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This paper includes evaluations of composite tanks or pressure vessels based on fracture mechanics and an improved method for tank design. Problems of exfoliation between the mouthpiece and composite in current composite pressure vessels are shown, and the simple solution by inducing a slit into the mouthpiece near the bonding interface is proposed. The effect of the slit is evaluated using a geometrically simple model as well as a pressure vessel model designed for a rocket.

真空の科学と技術，大気の圧力の研究などのグエリケの業績は大変大きいにも関わらず，その全貌は不十分にしか紹介されていなかった．これは一つには彼が馬を用いて行ったマグデブルグの半球の実験があまりにも有名すぎたせいかもしれない．特にこの事情は我が国において著しいので，著者は 1. 叙説に続く 2. において現在得られる情報によりグエリケの伝記の概略を紹介することを試みた．さらに 3. において，彼の著作を中心に科学的業績について略説する．最後に 4. の結語において今後検討すべき課題について述べる．なお日本の文献は殆どが生まれたときの名前である Otto Gericke の姓であるゲーリケと書いてあるのに，本稿では“グエリケ”としたのは，現在欧米の文献は1666年の神聖ローマ帝国貴族の叙爵後の名前である Otto von Guericke を用いているから，それに従ったのである．

It is more than 40 years since 1960, when the first meeting of Symposium was convened. In these 40 years, human knowledge about plasma physics has increased enormously and technology has advanced a great deal to solve fusion energy problems, mainly thanks to the efforts of the Symposium member countries. Therefore, it is thought worthwhile to provide a written history of SOFT, which is practically representing the history of fusion research. Nowadays, the Symposium history suffers from the fact that it lacks formal records of its first few meetings. Because of this lack of formal records, it is difficult to know what technical and scientific subjects were discussed at those early meetings and what technological difficulties were recognized at such the first few SOFT meetings. We are not able to know what were agreed upon to solve the technological difficulties. This is the reason why I began gathering the records of the first few Symposium meetings. The efforts and difficulties I have made and encountered, respectively, are described in this paper. Time passes rapidly and it is becoming more and more difficult for me to complete my work. Therefore, since the Symposium usually has met in Europe, I wish European colleagues to read my paper, and would appreciate the importance of this problem. I am very glad if they take over the work from me.

This study presents the development and implementation of a photoelectron current measurement system on-board HORYU-IV satellite to take on-orbit measurements from conductive and insulator surfaces. The measurement system aims at providing critical information on photoelectron yield of materials widely used onboard spacecraft. HORYU-IV is the fourth satellites of the HORYU series developed at Kyushu Institute of Technology and it was piggy-back launched on-board H-IIA F30 rocket at an altitude of 575 km on February 17, 2016 (JST). The measurement system mainly consists of current-voltage amplifier circuits for AU, Kapton® and black Kapton® samples with gains of 1x, 3x and 1x amplification, respectively. In this article, the analysis of the on-orbit results is presented. The on-orbit results show that a photoelectron current of 2.9nA and 3.1nA was measured from black Kapton® sample at respective elevations of 70.7° and 71.1°. These results respectively correspond to a current density of 14.0μA/m2 and 18.0μA/m2 at 71.1°. This study also presents various ground-based tests results performed to verify and validate the effectiveness of the photoelectron current measurement system developed for space applications.

This paper describes effects of gravity on mobility performance of wheeled rovers for future lunar/planetary exploration missions. A series of model tests of a wheel‐terrain system were performed on an aircraft during variable gravity maneuvers, and it became clear that slip of the wheel becomes high when the gravity is less than 1/2G. In addition to the flight experiments, the same model tests were performed in a laboratory on the ground (1G condition). The experiments were demonstrated with variable wheel loads by using counterweights. As a result of the on‐ground experiments, the mobility performance under low wheel load conditions was found to be improved contrary to the flight experiments. In case of the flight experiments, not only the wheel load but also bearing in the terrain changes with respect to the gravity level, while only the wheel load changes in case of the on‐ground experiments. Thus, running under a reduced gravity condition becomes difficult because the terrain generates higher rolling...

A toroidal belt pump limiter has been designed, constructed, installed and operated in the TEXTOR tokamak. The Advanced Limiter TEST-II, or ALT-II, is carried out as a partnership under a joint agreement between the European Community, Japan and the United States. ALT-II is designed to withstand the high heat fluxes (greater than 500 W/cm 2 ) intrinsic to the boundary region of tokamak plasmas while simultaneously removing 5% to 10% of the core plasma efflux. The belt consists of eight segments, each 28 cm wide, 150 cm long, and 1.2 cm thick, and each is covered with shaped graphite tiles. Mounted behind each blade is a “scoop” system which captures plasma flowing past the leading edges and behind the blades. This plasma neutralizes on a collector plate and the resulting neutral gas is pumped. During ohmic discharges, 50 to 60 A of current is collected in the scoops and removal rates up to 0.25 Torr-l/s are achieved. The blades are instrumented with Langmuir probes and thermo couples, and other diagnostics include infrared cameras, H α -monitors, pressure gauges, helium charge exchange spectroscopy, and helium gas diagnostics. The plasma edge and the operation of the pump limiter system are described.

In the current space development, space explorations are focused on by many space agencies in the world. Next lunar missions will be required to land on steep surface among rocks and craters. For the purpose of lunar soft-landing, dynamics analysis is necessaly especially in contact dynamics with regolith. This paper discusses landing simulation using Mechanical Dynamics Software ADAMS (product by MSC. Software Corp.). Simulation model is based on the lander in the SELENE-B project by Japan Aerospace Exploration Agency. The lander has four landing-gears, and total mass is 400-500kg. Two specific characteristics of simulation model are expressions for honey-comb-core in a landing-gear, and contact dynamics with regolith on the lunar surface. Simulation in this paper especially focuses on influences onsoft-lamding by lander orientation, slope angle, and friction force.

Preparation of high current steady state ion source, fabrication of linac tanks by coating method, and development of high power high frequency power tube are described. The first one is the application of bombarded cathode to ion source with rather high operating pressure of 150 Pa, and the second is an application of coating technique primarily developed for tokamak divertor plate to linac cavity. Copper coating onto aluminium substrate is prepared and the measurements of the change of Q-value with coating thickness of 10 ∼ 30 μm is performed. The development of high power high frequency tube of 500 MHz frequency range for continuous operation is also described.

Vacuum technologies for fusion reactor are described from the stand point of the particle balance. At first, general view of the reactor vacuum system, and then the Rtokamak as a near term fusion device for D+ T reacting plasma are discussed. The efforts of development of the vacuum components and materials for vacuum systems are also described.

A communication system through distribution lines was developed for distribution automation. This system consists of a two level hierarchy system : a zero-phase-sequence carrier communication system through ungrounded 6kV distribution lines and an earth return communication system through grounded 100V/200V lines. In each system, transmission signals are generated by switching a passive element of small capacity between a line and the ground, and the signals are circulated through the line and the ground. By using this method, the influence of load impedance change and noises generated in loads is avoided sufficiently. Field tests were carried out at Ijiri Substation of the Kyushu Electric Power Co., Inc. for one year starting in September 1983. High reliability of the system was verified in terms of endurance in a severe environment and data transmission performance.

With objection of absolute measurement of sputtering yield, the microbalance has been constructed. In the balance system, weight change was followed from observation of the deflection of the balance. The deflection was optically magnified and was converted to electrical output by means of a linear photopotentiometer. To the weaker deflection signal due to smaller weight change than the noise, separation of the signal from the noise was an important problem. Of the noises, the fluctuating noises were induced from 1) propagation of mechanical vibration (1070 Hz) to the balance and the optical alignment, and 2) propagation of sample oscillation to the balance (1Hz), and periodical thermal expansion or shrink of the optical alignment in the thermostatic room (0.02 Hz). The amplitude of fluctuating noises having higher frequency components than 1 Hz could be damped by a factor of 5 by the use of a low pass filter (cutoff frequency is 0.1 Hz). Then the amplifier gain to the deflection signal could be increased by a factor of 5. As a result of the improvement of S/N, the increase of the sensitivity from 5×10-7 g/mV to 7.3×10-8 g/mV was achieved. The minimum detectable weight change per hour was also reduced from 10-6 g/hr to 3.7×10-8 g/hr.

Phase shift measurement with a microwave interferometer has been analysed to estimate the error in the measurement caused by mismatchings and unbalances of microwave elements in the detection system. When the most reasonable adjustments are made to balance the phase sensitive detection system. the error Δθ is estimated to be proportional to the degree of mismatch and unbalance γ, the intensity ratio of a transmitted wave to a reference wave ξ and the ratio of the wave attenuation through the plasma 1-α and is given as Δθ=¼γξ(1-α). This relation has been confirmed with simlation experiments. In an usual case where γ\lesssim0.4 and ξ=0.3, the error is about 0.05 radians, if the transmitted wave is attenuated to one tenth due to the presence of a plasma.

For a plasma column with a small diameter comparable to the wavelength of a microwave interferometer, the density can not be obtained from the phase shift measurement. We have estimated the density of this case by supposing that the received wave with an antenna consists of two components; one which is independent of the plasma density, transmitted in free space outside the plasma and the other which is dependent on density, transmitted through the plasma. The latter component has been shown to obey nearly the same relationship between the phase shift and the plasma density as in the case of a plasma slab by means of experiments and the scattering theory.

A power klystron amplifier and its driver system for a 6 MeV linear electron accelerator are described. The klystron is evacuated during its running by specially designed two oil diffusion pumps connected in series. Without using a liquid nitrogen trap the klystron works stable with the peak power output of 2–3 MW. The average life of the oxidecoated cathode was more than 500 hours. In order to keep a good frequency stability a feed back oscillator with an invar cavity and a travelling wave tube is used as a master oscillator. The output of this oscillator is 1–2 W at a frequency of 2759 Mc, with the fluctuation being less than 20 kc. The output signal of the oscillator is amplified by a pulsed travelling wave tube amplifier to drive the power klystron.

The measurement of the partial pressure of water is essential to monitor the conditioning during glow or ECR discharge cleaning. Usually QMF is adopted for this purpose, however, it has to be operated in better vacuum conditions of lower than 10 −2 Pa and with a hot filament for the electron source. The method described in this article is an application of the microwave spectroscopy so that measurement can be carried out with relatively high pressures of up to 100 Pa and needs no hot filament. The absorption rotational spectral line of water molecules at 22.235 GHz is used for this purpose. The spectrometer consists of a waveguide absorption cell with Stark electrode, a frequency-sweep microwave source and a phase-sensitive detector. The change in the intensity of the absorption spectrum of water could be detected during hydrogen glow discharge.

The exact solution of the magnetic field produced by the pulsive current flowing in the coils placed inside the metal vacuum chamber of ERA device in IPP-Nagoya, is calculated to design the compression system of the electron ring. Actual design of the compression coils and installations of power supply systems are also described.

A prototype of proton induction linac was developed to study the beam dynamics and the operational characteristics in this type of the accelerator speci-fically in the case of the intense ion beam acceleration. The driver system is composed of three identical unit modules, each of which consists three toroidal cores made of laminated silicon-iron foil of 0.1 mm thick and the driving circuit linked with the cores. The accelerating field of 28 kV/module is obtained typically during a period of 2 - 3 ?sec. A proton beam of about 200 mA is extracted directly with the field driven inductively by the first module and then accelerated with succeeding two units to give the particles of about 60 keV at the output of the modules. Preliminary results of the measurements of the beam characters are given with the design of the device.

Authors had opportunities to manufacture and to operate two power supply facilities, that is, 125 MVA computer controlled AC generator with a fly wheel for JIPP-T-2 stellerator in Institute of Plasma Physics, Nagoya University and 3 MW trial superconductive homopolar DC generator to the Japan Society for Promotion of Machine Industry have been manufactured.

Task problems on the site and facilities for a proposed DT-reacting plasma experiment (R-project) are given and discussed, with emphasis of minimizing environmental impacts, especially from the radiological safety point of view.

The Control of plasma current has been adopted in JIPP T-II tokamak/stellarator. The power supply for the control is a combined system of transistor and thyristor sections which are connected in series. A role of the transistor section is quick and fine control. This power supply is coupled to the primary circuit of current transformer with a stack of 24 semiconductor diodes. This stack also plays a role of crowbarring ohmic heating current.

A module of an induction Linac is developed, being aimed at application to ion acceleration. A proton beam of 30 mA is extracted from a reflex discharge ion source and accelerated up to 20 keV, directly by the applied inductive field in a 0.5–1.0 μs pulse.

A thermal interlock system with a quick response time has been developed to protect high‐power magnetic coil systems from thermal overloads. In this system thermal sensors are directly attached to coils and are electrically connected to other components through isolation transformers. The response time of the interlock system is estimated to be less than 1.5 seconds.

In parallel to the conceptual design of the R-tokamak, research and development efforts on the systems and the components have been carried out to obtain scopes to realize the device. Because we intended to introduce DT fuels into the device, the items of research and development works are quite different to that of non-burning machines. Alminium alloy developments to avoid activations by 14 MeV neutron irradiations, tritium safe handling and vacuum system with tritium are examples of this category. Beside specific requirement directly caused by DT introduction, highly reliable operation of the machine is strongly requested, because it is the necessary condition to perform experiments safely. However, these efforts are still in an early stage of investigation and many efforts are needed to prepare a rigid data base tokamak operation with reacting plasma.