NINETEENTH CENTURY MUSIC最新文献

{"title":"Safety and environmental considerations in the selection of fusion power plant design options","authors":"N. Taylor","doi":"10.1109/FUSION.2002.1027654","DOIUrl":"https://doi.org/10.1109/FUSION.2002.1027654","url":null,"abstract":"The neutron shielding provided by in-vessel components of a fusion power plant has an important influence on the safety and environmental performance. A number of issues related to the in-vessel shield design have been investigated, with a focus on waste minimization. Viable concepts have been identified to solve the conflict between low short-term decay heat and low long-term waste requirements, and for shields avoiding water coolant in plant designs employing beryllium neutron multiplier.","PeriodicalId":44192,"journal":{"name":"NINETEENTH CENTURY MUSIC","volume":"2 1","pages":"107-110"},"PeriodicalIF":0.4,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81384190","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":"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":"Status and plan of the HL-2A project","authors":"Jiancheng Yan, C. Zhou, Yong Liu, Dequan Liu","doi":"10.1109/FUSION.2002.1027735","DOIUrl":"https://doi.org/10.1109/FUSION.2002.1027735","url":null,"abstract":"This paper describes the outline of HL-2A project that is the first tokamak with a divertor in China. The recent achievements in the construction of the HL-2A tokamak is given. The development of major components and the installation of the machine are also described. The commissioning of HL-2A machine will start from the middle of 2002. The HL-2A experimental program and the future plan are sketched.","PeriodicalId":44192,"journal":{"name":"NINETEENTH CENTURY MUSIC","volume":"1 1","pages":"461-464"},"PeriodicalIF":0.4,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77500906","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":"Disruption design criteria for JET in-vessel components","authors":"V. Riccardo, P. Andrew, A. Kaye, P. Noll","doi":"10.1109/FUSION.2002.1027718","DOIUrl":"https://doi.org/10.1109/FUSION.2002.1027718","url":null,"abstract":"In view of the substantial modification in the JET plasma facing components foreseen for the 2004 shutdown, the design criteria for in-vessel components have been updated building up on the operational experience with divertor plasmas gained since the early '90s. Typically the most demanding design loads occur during disruptions and vertical displacement events (VDEs). In fast disruptions (e.g. density limit driven) the largest contribution to the loads comes from currents induced by fast change of the poloidal field, which tends to be proportional to the plasma current decay rate, the maximum of which has been observed to be linear with the pre-disruption plasma current. This implies that in the fastest events the current quench has a fixed duration at JET, about 10 ms. Usually VDEs take place on a longer time scale, and therefore halo currents determine the worst loading condition in these cases. Analysis of recent VDE data confirmed the previously observed magnitude of asymmetries: the toroidal peaking factor (TPF) up to 1.8 in upward VDEs and up to 1.4 in downward VDEs; the ratio average poloidal halo to initial plasma current (f) up to 23% in upward VDEs and up to 30% in downward VDEs. Experimental evidence to justify the new criteria and recipes on how to apply them to JET are included. The data used for the revision of the design criteria are discussed and compared with the assumptions used in the design of the components already present in the JET vacuum vessel.","PeriodicalId":44192,"journal":{"name":"NINETEENTH CENTURY MUSIC","volume":"91 1","pages":"384-387"},"PeriodicalIF":0.4,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80520710","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 and engineering of the Alcator C-Mod lower hybrid current drive system","authors":"G. Loesser, J. Rushinski, S. Bernabei, J. Hosea, J. Wilson, B. Beck, R. Parker","doi":"10.1109/FUSION.2002.1027632","DOIUrl":"https://doi.org/10.1109/FUSION.2002.1027632","url":null,"abstract":"The PSFC group of MIT and PPPL are jointly developing a Lower Hybrid Current Drive (LHCD) system for installation on the Alcator C-Mod tokamak, with the primary goal of driving plasma current. Twelve Klystrons will feed a coupler with an input power of 3 MW at 4.6 GHz and a pulse length of 5 seconds. The coupler is composed of 4 arrays, each with 24 wave-guides (96 total) which are stacked poloidally and are symmetric about both the vertical and horizontal planes. The four-stacked arrays are installed through a single equatorial port and can be axially adjusted to provide optimum plasma coupling. Material selections and spatial limitations required innovative design solutions that will be described.","PeriodicalId":44192,"journal":{"name":"NINETEENTH CENTURY MUSIC","volume":"8 1","pages":"20-22"},"PeriodicalIF":0.4,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80693699","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":"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":"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":"Nuclear considerations for FIRE","authors":"M. Sawan, H. Khater","doi":"10.1109/FUSION.2002.1027675","DOIUrl":"https://doi.org/10.1109/FUSION.2002.1027675","url":null,"abstract":"Nuclear analyses have been performed for the baseline design of the Fusion Ignition Research Experiment (FIRE). Nuclear heating, structural radiation damage, and magnet insulator dose were evaluated. Critical issues requiring additional R&D effort include low-temperature embrittlement of copper and identifying insulators that can handle a dose as high as 1.5/spl times/10/sup 10/ Rads under the FIRE load conditions. Activation calculations were performed to determine the amount of radioactivity and decay heat generated. Accessibility for hands-on maintenance was assessed. All components qualify as low level waste.","PeriodicalId":44192,"journal":{"name":"NINETEENTH CENTURY MUSIC","volume":"60 1","pages":"196-199"},"PeriodicalIF":0.4,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90949638","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}