NINETEENTH CENTURY MUSIC最新文献

{"title":"Electron cyclotron resonance frequency system on tokamak Aditya","authors":"B. Shukla, K. Sathyanarayana, D. Bora, S. Rajashree, K. Bhattacharya, B. Pal, S. Kulkarni, S. Gangopadhyay, Y. Srinivas, P. Khilar, M. Kushwah, R. Trivedi, D. Rathi, B. Kadia, A. Patel, C. Virani, P. Harsida, H. M. Jadav, K. Parmar, P. Shah, A. Makwana, S. Dani, P. Kirit, M. Harsha, J. Soni","doi":"10.1109/FUSION.2002.1027649","DOIUrl":"https://doi.org/10.1109/FUSION.2002.1027649","url":null,"abstract":"A 28 GHz ECRH system has been successfully commissioned on the tokamak Aditya to carry out breakdown, start up and heating experiments. The microwave source gyrotron VGA8000A19 capable of delivering 200 kW CW is commissioned and tested with a water dummy load for pulsed operation. The output mode of the gyrotron (TE/sub 02/) is externally converted to the HE/sub 11/ mode with the help of a mode converter and Matching Optics Unit of the transmission line. The transmission line consists of a mode converter, MOU, DC breaks, mitre bend, polarizer unit and different sizes of corrugated waveguides. The total transmission loss of the transmission line including 10 m long waveguides is measured to be less than 1.1 dB. The burn patterns at different locations of the transmission line confirm the mode purity to be better than 93% in the TE/sub 02/ mode. The transmission line terminates at a launcher box through a barrier window. The ECRH launcher consists of two mirrors to focus the microwave beam at the plasma center. The first mirror is convex while the second mirror is a concave focusing mirror. The mirrors are designed based on quasi optical analysis of the launcher system. The focal length of second mirror is 392.9 mm, which focuses the microwave beam to 35 mm (beam waist radius) at the plasma center. Beam steering in the plasma volume is restricted to /spl plusmn/2/spl deg/. The gyrotron is tested up to /spl sim/80 kW output power. A hard-wired interlock for various fault conditions, operates a rail-gap crowbar in less than 10 /spl mu/S to protect the gyrotron. The gyrotron output is coupled to the tokamak Aditya (O-mode, perpendicular launch from low field side) and successful breakdown of the neutral gas is observed at different tokamak parameters. The paper describes the technical aspects of commissioning of the ECRH system and breakdown results on Aditya.","PeriodicalId":44192,"journal":{"name":"NINETEENTH CENTURY MUSIC","volume":"26 1","pages":"88-90"},"PeriodicalIF":0.4,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83847489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"艺术学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Snowmass 2002: the fusion energy sciences summer study","authors":"N. Sauthoff, G. Navratil, R. Bangerter","doi":"10.2172/795778","DOIUrl":"https://doi.org/10.2172/795778","url":null,"abstract":"The Fusion Summer Study 2002 will be a forum for the critical technical assessment of major next-steps in the fusion energy sciences program, and will provide crucial community input to the long-range planning activities undertaken by the DOE and the FESAC. It will be an ideal place for a broad community of scientists to examine goals and proposed initiatives in burning plasma science in magnetic fusion energy and integrated research experiments in inertial fusion energy. This meeting is open to every member of the fusion energy science community and significant international participation is encouraged. The objectives of the Fusion Summer Study are three: 1. Review scientific issues in burning plasmas to establish the basis for the following two objectives and to address the relations of burning plasma in tokamaks to innovative magnetic fusion energy (MFE) confinement concepts and of ignition in inertial fusion energy (IFE) to integrated research facilities. 2. Provide a forum for critical discussion and review of proposed MFE burning plasma experiments (e.g., IGNITOR, FIRE, and ITER) and assess the scientific and technological research opportunities and prospective benefits of these approaches to the study of burning plasmas. 3. Provide a forum for the IFE community to present plans for prospective integrated research facilities, assess present status of the technical base for each, and establish a timetable and technical progress necessary to proceed for each. Based on significant preparatory work by the fusion community prior to the July Snowmass meeting, the Snowmass working groups will prepare a draft report that documents the scientific and technological benefits of studies of burning plasmas. The report will also include criteria by which the benefits of each approach to fusion science, fusion engineering/technology, and the fusion development path can be assessed. Finally, the report will present a uniform technical assessment of the benefits of the three approaches. The draft report will be presented and extensively discussed during the July meeting, leading to a final report. This report will provide critical fusion community input to the decision process of FESAC and DOE in 2002-2003, and to the review of burning plasma science by the National Academy of Sciences called for by FESAC and Energy Legislation which was passed by the House of Representatives. Members of the fusion community are encouraged to participate in the Snowmass working groups.","PeriodicalId":44192,"journal":{"name":"NINETEENTH CENTURY MUSIC","volume":"20 1","pages":"156-158"},"PeriodicalIF":0.4,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82436608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"艺术学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of the Quasi-Poloidal Stellarator Experiment (QPS)","authors":"B. Nelson, R. Benson, L. Berry, A. Brooks, M. Cole, P.J. Fogrty, P. Goranson, P. Heitzenroeder, S. Hirschman, G. Jones, J. Lyon, P. Mioduszewski, D. Monticello, D. Spong, D. Strickler, A. Ware, D. Williamson","doi":"10.1109/FUSION.2002.1027687","DOIUrl":"https://doi.org/10.1109/FUSION.2002.1027687","url":null,"abstract":"The engineering design status of the Quasi-Poloidal Stellarator Experiment (QPS) is presented. The purpose, configuration, and possible manufacturing and assembly techniques of the various components of the core are described.","PeriodicalId":44192,"journal":{"name":"NINETEENTH CENTURY MUSIC","volume":"104 1","pages":"248-251"},"PeriodicalIF":0.4,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75979199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"艺术学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nonlinear burn control in fusion reactors","authors":"E. Schuster, M. Krstić, G. Tynan","doi":"10.1109/FUSION.2002.1027729","DOIUrl":"https://doi.org/10.1109/FUSION.2002.1027729","url":null,"abstract":"Control of plasma density and temperature magnitudes, as well as their profiles, are among the most fundamental problems in fusion reactors. Unfortunately, the economy of fusion reactors often requires the reactor to operate under conditions in which the rate of thermonuclear reaction increases as the plasma temperature rises. In this thermally unstable zone, an active control system is necessary to stabilize the thermonuclear reaction. Existing efforts use control techniques for linear models. In this work, a zero-dimensional nonlinear model involving approximate conservation equations for the energy and the densities of the species was used to synthesize a nonlinear feedback controller for stabilizing the burn condition of a fusion reactor. The controller makes use simultaneously of the modulation of auxiliary power, the modulation of fueling rate and the controlled injection of impurities as actuators. A computer simulation study was performed to show the capability of the controller and compare it with previous linear controllers.","PeriodicalId":44192,"journal":{"name":"NINETEENTH CENTURY MUSIC","volume":"16 1","pages":"430-433"},"PeriodicalIF":0.4,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73037787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"艺术学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Alcator C-Mod inner divertor upgrade design and analysis","authors":"P. Titus, J. Zaks, M. DeMaria, B. LaBombard, R. Granetz, J. Irby, B. Lipshultz, E. Fitzgerald, R. Childs, W. Beck, E. Marmar, D. Gwinn, I. Hutchinson, R. Boivin, W. Burke","doi":"10.1109/FUSION.2002.1027705","DOIUrl":"https://doi.org/10.1109/FUSION.2002.1027705","url":null,"abstract":"In 1993 there were indications that the C-Mod inner divertor was being over-loaded. As a result, an inner divertor modification is being installed in C-Mod. The new design is intended to allow a change in profile of the divertor to accommodate a higher plasma triangularity, strengthen the inner vessel wall to survive 9.0 Tesla, 2.5 MA disruptions and, eliminate tile rotation. The thermal differentials between tiles and vessel wall, necessitated the introduction of compliance in the reinforcement hardware. Practical assembly within the vessel required manageable part size,and bolted interfaces which further reduced the strength and stiffness. A modest improvement of 22% was achieved while meeting the many design constraints.","PeriodicalId":44192,"journal":{"name":"NINETEENTH CENTURY MUSIC","volume":"2 1","pages":"333-336"},"PeriodicalIF":0.4,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86026951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"艺术学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of advanced physics and technology on the attractiveness of tokamak fusion power plants","authors":"F. Najmabadi","doi":"10.1109/FUSION.2002.1027630","DOIUrl":"https://doi.org/10.1109/FUSION.2002.1027630","url":null,"abstract":"During the past ten years, the ARIES Team has studied a variety of tokamak power plants with different degrees of extrapolation in plasma physics and technology from present database. Continuation of research has allowed us to apply lessons learned from each ARIES design to the next. The results of ARIES tokamak power plant studies provide a large body of data that highlight the tradeoffs and relative leverage of advanced plasma physics and fusion technology directions. Our results indicate that for the same plasma physics (e.g., first-stability) and technology extrapolation, steady state operation is more attractive than pulsed-plasma operation. Dramatic improvement over first-stability operation can be obtained through either utilization of high-field magnets (e.g., high-temperature superconductors) or operation in advanced-tokamak modes (e.g., reversed-shear). In particular, if full benefits of reversed-shear operation are realized, as is assumed in ARIES-AT, tokamak power plants will have a cost of electricity competitive with other sources of electricity. In technology area, emerging technologies such as advanced Baryon cycle, high-temperature superconductor, and advanced manufacturing techniques can improve the cost and attractiveness of fusion plants. For blankets, liquid breeder/coolants are the most attractive because most of neutron power is directly deposited in the coolant. This property can be exploited to arrive at a blanket design with a coolant outlet temperature higher than the structure temperature in the radiation zone. The high coolant temperature leads to a high thermal conversion efficiency (as in ARIES-ST and ARIES-AT blankets). The dual-cooled (He and LiPb) ARIES-ST blanket using ferritic steel structural material represents a near-term option for fusion systems and achieves a thermal efficiency of 45%. Development of high-performance SIC composites leads to the high-performance ARIES-AT blanket (SiC composite/LiPb coolant) that achieves 59% thermal conversion efficiency as well as the full potential safety and environmental features of fusion power.","PeriodicalId":44192,"journal":{"name":"NINETEENTH CENTURY MUSIC","volume":"201 1","pages":"10-15"},"PeriodicalIF":0.4,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80140424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"艺术学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Laser-induced damage of metal mirrors under long-term exposure at shallow angle of incidence","authors":"M. Zaghloul, M. Tillack, T. Mau","doi":"10.1109/FUSION.2002.1027693","DOIUrl":"https://doi.org/10.1109/FUSION.2002.1027693","url":null,"abstract":"Laser induced damage (LID) experiments were performed with a 2-J frequency-multiplied Nd:YAG laser at 1/2 /spl mu/m wavelength and a variety of metal mirrors (pure and impure diamond-turned) at shallow angle of incidence to study the sensitivity of these mirrors to LID under long term exposure. Practical lifetime curves for Al-1100 and 99.999% pure Al mirrors have been established up to 10/sup 4/ shots of operation. The results show general agreement with theoretical predictions.","PeriodicalId":44192,"journal":{"name":"NINETEENTH CENTURY MUSIC","volume":"5 1","pages":"272-275"},"PeriodicalIF":0.4,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90112853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"艺术学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Alcator C-Mod lower hybrid current drive experiment transmitter and power system","authors":"M. Grimes, D. Gwinn, R. Parker, D. Terry, J. Alex","doi":"10.1109/FUSION.2002.1027631","DOIUrl":"https://doi.org/10.1109/FUSION.2002.1027631","url":null,"abstract":"Alcator C-Mod is a high-field, high-density, diverted, compact tokamak, which, in its present form uses inductive current drive and is heated with 5 MW of ICRF auxiliary power. C-Mod is in the process of being upgraded with a 4.6 GHz Lower Hybrid heating and current drive system. The purpose of the experiment is to develop and explore the potential of \"Advanced Tokamak Regimes\", i.e., regimes with high bootstrap fraction (/spl sim/70%), high /spl beta//sub n/ (/spl sim/3) and high confinement (H/sub H//spl sim/1-2) under quasi-steady-state conditions. In this paper, an overview of the RF transmitter, high-voltage power supply and controls and protection systems for the Lower Hybrid Project is given. The transmitter will use twelve 250 kW klystrons operating simultaneously which will result in a total directed power of nearly 3 MW for a planned pulse width of 5 seconds. An expected upgrade of four additional klystrons will result in a total directed power of 4 MW. All klystrons will be powered in parallel by a single solid-state pulse-step-modulated (PSM) power supply with a rating of 50 kV and 208 amperes. Commissioning of the power supply is expected in February of 2002 with initial transmitter operation in late 2002.","PeriodicalId":44192,"journal":{"name":"NINETEENTH CENTURY MUSIC","volume":"57 1","pages":"16-19"},"PeriodicalIF":0.4,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89110997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"艺术学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polymer-derived SiC/sub f//SiC/sub m/ composite fabrication and microwave joining for fusion energy applications","authors":"R. Bruce, S. Guharay, F. Mako, W. Sherwood, E. Lara-Curzio","doi":"10.1109/FUSION.2002.1027728","DOIUrl":"https://doi.org/10.1109/FUSION.2002.1027728","url":null,"abstract":"Reports experimental results for the very first batch of products obtained by joining silicon carbide fiber-reinforced-silicon carbide matrix composites for fusion applications. The starting point of the work has been to fabricate and join matched pairs of SiC/sub f//SiC/sub m/ composites. The composites were joined in a microwave heating environment using preceramic polymer slurry as the joining material. Several key properties of these composites and joints were investigated, including measurements of density, flexural stress, and thermal conductivity. Measurements of our very first batch of products showed the average flexural stress for the intrinsic material at room temperature was 287.1 MPa. The composite exhibited crack deflection during fracture at room temperature. At 1100C, the average flexural stress dropped to 103.7 MPa and the composite exhibited brittle fracture. We obtained the in-plane thermal conductivity of the intrinsic material was 13.3 W/m-K at room temperature and 8.7 W/m-K at 1000C. The cross-plane thermal conductivity was 3.8 W/m-K at room temperature and 4.1 W/m-K at 1000C. Butt-joined bend bars had an average flexural stress of 31.9 MPa. Dovetail-joined bend bars had an average flexural stress of 39.0 MPa. The maximum value obtained for the dovetail-joined bend bars was 48.1 MPa. Optimization of the process parameters and detailed characterization are in progress to build a strong database and yield high-quality products for first wall structural material.","PeriodicalId":44192,"journal":{"name":"NINETEENTH CENTURY MUSIC","volume":"22 1","pages":"426-429"},"PeriodicalIF":0.4,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78137997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"艺术学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural design and analysis for the KSTAR cryostat","authors":"N. Her, S. Cho, J. Sa, K. Im, G. Hong, G.H. Kim, J.Y. Park, H. Kim, B.C. Kim, I. Yu, D.L. Kim, W. Kim, Y. Oh, C. Choi, J. Bak, M. Kwon, G.S. Lee, J.H. Kim, H. Ahn","doi":"10.1109/FUSION.2002.1027721","DOIUrl":"https://doi.org/10.1109/FUSION.2002.1027721","url":null,"abstract":"The KSTAR cryostat is a 8.8 m diameter vacuum vessel that provides the necessary thermal barrier between the ambient temperature test cell and the supercritical helium cooled superconducting magnet providing the base pressure of 1/spl times/10/sup -5/ torr. The cryostat is a single walled vessel consisting of central cylindrical section and two end closures, a flat base structure with external reinforcements and a dome-shaped lid structure. The base structure has 8 equally spaced support legs anchored on the concrete base. The cryostat vessel design was executed to satisfy the performance and operation requirements. The mechanical penetration components with bellows were designed to restrict the displacements of all kinds of ports due to EM loads and thermal loads within the allowable limits. The major loads considered in this paper for the design of cryostat vessel are the vacuum pressure, the dead weight of vacuum vessel, PFC, and magnet which are total about 400 tons, the electromagnetic load driven by plasma disruption, and seismic loads. Based on these loads, structural analyses were performed. It was found that the maximum stress intensity was below the allowable limit, and that the cryostat vessel had buckling safety of over 5. Based on the results, structural robustness of the cryostat vessel has been proved.","PeriodicalId":44192,"journal":{"name":"NINETEENTH CENTURY MUSIC","volume":"1 1","pages":"396-399"},"PeriodicalIF":0.4,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82914727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"艺术学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}