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Magnetic Sensorless Control of Plasma Position and Shape in a Tokamak

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Plasma Science and Technology 2006年第1期8卷 80-83页

作者： k.NAkAMURA 罗家融王华忠季振山王华王枫齐娜 k.N.SATO k.hanada M.SAkAMOTO H.IDEI M.HASEGAWA S.kAWASAkI H.NAkASHIMA A.HIGASHIJIMA Research Institute for Applied Mechanics Kyushu UniversityFukuoka816-8580Japan Institute of Plasma Physics Chinese Academy of SciencesHefei 230031China Interdisciplinary Graduate School of Engineering Sciences Kyushu UniversityFukuoka816-8580Japan

Magnetic sensorless sensing and control experiments with the plasma horizontal position have been carried out in the superconducting tokamak HT-7. The sensing is made to focus on the ripple frequency component of the power supply with thyristor and directly from them without time integration. There is no drift problem with the integrator of wagnetic sensors. Two kinds of control experiments have been carried out： to keep the position constant and swing the position in a triangular waveform, And magnetic sensorless sensing of plasma shape is discussed.

关键词： sensorless control drift problem HT-7 shape control EAST

Magnetic Sensorless Sensing of Plasma Position in the Superconducting Tokamak HT-7

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Plasma Science and Technology 2004年第5期6卷 2459-2462页

作者： k.Nakamura Z.S.Ji B.Shen P.J.Qin S.Itoh k.hanada M.Sakamoto E.Jotaki M.Hasegawa A.Iyomasa S.kawasaki H.Nakashima Research Institute for Applied Mechanics Kyushu University 6-1 Kasuga-koen Kasuga City Fukuoka 816-8580 JapanInstitute of Plasma Physics Chinese Academy of Sciences Hefei 230031 ChinaInstitute of Plasma Physics Chinese Academy of Sciences Hefei 230031 ChinaInstitute of Plasma Physics Chinese Academy of Sciences Hefei 230031 ChinaResearch Institute for Applied Mechanics Kyushu University 6-1 Kasuga-koen Kasuga City Fukuoka 816-8580 JapanResearch Institute for Applied Mechanics Kyushu University 6-1 Kasuga-koen Kasuga City Fukuoka 816-8580 JapanResearch Institute for Applied Mechanics Kyushu University 6-1 Kasuga-koen Kasuga City Fukuoka 816-8580 JapanInstitute of Plasma Physics Chinese Academy of Sciences Hefei 230031 ChinaResearch Institute for Applied Mechanics Kyushu University 6-1 Kasuga-koen Kasuga City Fukuoka 816-8580 JapanResearch Institute for Applied Mechanics Kyushu University 6-1 Kasuga-koen Kasuga City Fukuoka 816-8580 JapanResearch Institute for Applied Mechanics Kyushu University 6-1 Kasuga-koen Kasuga City Fukuoka 816-8580 JapanResearch Institute for Applied Mechanics Kyushu University 6-1 Kasuga-koen Kasuga City Fukuoka 816-8580 Japan

Magnetic sensorless sensing experiments of the plasma horizontal positionhave been carried out in the superconducting tokamak HT-7. The horizontal position is calculatedfrom the vertical field coil current and voltage without using signals of magnetic probes placednearby a plasma. The calculations are focused on the ripple frequency component of the power *** is no drift problem with the time integration of magnetic probe signals. The error of thederived plasma position is lower than 2% of the plasma minor radius.

关键词： sensorless sensing plasma position HT-7

Power Balance Estimation in Long Duration Discharges on QUEST

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Plasma Science and Technology 2016年第11期18卷 1069-1075页

作者： k.hanada H.ZUSHI H.IDEI k.NAkAMURA M.ISHIGURO S.TASHIMA E.I.kALINNIkOVA Y.NAGASHIMA M.HASEGAWA A.FUJISAWA A.HIGASHIJIMA S.kAWASAkI H.NAkASHIMA O.MITARAI A.FUkUYAMA Y.TAkASE X.GAO H.LIU J.QIAN M.ONO R.RAMAN Research Institute for Applied Mechanics Kyushu UniversityFukuoka 816-8580Japan Interdisciplinary Graduate School of Engineering Science Kyushu UniversityFukuoka 816-8580Japan School of Industrial Engineering Tokai UniversityKumamoto 862-8652Japan Graduate School of Technology Kyoto UniversityKyoto 615-8530Japan Graduate School of Frontier Science University of TokyoChiba 277-8561Japan Institute of Plasma Physics Chinese Academy of SciencesHefei 230031China Princeton Plasma Physics Laboratory Princeton NJ 08540USA SAeronautics&Astronautics University of WashingtonSeattle WA 98195-2400USA

Fully non-inductive plasma start-up was successfully achieved by using a well- controlled microwave source on the spherical tokamak, QUEST. Non-inductive plasmas were maintained for approximately 3-5 min, during which time power balance estimates could be achieved by monitoring wall and cooling-water temperatures. Approximately 70%-90% of the injected power could be accounted for by calorimetric measurements and approximately half of the injected power was found to be deposited on the vessel wall, which is slightly dependent on the magnetic configuration. The power distribution to water-cooled limiters, which are expected to be exposed to local heat loads, depends significantly on the magnetic configuration, however some of the deposited power is due to energetic electrons, which have large poloidal orbits and are likely to be deposited on the plasma facing components.

关键词： steady state operation spherical tokamak plasma wall interaction power balance

Two Dimensional Density FlUCtuation Measurements During the Non-Inductive Current Ramp-up Phase in the Compact Plasma Wall Interaction Experimental Device CPD

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Plasma Science and Technology 2009年第4期11卷 397-401页

作者： H.ZUSHI T.RYOUkAI k.kIkUkAWA T.MORISAkI R.BHATTACHARYAY T.YOSHINAGA k.hanada T.SAkIMURA H.IDEI k.DONO N.NISHINO H.HONMA S.TASHIMA T.MUTOH S.kUBO k.NAGASAkI M.SAkAMOTO Y.NAkASHIMA Y.HIGASHIZONO k.N.SATO k.NAkAMURA M.HASEGAWA S.kAWASAkI H.NAkASHIMA A.HIGASHIJIMA RIAM Kyushu University IGSES Kyushu University National Institute for Fusion Science Hiroshima University kyoto University University of Tsukuba

Two-dimensional structure of density fluctuations is examined during the current jump phase, indicating a change from the open magnetic fields to the closed ones. During the smooth current ramp-up phase the two-dimensional contour of the LiI intensity shows vertically alignment, consistent with the magnetic surfaces. At the inflection point in Ip ramp-up the LiI intensity contour becomes flat in the observation regime and then suddenly a steep gradient and higher intensity regime are formed in the vertical direction. This higher intensity corresponds to a burst of LiI waveform. According to these changes in the contour, it is found that, within ~1 ms around the burst of LiI, a low frequency coherent wave with a long wavelength rapidly grows. The relations with other signals （magnetic flux and microwave stray power） are discussed with respect to the topological change in the magnetic configuration and mode conversion of the incident electromagnetic waves.

关键词： Li sheet beam density fluctuations current ramp-up spherical tokamak

How are multiple satellites seen from the ground? Relative apparent motion and formation stabilization

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Astrodynamics 2024年第1期8卷 121-134页

作者： kenta Nakajima Yasuhiro Yoshimura Hongru Chen Toshiya hanada Department of Aeronautics and Astronautics Kyushu University744 Motooka Nishi-kuFukuoka819-0395Japan

This paper answers how multiple satellites are seen from the ground. This question is inspired by space-advertising, a public exhibition in the night sky using a dot matrix of satellites that are bright enough to be seen by the naked eye. Thus, it is important for space advertisement that the specific dot matrix is seen. Moreover, the stability of the dot matrix during a visible span is very valuable. To stabilize the dot matrix, this study formulates an apparent position of a dot from a representative dot seen from the ground. The formulation, linear functions of a set of relative orbital elements, reveals the appearance of the dot matrix. The proposed relative variable in the formulation drives the instability of the dot matrix, thereby revealing an initial stable configuration of deputies from a chief. The arbitrary dot matrix designed using the configuration is stable even at low elevations without orbital control during the visible span.

关键词： formation flying relative motion stabilization astrodynamics multi-apparent motions space advertisement

High performance micromachining of sapphire by laser induced plasma assisted ablation(LIPAA)using GHz burst mode femtosecond pulses

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Opto-Electronic Science 2024年第6期3卷 20-29页

作者： kotaro Obata Shota kawabata Yasutaka hanada Godai Miyaji koji Sugioka RIkEN Center for Advanced Photonics(RAP) Wako-shiSaitama 351-0198Japan Faculty of Engineering Tokyo University of Agriculture and TechnologyKoganeiTokyo 184-8588Japan Graduate School of Science and Technology Hirosaki UniversityHirosakiAomori 036-8561Japan

GHz burst-mode femtosecond(fs)laser,which emits a series of pulse trains with extremely short intervals of several hundred picoseconds,provides distinct characteristics in materials processing as compared with the conventional irradiation scheme of fs laser(single-pulse mode).In this paper,we take advantage of the moderate pulse interval of 205 ps(4.88 GHz)in the burst pulse for high-quality and high-efficiency micromachining of single crystalline sapphire by laser induced plasma assisted ablation(LIPAA).Specifically,the preceding pulses in the burst generate plasma by ablation of copper placed behind the sapphire substrate,which interacts with the subsequent pulses to induce ablation at the rear surface of sapphire *** a result,not only the ablation quality but also the ablation efficiency and the fabrication resolution are greatly improved compared to the other schemes including single-pulse mode fs laser direct ablation,single-pulse mode fs-LIPAA,and nanosecond-LIPAA.

关键词： femtosecond laser GHz burst mode ablation LIPAA laser induced plasma assisted ablation sapphire

Experimental investigation of the degradation mechanism of silicone rubber exposed to heat and gamma rays

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High Voltage 2017年第2期2卷 92-101页

作者： Shugo hanada Maki Miyamoto Naoshi Hirai Liuqing Yang Yoshimichi Ohki Department of Electrical Engineering and Bioscience Waseda University3-4-1 OhkuboShinjuku-kuTokyoJapan Research Institute for Materials Science and Technology Waseda University2-8-26 Nishi-WasedaShinjuku-kuTokyoJapan State key Laboratory for Electrical Insulation and Power Equipment Xi'an Jiaotong UniversityXi'anPeople's Republic of China Cooperative Major in Nuclear Energy Waseda University3-4-1 OhkuboShinjuku-kuTokyoJapan

Cable-grade silicone rubber was aged thermally or by combining heat and gamma-ray radiation,and resultant changes in chemical,thermal,mechanical and electrical properties were *** experimental results obtained in these analyses are clearly consistent with the mechanism that silicone rubber is degraded by forming cross-linked structures via formation of abundant siloxane *** further progress of degradation,decomposition becomes *** these mechanisms,mechanical properties deteriorate dramatically by losing *** the real and imaginary parts of complex permittivity decrease,which is a contrastive difference from typical ageing behaviour of organic insulating *** addition,both the elongation at break and indenter modulus are good indicators of degradation of silicone rubber.

关键词： rubber mechanism modulus

Determination of the free lunar libration modes from ephemeris DE430

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Research in Astronomy and Astrophysics 2017年第12期17卷 89-94页

作者： Yong-Zhang Yang Jin-Ling Li Jin-Song Ping Hideo hanada Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China National Astronomical Observatories Chinese Academy of SciencesBeijing 100012China University of Chinese Academy of Sciences Beijing 100049China RISE Project National Astronomical Observatory of JapanOshu 0230861Japan

The Moon’s physical librations have been extensively studied, and elaborate researches have been developed for the purpose of deriving accurate modes of free librations. Our motivation comes from the Planetary and Lunar Ephemeris DE430 by JPL/NASA, which was created in April 2013,and is reported to be the most accurate lunar ephemeris today using the data from Gravity Recovery and Interior Laboratory（GRAIL）. Therefore, the residuals after fitting the model have reduced owing to improvement in the libration models, and the free librations embedded in the Euler angles have also improved. We use Fourier analysis to extract the approximate frequencies from DE430 and then a quadratic interpolation method is used to determine higher accuracy frequencies. With the frequencies,the linear least-squares fitting method is employed to fit the lunar physical librations to DE430. From this analysis we identified the three modes of free physical librations, and estimated the amplitudes as 1.471′′in longitude, 0.025′′in latitude and 8.19′′× 3.31′′for the wobble, with the respective periods of1056.16, 8806.9 and 27262.99 d. Since the free librations damp with time, they require recent excitation or a continuous stimulating mechanism in order to sustain.

关键词： Moon physical librations Fourier analysis least squares method

Applications of same-beam VLBI in the orbit determination of multi-spacecrafts in a lunar sample-return mission

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Science China(Physics,Mechanics & Astronomy) 2010年第6期53卷 1153-1161页

作者： GOOSSENS Sander kIkUCHI Fuyuhiko MATSUMOTO koji hanada Hideo National Astronomical Observatory of Japan

Same-beam VLBI means that two spacecrafts with small separation angles that transmit multi-frequency signals specially designed are observed simultaneously through the main beam of receiving antennas. In same-beam VLBI,the differential phase delay between the two spacecrafts and the two receiving antennas can be obtained within a small error of several picoseconds. As a successful application,the short-arc orbit determination of several hours for Rstar and Vstar,which are two small sub-spacecrafts of SELENE,has been much improved by using the same-beam VLBI data together with the Doppler and range data. The long-arc orbit determination of several days has also been accomplished within an error of about 10 m with the same-beam VLBI data incorporated. These results show the value of the same-beam VLBI for the orbit determination of multi-spacecrafts. This paper introduces the same-beam VLBI and Doppler observations of SELENE and the orbit determination results. In addition,this paper introduces how to use the same-beam VLBI for a lunar sample-return mission,which usually consists of an orbiter,a lander and a return unit. The paper also offers the design for the onboard radio sources in the lunar sample-return mission,and introduces applications of S-band multi-frequency same-beam VLBI in lunar gravity exploration and applications during all stages in the position/orbit determinations such as orbiting,landing,sampling,ascending,and docking.

关键词： same-beam VLBI differential phase delay sample-return orbit determination lunar gravity field