[en] This issue is the collection of the papers presented at the title meeting. The 41 of the presented papers are indexed individually. (J.P.N.)

[en] Thermoluminescence dosimeter (TLD) is an integral type measuring unit characterized by small size and high sensitivity. In addition, there is no effects of electric noises on TLD, it was thought that TLD is very suitable for the measurement of X-ray generated by heating device in an early phase. In this study, three-dimensional X-ray distribution was determined using TLD set at 40 sites around NBI and ECH and the changes in X-ray distribution was monitored for 1 week using a reader VD-520B (National Co. Ltd.). Since the duration of 1 week was same as the period of NBI experiment, the results obtained well reflected the conditions of the experiments. Thus, the results from X-ray measurement provide useful informations to specify the source of X-ray generation. The X-ray generation from NBI could be reduced by shielding it with lead. These results were useful for the determination of the position to set a monitor. (M.N.)

[en] An inertial confinement fusion reaction is carried out by use of the glass laser system in Gekko 12. The object of experiment is to take out energy from the fusion reaction, which was begun by implosion of fuel pellet with deuterium and tritium at irradiating homogeneously by high power laser. The construction and apparatus of the measurement system were explained. There are scintillator, NE102A·Gate Pilot U and Ag counter for neutron in the primary reaction and scintillator, BC NEW and CR-39 for neutron in the second reaction, and TOF for measuring the ion temperature within the pellet using the neutron energy spectra. (S.Y.)

[en] The measurement of level in the liquid nitrogen vessel has been carried out by the weight conversion method using weigher or by putting directly a stick in the vessel. On a large CE tank, the pressure difference was read by manometer. These methods can not be used when the vessel does not put on the weigher or the pipe for manometer is stopped. We noticed the interaction between radiation (γ-ray) and substance and applied it to determine the liquid nitrogen level. The results proved it the easy method for measurement of the level in the large CE tank. Cesium 137 (γ-ray energy: 662 keV) was used as the radiation source. γ-ray transmission dose was determined by GM survey meter. The liquid nitrogen level could be determined by using the change of the transmission dose with amount of liquid nitrogen. (S.Y.)

[en] The Large Helical Device itself with about 8 m diameter, 1.2 m diameter of plasma and 30,000 gauss of the strength of magnetic field belongs the largest class of helical device in the world. Superconducting coil is used. It's construction has been projected from 1990 to 1998. Now we are going to forward the large helical project to aim at ignition of plasma in the end of the fiscal year 1997. The large helical laboratory and the peripheral equipment room had been built except some parts. An assembling of the device has been started. The model of device has been made, but the models of peripheral equipment, has just been completed the technical investigation and estimation of the cost on the basis of the collective data about them. (S.Y.)

[en] The control system for the large tokamak nuclear fusion device, JT-60, consists of the individual control systems for the facilities such as the device proper, gas injection system, poloidal magnetic coil power source and so on and the whole system control facility which generalizes them. This whole system control facility and individual control systems are connected by CAMAC system and VME bus system, and control command and response, timing signals and others are given and received. Discharge sequence control operates the facilities required for forming and maintaining plasma according to certain order and conditions, and its functions consist of three treatment parts of sequence control, registration of check point state change and timer control. In order to efficiently do the addition and modifying of sequence logics and the tracing of sequence progress, automatic figure drawing tool, compilation tool and tracing tool are constructed on the work station. The way of thinking on the automatic figure drawing, the functioning environment of the automatic figure drawing tool, and the example of the sequence logic diagram made with this tool from logical information are described. (K.I.)

[en] National Institute for Fusion Science is constructing the LHD in Toki-shi, Gifu-ken. In order to evaluate the soundness of the LHD against earthquakes, the aseismatic analysis was carried out by using the structural analysis program ANSYS 5.0a. The object of analysis was heat insulation support legs, and it is necessary that the heat insulation support legs are so constructed as to maintain their strength in the occurrence of earthquakes (magnitude 5∼6, about 0.3G). This time, the analysis model for the time history response of total electromagnetic force-supporting structures was made, and the soundness of the heat insulation supporting legs against earthquakes was evaluated. The electromagnetic force-supporting structures and the heat insulation support legs are explained. Ten legs support the electromagnetic force-supporting structures at 4.2K while preventing heat intrusion, and absorb their thermal contraction. The analysis model for time history response, the conditions of the analysis and the results are reported. The results of analysis are reflected to the stress analysis of the heat insulation support legs. (K.I.)

[en] By the heightening of the processing capability of personal computers, also in the field of accelerator control, the system using personal computers as the main body can be constructed. Also it has become possible to supplement functions by combining different applications and offering the means of communication between applications by operating systems. At present, new accelerators are planned in Laboratory of Nuclear Science, Tohoku University, and National Laboratory for High Energy Physics, and the development environment using WAN was prepared for the purposes of the OMT analysis of accelerator domain from the viewpoint of control, the joint verification of the programs being made, and the efficient exchange of information. Windows NT was adopted, and its features are shown. The environment was constructed by using the personal computer on which Windows NT functions, and the specification of the used personal computer is shown. The performance was measured by using this environment, and its method and the results are reported. The operation mode for hereafter is explained. The construction of the development environment using Windows NT was completed with good results. (K.I.)

[en] Laboratory of Nuclear Science in Tohoku University has made a plan to construct a pulse beam stretcher boostering (STB) the fiscal year from 1995 to 1996. STB has two characteristic functions, one of them is pulse beam stretcher function to change 250 MeV pulse electron beam from Linac to direct current' beam and another is booster ring one to increase from 250 MeV to 1.2 GeV beam. Today, the detailed design is going to proceed. The subjects of control system are the direct current electromagnet, the pulse electromagnet, RF system, the vacuum system, the beam monitor system, the triggered system and the inter rock system. We will construct a control program of our own making. Another characteristic function is to adopt the directional object data base. The construction of hardware and software and the future planning are explained. (S.Y.)

[en] The ion cyclotron heating experiment at the large helical device has been planned for the large power of 12 MW at maximum and the steady state for 30 min at longest. In order to advance the experiment of making the oscillator with large power and steady state, since troubles occur frequently, often two oscillators are operated alternately while repairing and improving one of them. Accordingly, the works of reassembling for mutually switching antenna and dummy loads and two oscillators and the refilling and leak test of SF-6 insulation gas become necessary. In order to overcome these difficult works, it was decided to import the coaxial switching device from Zhongguo, and remodel it. The structure of the high frequency coaxial switching device is explained. Forced air cooling is adopted for it. The final target of high frequency power is 1.5 MW steady for 30 min at 20 - 120 MHz. The leak measurement of high frequency power was carried out as the coaxial tube was made into an open system, and this experiment is reported. The countermeasures to the local heat generation at the joint of water-cooled part and air-cooled part in the coaxial line are reported. (K.I.)