dissolved automatically. NPCS was experimentally applied to solve about 80 scheduling problems in a nuclear power plant construction and confirmed to reduce the scheduling time and to improve the quality of the schedule. (author)

[en] An ECR ion source for an AVF-Ring Cyclotron complex is now under construction at RIKEN. The source will be used to produce highly-charged relatively light heavy ions (up to Ar). The first beam is scheduled in April 1988. Through further one-year development, the beam from this source will be axially injected into the AVF cyclotron. The design of the ion source and the beam injection line is described. (author)