2007 IEEE 22nd Symposium on Fusion Engineering最新文献

{"title":"Design and test of the support elements of the W7-X superconducting magnets","authors":"P. van Eeten, D. Hathiramani, V. Bykov, A. Cardella, A. Dudek, J. Holluba, P. Junghanns, J. Lingertat, D. Pilopp, J. Reich, F. Schauer, L. Sonnerup, D. Zacharias","doi":"10.1109/FUSION.2007.4337899","DOIUrl":"https://doi.org/10.1109/FUSION.2007.4337899","url":null,"abstract":"The Wendelstein 7-X stellarator is presently under construction at the Max-Planck-Institute for Plasma Physics in Greifswald with the goal to verify that a stellarator magnetic confinement concept is a viable option for a fusion power plant. The superconducting magnet system has to fulfill demanding requirements regarding magnetic field, loads, manufacturing and assembly. The magnet support system consists of several types of structural components. The main one is the central support structure (CSS) to which the superconducting coils are connected through Central Support Elements (CSE). These are bolted interfaces that allow for flange opening to reduce loads on the components. The non-planar coils (NPC) are toroidially interconnected via lateral support elements (LSE) and narrow support elements (NSE). NSE are contact supports consisting of Al bronze pads that allow for sliding under large compressive loads between the coils. The planar coils (PC) are connected to the NPC through planar support elements (PSE). At the module and half-module separation planes Contact Elements (CTE) connect the neighbouring NPC. An integrated programme of design, FE analysis, experiments and assembly trials has been undertaken. The NSE experimental program provided confidence that the pads can cope with the requirements regarding loads and cycles. Weld trials provided procedures for installing the LSE whilst keeping shrinkage and distortion within tight limits. Tests have been carried out to provide insight on the functioning of the CSE, in particular of the bolts and high performance Superboltreg-nuts during pre-load. This paper gives an overview of the integrated program on the W7-X support elements.","PeriodicalId":124369,"journal":{"name":"2007 IEEE 22nd Symposium on Fusion Engineering","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116123627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of Damage-Resistant Metal Mirrors for Laser-IFE","authors":"M. Tillack, J. Pulsifer","doi":"10.1109/FUSION.2007.4337952","DOIUrl":"https://doi.org/10.1109/FUSION.2007.4337952","url":null,"abstract":"A grazing-incidence metal mirror has been developed and tested as a candidate design option that has the potential to survive acceptably high laser fluence as well as the harsh environment of a laser-driven inertial fusion reactor chamber. We have developed fabrication techniques for high damage threshold metal mirrors and performed laser-induced damage studies using prototypical short-pulse lasers. Our results indicate that grazing-incidence metal mirrors have the ability to survive high-cycle laser irradiation while satisfying the requirements on beam quality necessary for successful target implosions.","PeriodicalId":124369,"journal":{"name":"2007 IEEE 22nd Symposium on Fusion Engineering","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126843252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sensitivity Study of Mechanical Behavior of Busbar System Designed for Wendelstein 7-X Stellarator","authors":"A. Panin, B. Giesen, A. Charl, G. Czymek, A. John, O. Neubauer, M. Sauer, R. Schick, J. Wolters","doi":"10.1109/FUSION.2007.4337926","DOIUrl":"https://doi.org/10.1109/FUSION.2007.4337926","url":null,"abstract":"The Wendelstein 7-X stellarator is now under construction in Greifswald, Germany. The superconducting busbar system for the stellarator coils is designed and manufactured at the Forschungszentrum Jiilich, Germany. The electromagnetic forces on the long busbars, considerable relative tilting of the coils carrying the busbar supports, lack of available space required for the robust design of these supports, collisions with other systems during operation as well as the cooling down process had to be taken into account during design phase. Having a complex layout and complying with different, often contradictory requirements, the busbar system turned out to be sensitive to the manufacture and assembly tolerances. The modular structure of the magnet system implied the modular sequence of the busbar system production. The mechanical behavior of the busbar system has been numerically simulated for the module 5. The developed global model reflects main important features of the complex system in a relatively simple way. It proved to be useful tool for frequent iterations during design period and for numerous tolerance studies. The paper describes the main features of the numerical model and some results of the sensitivity study of the busbar system.","PeriodicalId":124369,"journal":{"name":"2007 IEEE 22nd Symposium on Fusion Engineering","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132669695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A powerful tool to quantitatively detect tiny amounts of 4He in a deuterium rich background for fusion research","authors":"A. Frattolillo, A. De Ninno","doi":"10.1109/FUSION.2007.4337900","DOIUrl":"https://doi.org/10.1109/FUSION.2007.4337900","url":null,"abstract":"The detection of tiny amounts of 4He in a deuterium rich atmosphere (as well as of 3He in a tritium background) is of great relevance in fusion research. One of the main concerns in a d-t fusion experiment is to prevent significant accumulation of 4He ashes in the core plasma, since this would result in a dilution of the d-t fuel and in a consequent reduction of the fusion power output. In order to control the impurity concentration in the core plasma and to sustain the fuel density, several active pumping methods for 4He (and other impurities) have been proposed, such as divertors or pump limiters. A quantitative analysis of the exhausts of such devices can provide a useful evaluation of the effectiveness of different methods and configurations, by comparing the related 4He content. Helium leak detection is a further major problem in fusion research. Vacuum tightness of the large torus vessel is indeed a rigorous requirement, in order to minimize the impurity content of the plasma. However, due to the strong deuterium release by the wall of the vacuum vessel, a conventional helium leak detector would not be able to discriminate a small amount of leaked 4He in such a high deuterium background. Determination of tritium activity by 3He in-growth method also requires a mass spectrometric analysis system capable to detect small changes of 3He content in a tritium background. A new method has been developed at ENEA Frascati, allowing quantitative detection of extremely small amounts of Helium isotopes (and other inert gases) in a deuterium rich atmosphere using a conventional (i.e. normal resolution) quadrupole mass spectrometer. This is accomplished by means of two non-evaporable getter (NEG) pumps, the first one operating at high temperature (300 divide 450degC) and the second one at room temperature, which effectively and quickly remove to a high degree all active components in the original gas mixture, with particular regard to hydrogen isotopes. Obviously, noble gases are preserved. The results of extensive tests carried out with such a facility are reported. A high-resolution quadrupole mass spectrometer was used during tests with 4He-D2 mixtures, just to provide evidence for the absence of deuterium in the final gaseous mixture. The minimum detectable peak ratio 4He/D2 has been found to be less than 10-6.","PeriodicalId":124369,"journal":{"name":"2007 IEEE 22nd Symposium on Fusion Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130374393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"He-cooled Divertor for DEMO Status of Design and HHF Tests","authors":"P. Norajitra, A. Gervash, R. Giniyatulin, T. Ihli, W. Krauss, R. Krüssmann, V. Kuznetsov, A. Makhankov, I. Mazul, I. Ovchinnikov, J. Reiser, R. Ruprecht, V. Widak","doi":"10.1109/FUSION.2007.4337885","DOIUrl":"https://doi.org/10.1109/FUSION.2007.4337885","url":null,"abstract":"A modular He-cooled divertor concept for DEMO has been developed at Forschungszentrum Karlsruhe in cooperation with the Efremov Institute. The work covers the areas of design, analyses, fabrication technology, and experimental design verification. The overall design goal is to reach a heat flux of 10 MW/m2 at least. The selected reference design HEMJ (He-cooled modular divertor with multiple-jet cooling) employs small tiles made of tungsten, which are brazed to a finger-like thimble structure, which is made of tungsten alloy. The finger module is cooled by multiple jets of helium (10 MPa, 634degC) directly impinging onto the inner heated surface of the thimble. For the experimental verification of the design, a combined facility at Efremov, comprising a helium loop and an electron beam facility, was used. Technological studies focussed on the fabrication of tungsten divertor mock-ups, combined with an Eurofer steel structure. The first series of 1-finger mock-ups manufactured in this way were successfully HHF-tested in 2006. The test results confirmed the feasibility and the required performance of the design. The 2007 test series use mock-ups which have been improved in terms of thermal stress reduction and increasing manufacturing quality of tungsten parts (tile and thimble) and show a tendency of lifetime enhancement, i.e. surviving larger thermal cycles.","PeriodicalId":124369,"journal":{"name":"2007 IEEE 22nd Symposium on Fusion Engineering","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117226742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Divertor Heat Loads from Thermal and Alpha Particles in a Compact Stellarator Reactor","authors":"T. Mau, T. Kaiser, J. Lyon, R. Maingi, A. Raffray, X. Wang, L. Ku, M. Zarnstorff","doi":"10.1109/FUSION.2007.4337872","DOIUrl":"https://doi.org/10.1109/FUSION.2007.4337872","url":null,"abstract":"Divertor heat load distributions due to thermal and alpha particles have been assessed in an NCSX-based compact stellarator reactor. A divertor plate system is envisaged, with 4 plates per field period and covering 7% of the plasma surface area. The field-line tracing technique is employed; for thermal flux, the conventional approach is used, while for alphas, their characteristic exit pattern from the plasma and subsequent gyro- orbits are approximated. For the ARIES-CS reference design point (R=7.75 m, A=4.5, B=5.7 T, beta=6.4% and Pnet=1000 MW), combined peak heat loads in the 5 -18 MW/m2 range on the plates have been obtained, assuming a 75% radiation fraction both in the core and at the edge, and a 5% alpha loss fraction. The alpha heat flux could be a dominant determining factor. Further optimization study is warranted to lower all peak heat loads to satisfy the accepted limit of les10 MW/m2.","PeriodicalId":124369,"journal":{"name":"2007 IEEE 22nd Symposium on Fusion Engineering","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114511784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Princeton FRC Rotating-Magnetic-Field-Experiment RF System","authors":"C. Brunkhorst, B. Berlinger, N. Ferraro, S. Cohen","doi":"10.1109/FUSION.2007.4337897","DOIUrl":"https://doi.org/10.1109/FUSION.2007.4337897","url":null,"abstract":"The Princeton FRC (PFRC) is a compact device that utilizes odd-parity[1] radio-frequency rotating magnetic fields (RMFo) to heat electrons[2] and drive azimuthal current in a cylindrical plasma column. A serendipitous discovery is that the RF system serves as a useful diagnostic tool, providing data on RF-field penetration into the plasma.[3] Efficient use of RF power is required to accommodate the small size of the device and for its development into a practical fusion reactor. The RF system is described along with its evolution and lessons learned.","PeriodicalId":124369,"journal":{"name":"2007 IEEE 22nd Symposium on Fusion Engineering","volume":"272 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116068278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preliminary Design of NCSX Central Computing and Control","authors":"P. Sichta, J. Lawson, D. Mastrovito, P. Roney, K. Tindall","doi":"10.1109/FUSION.2007.4337939","DOIUrl":"https://doi.org/10.1109/FUSION.2007.4337939","url":null,"abstract":"The National Compact Stellarator Experiment (NCSX) is the centerpiece of the U.S. effort to develop the physics understanding of the compact stellarator and evaluate its potential for future fusion energy systems. A core component of the NCSX project is central computing and control, which is comprised of seven elements: 1) Networking and fiber optic infrastructure, 2) Central instrumentation and controls, 3) Diagnostic data acquisition and facility computing, 4) Facility timing and synchronization, 5) Realtime plasma and power supply control, 6) central safety and interlock system, and 7) Control room facility. NCSX central computing will build upon the success of the central computing model of the National Spherical Torus Experiment (NSTX). Like NSTX, a key design principle for the NCSX computing system is to use commodity computing hardware, and open-source and collaborative software wherever practical. Three major software codes of this type will be used: EPICS, MDSplus, and the integrated plasma control software from General Atomics. This paper will present an overview of the primary elements of the Central Computing and Controls, illustrate the use of open-source and collaborative software, and describe the new technologies that will advance the computing and control capabilities for NCSX.","PeriodicalId":124369,"journal":{"name":"2007 IEEE 22nd Symposium on Fusion Engineering","volume":"134 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125312168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Energy Storage for Power Hole Mitigation on the Electric Grid due to the ITER Neutral Beam Injector","authors":"F. Milani, V. Toigo, L. Zanotto","doi":"10.1109/FUSION.2007.4337932","DOIUrl":"https://doi.org/10.1109/FUSION.2007.4337932","url":null,"abstract":"The paper compares different solutions able to mitigate the effects on the electric grid of active power holes caused by the ITER Neutral Beam Injector (NBI) load: when, during the NBI operation, a breakdown of the accelerator grids occurs, the main power supplies have to be shut down and then, within 130 ms, switched on again. To overcome the consequent power steps, different schemes based on energy storage devices have been evaluated and compared in the paper. One particular solution is analyzed with the help of numerical simulations.","PeriodicalId":124369,"journal":{"name":"2007 IEEE 22nd Symposium on Fusion Engineering","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125561364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal Analysis of the Vertical Target for the ITER Divertor Design","authors":"S. Grigoriev, I. Mazul, V. Tanchuk, I. Gornikel, R. Tivey","doi":"10.1109/FUSION.2007.4337947","DOIUrl":"https://doi.org/10.1109/FUSION.2007.4337947","url":null,"abstract":"Monoblock tile design for the vertical target of the ITER is used for the utilization of the high density power from the tokamak plasma. The presented thermal analysis of the vertical target subjected to highly concentrated (q0 ap 382 MW/m2) near normal heat load demonstrates the developed code high ability to perform the transient thermal analysis on 2-D models with the complex nonlinear boundary conditions and makes it possible to draw the following conclusions: the concentrated heat load onto the vertical target tile causes the erosion of the plasma facing tile surface; about 20% of the incident heat load is lost by material evaporation and radiation from the vertical target external surface, by this way helping to relieve slightly cooling channel from the heat load. The main purposes of the paper are (a) to present the mathematical model, which makes possible to simulate the following peculiarities of the discussed problem: the tile surface erosion due to evaporation resulting in evolution of the loaded surface profile; redistribution of the temperature field and heat fluxes inside the vertical target body due to highly concentrated lateral heat load and surface burn-out; heat lost by radiation; shifting of the heat removal mode closer to critical heat flux (CHF); and (b) basing on the thermal analysis performed by the developed code to investigate possible consequences of a tile failure to avoid the cascade effect during transients.","PeriodicalId":124369,"journal":{"name":"2007 IEEE 22nd Symposium on Fusion Engineering","volume":"134 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128170107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}