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Sample records for tftr device

  1. Structural analysis and optimization procedure of the TFTR device substructure

    International Nuclear Information System (INIS)

    Driesen, G.

    1975-10-01

    A structural evaluation of the TFTR device substructure is performed in order to verify the feasibility of the proposed design concept as well as to establish a design optimization procedure for minimizing the material and fabrication cost of the substructure members. A preliminary evaluation of the seismic capability is also presented. The design concept on which the analysis is based is consistent with that described in the Conceptual Design Status Briefing report dated June 18, 1975

  2. Particle and energy transport studies on TFTR and implications for helium ash in future fusion devices

    International Nuclear Information System (INIS)

    Synakowski, E.J.; Efthimion, P.C.; Rewoldt, G.; Stratton, B.C.; Tang, W.M.; Bell, R.E.; Grek, B.; Hulse, R.A.; Johnson, D.W.; Hill, K.W.; Mansfield, D.K.; McCune, D.; Mikkelsen, D.R.; Park, H.K.; Ramsey, A.T.; Scott, S.D.; Taylor, G.; Timberlake, J.; Zarnstorff, M.C.

    1992-01-01

    Particle and energy transport in tokamak plasmas have long been subjects of vigorous investigation. Present-day measurement techniques permit radially resolved studies of the transport of electron perturbations, low- and high-Z impurities, and energy. In addition, developments in transport theory provide tools that can be brought to bear on transport issues. Here, we examine local particle transport measurements of electrons, fully-stripped thermal helium, and helium-like iron in balanced-injection L-mode and enhanced confinement deuterium plasmas on TFTR of the same plasma current, toroidal field, and auxiliary heating power. He 2+ and Fe 24+ transport has been studied with charge exchange recombination spectroscopy, while electron transport has been studied by analyzing the perturbed electron flux following the same helium puff used for the He 2+ studies. By examining the electron and He 2+ responses following the same gas puff in the same plasmas, an unambiguous comparison of the transport of the two species has been made. The local energy transport has been examined with power balance analysis, allowing for comparisons to the local thermal fluxes. Some particle and energy transport results from the Supershot have been compared to a transport model based on a quasilinear picture of electrostatic toroidal drift-type microinstabilities. Finally, implications for future fusion reactors of the observed correlation between thermal transport and helium particle transport is discussed

  3. Impurity control in TFTR

    International Nuclear Information System (INIS)

    Cecchi, J.L.

    1980-06-01

    The control of impurities in TFTR will be a particularly difficult problem due to the large energy and particle fluxes expected in the device. As part of the TFTR Flexibility Modification (TEM) project, a program has been implemented to address this problem. Transport code simulations are used to infer an impurity limit criterion as a function of the impurity atomic number. The configurational designs of the limiters and associated protective plates are discussed along with the consideration of thermal and mechanical loads due to normal plasma operation, neutral beams, and plasma disruptions. A summary is given of the materials-related research, which has been a collaborative effort involving groups at Argonne National Laboratory, Sandia Laboratories, and Princeton Plasma Physics Laboratory. Conceptual designs are shown for getterng systems capable of regenerating absorbed tritium. Research on this topic by groups at the previously mentioned laboratories and SAES Research Laboratory is reviewed

  4. Proposed TFTR electrical system

    International Nuclear Information System (INIS)

    Bronner, G.; Murray, J.

    1975-01-01

    The development of controlled thermonuclear fusion has progressed to the stage where the present facilities and energy available for future devices are not sufficient and must be increased by about a factor of ten. This report describes the proposed TFTR ac utility power distribution system, an energy storage motor generator flywheel facility, and the rectifier conversion equipment for the Toroidal Field Confining System (TF), Ohmic Heating System (OH), Equilibrium Field System (EF) and the Neutral Beam Heating System (NB). The general requirements are described and the special design considerations identified

  5. Disruptions in the TFTR tokamak

    International Nuclear Information System (INIS)

    Janos, A.; Fredrickson, E.D.; McGuire, K.; Batha, S.H.; Bell, M.G.; Bitter, M.; Budny, R.; Bush, C.E.; Efthimion, P.C.; Hawryluk, R.J.; Hill, K.W.; Hosea, J.; Jobes, F.C.; Johnson, D.W.; Levinton, F.; Mansfield, D.; Meade, D.; Medley, S.S.; Monticello, D.; Mueller, D.; Nagayama, Y.; Owens, D.K.; Park, H.; Park, W.; Post, D.E.; Schivell, J.; Strachan, J.D.; Taylor, G.; Ulrickson, M.; Goeler, S. von; Wilfrid, E.; Wong, K.L.; Yamada, M.; Young, K.M.; Zarnstorff, M.C.; Zweben, S.J.; Drake, J.F.; Kleva, R.G.; Fleischmann, H.H.

    1993-03-01

    For a successful reactor, it will be useful to predict the occurrence of disruptions and to understand disruption effects including how a plasma disrupts onto the wall and how reproducibly it does so. Studies of disruptions on TFTR at both high-β pol and high-density have shown that, in both types, a fast growing m/n=1/1 mode plays an important role. In highdensity disruptions, a newly observed fast m/n = 1/1 mode occurs early in the thermal decay phase. For the first time in TFTR q-profile measurements just prior to disruptions have been made. Experimental studies of heat deposition patterns on the first wall of TFTR due to disruptions have provided information on MHD phenomena prior to or during the disruption, how the energy is released to the wall, and the reproducibility of the heat loads from disruptions. This information is important in the design of future devices such as ITER. Several new processes of runaway electron generation are theoretically suggested and their application to TFTR and ITER is considered, together with a preliminary assessment of x-ray data from runaways generated during disruptions

  6. Operations and maintenance plans for the TFTR

    International Nuclear Information System (INIS)

    Allen, H.L.; Fedor, B.J.

    1978-01-01

    Princeton University Plasma Physics Laboratory (PPPL) is constructing a Tokamak Fusion Test Reactor (TFTR) scheduled to begin operation for fusion research experiments in late 1981, first with hydrogen and deuterium plasmas and later, in the second phase, using tritium for high power fusion studies. This latter mode will introduce considerable complexity to operation and maintenance of the TFTR in terms of meeting requirements for tritium handling, adequate radiation shielding, and corrective and preventive maintenance procedures. In this paper we discuss plans for the installation and preoperational testing of the major subsystems of TFTR, proposed start-up and operating scenarios for the device and the system of operational control. In addition, the TFTR Maintenance Plan and related procedures for specific major maintenance tasks are described, including the use of remote handling equipment and remote manipulators. Each of these topics is addressed in terms of the current status of planning and development

  7. TFTR data management system

    International Nuclear Information System (INIS)

    Randerson, L.; Chu, J.; Ludescher, C.; Malsbury, J.; Stark, W.

    1986-01-01

    Developments in the tokamak fusion test reactor (TFTR) data-management system supporting data acquisition and off-line physics data reduction are described. Data from monitor points, timing channels, transient recorder channels, and other devices are acquired and stored for use by on-line tasks. Files are transferred off line automatically. A configuration utility determines data acquired and files transferred. An event system driven by file arrival activates off-line reduction processes. A post-run process transfers files not shipped during runs. Files are archived to tape and are retrievable by digraph and shot number. Automatic skimming based on most recent access, file type, shot numbers, and user-set protections maintains the files required for post-run data reduction

  8. TFTR data management system

    International Nuclear Information System (INIS)

    Randerson, L.; Chu, J.; Ludescher, C.; Malsbury, J.; Stark, W.

    1986-01-01

    Developments in the tokamak fusion test reactor (TFTR) data management system supporting data management system supporting data acquisition and off-line physics data reduction are described. Data from monitor points, timing channels, and transient recorder channels and other devices are acquired and stored for use by on-line tasks. Files are transferred off-line automatically. A configuration utility determines data acquired and files transferred. An event system driven by file arrival activates off-line reduction processes. A post-run process transfers files not shipped during runs. Files are archived to tape and are retrievable by digraph and shot number. Automatic skimming based on most recent access, file type, shot numbers, and user-set protection maintains the files required for post-run data reduction

  9. TFTR materials issues and problems during design and construction

    International Nuclear Information System (INIS)

    Sabado, M.; Little, R.

    1984-01-01

    TFTR as well as its contemporaries, T15, JT60, and JET, have important contributions to make towards our understanding of plasma conditions in the thermonuclear regime. One of the main objectives of TFTR is to produce fusion power densities approaching those in a fusion reactor, approx.= 1 Wcm -3 at Q approx.= 1-2. TFTR will be the first tokamak to routinely use deuterium tritium, and produce approx.= 10 19 fusion neutrons per pulse. With startup of TFTR on December 24, 1982, the demonstration of physics feasibility of 'breakeven' is close at hand. Since TFTR performance will be reactor relevant, the capability of materials/components to withstand the hostile effects of a plasma environment will be presented. It is intended that designers of future fusion devices benefit from the materials technology developments and applications on TFTR. In an attempt to comply with this mandate, this paper will describe TFTR issues on materials, their developments, selections, problems, and solutions. Special emphasis will be given, in particular, to the impurity control devices in TFTR, namely, the limiter and surface pumping system located inside the vacuum vessel. The plasma will interact with these components and they will be subjected to disruptions, a vacuum of 10 -6 to 10 -8 torr and a nominal temperatures of 0 C. 'Painful' materials development problems encountered will be reviewed, as well as important 'lessons learned'. A briefing on the materials of construction will be given, with some comments on the problems that developed and their solutions. (orig.)

  10. Radiation shielding for TFTR DT diagnostics

    International Nuclear Information System (INIS)

    Ku, L.P.; Johnson, D.W.; Liew, S.L.

    1994-01-01

    The authors illustrate the designs of radiation shielding for the TFTR DT diagnostics using the ACX and TVTS systems as specific examples. The main emphasis here is on the radiation transport analyses carried out in support of the designs. Initial results from the DT operation indicate that the diagnostics have been functioning as anticipated and the shielding designs are satisfactory. The experience accumulated in the shielding design for the TFTR DT diagnostics should be useful and applicable to future devices, such as TPX and ITER, where many similar diagnostic systems are expected to be used

  11. Status report on TFTR

    International Nuclear Information System (INIS)

    Reardon, P.J.

    1978-01-01

    The primary objectives of the TFTR are the generation and confinement of 5 to 10 keV (50 to 100 million degrees) reactor-grade plasmas in a tokamad magnetic-field configuration, and the production of fusion energy on a pulsed basis, from the reaction of deuterum and tritium. The TFTR will be used to study the physics of burning plasmas and the engineering aspects of a D-T burning tokamak operating with reactor-level plasma conditions. The overall TFTR program is intended to produce scientific and technical information, component hardware, and the design, construction, and operating experience necessary as input for the future design, construction, and operation of ignition and experimental fusion power reactors. In a very real way the TFTR is prototypical of an Experimenta Power Reactor

  12. TFTR diagnostic vacuum controller

    International Nuclear Information System (INIS)

    Olsen, D.; Persons, R.

    1981-01-01

    The TFTR diagnostic vacuum controller (DVC) provides in conjunction with the Central Instrumentation Control and Data Acquisition System (CICADA), control and monitoring for the pumps, valves and gauges associated with each individual diagnostic vacuum system. There will be approximately 50 systems on TFTR. Two standard versions of the controller (A and B) wil be provided in order to meet the requirements of two diagnostic manifold arrangements. All pump and valve sequencing, as well as protection features, will be implemented by the controller

  13. DATA management for TFTR

    International Nuclear Information System (INIS)

    Christianson, G.B.; Chu; Randerson, L.R.

    1983-01-01

    The TFTR experiment generates such a large amount of data each shot that only a restricted subset of the acquired data is displayed quickly, so that operational physicists can control and direct the experiments. The authors discuss the software tasks and data structures used to acquire this summary data and present it in a graphical form. After the summary data has been acquired and displayed, the large quantity of diagnostic physics and engineering data must be acquired and placed on bulk storage devices. They describe the software tasks and data bases used to accomplish this, and indicate future enhancements. Experimental systems often require peripheral data files and data bases. They describe the means by which auxiliary files are associated with primary acquired data for a shot, and discuss ancillary data bases. The authors outline future plans for auxiliary data base management to aid in the offline analysis of past data. Summary, raw and processed data must be reliably archived to a permanent storage medium. The archival procedure and management of the archival directory to permit orderly retrieval of data for offline analysis are described. Finally, archived data must be formatted in a standardized fashion to permit access by a broad community of users. At the same time, the large amounts of data to be archived make an efficient format necessary. The formatting of data files and outline future plans for transmittal of archived data to other computer systems are described

  14. Helium transport in TFTR

    International Nuclear Information System (INIS)

    Strachan, J.D.; Chan, A.

    1986-09-01

    Initial measurements of the 15 MeV protons produced in TFTR by the d( 3 He, p)α fusion reaction have been used to determine the time evolution of the central 3 He density. The signals following short 3 He gas puffs indicate inward transport times of about 100 msec

  15. Coil protection calculator for TFTR

    International Nuclear Information System (INIS)

    Marsala, R.J.; Woolley, R.D.

    1987-01-01

    A new coil protection calculator (CPC) is presented in this paper. It is now being developed for TFTR's magnetic field coils will replace the existing coil fault detector. The existing fault detector sacrifices TFTR operating capability for simplicity. The new CPC will permit operation up to the actual coil limits by accurately and continuously computing coil parameters in real-time. The improvement will allow TFTR to operate with higher plasma currents and will permit the optimization of pulse repetition rates

  16. Safety review and approval process for the TFTR

    International Nuclear Information System (INIS)

    Levine, J.D.; Howe, H.J.; Howe, K.E.

    1983-01-01

    The design, construction, and operation of the Tokamak Fusion Test Reactor (TFTR) has undergone an extensive safety and enviromental analysis involving Princeton Plasma Physics Laboratory (PPPL), the U.S. Department of Energy (DOE), the Ebasco/Grumman Industrial Subcontractor Team, and other organizations. This analysis, which is continuing during the TFTR operational phase, has been facilitated by the preparation, review and approval of several documents, including an Environmental Statement (Draft and Final), a Preliminary Safety Analysis Report (PSAR), a Final Safety Analysis Report (FSAR), Operations Safety Requirements (OSRs) and Safety Requirements (SRs), and various Operating and Maintenance Manuals. Through TFTR Safety Group participation in formal system design evaluations, change control boards, and reviews of project procurement and installation documentation, the TFTR Management Configuration Control System assures that all aspects of the project, including proposed design, installation and operational changes, receive prompt and thorough safety analyses. These efforts will continue as the TFTR Program moves into the neutral beam and D-T operational phases. The safety review and approval experience that has been acquired on the TFTR Project should serve as a foundation for similar efforts on future fusion devices

  17. TFTR Motor Generator

    International Nuclear Information System (INIS)

    Murray, J.G.; Bronner, G.; Horton, M.

    1977-01-01

    A general description is given of 475 MVA pulsed motor generators for TFTR at Princeton Plasma Physics Laboratory. Two identical generators operating in parallel are capable of supplying 950 MVA for an equivalent square pulse of 6.77 seconds and 4,500 MJ at 0.7 power factor to provide the energy for the pulsed electrical coils and heating system for TFTR. The description includes the operational features of the 15,000 HP wound rotor motors driving each generator with its starting equipment and cycloconverter for controlling speed, power factor, and regulating line voltage during load pulsing where the generator speed changes from 87.5 to 60 Hz frequency variation to provide the 4,500 MJ or energy. The special design characteristics such as fatigue stress calculations for 10 6 cycles of operation, forcing factor on exciter to provide regulation, and low generator impedance are reviewed

  18. TFTR generator load assessment

    International Nuclear Information System (INIS)

    Heck, F.M.

    1975-10-01

    Typical experimental load demands on the TFTR generators are illustrated based on the electrical characteristics of the field coils, the coil leads, the main bus work, the various auxiliary bus work, the rectifiers, and transformers. The generator MW capacities are shown to be adequate for the proposed experimental operations with allowances made for variations in the final designs. The generator MVA capacities are shown to be adequate provided portions of the TF and EF rectifiers are freewheeled at selected times

  19. The TFTR maintenance manipulator

    International Nuclear Information System (INIS)

    Kungl, D.; Loesser, D.; Heitzenroeder, P.; Cerdan, G.

    1989-01-01

    TFTR plans to begin D-T experiments in mid 1990. The D-T experimental program will produce approximately one hundred shots, with a neutron generation rate of 10 19 neutrons per shot. This will result in high levels of activation in TFTR, especially in the vacuum vessel. The primary purpose of the Maintenance Manipulator is to provide a means of remotely performing certain defined maintenance and inspection tasks inside the vacuum torus so as to minimize personnel exposure to radiation. The manipulator consists of a six-link folding boom connected to a fixed boom on a movable carriage. The entire manipulator is housed in a vacuum antechamber connected to the vacuum torus, through a port formerly used for a vacuum pumping duct. The configuration extends 180 0 in either direction to provide complete coverage of the torus. The four 3500 l/s turbopumps which were formerly used in the pumping duct will be mounted on the antechamber. The manipulator will utilize two end effectors. The first, called a General Inspection Arm (GIA) provides a movable platform to an inspection camera and an in-vacuum leak detector. The second is a bilateral, force-reflecting pair of slave arms which utilize specially developed tools to perform several maintenance functions. All components except the slave arms are capable of operating in TFTR's vacuum environment and during 150 0 C bakeout of the torus. (orig.)

  20. TFTR DT preparation project status

    Energy Technology Data Exchange (ETDEWEB)

    Perry, E.D.; Dudek, L.E.

    1993-11-01

    The Tokamak Fusion Test Reactor (TFTR) research program is preparing to commence the first high power Deuterium-Tritium (DT) experiments of the US Fusion Program. Hardware upgrades to TFTR required for DT operations have been completed. This paper discusses these hardware preparations.

  1. Handling of tritium at TFTR

    International Nuclear Information System (INIS)

    Pierce, C.W.; Howe, H.J.; Yemin, L.; Lind, K.

    1977-01-01

    Some of the engineering approaches taken at TFTR for the tritium control systems are discussed as the requirements being placed on the tritium systems by the operating scenarios of the Tokamak. The tritium control systems presently being designed for TFTR will limit the annual release to the environment to less than 100 curies

  2. Mechanical engineering aspects of TFTR

    International Nuclear Information System (INIS)

    Citrolo, J.C.

    1983-04-01

    This paper briefly presents the principles which characterize a tokamak and discusses the mechanical aspects of TFTR, particularly the toroidal field coils and the vacuum chamber, in the context of being key components common to all tokamaks. The mechanical loads on these items as well as other design requirements are considered and the solutions to these requirements as executed in TFTR are presented. Future technological developments beyond the scope of TFTR, which are necessary to bring the tokamak concept to a full fusion-power system, are also presented. Additional methods of plasma heating, current drive, and first wall designs are examples of items in this category

  3. TFTR initial operations

    International Nuclear Information System (INIS)

    Young, K.M.; Bell, M.; Blanchard, W.R.

    1984-01-01

    TFTR (Tokamak Fusion Test Reactor) has operated since December 1982 with ohmically heated plasmas. Routine operation with feedback control of plasma current, position and density has been obtained for plasmas with Isub(p) approx.= 800 kA, a = 68 cm, R = 250 cm, and Bsub(t) = 27 kG. A maximum plasma current of 1 MA was achieved with q approx.= 2.5. Energy confinement times of approx. 150 msec were measured for hydrogen and deuterium plasmas with n-barsub(e) approx.= 2 x 10 13 cm -3 , Tsub(e)(O) approx.= 1.5 keV, Tsub(i)(O) approx.= 1.5 keV and Zsub(eff) approx.= 3. The preliminary results suggest a size-cubed scaling from PLT, and are consistent with Alcator C scaling where tau approx. nR 2 a. Initial measurements of plasma disruption characteristics indicate current decay rates of approx. 800 kA in 8 ms which is within the TFTR design requirement of 3 MA in 3 ms. (author)

  4. TFTR initial operations

    International Nuclear Information System (INIS)

    Young, K.M.; Bell, M.; Blanchard, W.R.

    1983-11-01

    The Tokamak Fusion Test Reactor (TFTR) has operated since December 1982 with ohmically heated plasmas. Routine operation with feedback control of plasma current, position, and density has been obtained for plasmas with I/sub p/ approx. = 800 kA, a = 68 cm, R = 250 cm, and B/sub t/ = 27 kG. A maximum plasma current of 1 MA was achieved with q approx. = 2.5. Energy confinement times of approx. 150 msec were measured for hydrogen and deuterium plasmas with anti n/sub e/ approx. = 2 x 10 13 cm -3 , T/sub e/ (0) approx. = 1.5 keV, T/sub i/ (0) approx. = 1.5 keV, and Z/sub eff/ approx. = 3. The preliminary results suggest a size-cubed scaling from PLT and are consistent with Alcator C scaling where tau approx. nR 2 a. Initial measurements of plasma disruption characteristics indicate current decay rates of approx. 800 kA in 8 ms which is within the TFTR design requirement of 3 MA in 3 ms

  5. Recent results from TFTR

    International Nuclear Information System (INIS)

    Hawryluk, R.J.; Bell, M.G.; Bitter, M.

    1984-05-01

    During the past year, the research activities on TFTR have encompassed three broad areas. The first was to extend the operating range of TFTR. Plasma currents up to 1.5 MA were achieved in discharges with a = 0.83 m, R = 2.55 m at a toroidal field of 2.7 T. In these large plasmas, the maximum line average density was 3.35 x 10 19 m -3 . The second activity was a study of the scaling of the energy confinement time, tau/sub E/, in ohmically heated discharges as a function of plasma current, density, and plasma size. These experiments indicate a favorable scaling of tau/sub E/ with size and density. Energy confinement times in excess of 0.25 s were obtained in deuterium discharges. The third activity was a study of adiabatic compression. During compression, the plasma current and ion temperature scaled approximately as predicted; however, the electron temperature and density scaled less strongly than predicted for ideal compression

  6. TFTR diagnostic control and data acquisition system

    International Nuclear Information System (INIS)

    Sauthoff, N.R.; Daniels, R.E.; PPL Computer Division

    1985-01-01

    General computerized control and data-handling support for TFTR diagnostics is presented within the context of the Central Instrumentation, Control and Data Acquisition (CICADA) System. Procedures, hardware, the interactive man--machine interface, event-driven task scheduling, system-wide arming and data acquisition, and a hierarchical data base of raw data and results are described. Similarities in data structures involved in control, monitoring, and data acquisition afford a simplification of the system functions, based on ''groups'' of devices. Emphases and optimizations appropriate for fusion diagnostic system designs are provided. An off-line data reduction computer system is under development

  7. Recent TFTR results

    International Nuclear Information System (INIS)

    Meade, D.M.; Arunasalam, V.; Bell, M.G.; Bell, R.; Bitter, M.; Boivin, R.; Bretz, N.L.; Budny, R.; Cavallo, A.; Cheng, C.Z.; Chu, T.K.; Cohen, S.A.; Cowley, S.; Davis, S.L.; Dimock, D.L.; Efthimion, P.C.; Ehrhardt, A.B.; Fredrickson, E.; Furth, H.P.; Goldston, R.J.; Greene, G.; Grek, B.; Grisham, L.R.; Hammett, G.; Hawryluk, R.J.; Hill, K.W.; Hosea, J.C.; Hulse, R.A.; Hsuan, H.; Janos, A.; Jassby, D.L.; Jobes, F.C.; Johnson, D.W.; Johnson, L.C.; Kaita, R.; Kaye, S.; Kieras-Phillips, C.; Kilpatrick, S.J.; Kugel, H.; La Marche, P.H.; LeBlanc, B.; Manos, D.M.; Mansfield, D.K.; Mazzucato, E.; McCarthy, M.P.; McCune, D.C.; McGuire, K.M.; Medley, S.S.; Mikkelsen, D.R.; Monticello, D.; Motley, R.; Mueller, D.; Murphy, J.; Nazikian, R.; Owens, D.K.; Park, H.; Park, W.; Paul, S.; Perkins, R.; Ramsey, A.T.; Redi, M.H.; Rewoldt, G.; Roquemore, A.L.; Rutherford, P.H.; Schilling, G.; Schivell, J.; Schmidt, G.L.; Scott, S.D.; Stevens, J.; Stodiek, W.; Stratton, B.C.; Synakowski, E.; Tang, W.A.; Taylor, G.; Timberlake, J.R.; Towner, H.H.; Ulrickson, M.; von Goeler, S.; Wieland, R.; Williams, M.D.; Wilson, J.R.; Wong, K.L.; Yamada, M.; Yoshikawa, S.; Young, K.M.; Zarnstorff, M.C.; Zweben, S.J.; Bush, C.E.; Dooling, J.; Dylla, H.F.; Fonck, R.J.; Roberts, D.; Howell, R.B.; Kesner, J.; Marmar, E.S.; Snipes, J.; Terry, J.L.; Nagayama, Y.; Pitcher, S.

    1991-07-01

    TFTR experiments have emphasized the optimization of high performance plasmas as well as studies of transport in high temperature plasmas. The recent installation of carbon composite tiles on the main bumper limiter has allowed operation with up to 32 MW of neutral beam injection without degradation of plasma performance by large bursts of carbon impurities (''carbon blooms''). Plasma parameters have been extended to T i (0) ∼ 35 keV, T e (0) ∼ 12 keV, n e (0) ∼1.2 x 10 20 m -3 producing D-D reaction rates of 8.8 x 10 16 reactions per second. The fusion parameter n e (0)τ E T i (0) in supershot plasmas is an increasing function of heating power up to an MHD stability limit, reaching values of ∼4.4 x 10 20 m -3 sec keV. Peaked-density-profile hot-ion plasmas with the edge characteristics of the H-mode have been produced in a circular cross-section limiter configuration with n e (0)τ E T i (0) values characteristic of supershots, namely up to four times those projected for standard H-modes with broad density profiles. Reduced transport is also observed in the core of high-density ICRF-heated plasmas when the density profile is peaked. At the highest performance, the central plasma pressure in TFTR reaches reactor level values of 6.5 atmospheres. In these regimes, MHD instabilities with m/n = 1/1, 2/1, 3/2 and 4/3 are often observed concurrent with a degradation in performance. High β p plasmas with var-epsilon β p ∼ 1.6 and β/(I/aB) ∼ 4.7 (%mT/MA) have demonstrated confinement enhancement over the low-mode confinement time with τ E /τ L ∼ 3.5 and a bootstrap current of about 65% of the total plasma current

  8. Material selection for TFTR limiters

    International Nuclear Information System (INIS)

    Ulrickson, M.

    1980-10-01

    The requirements for the material to be used as the first surface of limiters in TFTR are that it: (1) withstand a heat flux of 1 kw/cm 2 for a pulse length of 1.5s and a duty cycle of 1/200 for 10 5 cycles, (2) withstand the thermal and electro-magnetic loads from 10 4 plasma current disruptions lasting about 200 μs, (3) generate impurities at a rate low enough to meet impurity control requirements (which depend on the atomic number of the material) for TFTR, and (4) have tritium retention characteristics consistent with tritium inventory requirements for TFTR. An extensive set of material tests using electron beams, neutral beams, and plasma bombardment have been carried out to identify materials which can meet the thermal requirements of the above

  9. The ICRF antennas for TFTR

    International Nuclear Information System (INIS)

    Hoffman, D.J.; Colestock, P.L.; Gardner, W.L.; Hosea, J.C.; Nagy, A.; Stevens, J.; Swain, D.W.; Wilson, J.R.

    1988-01-01

    Two compact loop antennas have been designed to provide ion cyclotron resonant frequency (ICRF) heating for TFTR. The antennas can convey a total of 10 MW to accomplish core heating in either high-density or high-temperature plasmas. The near-term goal of heating TFTR plasmas and the longer-term goals of ease in handling (for remote maintenance) and high reliability (in an inaccessible tritium tokamak environment) were major considerations in the antenna designs. The compact loop configuration facilitates handling because the antennas fit completely through their ports. Conservative design and extensive testing were used to attain the reliability required for TFTR. This paper summarizes how these antennas will accomplish these goals. 5 figs, 1 tab

  10. TFTR CAMAC instrumentation system

    International Nuclear Information System (INIS)

    Del Gatto, H.J.; Bradish, C.J.

    1983-01-01

    The TFTR Central Instrumentation Control and Data Acquisition (CICADA) system makes extensive use of CAMAC equipment. The system consists of eight CAMAC highways operating from eight Gould 75/32 computers. Links up to 3.5 miles in length with more than fifty CAMAC crates have been implemented and are currently in use. Data transfer along the highway is implemented in bit serial format. The link speed is run at 5MHz. The length and complexity of the link requires the reformatting of the NRZ input/output format of the L-2 crate controller. U-Port adapter modules are used to interface the modified serial highway to the L-2 controllers. The modified serial highway uses a transmission technique that requires the distribution of both Bi-Phase encoded data and a 5MHz clock. The Serial Driver interfaces to the GOULD computer through use of a High Speed Data (HSD) interface board which attaches to the computers internal bus. All transfers to and from the computer are accomplished by direct memory access (DMA). In addition to the standard CAMAC link the system also includes a Block Transfer (BT) system. This system provides an alternate path for transferring data between the computers and the CAMAC modules. The BT system is interfaced to the host computers through HSD boards and to the CAMAC crates through use of an auxiliary crate controllers

  11. Neutron emission from TFTR supershots

    International Nuclear Information System (INIS)

    Strachan, J.D.; Bell, M.G.; Bitter, M.; Budny, R.; Hawryluk, R.; Hill, K.W.; Hsuan, H.; Jassby, D.L.; Johnson, L.C.; LeBlanc, B.; Mansfield, D.; Meade, D.; Mikkelsen, D.R.; Mueller, D.; Park, H.; Ramsey, A.; Scott, S.; Synakowski, E.; Taylor, G.; Marmer, E.; Snipes, J.; Terry, J.

    1992-10-01

    Empirical scaling relations are deduced describing the neutron emission from TFTR supershots using a data base that includes all of the supershot plasmas (525) from the 1990 campaign. A physics-based scaling for the neutron emission is derived from the dependence of the central plasma parameters on machine settings and the energy confinement time. This scaling has been used to project the fusion rate for equivalent DT plasmas in TFTR, and to explore machine operation space which optimizes the fusion rate. Increases in neutron emission are possible by either increasing the toroidal magnetic field or further improving the limiter conditioning

  12. Diagnostic interface problems on TFTR

    International Nuclear Information System (INIS)

    Goldfarb, S.

    1977-01-01

    Diagnostic equipment on TFTR has functional interfaces with many machine systems. Salient requirements include plasma access, environmental resistance to thermal, magnetic and radiation effects, automated data acquisition and controls, remote handling and personnel safety. Problems imposed by these requirements and the solutions being considered are described

  13. Compilation of TFTR materials data

    International Nuclear Information System (INIS)

    Havener, W.J.

    1975-12-01

    In order to document the key thermophysical property data used in the conceptual design of Tokamak Fusion Test Reactor (TFTR) systems and components, a series of data packages has been prepared. It is expected that data for additional materials will be added and the information already provided will be updated to provide a project-wide data base

  14. TFTR tritium operations lessons learned

    International Nuclear Information System (INIS)

    Gentile, C.A.; Raftopoulos, S.; LaMarche, P.

    1996-01-01

    The Tokamak Fusion Test Reactor which is the progenitor for full D-T operating tokamaks has successfully processed > 81 grams of tritium in a safe and efficient fashion. Many of the fundamental operational techniques associated with the safe movement of tritium through the TFTR facility were developed over the course of many years of DOE tritium facilities (LANL, LLNL, SRS, Mound). In the mid 1980's The Tritium Systems Test Assembly (TSTA) at LANL began reporting operational techniques for the safe handling of tritium, and became a major conduit for the transfer of safe tritium handling technology from DOE weapons laboratories to non-weapon facilities. TFTR has built on many of the TSTA operational techniques and has had the opportunity of performing and enhancing these techniques at America's first operational D-T fusion reactor. This paper will discuss negative pressure employing 'elephant trunks' in the control and mitigation of tritium contamination at the TFTR facility, and the interaction between contaminated line operations and Δ pressure control. In addition the strategy employed in managing the movement of tritium through TFTR while maintaining an active tritium inventory of < 50,000 Ci will be discussed. 5 refs

  15. Tritium pellet injector for TFTR

    International Nuclear Information System (INIS)

    Gouge, M.J.; Baylor, L.R.; Cole, M.J.; Combs, S.K.; Dyer, G.R.; Fehling, D.T.; Fisher, P.W.; Foust, C.R.; Langley, R.A.; Milora, S.L.; Qualls, A.L.; Wilgen, J.B.; Schmidt, G.L.; Barnes, G.W.; Persing, R.G.

    1992-01-01

    The tritium pellet injector (TPI) for the Tokamak Fusion Test Reactor (TFTR) will provide a tritium pellet fueling capability with pellet speeds in the 1- to 3-km/s range for the TFTR deuterium-tritium (D-T) phase. The existing TFTR deuterium pellet injector (DPI) has been modified at Oak Ridge National Laboratory (ORNL) to provide a four-shot, tritium-compatible, pipe-gun configuration with three upgraded single-stage pneumatic guns and a two-stage light gas gun driver. The TPI was designed to provide pellets ranging from 3.3 to 4.5 mm in diameter in arbitrarily programmable firing sequences at speeds up to approximately 1.5 km/s for the three single-stage drivers and 2.5 to 3 km/s for the two-stage driver. Injector operation is controlled by a programmable logic controller. The new pipe-gun injector assembly was installed in the modified DPI guard vacuum box, and modifications were made to the internals of the DPI vacuum injection line, including a new pellet diagnostics package. Assembly of these modified parts with existing DPI components was then completed, and the TPI was tested at ORNL with deuterium pellet. Results of the limited testing program at ORNL are described. The TPI is being installed on TFTR to support the D-D run period in 1992. In 1993, the tritium pellet injector will be retrofitted with a D-T fuel manifold and secondary tritium containment systems and integrated into TFTR tritium processing systems to provide full tritium pellet capability

  16. High beta and confinement studies on TFTR

    International Nuclear Information System (INIS)

    1990-01-01

    In the first 8 months of this project we have made substantial progress toward the goals set out in our original proposal. Our plan to access new regimes of operation at high values of var-epsilon β p using low current discharges in TFTR has worked extremely well and a new regime of operation has indeed been found in the course of our execution of TFTR Experimental Proposal 146 which involved our operation of TFTR on 9 November 1989, 19--20 January 1990 and 1--2 February 1990. The status of our high var-epsilon β p work on TFTR is given and is extracted from our paper submitted for presentation to the 1990 EPS meeting in Amsterdam. We have also performed an analysis of the energetic particle stabilization requirements for TFTR Supershots, and developed methods for analysis and a theory of perturbative transport measurements in TFTR

  17. Observations of Flaking of Co-deposited Layers in TFTR

    International Nuclear Information System (INIS)

    Gentile, C.A.; Skinner, C.H.; Young, K.M.

    1999-01-01

    Flaking of co-deposited layers in the Tokamak Fusion Test Reactor (TFTR) has been observed after the termination of plasma operations. This unexpected flaking affects approximately 15% of the tiles and appears on isotropic graphite tiles but not on carbon fiber composite tiles. Samples of tiles, flakes and dust were recently collected from the inside of the vacuum vessel and will be analyzed to better characterize the behavior of tritium on plasma facing components in DT fusion devices

  18. Synchronization of timing systems on TFTR

    International Nuclear Information System (INIS)

    Montague, J.; Sichta, P.

    1992-01-01

    This paper reports on the TOKAMAK Fusion Test Reactor (TFTR) facility clock system which has four related timing subsystems: the TFTR shot clock, the Neutral Beams clocks, the Ion Cyclotron Range of Frequencies (ICRF) system clock, and the Disruption Trigger System. These systems have been integrated to support increasingly fast sampling rates in data acquisition and greater accuracy in the firing of the Neutral Beams and ICRF systems during TFTR shots

  19. TFTR toroidal field coil design

    International Nuclear Information System (INIS)

    Smith, G.E.; Punchard, W.F.B.

    1977-01-01

    The design of the Tokamak Fusion Test Reactor (TFTR) Toroidal Field (TF) magnetic coils is described. The TF coil is a 44-turn, spiral-wound, two-pancake, water-cooled configuration which, at a coil current of 73.3 kiloamperes, produces a 5.2-Tesla field at a major radius of 2.48 meters. The magnetic coils are installed in titanium cases, which transmit the loads generated in the coils to the adjacent supporting structure. The TFTR utilizes 20 of these coils, positioned radially at 18 0 intervals, to provide the required toroidal field. Because it is very highly loaded and subject to tight volume constraints within the machine, the coil presents unique design problems. The TF coil requirements are summarized, the coil configuration is described, and the problems highlighted which have been encountered thus far in the coil design effort, together with the development tests which have been undertaken to verify the design

  20. Transport analysis of TFTR experiments

    International Nuclear Information System (INIS)

    Goldston, R.; McCune, D.; Zarnstorff, M.; Hammett, G.; Scott, S.

    1991-01-01

    The purpose of this investigation was to complete the analysis of TFTR data which was under progress. The main emphasis was to study the effects of heating profile and resulting density and temperature profiles on transport through the comparison between beam heated plasmas with hollow and centrally peaked heating profiles (edge vs. center heating). The analysis has been completed and a manuscript has been prepared for publication in Nuclear Fusion. A proposal to perform a similar experiment using ICRF heating to decouple heating profile effects from density profile effects was submitted and was approved by the TFTR. ICRF heating enables the heating profile and the power partition between ions and electrons to be controlled. The experiment was scheduled twice, but it had to be postponed both times

  1. TFTR neutral beam power system

    International Nuclear Information System (INIS)

    Deitz, A.; Murray, H.; Winje, R.

    1977-01-01

    The TFTR NB System will be composed of four beam lines, each containing three ion sources presently being developed for TFTR by the Lawrence Berkeley Laboratories (LBL). The Neutral Beam Power System (NBPS) will provide the necessary power required to operate these Ion Sources in both an experimental or operational mode as well as test mode. This paper describes the technical as well as the administrative/management aspects involved in the development and building of this system. The NBPS will combine the aspects of HV pulse (120 kV) and long pulse width (0.5 sec) together to produce a high power system that is unique in the Electrical Engineering field

  2. TFTR magnetic field design analyses

    International Nuclear Information System (INIS)

    Davies, K.; Iwinski, E.; McWhirter, J.M.

    1975-11-01

    The three main magnetic field windings for the TFTR are the toroidal field (TF) windings, the ohmic heating (OH) winding, and the equilibrium field (EF) winding. The following information is provided for these windings: (1) descriptions, (2) functions, (3) magnetic designs, e.g., number and location of turns, (4) design methods, and (5) descriptions of resulting magnetic fields. This report does not deal with the thermal, mechanical support, or construction details of the windings

  3. Central ignition scenarios for TFTR

    International Nuclear Information System (INIS)

    Zweben, S.J.; Redi, M.H.; Bateman, G.

    1986-03-01

    The possibility of obtaining ignition in TFTR by means of very centrally peaked density profiles is examined. It is shown that local central alpha heating can be made to exceed local central energy losses (''central ignition'') under global conditions for which Q greater than or equal to 1. Time dependent 1-D transport simulations show that the normal global ignition requirements are substantially relaxed for plasmas with peaked density profiles. 18 refs., 18 figs

  4. TFTR Experimental Data Analysis Collaboration

    International Nuclear Information System (INIS)

    Callen, J.D.

    1993-01-01

    The research performed under the second year of this three-year grant has concentrated on a few key TFTR experimental data analysis issues: MHD mode identification and effects on supershots; identification of new MHD modes; MHD mode theory-experiment comparisons; local electron heat transport inferred from impurity-induced cool pulses; and some other topics. Progress in these areas and activities undertaken in conjunction with this grant are summarized briefly in this report

  5. Coil protection calculator for TFTR

    International Nuclear Information System (INIS)

    Marsala, R.J.; Lawson, J.E.; Persing, R.G.; Senko, T.R.; Woolley, R.D.

    1989-01-01

    A new coil protection system (CPS) is being developed to replace the existing TFTR magnetic coil fault detector. The existing fault detector sacrifices TFTR operating capability for simplicity. The new CPS, when installed in October of 1988, will permit operation up to the actual coil stress limits parameters in real-time. The computation will be done in a microprocessor based Coil Protection Calculator (CPC) currently under construction at PPL. THe new CPC will allow TFTR to operate with higher plasma currents and will permit the optimization of pulse repetition rates. The CPC will provide real-time estimates of critical coil and bus temperatures and stresses based on real-time redundant measurements of coil currents, coil cooling water inlet temperature, and plasma current. The critical parameter calculations are compared to prespecified limits. If these limits are reached or exceeded, protection action will be initiated to a hard wired control system (HCS), which will shut down the power supplies. The CPC consists of a redundant VME based microprocessor system which will sample all input data and compute all stress quantities every ten milliseconds. Thermal calculations will be approximated every 10ms with an exact solution occurring every second. The CPC features continuous cross-checking of redundant input signal, automatic detection of internal failure modes, monitoring and recording of calculated results, and a quick, functional verification of performance via an internal test system. (author)

  6. Experimental results from detached plasmas in TFTR

    International Nuclear Information System (INIS)

    Strachan, J.D.; Boody, F.P.; Bush, C.E.

    1986-10-01

    Detached plasmas are formed in TFTR which have the principal property of the boundary to the high temperature plasma core being defined by a radiating layer. This paper documents the properties of TFTR ohmic-detached plasmas with a range of plasma densities at two different plasma currents

  7. Automatic generation of computer programs servicing TFTR console displays

    International Nuclear Information System (INIS)

    Eisenberg, H.

    1983-01-01

    A number of alternatives were considered in providing programs to support the several hundred displays required for control and monitoring of TFTR equipment. Since similar functions were performed, an automated method of creating programs was suggested. The complexity of a single program servicing as many as thirty consoles mitigated against that approach. Similarly, creation of a syntactic language while elegant, was deemed to be too time consuming, and had the disadvantage of requiring a working knowledge of the language on a programming level. It was elected to pursue a method of generating an individual program to service a particular display. A feasibility study was conducted and the Control and Monitor Display Generator system (CMDG) was developed. A Control and Monitor Display Service Program (CMDS) provides a means of performing monitor and control functions for devices associated with TFTR subsystems, as well as other user functions, via TFTR Control Consoles. This paper discusses the specific capabilities provided by CMDS in a usage context, as well as the mechanics of implementation

  8. Control of TFTR during DT operations

    International Nuclear Information System (INIS)

    Pearson, G.G.; Alling, P.D.; Blanchard, W.; Camp, R.A.; Hawryluk, R.J.; Hosea, J.C.; Nagy, A.

    1995-01-01

    Since beginning routine D-T operations in December, 1993, there have been more than 500 DT plasmas and approximately 600,000 Ci of tritium processed through TFTR culminating in greater than 10 MW of fusion power produced in a single discharge in November, 1994. These performance levels were achieved while maintaining the highest levels of personnel and equipment safety. Prior to D-T operations, a Chain of Command structure and a TFTR Shift Supervisor (TFTRSS) position were developed for centralized control of the facility with all subsystems reporting to this position. A comprehensive surveillance system was incorporated such that the TFTR SS could easily review the operational readiness of subsystems for D-T operations. A TFTR SS Station was constructed to facilitate monitoring and control of TFTR. This station includes a camera system, FAX, a networked personal computer, a computerized tritium monitor and control system and a hardware interlock system. In the transition from D-D to D-T operations, TFTR's procedures were reviewed/revised and a number of additional procedures developed for control of activities at the facility. This paper details the equipment, administrative and organizational configurations used for controlling TFTR during D-T operations

  9. TFTR CAMAC power supplies reliability

    International Nuclear Information System (INIS)

    Camp, R.A.; Bergin, W.

    1989-01-01

    Since the expected life of the Tokamak Fusion Test Reactor (TFTR) has been extended into the early 1990's, the issues of equipment wear-out, when to refurbish/replace, and the costs associated with these decisions, must be faced. The management of the maintenance of the TFTR Central Instrumentation, Control and Data Acquisition System (CICADA) power supplies within the CAMAC network is a case study of a set of systems to monitor repairable systems reliability, costs, and results of action. The CAMAC network is composed of approximately 500 racks, each with its own power supply. By using a simple reliability estimator on a coarse time interval, in conjunction with determining the root cause of individual failures, a cost effective repair and maintenance program has been realized. This paper describes the estimator, some of the specific causes for recurring failures and their correction, and the subsequent effects on the reliability estimator. By extension of this program the authors can assess the continued viability of CAMAC power supplies into the future, predicting wear-out and developing cost effective refurbishment/replacement policies. 4 refs., 3 figs., 1 tab

  10. Engineering analysis of TFTR disruption

    International Nuclear Information System (INIS)

    Murray, J.G.; Rothe, K.E.; Bronner, G.

    1984-09-01

    This report covers an engineering approach quantifying the currents, forces, and times, as well as plasma position, for the worst-case disruption based on engineerign circuit assumptions for the plasma. As the plasma moves toward the wall during the current-decay phase of disruption, the wall currents affect the rate of movement and, hence, the decay time. The calculated structure-induced currents differ considerably from those calculated using a presently available criterion, which specifies that the plasma remains stationary in the center of the torus while decaying in 10 ms. This report outlines the method and basis for the engineering calculation used to determine the current and forces as a function of the circuit characteristics. It provides specific calculations for the Tokamak Fusion Test Reactor (TFTR) with variations in parameters such as the thermal decay time, the torus resistance, and plasma temperature during the current decay. The study reviews possible ways to reduce the disruption damage of TFTR by reducing the magnitude of the plasma external field energy that is absorbed by the plasma during the current decay

  11. Engineering analysis of TFTR disruption

    Energy Technology Data Exchange (ETDEWEB)

    Murray, J.G.; Rothe, K.E.; Bronner, G.

    1984-09-01

    This report covers an engineering approach quantifying the currents, forces, and times, as well as plasma position, for the worst-case disruption based on engineerign circuit assumptions for the plasma. As the plasma moves toward the wall during the current-decay phase of disruption, the wall currents affect the rate of movement and, hence, the decay time. The calculated structure-induced currents differ considerably from those calculated using a presently available criterion, which specifies that the plasma remains stationary in the center of the torus while decaying in 10 ms. This report outlines the method and basis for the engineering calculation used to determine the current and forces as a function of the circuit characteristics. It provides specific calculations for the Tokamak Fusion Test Reactor (TFTR) with variations in parameters such as the thermal decay time, the torus resistance, and plasma temperature during the current decay. The study reviews possible ways to reduce the disruption damage of TFTR by reducing the magnitude of the plasma external field energy that is absorbed by the plasma during the current decay.

  12. Development of a maintenance manipulator for TFTR

    International Nuclear Information System (INIS)

    Holloway, C.

    1986-01-01

    The maintenance manipulator is a device permanently connected to the Tokamak Fusion Test Reactor (TFTR) vacuum vessel and is located in close proximity to the tokamak. It is used for the inspection and maintenance of in-vessel components whilst the machine remains under vacuum. The total system comprises a vacuum vessel ante-chamber that houses the manipulator, an articulated boom and carriage that transports and positions a dexterous end-effector, and end-effector that supports maintenance tooling, and an inspection system. Because of the maintenance manipulator's operating environment, there are many challenging engineering features, i.e., temperatures up to 150 0 C, changing magnetic fields in space and time that act on the manipulator whilst it is at rest, neutron neutron fluxes of up to 10/sup 11/cm/sup -2/s/sup -1/, and, last but not least, UHV conditions. This paper describes the development of the vacuum system, the maintenance manipulator, and inspective devices. It includes the methods employed to overcome the engineering difficulties and the application of information gained from other advanced technology programs, such as space and nuclear fission

  13. Absolute calibration of TFTR helium proportional counters

    International Nuclear Information System (INIS)

    Strachan, J.D.; Diesso, M.; Jassby, D.; Johnson, L.; McCauley, S.; Munsat, T.; Roquemore, A.L.; Loughlin, M.

    1995-06-01

    The TFTR helium proportional counters are located in the central five (5) channels of the TFTR multichannel neutron collimator. These detectors were absolutely calibrated using a 14 MeV neutron generator positioned at the horizontal midplane of the TFTR vacuum vessel. The neutron generator position was scanned in centimeter steps to determine the collimator aperture width to 14 MeV neutrons and the absolute sensitivity of each channel. Neutron profiles were measured for TFTR plasmas with time resolution between 5 msec and 50 msec depending upon count rates. The He detectors were used to measure the burnup of 1 MeV tritons in deuterium plasmas, the transport of tritium in trace tritium experiments, and the residual tritium levels in plasmas following 50:50 DT experiments

  14. TFTR D-T results

    International Nuclear Information System (INIS)

    Meade, D.M.

    1994-01-01

    Temperatures, densities and confinement of deuterium plasmas confined in tokamaks have been achieved within the last decade that are approaching those required for a D-T reactor. As a result, the unique phenomena present in a D-T reactor plasma (D-T plasma confinement, alpha confinement, alpha heating and possible alpha driven instabilities) can now be studied in the laboratory. Recent experiments on the Tokamak Fusion Test Reactor (TFTR) have been the first magnetic fusion experiments to study plasmas with reactor fuel concentrations of tritium. The injection of ∼ 20 MW of tritium and 14 MW of deuterium neutral beams into the TFTR produced a plasma with a T/D density ratio of ∼1 and yielded a maximum fusion power of ∼ 9.2 MW. The fusion power density in the core of the plasma was ∼ 1.8 MW m -3 approximating that expected in a D-T fusion reactor. A TFTR plasma with T/D density ratio of ∼ 1 was found to have ∼ 20% higher energy confinement time than a comparable D plasma, indicating a confinement scaling with average ion mass, A, of τ E ∼ A 0.6 . The core ion temperature increased from 30 keV to 37 keV due to a 35% improvement of ion thermal conductivity. Using the electron thermal conductivity from a comparable deuterium plasma, about 50% of the electron temperature increase from 9 keV to 10.6 keV can be attributed to electron heating by the alpha particles. The ∼ 5% loss of alpha particles, as observed on detectors near the bottom edge of the plasma, was consistent with classical first orbit loss without anomalous effects. Initial measurements have been made of the confined energetic alphas and the resultant alpha ash density. At fusion power levels of 7.5 MW, fluctuations at the Toroidal Alfven Eigenmode frequency were observed by the fluctuation diagnostics. However, no additional alpha loss due to the fluctuations was observed

  15. The tritium operations experience on TFTR

    International Nuclear Information System (INIS)

    Halle, A. von; Anderson, J.L.; Gentile, C.; Grisham, L.; Hosea, J.; Kamperschroer, J.; LaMarche, P.; Oldaker, M.; Nagy, A.; Raftopoulos, S.; Stevenson, T.

    1995-01-01

    The Tokamak Fusion Test Reactor (TFTR) tritium gas system is administratively limited to 5 grams of tritium and provides the feedstock gas for the neutral beam and torus injection systems. Tritium operations on TFTR began with leak checking of gas handling systems, qualification of the gas injection systems, and high power plasma operations using trace amounts of tritium in deuterium feedstock gas. Full tritium operation commenced with four highly diagnosed neutral beam pulses into a beamline calorimeter to verify planned tritium beam operating routines and to demonstrate the deuterium to tritium beam isotope exchange. Since that time, TFTR has successfully operated each of the twelve neutral beam ion sources in tritium during hundreds of tritium beam pulses and torus gas injections. This paper describes the TFTR tritium gas handling systems and TFTR tritium operations of the gas injection systems and the neutral beam ion sources. Tritium accounting and accountability is discussed, including tritium retention issues of the torus limiters and beam impinged surfaces of the beamline components. Also included is tritium beam velocity analysis that compares the neutral beam extracted ion species composition for deuterium and tritium and that determines the extent of beam isotope exchange on subsequent deuterium and tritium beam pulses. The required modifications to TFTR operating routines to meet the U.S. Department of Energy regulations for a low hazard nuclear facility and the problems encountered during initial tritium operations are described. (orig.)

  16. The tritium operations experience on TFTR

    International Nuclear Information System (INIS)

    von Halle, A.; Gentile, C.

    1994-01-01

    The Tokamak Fusion Test Reactor (TFTR) tritium gas system is administratively limited to 5 grains of tritium and provides the feedstock gas for the neutral beam and torus injection systems. Tritium operations on TFTR began with leak checking of gas handling systems, qualification of the gas injection systems, and high power plasma operations using using trace amounts of tritium in deuterium feedstock gas. Full tritium operation commenced with four highly diagnosed neutral beam pulses into a beamline calorimeter to verify planned tritium beam operating routines and to demonstrate the deuterium to tritium beam isotope exchange. Since that time, TFTR has successfully operated each of the twelve neutral beam ion sources in tritium during hundreds of tritium beam pulses and torus gas injections. This paper describes- the TFTR tritium gas handling systems and TFTR tritium operations of the gas injection systems and the neutral beam ion sources. Tritium accounting and accountability is discussed, including tritium retention issues of the torus limiters and beam impinged surfaces of the beamline components. Also included is tritium beam velocity analysis that compares the neutral beam extracted ion species composition for deuterium and tritium and that determines the extent of beam isotope exchange on subsequent deuterium and tritium beam pulses. The required modifications to TFTR operating routines to meet the US Department of Energy regulations for a low hazard nuclear facility and the problems encountered during initial tritium operations are described

  17. Structural analysis of equilibrium and ohmic heating coil assemblies for the TFTR

    International Nuclear Information System (INIS)

    Chattopadhyay, S.

    1975-10-01

    The structural adequacy of the equilibrium and ohmic heating coils and their support systems for the TFTR device has been investigated. The capability of the coils to span ribs of the support structure has been established. The support structure has been found to be effective in resisting the magnetic forces in the coils. The bands encircling the outboard coils and the band tensioning devices have been found to perform adequately. The analysis is based on October 1975 conceptual design

  18. Fast current ramp experiments on TFTR

    International Nuclear Information System (INIS)

    Fredrickson, E.D.; McGuire, K.; Goldston, R.J.

    1987-05-01

    Electron heat transport on TFTR and other tokamaks is several orders of magnitude larger than neoclassical calculations would predict. Despite considerable effort, there is still no clear theoretical understanding of this anomalous transport. The electron temperature profile T/sub e/(r), shape has shown a marked consistency on many machines, including TFTR, for a wide range of plasma parameters and heating profiles. This could be an important clue as to the process responsible for this enhanced thermal transport. In this paper 'profile consistency' in TFTR is described and an experiment which uses a fast current ramp to transiently decouple the current density profile J(r), and the T/sub e/(r) profiles is discussed. From this experiment the influence of J(r) on electron temperature profile consistency can be determined

  19. PBX/TFTR pellet program PPPL

    International Nuclear Information System (INIS)

    Schmidt, G.

    1986-01-01

    Goals, current results and plans for pellet injection work for the PBX and TFTR programs are outlined. The present PBX injector is a prototype for ORNL 4 pellet condensing injectors. It has demonstrated that pellet injection on PBX can be used to increase overall density and alter the density profile. Future PBX operation requires reliable operation in deuterium and tritium, multiple pellet capability and ability to vary the size of pellets. These goals will require the construction of a new injector similar to the TFTR DPI system. It has also been demonstrated that pellets can efficiently fuel TFTR, producing a clean, high density plasma. Issues which are still outstanding include isotope exchange effects, use of different pellet sizes, optimization of pellet density perturbations and pellet penetration at high beam power

  20. Chromium getter studies in TFTR

    International Nuclear Information System (INIS)

    Dylla, H.F.; LaMarche, P.H.; Blanchard, W.R.

    1986-02-01

    We have studied the effects of the deposition of thin films (approx.0.1 μm) of chromium onto approx.70% of the torus area of the Tokamak Fusion Test Reactor (TFTR). The purpose of these experiments was to test the difference between high surface coverage and high pumping speed gettering schemes with respect to minimizing oxygen impurity generation in high power tokamak discharges. The initial Cr deposition had significant effects on vessel outgassing and subsequent plasma performance: the outgassing of H 2 O, CO, and CO 2 decreased by a factor of ten, oxygen impurity radiation decreased by a factor of two, the plasma Z/sub eff/ decreased from 1.3 to 1.1, and the plasma density limit increased by 20%. This improvement correlates with a significant reduction of the edge radiation as the density limit is approached. The effects of the initial and subsequent Cr depositions were relatively long lasting, exhibiting time constants of the order of weeks. We attribute the observed impurity reduction to a modification of the oxide surface on the vessel wall, which is apparently a significant impurity source for oxygen. 17 refs., 6 figs

  1. Overview of TFTR transport studies

    International Nuclear Information System (INIS)

    Hawryluk, R.J.; Arunasalam, V.; Beer, M.; Bell, M.; Bell, R.; Biglari, H.; Bitter, M.; Boivin, R.; Bretz, N.L.; Budny, R.; Cheng, C.Z.; Chu, T.K.; Cohen, S.A.; Cowley, S.; Efthimion, P.C.; Fredrickson, E.; Furth, H.P.; Goldston, R.J.; Greene, G.; Grek, B.; Grisham, L.R.; Hammett, G.; Hill, K.W.; Hosea, J.; Hulse, R.A.; Hsuan, H.; Janos, A.; Jassby, D.; Jobes, F.C.; Johnson, D.W.; Johnson, L.C.; Kieras-Phillips, C.; Kilpatrick, S.J.; Kugel, H.; La Marche, P.H.; LeBlanc, B.; Manos, D.M.; Mansfield, D.K.; Mazzucato, E.; McCarthy, M.P.; McCune, D.C.; McGuire, K.M.; Meade, D.M.; Medley, S.S.; Mikkelsen, D.R.; Monticello, D.; Motley, R.; Mueller, D.; Nazikian, R.; Owens, D.K.; Park, H.; Park, W.; Paul, S.; Perkins, F.; Ramsey, A.T.; Redi, M.H.; Rewoldt, G.; Roquemore, A.L.; Rutherford, P.H.; Schilling, G.; Schivell, J.; Schmidt, G.L.; Scott, S.D.; Stevens, J.; Stratton, B.C.; Stodiek, W.; Synakowski, E.; Tang, W.; Taylor, G.; Timberlake, J.R.; Towner, H.H.; Ulrickson, M.; von Goeler, S.; Wieland, R.; Williams, M.; Wilson, J.R.; Wong, K.L.; Yamada, M.; Yoshikawa, S.; Young, K.M.; Zarnstorff, M.C.; Zweben, S.J.; Bush, C.E.; Fonck, R.J; Roberts, D.; Heidbrink, W.; Kesner, J.; Marmar, E.S.; Snipes, J.; Takase, Y.; Terry, J.; Mauel, M.; Navratil, G.A.; Sabbagh, S.; Nagayama, Y.; Pitcher, S.

    1991-10-01

    A review of TFTR plasma transport studies is presented. Parallel transport and the confinement of suprathermal ions are found to be relatively well described by theory. Cross-field transport of the thermal plasma, however, is anomalous with the momentum diffusivity being comparable to the ion thermal diffusivity and larger than the electron thermal diffusivity in neutral beam heated discharges. Perturbative experiments have studied non-linear dependencies in the transport coefficients and examined the role of possible non-local phenomena. The underlying turbulence has been studied using microwave scattering, beam emission spectroscopy and microwave reflectometry over a much broader range in k perpendicular than previously possible. Results indicate the existence of large-wavelength fluctuations correlated with enhanced transport. MHD instabilities set important operational constraints. However, by modifying the current profile using current ramp-down techniques, it has been possible to extend the operating regime to higher values of both var-epsilon β p and normalized β T . In addition, the interaction of MHD fluctuations with fast ions, of potential relevance to α-particle confinement in D-T plasmas, has been investigated. The installation of carbon-carbon composite tiles and improvements in wall conditioning, in particular the use of Li pellet injection to reduce the carbon recycling, continue to be important in the improvement of plasma performance. 96 refs., 16 figs

  2. High beta and confinement studies on TFTR

    International Nuclear Information System (INIS)

    Navratil, G.A.; Bhattacharjee, A.; Iacono, R.; Mauel, M.E.; Sabbagh, S.A.; Kesner, J.

    1992-01-01

    A new regime of high poloidal beta operation in TFTR was developed in the course of the first two years of this project (9/25/89 to 9/24/91). Our proposal to continue this successful collaboration between Columbia University and the Massachusetts Institute of Technology with the Princeton Plasma Physics Laboratory for a three year period (9/25/91 to 9/24/94) to continue to investigate improved confinement and tokamak performance in high poloidal beta plasmas in TFTR through the DT phase of operation was approved by the DOE and this is a report of our progress during the first 9 month budget period of the three year grant (9/25/91 to 6/24/92). During the approved three year project period we plan to (1) extend and apply the low current, high QDD discharges to the operation of TFTR using Deuterium and Tritium plasma; (2) continue the analysis and plan experiments on high poloidal beta phenomena in TFTR including: stability properties, enhanced global confinement, local transport, bootstrap current, and divertor formation; (3) plan and carry out experiments on TFTR which attempt to elevate the central q to values > 2 where entry to the second stability regime is predicted to occur; and (4) collaborate on high beta experiments using bean-shaped plasmas with a stabilizing conducting shell in PBX-M. In the seven month period covered by this report we have made progress in each of these four areas through the submission of 4 TFTR Experimental Proposals and the partial execution of 3 of these using a total of 4.5 run days during the August 1991 to February 1992 run

  3. Recent D-T results on TFTR

    International Nuclear Information System (INIS)

    Johnson, D.W.; Arunasalam, V.

    1995-10-01

    Routine tritium operation in TFTR has permitted investigations of alpha particle physics in parameter ranges resembling those of a reactor core. ICRF wave physics in a DT plasma and the influence of isotopic mass on supershot confinement have also been studied. Continued progress has been made in optimizing fusion power production in TFTR, using extended machine capability and Li wall conditioning. Performance is currently limited by MHD stability. A new reversed magnetic shear regime is being investigated with reduced core transport and a higher predicted stability limit

  4. TFTR neutral-beam power system

    International Nuclear Information System (INIS)

    Winje, R.A.

    1982-10-01

    The TFTR Neutral Beam Power System (NBPS) consists of the accelerator grid power supply and the auxiliary power supplies required to operate the TFTR 120-keV ion sources. The current configuration of the NBPS including the 11-MVA accelerator grid power supply and the Arc and Filament power supplies isolated for operation at accelerator grid voltages up to 120 kV, is described. The prototype NBPS has been assembled at the Princeton Plasma Physics Laboratory and has been operated. The results of the initial operation and the description and resolution of some of the technical problems encountered during the commissioning tests are presented

  5. Impurity pellet injection experiments at TFTR

    International Nuclear Information System (INIS)

    Marmar, E.S.

    1991-01-01

    Impurity (Li and C) pellet experiments, which began at TFTR in 1989, and are expected to continue at least through 1991, have continued to produce new and significant results. The most significant of these are: (1) improvements in TFTR supershots after wall-conditioning by Li pellet injection; (2) accurate measurements of the pitch angle profiles of the internal magnetic field using the polarization angles of line emission from Li + in the pellet ablation cloud; and (3) initial measurements of pitch angle profiles using the tilt of the LI + emission region of the ablation cloud which is stretched out along the field lines

  6. Nondimensional transport studies in TFTR

    International Nuclear Information System (INIS)

    Scott, S.D.; Mikkelsen, D.R.; Perkins, F.W.; Bell, M.G.; Bell, R.E.; Bush, C.E.; Fredrickson, E.D.; Grek, B.; Hill, K.W.; Janos, A.; Jobes, F.; Johnson, D.; Mansfield, D.K.; Owens, D.K.; Park, H.; Paul, S.; Ramsey, A.T.; Schivell, J.; Stratton, B.C.; Synakowski, E.J.; Tang, W.M.; Zarnstorff, M.C.; Ernst, D.

    1993-04-01

    The machine parameters (I p , P heat , R) required for ignition in ITER have generally been extrapolated from power-law regression fits to global τ E measurements on existing tokamaks. There remain important choices to be made in the form of the scaling relation which have not yet been resolved by theory. In particular, power flow Q(r) through a magnetic flux surface should scale as Q(r) = Q Bohm F where F = F(ρ*,β,ν*,s,T e /T i ,...) is a function of local, nondimensional plasma parameters and Q Bohm ∝ [n e T e 2 a/eB]. Projections to ITER can be reduced to establishing the dependence of F on ρ* = ρ i /a, because one can create plasmas in today's tokamaks which have similar values of the other nondimensional parameters. Two common scalings suggested by theory are Bohm (F independent of ρ*) and gyroBohm (F ∝ ρ*). Experiments have been carried out on TFTR to ascertain the dependence of F on ρ*, ν*, and β in L-mode plasmas, holding the other nondimensional parameters fixed. The observed variation of heat flow with ρ* was observed to be better described by Bohm scaling than gyroBohm. Comparisons with the critical gradient temperature transport model, which is gyroBohm in character, show that it overpredicts the temperature increase expected with increasing magnetic field. The ν* scan (remaining in the collisionless regime) revealed that the Bohm-normalized power flow is remarkably insensitive to collisionality, in agreement with ITER-P scaling. The β scan identified a deterioration of confinement with increasing β at fixed ρ* and ν*, of approximately the correct magnitude required to reconcile Bohm local transport scaling with ITER-P global scaling of τ E . This may suggest a role for electromagnetic phenomena in governing tokamak transport even at very low beta

  7. Experimental results from the TFTR tokamak

    International Nuclear Information System (INIS)

    Hawryluk, R.J.; Arunasalam, V.; Bell, J.D.

    1986-10-01

    Recent experiments on TFTR have extended the operating regime of TFTR in both ohmic- and neutral-beam-heated discharges. The TFTR tokamak has reached its original machine design specifications (I/sub p/ = 2.5 MA and B/sub T/ = 5.2 T). Initial neutral-beam-heating experiments used up to 6.3 MW of deuterium beams. With the recent installation of two additional beamlines, the power has been increased up to 11 MW. A deuterium pellet injector was used to increase the central density to 2.5 x 10 20 m -3 in high current discharges. At the opposite extreme, by operating at low plasma current (I/sub p/ ∼ 0.8 MA) and low density (anti n/sub e/ ∼ 1 x 10 19 m -3 ), high ion temperatures (9 +- 2 keV) and rotation speeds (7 x 10 5 m/s) have been achieved during injection. In addition, plasma compression experiments have demonstrated acceleration of beam ions from 82 keV to 150 keV, in accord with expectations. The wide operating range of TFTR, together with an extensive set of diagnostics and a flexible control system, has facilitated transport and scaling studies of both ohmic- and neutral-beam-heated discharges. The results of these confinement studies are presented

  8. Enhanced carbon influx into TFTR supershots

    International Nuclear Information System (INIS)

    Ramsey, A.T.; Bush, C.E.; Dylla, H.F.; Owens, D.K.; Pitcher, C.S.; Ulrickson, M.

    1990-12-01

    Under some conditions, a very large influx of carbon into TFTR occurs during beam injection into low recycling plasmas (the Supershot regime). These carbon ''blooms'' result in serious degradation of plasma parameters. The sources of this carbon have been identified as hot spots on the TFTR bumper limiter at or near the last closed flux surface. Two separate temperature thresholds have been identified. One, at about 1650 degree C, is consistent with radiation enhanced sublimation. The other, at about 2300 degree C, appears to be thermal sublimation of carbon from the limiter. To account for the increased density caused by the blooms, near unity recycling of the carbon at the limiter by physical sputtering is required; this effect is expected from laboratory measurements, and we believe we are seeing it on TFTR. The sources of the carbon blooms are sites which have either loosely attached fragments of limiter material (caused by damage) or surfaces nearly perpendicular to the magnetic field lines. Such surfaces may have local power depositions two orders of magnitude higher than usual. The TFTR team modified the limiter during the opening of Winter 1989--90. The modifications greatly reduced the number and magnitude of the blooms, so that they are no longer a problem

  9. Enhanced carbon influx into TFTR supershots

    International Nuclear Information System (INIS)

    Ramsey, A.T.; Bush, C.E.; Dylla, H.F.; Owens, D.K.; Pitcher, C.S.; Ulrickson, M.A.

    1991-01-01

    Under some conditions, a very large influx of carbon into TFTR occurs during neutral beam injection into low recycling plasmas (the supershot regime). These carbon ''blooms'' result in serious degradation of plasma parameters. The sources of this carbon have been identified as hot spots on the TFTR bumper limiter at or near the last closed flux surface. Two separate temperature thresholds have been identified. One threshold, at about 1650 deg. C, is consistent with radiation enhanced sublimation (RES). The other, at about 2300 deg. C, appears to be thermal sublimation of carbon from the limiter. The carbon influx can be quantitatively accounted for by taking laboratory values for RES rates, making reasonable assumptions about the extent of the blooming area and assuming unity carbon recycling at the limiter. Such high carbon recycling is expected, and it is shown that, in target plasmas at least, it is observed on TFTR. The sources of the carbon blooms are sites which have either loosely attached fragments of limiter material (caused by damage) or surfaces that are nearly perpendicular to the magnetic field lines. Such surfaces may have local power depositions two orders of magnitude higher than usual. The TFTR team modified the limiter during the opening of winter 1989-1990. The modifications greatly reduced the number and magnitude of the blooms, so that they are no longer a problem. (author). 27 refs, 9 figs

  10. Possible neutral beam requirements for TFTR upgrades

    International Nuclear Information System (INIS)

    Prichard, B.A. Jr.; Little, R.; Post, D.E.; Schmidt, J.A.

    1977-01-01

    A discussion is provided of possible neutral beam requirements and constraints for a TFTR upgrade. The time scale is the early 80s and beams of 250 keV D 0 , probably using 65 ampere negative ion sources, existing power supplies and vacuum enclosures would be required

  11. Conceptual design of a neutral-beam injection system for the TFTR

    International Nuclear Information System (INIS)

    Ehlers, K.W.; Berkner, K.H.; Cooper, W.S.; Hooper, E.B.; Pyle, R.V.; Stearns, J.W.

    1975-11-01

    The neutral-beam injection requirements for heating and fueling the next generation of fusion reactor experiments far exceed those of present devices; the neutral-beam systems needed to meet these requirements will be large and complex. A conceptual design of a TFTR tokamak injection system to produce 120 keV deuterium-ion beams with a total power of about 80 MW is given

  12. Engineering design of TFTR and it's impact on future tokamaks

    International Nuclear Information System (INIS)

    Sabado, M.M.

    1981-01-01

    TFTR is a second generation tokamak whose key objective is scientific break-even. TFTR is expected to be the first machine to demonstrate proper combination of plasma confinement time, density, and temperature to obtain this objective. A summary of major TFTR design parameters, including TFM, is presented, and their potential impact on future tokamaks discussed. Details of the updated engineering design and analysis of components are described. Status of major hardware fabrication, assembly installation and test are reviewed. TFTR features, technology, predicted performance and their potential implication for future tokamaks are summarized

  13. Tritium pellet injection sequences for TFTR

    International Nuclear Information System (INIS)

    Houlberg, W.A.; Milora, S.L.; Attenberger, S.E.; Singer, C.E.; Schmidt, G.L.

    1983-01-01

    Tritium pellet injection into neutral deuterium, beam heated deuterium plasmas in the Tokamak Fusion Test Reactor (TFTR) is shown to be an attractive means of (1) minimizing tritium use per tritium discharge and over a sequence of tritium discharges; (2) greatly reducing the tritium load in the walls, limiters, getters, and cryopanels; (3) maintaining or improving instantaneous neutron production (Q); (4) reducing or eliminating deuterium-tritium (D-T) neutron production in non-optimized discharges; and (5) generally adding flexibility to the experimental sequences leading to optimal Q operation. Transport analyses of both compression and full-bore TFTR plasmas are used to support the above observations and to provide the basis for a proposed eight-pellet gas gun injector for the 1986 tritium experiments

  14. Parametric variations of ion transport in TFTR

    International Nuclear Information System (INIS)

    Scott, S.D.; Ernst, D.

    1993-01-01

    This paper is divided into three roughly independent sections. The first is a historical review of the twenty year history of experimental ion heat transport measurements from many tokamaks. The second is a study of ion heat transport in Ohmic TFTR plasmas which shows that χi ∼ χe ∼ 15χi neo . Thus, ion heat transport is demonstrated to be strongly anomalous even the absence of auxiliary heating. The third section describes the variation of χi with local ion temperature in TFTR during auxiliary heating, with emphasis on characterizing the differecens between transport in the L-mode and supershot regimes. The results are consistent with the conjecture that improved ion energy confinement in supershot plasmas is caused by a high ratio of T 1 /T e

  15. TFTR neutral-beam test facility

    International Nuclear Information System (INIS)

    Turitzin, N.M.; Newman, R.A.

    1981-11-01

    TFTR Neutral Beam System will have thirteen discharge ion sources, each with its own power supply. Twelve of these will be utilized for supplemental heating of the TFTR tokamak plasma, while the thirteenth will be dedicated to an off-machine test chamber for source development and/or conditioning. A test installation for one source was set up using prototype equipment to discover and correct possible deficiencies, and to properly coordinate the equipment. This test facility represents the first opportunity for assembling an integrated system of hardware supplied by diverse vendors, each of whom designed and built his equipment to performance specifications. For the installation and coordination of the different portions of the total system, particular attention was given to personnel safety and safe equipment operation. This paper discusses various system components, their characteristics, interconnection and control. Results of the recently initiated test phase will be reported at a later date

  16. β limit disruptions in the TFTR tokamak

    International Nuclear Information System (INIS)

    Fredrickson, E.D.; McGuire, K.; Janos, A.; Bell, M.; Budny, R.V.; Bush, C.E.; Manickam, J.; Mynick, H.; Nazikian, R.; Taylor, G.

    1994-11-01

    A disruptive β limit (β = plasma pressure/magnetic pressure) is observed in high performance plasmas in TFTR. The MHD character of these disruptions differs substantially from the disruptions in high density plasmas (density limit disruptions) on TFTR. The high β disruptions can occur with less than a milliseconds warning in the form of a fast growing precursor. The precursor appears to be an external kink or internal (m,n)=(1,1) kink strongly coupled through finite β effects and toroidal terms to higher m components. It does not have the open-quote cold bubble close-quote structure found in density limit disruptions. There is also no evidence for a change in the internal inductance, i.e., a major reconnection of the flux, at the time of the thermal quench

  17. In situ calibration of TFTR neutron detectors

    International Nuclear Information System (INIS)

    Hendel, H.W.; Palladino, R.W.; Barnes, C.W.; Diesso, M.; Felt, J.S.; Jassby, D.L.; Johnson, L.C.; Ku, L.; Liu, Q.P.; Motley, R.W.; Murphy, H.B.; Murphy, J.; Nieschmidt, E.B.; Roberts, J.A.; Saito, T.; Strachan, J.D.; Waszazak, R.J.; Young, K.M.

    1990-01-01

    We report results of the TFTR fission detector calibration performed in December 1988. A NBS-traceable, remotely controlled 252 Cf neutron source was moved toroidally through the TFTR vacuum vessel. Detection efficiencies for two 235 U detectors were measured for 930 locations of the neutron point source in toroidal scans at 16 different major radii and vertical heights. These scans effectively simulated the volume-distributed plasma neutron source and the volume-integrated detection efficiency was found to be insensitive to plasma position. The Campbell mode is useful due to its large overlap with the count rate mode and large dynamic range. The resulting absolute plasma neutron source calibration has an uncertainty of ±13%

  18. Two frequency ICRF operation on TFTR

    International Nuclear Information System (INIS)

    Rogers, J.H.; Majeski, R.; Wilson, J.R.; Hosea, J.C.; Schilling, G.; Stevens, J.; Phillips, C.K.

    1993-01-01

    Modifications have been made recently to allow two of the ICRF antennas (bays L and M) on TFTR to operate at either of two frequencies, 43 MHz or 64 MHz. This was accomplished by lengthening the resonant loops (2Λ at 43 MHz, 3Λ at 64 MHz) and replacing the conventional quarter wave impedance transformers with a tapered impedance design. The other two antennas (bays K and N) will operate at a fixed frequency, 43 MHz. The two frequency operation will allow a combination of 3 He-minority and H-minority heating at near full field on TFTR. The higher frequency, 64 MHz, may also be useful in direct electron heating and current drive experiments at lower toroidal fields. Models of the antenna, resonant loops and impedance matching system are presented

  19. X-ray diagnostics for TFTR

    International Nuclear Information System (INIS)

    von Goeler, S.; Hill, K.W.; Bitter, M.

    1982-12-01

    A short description of the x-ray diagnostic preparation for the TFTR tokamak is given. The x-ray equipment consists of the limiter x-ray monitoring system, the soft x-ray pulse-height-analysis-system, the soft x-ray imaging system and the x-ray crystal spectrometer. Particular attention is given to the radiation protection of the x-ray systems from the neutron environment

  20. TFTR control and monitoring system (CICADA)

    International Nuclear Information System (INIS)

    Daniels, R.E.

    1981-01-01

    The TFTR Central Instrumentation, Control and Data Acquisition System (CICADA) is described. This is a computer based system, supporting three types of user interfaces and supporting real time, terminal, and batch operations. Over one hundred graphic display generators will be supported by the system, four array processors will greatly increase the analysis capabilities, and closed circuit television will distribute performance data throughout the facility. Approximately twenty thousand points wll be interfaced to the system

  1. 1987 calibration of the TFTR neutron spectrometers

    International Nuclear Information System (INIS)

    Barnes, C.W.; Strachan, J.D.; Princeton Univ., NJ

    1989-12-01

    The 3 He neutron spectrometer used for measuring ion temperatures and the NE213 proton recoil spectrometer used for triton burnup measurements were absolutely calibrated with DT and DD neutron generators placed inside the TFTR vacuum vessel. The details of the detector response and calibration are presented. Comparisons are made to the neutron source strengths measured from other calibrated systems. 23 refs., 19 figs., 6 tabs

  2. Pneumatic pellet injectors for TFTR and JET

    International Nuclear Information System (INIS)

    Combs, S.K.; Milora, S.L.

    1986-01-01

    This paper describes the development of pneumatic hydrogen pellet injectors for plasma fueling applications on the Tokamak Fusion Test Reactor (TFTR) and the Joint European Torus (JET). The performance parameters of these injectors represent an extension of previous experience and include pellet sizes in the range 2-6 mm in diameter and speeds approaching 2 km/s. Design features and operating characteristics of these pneumatic injectors are presented

  3. TFTR vertically viewing electron cyclotron emission diagnostic

    International Nuclear Information System (INIS)

    Taylor, G.

    1990-01-01

    The Tokamak Fusion Test Reactor (TFTR) Michelson interferometer has a spectral coverage of 75--540 GHz, allowing measurement of the first four electron cyclotron harmonics. Until recently the instrument has been configured to view the TFTR plasma on the horizontal midplane, primarily in order to measure the electron temperature profile. Electron cyclotron emission (ECE) extraordinary mode spectra from TFTR Supershot plasmas exhibit a pronounced, spectrally narrow feature below the second harmonic. A similar feature is seen with the ECE radiometer diagnostic below the electron cyclotron fundamental frequency in the ordinary mode. Analysis of the ECE spectra indicates the possibility of a non-Maxwellian 40--80 keV tail on the electron distribution in or near the core. During 1990 three vertical views with silicon carbide viewing targets will be installed to provide a direct measurement of the electron energy distribution at major radii of 2.54, 2.78, and 3.09 m with an energy resolution of approximately 20% at 100 keV. To provide the maximum flexibility, the optical components for the vertical views will be remotely controlled to allow the Michelson interferometer to be reconfigured to either the midplane horizontal view or one of the three vertical views between plasma shots

  4. Scope and status of the USA Engineering Test Facility including relevant TFTR research and development

    International Nuclear Information System (INIS)

    Becraft, W.R.; Reardon, P.J.

    1980-01-01

    The vehicle by which the fusion program would move into the engineering testing phase of fusion power development is designated the Engineering Test Facility (ETF). The progress toward the design and construction of the ETF will reflect the significant achievements of past, present, and future experimental tokamak devices. Some of the features of this foundation of experimental results and relevant engineering designs and operation will derive from the Tokamak Fusion Test Reactor (TFTR) Project, now nearing the completion of its construction phase. The ETF would provide a test-bed for reactor components in the fusion environment. In order to initiate preliminary planning for the ETF decision, the Office of Fusion Energy (OFE) established the ETF Design Center activity to prepare the design of the ETF. This paper describes the design status of the ETF and discusses some highlights of the TFTR R and D work

  5. Scope and status of the USA Engineering Test Facility including relevant TFTR research and development

    International Nuclear Information System (INIS)

    Becraft, W.R.; Reardon, P.J.

    1981-01-01

    The vehicle by which the fusion programme would move into the engineering testing phase of fusion power development is designated the Engineering Test Facility (ETF). The progress toward the design and construction of the ETF will reflect the significant achievements of past, present, and future experimental tokamak devices. Some of the features of this foundation of experimental results and relevant engineering designs and operation will derive from the Tokamak Fusion Test Reactor (TFTR) Project, now nearing the completion of its construction phase. The ETF would provide a test-bed for reactor components in the fusion environment. To initiate preliminary planning for the ETF decision, the Office of Fusion Energy (OFE) established the ETF Design Center activity to prepare the design of the ETF. This paper describes the design status of the ETF and discusses some highlights of the TFTR R and D work. (author)

  6. TFTR D and D Project: Final Examination and Testing of the TFTR TF-Coils

    International Nuclear Information System (INIS)

    Zatz, Irving J.

    2003-01-01

    In operation for nearly 15 years, TFTR (Tokamak Fusion Test Reactor) was not only a fusion science milestone, but a milestone of achievement in engineering as well. The TFTR DandD (Decommissioning and Decontamination) program provided a rare opportunity to examine machine components that had been exposed to a unique performance environment of greater than 100,000 mechanical and thermal load cycles. In particular, the possible examination of the TFTR toroidal-field (TF) coils, which met, then exceeded, the 5.2 Tesla magnetic field machine specification, could supply the answers to many questions that have been asked and debated since the coils were originally designed and built. A test program conducted in parallel with the DandD effort was the chance to look inside and examine, in detail, the TFTR TF coils for the first time since they were delivered encased to PPPL (Princeton Plasma Physics Laboratory). The results from such a program would provide data and insight that would not only be nefit PPPL and the fusion community, but the broader scientific community as well

  7. Results from D-T experiments on TFTR and implications for achieving an ignited plasma

    International Nuclear Information System (INIS)

    Hawryluk, R.J.; Blanchard, W.

    1998-01-01

    Progress in the performance of tokamak devices has enable not only the production of significant bursts of fusion energy from deuterium-tritium plasmas in the Tokamak Fusion Test Reactor (TFTR) and the Joint European Torus (JET) but, more importantly, the initial study of the physics of burning magnetically confined plasmas. As a result of the worldwide research on tokamaks, the scientific and technical issues for achieving an ignited plasma are better understood and the remaining questions more clearly defined. The principal research topics which have been studied on TFTR are transport, magnetohydrodynamic stability, and energetic particle confinement. The integration of separate solutions to problems in each of these research areas has also been of major interest. Although significant advances, such as the reduction of turbulent transport by means of internal transport barriers, identification of the theoretically predicted bootstrap current, and the study of the confinement of energetic fusion alpha-particles have been made, interesting and important scientific and technical issues remain. In this paper, the implications for the TFTR experiments for overcoming these remaining issues will be discussed

  8. TFTR centralized torus interface valve control system

    International Nuclear Information System (INIS)

    Pearson, G.G.; Olsen, D.H.

    1983-01-01

    A system developed especially for the TFTR to monitor and control the interface between the vacuum vessel and associated diagnostics will be described in this paper. Diagnostics which must be connected to the machine vacuum are required to do so through a Torus Interface Valve (TIV). Two types of TIV's are used on TFTR. The first type is a non-latching valve which must be held in the opened position by a sustained OPEN command, returning automatically to the closed position when the OPEN command is removed. This type of TIV is used on all systems which never insert a probe into the vacuum vessel through the TIV. The second type of TIV is a latching valve which requires a momentary OPEN command to open and a momentary CLOSE command to close. Each TIV is linked to its own dedicated logic controller. Each logic controller is hardwired to the appropriate TIV OPEN/CLOSED limit switches, probe IN/OUT limit switches, TFTR vacuum vessel pressure setpoint switches, and diagnostic pressure setpoint switches. The logic controller can be configured for local (push-button) or remote (computer) control. Each controller has a uniquely coded keyswitch to determine the configuration. Whether under local or remote control, all OPEN and CLOSE commands must be approved by the TIV controller (TIVC). In the case of systems with probes, the controller must receive a positive indication that the probe is completely backed out before a CLOSE command will be transmitted from the TIVC to the TIV. Before a valve will be opened by a controller, the differential pressure across the valve must be within certain limits

  9. A comparative study of core and edge transport barrier dynamics of DIII-D and TFTR tokamak plasmas

    International Nuclear Information System (INIS)

    Synakowski, E.J.; Beer, M.; Bell, R.E.

    2001-01-01

    Confinement bifurcations and subsequent plasma dynamics in the TFTR core and the DIII-D core and edge are compared in order to identify a common physics basis. Observations suggest a framework in which ExB shear plays a dominant role in the barrier dynamics. In TFTR, bifurcations from the reverse shear (RS) into the enhanced reverse shear (ERS) regime with high power balanced neutral beam heating (above 25 MW at 4.8 T) resemble edge H mode transitions observed on DIII-D. In both, radial electric field (E r ) excursions precede confinement changes and are manifest as localized changes in the impurity poloidal rotation. Reduced transport follows the excursions, and in both cases strong E r shear is reinforced by the plasma pressure. These characteristics are contrasted with DIII-D negative central shear (NCS) barrier evolution with unidirectional beam injection. There, the improved confinement region can develop slowly, depending on the neutral beam input power and torque. Rapid expansion and deepening of this region follows an increase in the neutral beam heating power. The initial formation phase is modulated by confinement steps and interruptions. An analog for these steps is found in TFTR RS plasmas. Although these do not dominate the TFTR plasma evolution during low power (7 MW) heating, they can represent significant transport reductions when additional heating is applied. In both devices, no strong excursion in E r precedes these latter confinement bifurcations. The triggering event of these steps may be related to current profile relaxation, but it is not always connected with simple integral or half-integer values of the minimum in the q profile. Finally, variations of E r and the ExB shear through the application of unidirectional injection on TFTR yielded plasmas with confinement characteristics and barrier dynamics similar to those of DIII-D NCS plasmas. The data underscore that the physics responsible for the enhanced confinement states is fundamentally

  10. A comparative study of core and edge transport barrier dynamics of DIII-D and TFTR tokamak plasmas

    International Nuclear Information System (INIS)

    Synakowski, E.J.; Beer, M.A.; Bell, R.E.

    1999-01-01

    Confinement bifurcations and subsequent plasma dynamics in the TFTR core and the DIII-D core and edge are compared in order to identify a common physics basis. Observations suggest a framework in which ExB shear plays a dominant role in the barrier dynamics. In TFTR, bifurcations from the reverse shear (RS) into the enhanced reverse shear (ERS) regime with high power balanced neutral beam heating (above 25 MW at 4.8 T) resemble edge H mode transitions observed on DIII-D. In both, radial electric field (E r ) excursions precede confinement changes and are manifest as localized changes in the impurity poloidal rotation. Reduced transport follows the excursions, and in both cases strong E r shear is reinforced by the plasma pressure. These characteristics are contrasted with DIII-D negative central shear (NCS) barrier evolution with unidirectional beam injection. There, the improved confinement region can develop slowly, depending on the neutral beam input power and torque. Rapid expansion and deepening of this region follows an increase in the neutral beam heating power. The initial formation phase is modulated by confinement steps and interruptions. An analog for these steps is found in TFTR RS plasmas. Although these do not dominate the TFTR plasma evolution during low power (7 MW) heating, they can represent significant transport reductions when additional heating is applied. In both devices, no strong excursion in E r precedes these latter confinement bifurcations. The triggering event of these steps may be related to current profile relaxation, but it is not always connected with simple integral or half-integer values of the minimum in the q profile. Finally, variations of E r and the ExB shear through the application of unidirectional injection on TFTR yielded plasmas with confinement characteristics and barrier dynamics similar to those of DIII-D NCS plasmas. The data underscore that the physics responsible for the enhanced confinement states is fundamentally

  11. Alpha particle collective Thomson scattering in TFTR

    International Nuclear Information System (INIS)

    Machuzak, J.S.; Woskov, P.P.; Rhee, D.Y.; Gilmore, J.; Bindslev, H.

    1993-01-01

    A collective Thomson scattering diagnostic is being implemented on TFTR to measure alpha particle, energetic and thermal ion densities and velocity distributions. A 60 GHz, 0.1-1 kW gyrotron will be used as the transmitter source, and the scattering geometry will be perpendicular to the magnetic field in the extraordinary mode polarization. An enhanced scattered signal is anticipated from fluctuations in the lower hybrid frequency range with this scattering geometry. Millimeter wave collective Thomson scattering diagnostics have the advantage of larger scattering angles to decrease the amount of stray light, and long, high power, modulated pulses to obtain improved signal to noise through synchronous detection techniques

  12. TPX/TFTR Neutral Beam energy absorbers

    International Nuclear Information System (INIS)

    Dahlgren, F.; Wright, K.; Kamperschroer, J.; Grisham, L.; Lontai, L.; Peters, C.; VonHalle, A.

    1993-01-01

    The present beam energy absorbing surfaces on the TFTR Neutral Beams such as Ion Dumps, Calorimeters, beam defining apertures, and scrapers, are simple water cooled copper plates which wee designed to absorb (via their thermal inertia) the incident beam power for two seconds with a five minute coal down interval between pulses. These components are not capable of absorbing the anticipated beam power loading for 1000 second TPX pulses and will have to be replaced with an actively cooled design. While several actively cooled energy absorbing designs were considered,, the hypervapotron elements currently being used on the JET beamlines were chosen due to their lower cooling water demands and reliable performance on JET

  13. Demonstrating diamond wire cutting of the TFTR

    International Nuclear Information System (INIS)

    Rule, K.; Perry, E.; Larson, S.; Viola, M.

    2000-01-01

    The Tokamak Fusion Test Reactor (TFTR) ceased operation in April 1997 and decommissioning commenced in October 1999. The deuterium-tritium fusion experiments resulted in contaminating the vacuum vessel with tritium and activating the materials with 14 Mev neutrons. The total tritium content within the vessel is in excess of 7,000 Curies while dose rates approach 50 mRem/hr. These radiological hazards along with the size of the Tokamak (100 cubic meters) present a unique and challenging task for dismantling. Plasma arc cutting is the current baseline technology for the dismantlement of fission reactors. This technology is typically used because of its faster cutting times. Alternatively, an innovative approach for dismantlement of the TFTR is the use of diamond wire cutting technology. Recent improvements in diamond wire technology have allowed the cutting of carbon steel components such as pipe, plate, and tube bundles in heat exchangers. Some expected benefits of this technology include: significantly reduction in airborne contaminates, reduced personnel exposure, a reduced risk of spread of tritium contamination, and reduced overall costs as compared to using plasma arc cutting. This paper will provide detailed results of the diamond wire cutting demonstration that was completed in September of 1999, on a mock-up of this complex reactor. The results will identify cost, safety, industrial and engineering parameters, and the related performance of each situation

  14. DT results of TFTR's alpha collector

    International Nuclear Information System (INIS)

    Herrmann, H.W.; Zweben, S.J.; Darrow, D.S.; Timberlake, J.R.; Macaulay-Newcombe, R.G.

    1996-01-01

    An escaping alpha collector probe has been developed for TFTR's DT phase to complement the results of the lost alpha scintillator detectors which have been operating on TFTR since 1988. Measurements of the energy distribution of escaping alphas have been made by measuring the range of alphas implanted into nickel foils located within the alpha collector. Exposed samples have been analyzed for 4 DT plasma discharges at plasma currents of 1.0 and 1.8 MA. The results at 1.0 MA are in good agreement with predictions for first orbit alpha loss at 3.5 MeV. The 1.8 MA results, however, indicate a large anomalous loss of partially thermalized alphas at an energy ∼30% below the birth energy and at a total fluence nearly an order of magnitude above expected first orbit loss. This anomalous loss is not observed with the lost alpha scintillator detectors in DT plasmas but does resemble the anomalous delayed loss seen in DD plasmas. Several potential explanations for this loss process are examined. None of the candidate explanations proposed thus far are fully consistent with the anomalous loss observations

  15. The TFTR lithium blanket module program

    International Nuclear Information System (INIS)

    Jassby, D.L.; Bertone, P.C.; Creedon, R.L.; File, J.; Graumann, D.W.

    1985-01-01

    The Lithium Blanket Module (LBM) is an approximately 80X80X80 cm cubic module, representative of a helium-cooled lithium oxide fusion reactor blanket module, that will be installed on the TFTR (Tokamak Fusion Test Reactor) in late 1986. The principal objective of the LBM Program is to perform a series of neutron transport and tritium-breeding measurements throughout the LBM when it is exposed to the TFTR toroidal fusion neutron source, and to compare these data with the predictions of Monte Carlo (MCNP) neutronics codes. The LBM consists of 920 2.5-cm diameter breeder rods constructed of lithium oxide (Li 2 O) pellets housed in thin-walled stainless steel tubes. Procedures for mass-producing 25,000 Li 2 O pellets with satisfactory reproducibility were developed using purified Li 2 O powder, and fabrication of all the breeder rods was completed in early 1985. Tritium assay methods were investigated experimentally using both small lithium metal samples and LBM-type pellets. This work demonstrated that the thermal extraction method will be satisfactory for accurate evaluation of the minute concentrations of tritium expected in the LBM pellets (0.1-1nCi/g)

  16. Demonstrating diamond wire cutting of the TFTR

    Energy Technology Data Exchange (ETDEWEB)

    Rule, K.; Perry, E.; Larson, S.; Viola, M. [and others

    2000-02-24

    The Tokamak Fusion Test Reactor (TFTR) ceased operation in April 1997 and decommissioning commenced in October 1999. The deuterium-tritium fusion experiments resulted in contaminating the vacuum vessel with tritium and activating the materials with 14 Mev neutrons. The total tritium content within the vessel is in excess of 7,000 Curies while dose rates approach 50 mRem/hr. These radiological hazards along with the size of the Tokamak (100 cubic meters) present a unique and challenging task for dismantling. Plasma arc cutting is the current baseline technology for the dismantlement of fission reactors. This technology is typically used because of its faster cutting times. Alternatively, an innovative approach for dismantlement of the TFTR is the use of diamond wire cutting technology. Recent improvements in diamond wire technology have allowed the cutting of carbon steel components such as pipe, plate, and tube bundles in heat exchangers. Some expected benefits of this technology include: significantly reduction in airborne contaminates, reduced personnel exposure, a reduced risk of spread of tritium contamination, and reduced overall costs as compared to using plasma arc cutting. This paper will provide detailed results of the diamond wire cutting demonstration that was completed in September of 1999, on a mock-up of this complex reactor. The results will identify cost, safety, industrial and engineering parameters, and the related performance of each situation.

  17. Three novel tokamak plasma regimes in TFTR

    International Nuclear Information System (INIS)

    Furth, H.P.

    1985-10-01

    Aside from extending ''standard'' ohmic and neutral beam heating studies to advanced plasma parameters, TFTR has encountered a number of special plasma regimes that have the potential to shed new light on the physics of tokamak confinement and the optimal design of future D-T facilities: (1) High-powered, neutral beam heating at low plasma densities can maintain a highly reactive hot-ion population (with quasi-steady-state beam fueling and current drive) in a tokamak configuration of modest bulk-plasma confinement requirements. (2) Plasma displacement away from limiter contact lends itself to clarification of the role of edge-plasma recycling and radiation cooling within the overall pattern of tokamak heat flow. (3) Noncentral auxiliary heating (with a ''hollow'' power-deposition profile) should serve to raise the central tokamak plasma temperature without deterioration of central region confinement, thus facilitating the study of alpha-heating effects in TFTR. The experimental results of regime (3) support the theory that tokamak profile consistency is related to resistive kink stability and that the global energy confinement time is determined by transport properties of the plasma edge region

  18. Impurity pellet injection experiments at TFTR

    International Nuclear Information System (INIS)

    Marmar, E.S.

    1992-01-01

    Impurity (Li and C) pellet injection experiments on TFTR have produced a number of new and significant results. (1) We observe reproducible improvements of TFTR supershots after wall-conditioning by Li pellet injection ('lithiumization'). (2) We have made accurate measurements of the pitch angle profiles of the internal magnetic field using two novel techniques. The first measures the internal field pitch from the polarization angles of Li + line emission from the pellet ablation cloud, while the second measures the pitch angle profiles by observing the tilt of the cigar-shaped Li + emission region of the ablation cloud. (3) Extensive measurements of impurity pellet penetration into plasmas with central temperatures ranging from ∼0.3 to ∼7 keV have been made and compared with available theoretical models. Other aspects of pellet cloud physics have been investigated. (4) Using pellets as a well defined perturbation has allowed study of transport phenomena. In the case of small pellet perturbations, the characteristics of the background plasmas are probed, while with large pellets, pellet induced effects are clearly observed. These main results are discussed in more detail in this paper

  19. Simulations of DT experiments in TFTR

    International Nuclear Information System (INIS)

    Budny, R.; Bell, M.G.; Biglari, H.; Bitter, M.; Bush, C.; Cheng, C.Z.; Fredrickson, E.; Grek, B.; Hill, K.W.; Hsuan, H.; Janos, A.; Jassby, D.L.; Johnson, D.; Johnson, L.C.; LeBlanc, B.; McCune, D.C.; Mikkelsen, D.R.; Park, H.; Ramsey, A.T.; Sabbagh, S.A.; Scott, S.; Schivell, J.; Strachan, J.D.; Stratton, B.C.; Synakowski, E.; Taylor, G.; Zarnstorff, M.C.; Zweben, S.J.

    1991-12-01

    A transport code (TRANSP) is used to simulate future deuterium-tritium experiments (DT) in TFTR. The simulations are derived from 14 TFTR DD discharges, and the modeling of one supershot is discussed in detail to indicate the degree of accuracy of the TRANSP modeling. Fusion energy yields and α-particle parameters are calculated, including profiles of the α slowing down time, average energy, and of the Alfven speed and frequency. Two types of simulations are discussed. The main emphasis is on the DT equivalent, where an equal mix of D and T is substituted for the D in the initial target plasma, and for the D O in the neutral-beam injection, but the other measured beam and plasma parameters are unchanged. This simulation does not assume that α heating will enhance the plasma parameters, or that confinement will increase with T. The maximum relative fusion yield calculated for these simulations is Q DT ∼ 0.3, and the maximum α contribution to the central toroidal β is β α (0) ∼ 0.5%. The stability of toroidicity-induced Alfven eigenmodes (TAE) and kinetic ballooning modes (KBM) is discussed. The TAE mode is predicted to become unstable for some of the equivalent simulations, particularly after the termination of neutral beam injection. In the second type of simulation, empirical supershot scaling relations are used to project the performance at the maximum expected beam power. The MHD stability of the simulations is discussed

  20. Coherent and turbulent fluctuations in TFTR

    International Nuclear Information System (INIS)

    McGuire, K.; Arunasalam, V.; Bell, M.G.

    1987-04-01

    Classification of the sawteeth observed in the TFTR tokamak has been carried out to highlight the differences between the many types observed. Three types of sawteeth are discussed: ''simple,'' ''small,'' and ''compound.'' During the enhanced confinement discharges on TFTR, sawteeth related to q = 1 are usually not present, but a sawtooth-like event is sometimes observed. β approaches the Troyon limit only at low q/sub cyl/ with a clear reduction of achievable β/sub n/ at high q/sub cyl/. This suggests that a β/sub p/ limit, rather than the Troyon-Gruber limit, applies at high q/sub cyl/ in the enhanced confinement discharges. These discharges also reach the stability boundary for n → ∞ ideal MHD ballooning modes. Turbulence measurements in the scrape-off region with Langmuir and magnetic probes show strong edge density turbulence n/n = 0.3 - 0.5, with weak magnetic turbulence B/sub θ/B/sub θ/ > 5 x 10 -6 measured at the wall, but these measurements are very sensitive to local edge conditions

  1. Design of the TFTR [Tokamak Fusion Test Reactor] maintenance manipulator

    International Nuclear Information System (INIS)

    Loesser, G. D.; Heitzenroeder, P.; Bohme, G.; Selig, M.

    1987-01-01

    The Tokamak Fusion Test Reactor (TFTR) plans to generate a total of 3 x 10 21 neutrons during its deuterium-tritium run period in 1900. This will result in high levels of radiation, especially within the TFTR vacuum vessel. The maintenance manipulator's mission is to assist TFTR in meeting Princeton Plasma Physics Laboratory's personnel radiation exposure criteria and in maintaining as-low-as-reasonably-achievable principals by limiting the radiation exposure received by operating and maintenance personnel. The manipulator, which is currently being fabricated and tested by Kernforschungszentrum Karlsruhe, is designed to perform limited, but routine and necessary, functions within the TFTR vacuum torus after activation levels within the torus preclude such functions being performed by personnel. These functions include visual inspection, tile replacement, housekeeping tasks, diagnostic calibrations, and leak detection. To meet its functional objectives, the TFTR maintenance manipulator is required to be operable in TFTR's very high vacuum environment (typically 2 x 10 -8 Torr). It must also be bakeable at 150 degree C and able to withstand the radiation environment

  2. Tritium environmental transport studies at TFTR

    International Nuclear Information System (INIS)

    Ritter, P.D.; Dolan, T.J.; Longhurst, G.R.

    1993-01-01

    Environmental tritium concentrations will be measured near the Tokamak Fusion Test Reactor (TFTR) to help validate dynamic models of tritium transport in the environment. For model validation the database must contain sequential measurements of tritium concentrations in key environmental compartments. Since complete containment of tritium is an operational goal, the supplementary monitoring program should be able to glean useful data from an unscheduled acute release. Portable air samplers will be used to take samples automatically every 4 hours for a weak after an acute release, thus obtaining the time resolution needed for code validation. Samples of soil, vegetation, and foodstuffs will be gathered daily at the same locations as the active air monitors. The database may help validate the plant/soil/air part of tritium transport models and enhance environmental tritium transport understanding for the International Thermonuclear Experimental Reactor (ITER)

  3. Tritium environmental transport studies at TFTR

    Science.gov (United States)

    Ritter, P. D.; Dolan, T. J.; Longhurst, G. R.

    1993-06-01

    Environmental tritium concentrations will be measured near the Tokamak Fusion Test Reactor (TFTR) to help validate dynamic models of tritium transport in the environment. For model validation the database must contain sequential measurements of tritium concentrations in key environmental compartments. Since complete containment of tritium is an operational goal, the supplementary monitoring program should be able to glean useful data from an unscheduled acute release. Portable air samplers will be used to take samples automatically every 4 hours for a week after an acute release, thus obtaining the time resolution needed for code validation. Samples of soil, vegetation, and foodstuffs will be gathered daily at the same locations as the active air monitors. The database may help validate the plant/soil/air part of tritium transport models and enhance environmental tritium transport understanding for the International Thermonuclear Experimental Reactor (ITER).

  4. Analysis of IBW experiments on TFTR

    International Nuclear Information System (INIS)

    LeBlanc, B.P.; Bell, R.E.; Bush, C.E.; Cesario, R.; Hanson, G.R.; Hosea, J.; Majeski, R.; Ono, M.; Paoletti, F.; Phillips, C.K.; Rogers, J.H.; Schilling, G.; Wilson, J.R.

    1997-01-01

    A direct launch IBW antenna has been commissioned during the last TFTR experimental campaign. While we did observed IBW-induced poloidal drive, we did not reproduce the CH mode. In this first cut analysis, we concentrate on discharges with hydrogenic resonant species (D or T) combining IBW and neutral beam heating (NBI) at 76 MHz. The experimental data suggest poor power coupling to the main plasma as a limiting factor. A ray tracing code computes the power deposition and results are fed in data reduction code TRANSP to ascertain the coupling efficiency. The density increase observed during IBW is in part caused by influx of impurity, in particular during the latter part of the RF pulse. copyright 1997 American Institute of Physics

  5. Temporary fire sealing of penetrations on TFTR

    International Nuclear Information System (INIS)

    Hondorp, H.L.

    1981-02-01

    The radiation shielding provided for TFTR for D-D and D-T operation will be penetrated by numerous electrical and mechanical services. Eventually, these penetrations will have to be sealed to provide the required fire resistance, tritium sealability, pressure integrity and radiation attenuation. For the initial hydrogen operation, however, fire sealing of the penetrations in the walls and floor is the primary concern. This report provides a discussion of the required and desirable properties of a temporary seal which can be used to seal these penetrations for the hydrogen operation and then subsequently be removed and replaced as required for the D-D and D-T operations. Several candidate designs are discussed and evaluated and recommendations are made for specific applications

  6. Particle reflection and TFTR neutral beam diagnostics

    International Nuclear Information System (INIS)

    Kamperschroer, J.H.; Grisham, L.R.; Kugel, H.W.; O'Connor, T.E.; Newman, R.A.; Stevenson, T.N.; von Halle, A.; Williams, M.D.

    1992-04-01

    Determination of two critical neutral beam parameters, power and divergence, are affected by the reflection of a fraction of the incident energy from the surface of the measuring calorimeter. On the TFTR Neutral Beam Test Stand, greater than 30% of the incident power directed at the target chamber calorimeter was unaccounted for. Most of this loss is believed due to reflection from the surface of the flat calorimeter, which was struck at a near grazing incidence (12 degrees). Beamline calorimeters, of a ''V''-shape design, while retaining the beam power, also suffer from reflection effects. Reflection, in this latter case, artificially peaks the power toward the apex of the ''V'', complicating the fitting technique, and increasing the power density on axis by 10 to 20%; an effect of import to future beamline designers. Agreement is found between measured and expected divergence values, even with 24% of the incident energy reflected

  7. Initial conditioning of the TFTR vacuum vessel

    International Nuclear Information System (INIS)

    Dylla, H.F.; Blanchard, W.R.; Krawchuk, R.B.; Hawryluk, R.J.; Owens, D.K.

    1984-01-01

    We report on the initial conditioning of the Tokamak Fusion Test Reactor (TFTR) vacuum vessel prior to the initiation of first plasma discharges, and during subsequent operation with high power ohmically-heated plasmas. Following evacuation of the 86 m 3 vessel with the 10 4 1/s high vacuum pumping system, the vessel was conditioned by a 15 A dc glow discharge in H 2 at a pressure of 5 mTorr. Rapid-pulse discharge cleaning was used subsequently to preferentially condition the graphite plasma limiters. The effectiveness of the discharge cleaning was monitored by measuring the exhaust rates of the primary discharge products (CO/C 2 H 4 , CH 4 , and H 2 O). After 175 hours of glow discharge treatment, the equivalent of 50 monolayers of C and O was removed from the vessel, and the partial pressures of impurity gases were reduced to the range of 10 -9 -10 -10 Torr

  8. Visible imaging of edge fluctuations in TFTR

    International Nuclear Information System (INIS)

    Zweben, S.J.; Medley, S.S.

    1989-03-01

    Images of the visible light emission from the inner wall region of TFTR have been made using a rapidly gated, intensified TV camera. Strong ''filamentation'' of the neutral deuterium Dα light is observed when the camera gating time is <100 μsec during neutral-beam-heated discharges. These turbulent filaments vary in position randomly vs. time and have a poloidal wavelength of ∼3-5 cm which is much shorter than their parallel wavelength of ∼100 cm. A second and new type of edge fluctuation phenomenon, which we call a ''merfe,'' is also described. Merfes are a regular poloidal pattern of toroidally symmetric, small-scale marfes which move away from the inner midplane during the current decay after neutral beam injection. Some tentative interpretations of these two phenomena are presented. 27 refs., 8 figs

  9. Soft x-ray tomography on TFTR

    International Nuclear Information System (INIS)

    Kuo-Petravic, G.

    1988-12-01

    The tomographic method used for deriving soft x-ray local emissivities on TFTR, using one horizontal array of 60 soft x-ray detectors, is described. This method, which is based on inversion of Fourier components and subsequent reconstruction, has been applied to the study of a sawtooth crash. A flattening in the soft x-ray profile, which we interpret as an m = 1 island, is clearly visible during the precursor phase and its location and width correlate well with those from electron temperature profiles reconstructed from electron cyclotron emission measurement. The limitations of the Fourier method, due notably to the aperiodic nature of the signals in the fast crash phase and the difficulty of obtaining accurately the higher Fourier harmonics, are discussed. 9 refs., 13 figs

  10. Heat pulse propagation studies in TFTR

    Energy Technology Data Exchange (ETDEWEB)

    Fredrickson, E.D.; Callen, J.D.; Colchin, R.J.; Efthimion, P.C.; Hill, K.W.; Izzo, R.; Mikkelsen, D.R.; Monticello, D.A.; McGuire, K.; Bell, J.D.

    1986-02-01

    The time scales for sawtooth repetition and heat pulse propagation are much longer (10's of msec) in the large tokamak TFTR than in previous, smaller tokamaks. This extended time scale coupled with more detailed diagnostics has led us to revisit the analysis of the heat pulse propagation as a method to determine the electron heat diffusivity, chi/sub e/, in the plasma. A combination of analytic and computer solutions of the electron heat diffusion equation are used to clarify previous work and develop new methods for determining chi/sub e/. Direct comparison of the predicted heat pulses with soft x-ray and ECE data indicates that the space-time evolution is diffusive. However, the chi/sub e/ determined from heat pulse propagation usually exceeds that determined from background plasma power balance considerations by a factor ranging from 2 to 10. Some hypotheses for resolving this discrepancy are discussed. 11 refs., 19 figs., 1 tab.

  11. Remote leak detection for the TFTR

    International Nuclear Information System (INIS)

    Walthers, C.R.

    1977-01-01

    The planned design for the TFTR (TOKAMAK Fusion Test Reactor) remote leak detection system consists of a central console which controls the application of tracer gas to possible leak areas. Seals are tested by admitting tracer gas to machined cavities on the atmospheric side of the seal. The tracer gas is brought to the seal cavity by 1 / 8 -inch diameter tubes which connect to local tracer gas/vacuum manifolds located outside the protective radiation shielding. Vacuum shell walls and welds are checked by flowing tracer gas through annular heating/cooling passages. The detector will be either an MSLD (mass spectrometer leak detector) or an RGA (residual gas analyzer), the location of which is not finalized. Feasibility tests performed and planned include response and sensitivity measurements of possible tubing/detector configurations with several tracer gases

  12. Heat pulse propagation studies in TFTR

    International Nuclear Information System (INIS)

    Fredrickson, E.D.; Callen, J.D.; Colchin, R.J.

    1986-02-01

    The time scales for sawtooth repetition and heat pulse propagation are much longer (10's of msec) in the large tokamak TFTR than in previous, smaller tokamaks. This extended time scale coupled with more detailed diagnostics has led us to revisit the analysis of the heat pulse propagation as a method to determine the electron heat diffusivity, chi/sub e/, in the plasma. A combination of analytic and computer solutions of the electron heat diffusion equation are used to clarify previous work and develop new methods for determining chi/sub e/. Direct comparison of the predicted heat pulses with soft x-ray and ECE data indicates that the space-time evolution is diffusive. However, the chi/sub e/ determined from heat pulse propagation usually exceeds that determined from background plasma power balance considerations by a factor ranging from 2 to 10. Some hypotheses for resolving this discrepancy are discussed. 11 refs., 19 figs., 1 tab

  13. Ohmic Heating System for the TFTR Tokamak

    International Nuclear Information System (INIS)

    Petree, F.; Cassel, R.

    1977-01-01

    The TFTR Ohmic Heating (OH) System will apply 140,000 volt impulses upon the OH coils to start the plasma. In order to reduce the voltage stress to ground on the OH coils to 12 kV without changing the magnetic field induced by the OH system in the plasma, six d-c current interrupters will be applied to six entry points in the OH coil system. And in order to impart a nearly rectangular shape to these impulses, the voltage determining elements will be nonlinear resistances placed in parallel with the interrupters. These nonlinear resistors, made of semiconducting material, are not normally used in repetitive or continuous duty, and their proper functioning is crucial to the reliable operation of the system. The system described herein, is being revised owing to the impact of revisions to the Toroidal Field Coil System, and to refinements to the OH System design

  14. Current configuration and performance of the TFTR computer system

    International Nuclear Information System (INIS)

    Sauthoff, N.R.; Barnes, D.J.; Daniels, R.; Davis, S.; Reid, A.; Snyder, T.; Oliaro, G.; Stark, W.; Thompson, J.R. Jr.

    1986-01-01

    Developments in the TFTR (Tokamak Fusion Test Reactor) computer support system since its startup phases are described. Early emphasis on tokamak process control have been augmented by improved physics data handling, both on-line and off-line. Data acquisition volume and rate have been increased, and data is transmitted automatically to a new VAX-based off-line data reduction system. The number of interface points has increased dramatically, as has the number of man-machine interfaces. The graphics system performance has been accelerated by the introduction of parallelism, and new features such as shadowing and device independence have been added. To support multicycle operation for neutral beam conditioning and independence, the program control system has been generalized. A status and alarm system, including calculated variables, is in the installation phase. System reliability has been enhanced by both the redesign of weaker components and installation of a system status monitor. Development productivity has been enhanced by the addition of tools

  15. Segmentation strategies for the irradiated and tritium contaminated PPPL TFTR

    International Nuclear Information System (INIS)

    Walton, G.R.; Spampinato, P.T.

    1995-01-01

    The Tokamak Fusion Test Reactor (TFTR) at Princeton Plasma Physics Laboratory is scheduled to complete its final experiments in the Fall of 1995. As a result, the TFTR will be activated and tritium contaminated. After the experiments are complete, the TFTR will undergo Shutdown and Removal (S and R). The space vacated by the TFTR will be used for a new test reactor, the Tokamak Physics Experiment (TPX). Remote methods may be required to remove components and to segment the Vacuum Vessel. The TFTR has been studied to determine alternatives for the segmentation of the Vacuum Vessel from the inside (In-Vessel). The methodology to determine suitable strategies to segment the Vacuum Vessel from In-Vessel included several areas of concentration. These areas were segmentation locations, cutting/removal technologies, pros and cons, and cutting/removal technology delivery systems. The segmentation locations for easiest implementation and minimal steps in cutting and removal have been identified. Each of these will also achieve the baseline for packaging and shipment. The methods for cutting and removal of components were determined. In addition, the delivery systems were conceptualized

  16. Segmentation strategies for the irradiated and tritium contaminated PPPL TFTR

    Energy Technology Data Exchange (ETDEWEB)

    Walton, G.R. [Princeton Univ., NJ (United States). Plasma Physics Lab.; Litka, T.J. [Advanced Consulting Group, Inc., Chicago, IL (United States); Spampinato, P.T. [RHD Consultants, Inc., Princeton, NJ (United States)

    1995-02-09

    The Tokamak Fusion Test Reactor (TFTR) at Princeton Plasma Physics Laboratory is scheduled to complete its final experiments in the Fall of 1995. As a result, the TFTR will be activated and tritium contaminated. After the experiments are complete, the TFTR will undergo Shutdown and Removal (S and R). The space vacated by the TFTR will be used for a new test reactor, the Tokamak Physics Experiment (TPX). Remote methods may be required to remove components and to segment the Vacuum Vessel. The TFTR has been studied to determine alternatives for the segmentation of the Vacuum Vessel from the inside (In-Vessel). The methodology to determine suitable strategies to segment the Vacuum Vessel from In-Vessel included several areas of concentration. These areas were segmentation locations, cutting/removal technologies, pros and cons, and cutting/removal technology delivery systems. The segmentation locations for easiest implementation and minimal steps in cutting and removal have been identified. Each of these will also achieve the baseline for packaging and shipment. The methods for cutting and removal of components were determined. In addition, the delivery systems were conceptualized.

  17. First-wall and limiter conditioning in TFTR

    International Nuclear Information System (INIS)

    Dylla, H.F.; Blanchard, W.R.; Hawryluk, R.J.

    1984-10-01

    A progress report on the experimental studies of vacuum vessel conditioning during the first year of TFTR operation is presented. A previous paper described the efforts expended to condition the TFTR vessel prior to and during the initial plasma start-up experiments. During the start-up phase, discharge cleaning was performed with the vessel at room temperature. For the second phase of TFTR operations, which was directed towards the optimization of ohmically heated plasmas, the vacuum vessel could be heated to 150 0 C. The internal configuration of the TFTR vessel was more complex during the second phase with the addition of a TiC/C moveable limiter array, Inconel bellows cover plates, and ZrAl getter pumps. A quantitative comparison is given on the effectiveness of vessel bakeout, glow discharge cleaning, and pulse discharge cleaning in terms of the total quantity of removed carbon and oxygen, residual gas base pressures and the resulting plasma impurity levels as measured by visible, uv, and soft x-ray spectroscopy. The initial experience with hydrogen isotope changeover in TFTR is presented including the results of the attempt to hasten the changeover time by using a glow discharge to precondition the vessel with the new isotope

  18. Scheduling and control of programs in the CICADA computer system for TFTR

    International Nuclear Information System (INIS)

    Christianson, G.B.; Sherrick, M.; Stark, W.

    1983-01-01

    The CICADA computer system is a network of super minicomputers for data acquisition, reduction, display and device control on the TFTR experiment. Human interaction with the CICADA system is accomplished by consoles offering color displays with a high degree of operator interaction with the computer system, and by interactive terminals offering a limited degree of operator interaction. The authors describe the software packages and data bases used to control the consoles and provide communication to an application program attached to a console. The console control program in its turn schedules the execution of control programs that furnish operating system interfaces to applications programs executing at a console or terminal (in response to human activation), or upon activation by scheduling tasks. The control programs handle functions such as applications task activation. They discuss the implementation of the control programs in the multi-computer CICADA environment, and describe the control program data bases. In a TFTR shot cycle, applications programs must be scheduled for activation at operator-defined stages, in order to accomplish the arming of hardware devices, acquisition of summary waveform data, and the acquisition and archiving of raw data. The authors describe the software tasks and data bases of the CICADA event system, which accomplishes this scheduling of applications task activation in conjunction with the control programs. Future enhancements planned for the console control, program control, and event systems are outlined

  19. Non-superconducting magnet structures for near-term, large fusion experimental devices

    International Nuclear Information System (INIS)

    File, J.; Knutson, D.S.; Marino, R.E.; Rappe, G.H.

    1980-10-01

    This paper describes the magnet and structural design in the following American tokamak devices: the Princeton Large Torus (PLT), the Princeton Divertor Experiment (PDX), and the Tokamak Fusion Test Reactor (TFTR). The Joint European Torus (JET), also presented herein, has a magnet structure evolved from several European programs and, like TFTR, represents state of the art magnet and structure design

  20. Plasma wall interaction and tritium retention in TFTR

    International Nuclear Information System (INIS)

    Skinner, C.H.; Amarescu, E.; Ascione, G.

    1996-01-01

    The Tokamak Fusion Test Reactor (TFTR) has been operating safely and routinely with deuterium-tritium fuel for more than two years. In this time, TFTR has produced an impressive number of record breaking results including core fusion power, ∼ 2 MW/m 3 , comparable to that expected for ITER. Advances in wall conditioning via lithium pellet injection have played an essential role in achieving these results. Deuterium-tritium operation has also provided a special opportunity to address the issues of tritium recycling and retention. Tritium retention over two years of operation was approximately 40%. Recently, the in-torus tritium inventory was reduced by half through a combination of glow discharge cleaning, moist-air soaks, and plasma discharge cleaning. The tritium inventory is not a constraint in continued operations. The authors present recent results from TFTR in the context of plasma wall interactions and deuterium-tritium issues

  1. Plasma wall interaction and tritium retention in TFTR

    International Nuclear Information System (INIS)

    Skinner, C.H.; Amarescu, E.; Ascione, G.

    1997-01-01

    The Tokamak Fusion Test Reactor (TFTR) has been operating safely and routinely with deuterium-tritium fuel for more than two years. In this time, TFTR has produced a number of record breaking results including core fusion power, ∝2 MW/m 3 , comparable to that expected for ITER. Advances in wall conditioning via lithium pellet injection have played an essential role in achieving these results. Deuterium-tritium operation has also provided a special opportunity to address the issues of tritium recycling and retention. Tritium retention over two years of operation was approximately 40%. Recently the in-torus tritium inventory was reduced by half through a combination of glow discharge cleaning, moist-air soaks, and plasma discharge cleaning. The tritium inventory is not a constraint in continued operations. Recent results from TFTR in the context of plasma wall interactions and deuterium-tritium issues are presented. (orig.)

  2. Measurement of Tritium Surface Distribution on TFTR Bumper Limiter Tiles

    International Nuclear Information System (INIS)

    Sugiyama, K.; Tanabe, T.; Skinner, C.H.; Gentile, C.A.

    2004-01-01

    The tritium surface distribution on graphite tiles used in the Tokamak Fusion Test Reactor (TFTR) bumper limiter and exposed to TFTR deuterium-tritium (D-T) discharges from 1993 to 1997 was measured by the Tritium Imaging Plate Technique (TIPT). The TFTR bumper limiter shows both re-/co-deposition and erosion. The tritium images for all tiles measured are strongly correlated with erosion and deposition patterns, and long-term tritium retention was found in the re-/co-depositions and flakes. The CFC tiles located at erosion dominated areas clearly showed their woven structure in their tritium images owing to different erosion yields between fibers and matrix. Significantly high tritium retention was observed on all sides of the erosion tiles, indicating carbon transport via repetition of local erosion/deposition cycles

  3. TFTR L mode energy confinement related to deuterium influx

    International Nuclear Information System (INIS)

    Strachan, J.D.

    1999-01-01

    Tokamak energy confinement scaling in TFTR L mode and supershot regimes is discussed. The main result is that TFTR L mode plasmas fit the supershot scaling law for energy confinement. In both regimes, plasma transport coefficients increased with increased edge deuterium influx. The common L mode confinement scaling law on TFTR is also inversely proportional to the volume of wall material that is heated to a high temperature, possibly the temperature at which the deuterium sorbed in the material becomes detrapped and highly mobile. The deuterium influx is increased by: (a) increased beam power due to a deeper heated depth in the edge components and (b) decreased plasma current due to an increased wetted area as governed by the empirically observed dependence of the SOL width upon plasma current. (author). Letter-to-the-editor

  4. Engineering test station for TFTR blanket module experiments

    International Nuclear Information System (INIS)

    Jassby, D.L.; Leinoff, S.

    1979-12-01

    A conceptual design has been carried out for an Engineering Test Station (ETS) which will provide structural support and utilities/instrumentation services for blanket modules positioned adjacent to the vacuum vessel of the TFTR (Tokamak Fusion Test Reactor). The ETS is supported independently from the Test Cell floor. The ETS module support platform is constructed of fiberglass to eliminate electromagnetic interaction with the pulsed tokamak fields. The ETS can hold blanket modules with dimensions up to 78 cm in width, 85 cm in height, and 105 cm in depth, and with a weight up to 4000 kg. Interfaces for all utility and instrumentation requirements are made via a shield plug in the TFTR igloo shielding. The modules are readily installed or removed by means of TFTR remote handling equipment

  5. Development of the TFTR neutral beam injection system

    International Nuclear Information System (INIS)

    Prichard, B.A. Jr.

    1978-01-01

    The TFTR Neutral Beam Lines are designed to inject 20 MW of 120 keV neutral deuterium atoms into the plasma. This is accomplished using 12 sources, 65 amperes each, mounted in 4 beam lines. The 120 kV sources are being developed by LBL and a prototype beam line which will be tested at Berkeley is being developed as a cooperative effort by LLL and LBL. The implementation of these beam lines has required the development of several associated pieces of hardware. The control and monitoring of the 12 sources will be done via the TFTR computer control system (CICADA) as will other parts of the machine, and software is being developed to condition and operate the sources automatically. The prototype beam line is scheduled to begin operation in the fall of 1978 and all four production beam lines on TFTR in 1982

  6. Discharge control and evolution in TFTR

    International Nuclear Information System (INIS)

    Mueller, D.; Bell, M.; Boody, F.; Bush, C.; Cecchi, J.L.; Davis, S.; Dylla, H.F.; Efthimion, P.C.

    1985-01-01

    The Tokamak Fusion Test Reactor (TFTR) was designed to explore plasma confinement and heating at reactor-like parameters. Operation of both the toroidal field and plasma current at full design parameters has been achieved and the plasma parameters are summarized in this work. Control of the discharge evolution has played an important role in attaining these parameters. The control of impurities in a tokamak is largely a result of the choice of limiter and wall materials, conditioning techniques and gettering. The impurity control procedures adopted during the run period ending April 13, 1985 are discussed. The discussion of discharge evolution and control is broken down into discharge initiation, volt-second consumption, current and density ramp-up and ramp-down. Also discussed is control of the current ramp-up using a plasma growing technique and the control of density using gas puffing, pellet injection and neutral beam fueling, along with a discussion of the density range which is found to increase plasma current

  7. Discharge cleaning on TFTR after boronization

    International Nuclear Information System (INIS)

    Mueller, D.; Dylla, H.F.; LaMarche, P.H.; Bell, M.G.; Blanchard, W.; Bush, C.E.; Gentile, C.; Hawryluk, R.J.; HIll, K.W.; Janos, A.C.; Jobes, F.C; Owens, D.K.; Pearson, G.; Schivell, J.; Ulrickson, M.A.; Vannoy, C.; Wong, K.L.

    1991-05-01

    At the beginning of the 1990 TFTR experimental run, after replacement of POCO-AXF-5Q graphite tiles on the midplane of the bumper limiter by carbon fiber composite (CFC) tiles and prior to any Pulse Discharge Cleaning (PDC), boronization was performed. Boronization is the deposition of a layer of boron and carbon on the vacuum vessel inner surface by a glow discharge in a diborane, methane and helium mixture. The amount of discharge cleaning required after boronization was substantially reduced compared to that which was needed after previous openings when boronization was not done. Previously, after a major shutdown, about 10 5 low current (∼20 kA) Taylor Discharge Cleaning (TDC) pulses were required before high current (∼400 kA) aggressive Pulse Discharge Cleaning (PDC) pulses could be performed successfully. Aggressive PDC is used to heat the limiters from the vessel bakeout temperature of 150 degrees C to 250 degrees C for a period of several hours. Heating the limiters is important to increase the rate at which water is removed from the carbon limiter tiles. After boronization, the number of required TDC pulses was reduced to <5000. The number of aggressive PDC pulses required was approximately unchanged. 14 refs., 1 tab

  8. Investigation of global Alfven instabilities in TFTR

    International Nuclear Information System (INIS)

    Wong, K.L.; Paul, S.F.; Fredrickson, E.D.; Nazikian, R.; Park, H.K.; Bell, M.; Bretz, N.L.; Budny, R.; Cheng, C.Z.; Cohen, S.; Hammett, G.W.; Jobes, F.C.; Johnson, L.; Meade, D.M.; Medley, S.S.; Mueller, D.; Nagayama, Y.; Owens, D.K.; Synakowski, E.J.; Roberts, D.R.; Sabbagh, S.

    1992-01-01

    Toroidal Alfven Eigenmodes (TAE) were excited by the energetic neutral beam ions tangentially injected into TFTR plasmas at low magnetic field such that the injection velocities were comparable to the Alfven speed. The modes were identified by measurements from Mirnov coils and beam emission spectroscopy (BES). TAE modes appear in bursts whose repetition rate increases with beam power. The neutron emission rate exhibits sawtooth-like behavior and the crashes always coincide with TAE bursts. This indicates ejection of fast ions from the plasma until these modes are stabilized. The dynamics of growth and stabilization was investigated at various plasma current and magnetic field. The results indicate that the instability can effectively clamp the number of energetic ions in the plasma. The observed instability threshold is discussed in the light of recent theories. In addition to these TAE modes, intermittent oscillations at three times the fundamental TAE frequency were observed by Mirnov coils, but no corresponding signal was found in BES. It appears that these high frequency oscillations do not have direct effect on the plasma neutron source strength

  9. Resistive MHD studies of TFTR discharges

    International Nuclear Information System (INIS)

    Hughes, M.H.; Phillips, M.W.; Sabbagh, S.A.; Budny, R.V.

    1991-01-01

    MHD instabilities, thought to be resistive in character, are frequently observed in the supershot operating regime of TFTR (var-epsilon β p ≤ 0.7). These instabilities are always accompanied by substantial degradation of the confinement. Similarly of interest are recent experiments at much larger β p (var-epsilon β p ≤ 1.6), achieved through ramping the current during the beam heating phase of the discharge. In this latter regime the confinement can exceed three times the corresponding L-mode value and the β value normalized to I/aB can be as large as 4.7. Representative discharges from each of these operating regimes have been analyzed using a linear resistive MHD stability code with equilibrium pressure and q profiles obtained initially from the TRANSP analysis code. The main difference between the two types of discharge, as far as stability is concerned is shown to be the shape of the current density profile. The sensitivity to the assumed parameters is discussed. 1 ref

  10. TFTR movable limiter instrumentation and controls

    International Nuclear Information System (INIS)

    Frankenberg, J.; Collins, D.; Kaufmann, D.; Mamoun, A.

    1983-01-01

    The TFTR movable limiter is a single poloidal limiter located within one 18 /SUP o/ segment of the vacuum vessel. It consists of three (3) interconnected inconel backing plates covered with titanium carbide coated graphite tiles. The backing plates are positioned by three independent screw drive actuators. Cooling water is fed through the horizontal port cover to tubes brazed onto the backs of the backing plates. Thermocouples monitor the limiter temperature. (1) and more fully described in refs. (1) and (2). The positioning actuators are driven by independently controlled DC servo motors, controlled either locally or from CICADA. Drive motor shaft position is monitored by chain driven encoders and potentiometers. Limiter blade position can be varied to suit any plasma within the operating range. CICADA is programmed to keep the limiter stroke within safe operating limits. A microprocessor duplicates the CICADA protective function allowing limiter operation without CICADA. The potentiometer signal is sent to an analog computer, which safeguards the limiter against failure of the encoders or the micro-processor. Cooling water flows through the limiter in 3 separate paths, one for each blade. The flow rate and temperature rise through each loop are measured accurately to allow CICADA to calculate the heat into each blade. The water system is also interlocked and alarmed to prevent dumping of water into the vacuum vessel

  11. TFTR power conversion and plasma feedback systems

    International Nuclear Information System (INIS)

    Neumeyer, C.

    1985-01-01

    Major components of the Tokamak Fusion Test Reactor (TFTR) power conversion system include 39 thyristor rectifier power supplies, 12 energy storage capacitor banks, and 6 ohmic heating interrupters. These components are connected in various series/parallel configurations to provide controlled pulses of current to the Toroidal Field (TF), Ohmic Heating (OH), Equilibrium (vertical) Field (EF), and Horizontal Field (HF) magnet coil systems. Real-time control of the power conversion system is accomplished by a centralized dedicated computer; local control is minimal. Power supply firing angles, capacitor bank charge and discharge commands, interrupter commands, etc., are all determined and issued by the central computer. Plasma Position and Current Control (PPCC) reference signals to power conversion (OH, EF, HF) are determined by separate analog electronics but invoked through the power conversion computer. Real-time fault sensing of plasma parameters, gas injection, neutral beams, etc., are monitored by a separate Discharge Fault System (DFS) but routed through the power conversion computer for pre-programmed shutdown response

  12. A tritium vessel cleanup experiment in TFTR

    International Nuclear Information System (INIS)

    Caorlin, M.; Kamperschroer, J.; Owens, D.K.; Voorhees, D.; Mueller, D.; Ramsey, A.T.; La Marche, P.H.; Loughlin, M.J.

    1995-03-01

    A simple tritium cleanup experiment was carried out in TFTR following the initial high power deuterium-tritium discharges in December 1993. A series of 34 ohmic and deuterium neutral beam fueled shots was used to study the removal of tritium implanted into the wall and limiters. A very large plasma was created in each discharge to ''scrub'' an area as large as possible. Beam-fueled shots at 2.5 to 7.5 MW of injected power were used to monitor tritium concentration levels in the plasma by detection of DT-neutrons. The neutron signal decreased by a factor of 4 during the experiment, remaining well above the expected T-burnup level. The amount of tritium recovered at the end of the cleanup was about 8% of the amount previously injected with high power DT discharges. The experience gained suggests that measurements of tritium inventory in the torus are very difficult to execute and require dedicated systems with overall accuracy of 1%

  13. Plasma-material interactions in TFTR

    International Nuclear Information System (INIS)

    Dylla, H.F.; Bell, M.G.; Blanchard, W.R.; Boody, F.P.; Bretz, N.; Budny, R.; Bush, C.E.; Cecchi, J.L.; Cohen, S.A.; Combs, S.K.; Davis, S.L.; Doyle, B.L.; Efthimion, P.C.; England, A.C.; Eubank, H.P.; Fonck, R.; Fredrickson, E.; Grisham, L.R.; Goldston, R.J.; Grek, B.; Groebner, R.; Hawryluk, R.J.; Heifetz, D.; Hendel, H.; Hill, K.W.; Hiroe, S.; Hulse, R.; Johnson, D.; Johnson, L.C.; Kilpatrick, S.; Lamarche, P.H.; Little, R.; Manos, D.M.; Mansfield, D.; Meade, D.M.; Medley, S.S.; Milora, S.L.; Mikkelsen, D.R.; Mueller, D.; Murakami, M.; Nieschmidt, E.; Owens, D.K.; Park, H.; Pontau, A.; Prichard, B.; Ramsey, A.T.; Redi, M.H.; Schivell, J.; Schmidt, G.L.; Scott, S.D.; Sesnic, S.; Shimada, M.; Simpkins, J.E.; Sinnis, J.; Stauffer, F.; Stratton, B.; Tait, G.D.; Taylor, G.; Ulrickson, M.; Von Goeler, S.; Wampler, W.R.; Wilson, K.; Williams, M.; Wong, K.L.; Young, K.M.; Zarnstorff, M.C.; Zweben, S.

    1987-01-01

    This paper presents a summary of plasma-material interactions which influence the operation of TFTR with high current (≤ 2.2 MA) ohmically heated, and high-power (≅ 10 MW) neutral-beam heated plasmas. The conditioning procedures which are applied routinely to the first-wall hardware are reviewed. Fueling characteristics during gas, pellet, and neutral-beam fueling are described. Recycling coefficients near unity are observed for most gas fueled discharges. Gas fueled discharges after helium discharge conditioning of the toroidal bumper limiter, and discharges fueled by neutral beams and pellets, show R e = 5-6x10 19 m -3 ) values of Z eff are ≤ 1.5. Increases in Z eff of ≤ 1 have been observed with neutral beam heating of 10 MW. The primary low Z impurity is carbon with concentrations decreasing from ≅ 10% to e . Oxygen densities tend to increase with n e , and at the ohmic plasma density limit oxygen and carbon concentrations are comparable. Chromium getter experiments and He 2+ /D + plasma comparisons indicate that the limiter is the primary source of carbon and that the vessel wall is a significant source of the oxygen impurity. Metallic impurities, consisting of the vacuum vessel metals (Ni, Fe, Cr) have significant (≅ 10 -4 n e ) concentrations only at low plasma densities (n e 19 m -3 ). The primary source of metallic impurities is most likely ion sputtering from metals deposited on the carbon limiter surface. (orig.)

  14. ICRF stabilization of sawteeth on TFTR

    International Nuclear Information System (INIS)

    Phillips, C.K.; Hosea, J.; Stevens, J.; Wilson, J.R.; Bell, M.; Bitter, M.; Cheng, C.Z.; Darrow, D.; Fredrickson, E.; Hammett, G.W.; Hill, K.; Hsuan, H.; Jassby, D.; McCune, D.; McGuire, K.; Owens, D.K.; Park, H.; Ramsey, A.; Schilling, G.; Schivell, J.; Stratton, B.; Synakowski, E.; Taylor, G.; Towner, H.; White, R.; Zweben, S.; Phillips, M.W.; Hughes, M.; Bush, C.; Goldfinger, R.; Hoffman, D.; Houlberg, W.; Nagayama, Y.; Smithe, D.N.

    1992-01-01

    Results obtained from experiments utilizing high power ICRF (ion cyclotron range of frequency) heating to stabilize sawtooth oscillations on TFTR are reviewed. The key observations include existence of a minimum ICRF power required to achieve stabilization, a dependence of the stabilization threshold on the relative size of the ICRF power deposition profile to the q=1 volume, and a peaking of the equilibrium pressure and current profiles during sawtooth-free phases of the discharges. In addition, preliminary measurements of the poloidal magnetic field profile indicate that q on axis decreases to a value of 0.55±0.15 after a sawtooth-stabilized period of ∼0.5 sec has transpired. The results are discussed in the context of theory, which suggests that the fast ions produced by the ICRF heating suppress sawteeth by stabilizing the m=1 MHD instabilities believed to be the trigger for the sawtooth oscillations. Though qualitative agreement is found between the observations and the theory, further refinement of the theory coupled with more accurate measurements of experimental profiles will be required in order to complete quantitative comparisons

  15. Thermal consequences of plasma disruptions in TFTR and ETF

    International Nuclear Information System (INIS)

    Budny, R.; Ludescher, C.

    1981-01-01

    We studied thermal responses of first walls for TFTR and ETF during plasma disruptions. To model the flux, we assumed the entire kinetic energy is deposited by axisymmetric horizontal displacement of the plasma. The deposition time is a free parameter. In TFTR, the minimum deposition time which does not cause the toroidal limiter to melt is 7 or 14 ms depending on whether or not the limiter is actively cooled. In ETF, the minimum time which does not cause surface melting of the cooling tubes is 80 ms. (author)

  16. Neutron diagnostics on TFTR utilizing the Campbelling technique

    International Nuclear Information System (INIS)

    England, A.C.; Hendel, H.W.; Neischmidt, E.B.

    1986-01-01

    The authors report modified commercial neutron counting equipment installed on a tokamak fusion test reactor (TFTR) which utilizes the Campbelling theorem to monitor the neutron source strength at very high neutron count rates. Campbelling utilizes the large amplitude fluctuation from neutron events in the detectors to discriminate against small amplitude noise events. Source strengths yielding equivalent count rates a factor of five higher than possible in the conventional count rate mode have been obtained to date. The concept of Campbelling is discussed and the particular application to TFTR is illustrated

  17. Tritium Removal from JET and TFTR Tiles by a Scanning Laser; TOPICAL

    International Nuclear Information System (INIS)

    C.H. Skinner; N. Bekris; J.P. Coad; C.A. Gentile; M. Glugla

    2002-01-01

    Fast and efficient tritium removal is needed for future D-T machines with carbon plasma-facing components. A novel method for tritium release has been demonstrated on co-deposited layers on tiles retrieved from the Tokamak Fusion Test Reactor (TFTR) and from the Joint European Torus (JET). A scanning continuous wave neodymium laser beam was focused to=100 W/mm2 and scanned at high speed over the co-deposits, heating them to temperatures=2000 C for about 10 ms in either air or argon atmospheres. Fiber optic coupling between the laser and scanner was implemented. Up to 87% of the co-deposited tritium was thermally desorbed from the JET and TFTR samples. This technique appears to be a promising in-situ method for tritium removal in a next-step D-T device as it avoids oxidation, the associated de-conditioning of the plasma-facing surfaces, and the expense of processing large quantities of tritium oxide

  18. Tritium Removal from JET and TFTR Tiles by a Scanning Laser

    International Nuclear Information System (INIS)

    Skinner, C.H.; Bekris, N.; Coad, J.P.; Gentile, C.A.; Glugla, M.

    2002-01-01

    Fast and efficient tritium removal is needed for future D-T machines with carbon plasma-facing components. A novel method for tritium release has been demonstrated on co-deposited layers on tiles retrieved from the Tokamak Fusion Test Reactor (TFTR) and from the Joint European Torus (JET). A scanning continuous wave neodymium laser beam was focused to =100 W/mm2 and scanned at high speed over the co-deposits, heating them to temperatures =2000 C for about 10 ms in either air or argon atmospheres. Fiber optic coupling between the laser and scanner was implemented. Up to 87% of the co-deposited tritium was thermally desorbed from the JET and TFTR samples. This technique appears to be a promising in-situ method for tritium removal in a next-step D-T device as it avoids oxidation, the associated de-conditioning of the plasma-facing surfaces, and the expense of processing large quantities of tritium oxide

  19. Alignment of the TFTR bumper limiter

    International Nuclear Information System (INIS)

    Barnes, G.W.; Owens, D.K.; Loesser, G.D.; Ulrickson, M.

    1989-01-01

    The TFTR Bumper Limiter (BL) is an axisymmetric toroidal limiter mounted on the inner wall of the vacuum vessel. It subtends 120 degree poloidally and has a surface area of 22 m 2 . The plasma facing surface consists of 1,000 kg of graphite tiles mounted on watercooled Inconel backing plates. During the initial installation in the Spring of 1985, the limiter surface was aligned to the toroidal magnetic field by mechanical and magnetic measurements to an estimated accuracy of ±2 mm. During subsequent operation, especially in the 1988 run period in which 30 MW of Neutral Beam Injection routinely occurred, several tiles at points on the limiter which protruded slightly into the plasma were severely damaged. The damage, cracked and spalled tiles, is believed to be initiated by high energy disruptions and aggravated by normal high power operation. The damage pattern and temperature rise during normal operation are consistent with this interpretation. A vacuum vessel opening to replace the damaged tiles and realign the limiter was required. The bumper limiter was reshaped to be circular to ±0.5 mm at the midplane by means of mechanical measurements in order to better distribute the heat loads and eliminate hot spots. The ±0.5 mm accuracy is determined by the variation in individual tile thickness which is ±0.5 mm. This paper describes the methods used to mechanically align the limiter and presents evidence based on machine operation with plasma that the limiter is reasonably well aligned with the toroidal field. Future work dealing with the alignment of the total limiter to the toroidal field using mechanical and magnetic measurements and the replacement of a subset of the carbon tiles with carbon-carbon composite material is also discussed. 7 refs., 4 figs

  20. Limiter H-mode experiments on TFTR

    Energy Technology Data Exchange (ETDEWEB)

    Bush, C [Oak Ridge National Lab., TN (USA); Bretz, N L; Fredrickson, E D; McGuire, K M; Nazikian, R; Park, H K; Schivell, J; Taylor, G; Bitter, B; Budny, R; Cohen, S A; Kilpatrick, S J; LeBlanc, B; Manos, D M; Meade, D; Paul, S F; Scott, S D; Stratton, B C; Synakowski, E J; Towner, H H; Weiland, R M; Arunasalam, V; Bateman, G; Bell, M G; Bell, R; Boivin, R; Cavallo, A; Cheng, C Z; Chu, T K; Cowl,

    1990-12-15

    Limiter H-modes with centrally peaked density profiles have been obtained in TFTR using a highly conditioned graphite limiter. The transition to these centrally peaked H-modes takes place from the supershot to the H-mode rather than the usual L- to H-mode transition observed on other tokamaks. Bi-directional beam heating is required to induce the transition. Density peaking factors, n{sub e}(0)/{l angle}n{sub e}{r angle}, >2.3 are obtained and at the same time the H-mode characteristics are similar to those of limiter H-modes on other tokamaks and the global confinement, {tau}{sub E}, can be >2.5 times L-mode scaling. The TRANSP analysis shows that transport in these H-modes is similar to that of supershots within the inner 60 cm of the plasma, but the stored electron energy (calculated using measured values of T{sub e} and n{sub e}) is higher for the H-mode at the plasma edge. Microwave scattering near the edge shows broad spectra at k = 5.5 cm{sup {minus}1} which begin at the drop in D{sub {alpha}} radiation and are strongly shifted in the electron diamagnetic drift direction. At the same time beam emission spectroscopy shows a coherent mode near the boundary with m = 15--20 at 20--30 kHz which is propagating in the ion direction. During an ELM event these apparent rotations cease and Mirnov fluctuations in the 50--500 kHz increase in intensity.

  1. Acceleration of beam ions during major radius compression in TFTR

    International Nuclear Information System (INIS)

    Wong, K.L.; Bitter, M.; Hammett, G.W.

    1985-09-01

    Tangentially co-injected deuterium beam ions were accelerated from 82 keV up to 150 keV during a major radius compression experiment in TFTR. The ion energy spectra and the variation in fusion yield were in good agreement with Fokker-Planck code simulations. In addition, the plasma rotation velocity was observed to rise during compression

  2. [Analysis of momentum and impurity confinment in TFTR (1990)

    International Nuclear Information System (INIS)

    1990-01-01

    Work during the present grant period has been concentrated in two areas and are discussed in this report: (1) a review of momentum confinement experiments in tokamaks, of momentum confinement theories and of previous comparisons of the two; and (2) analysis and documentation of the dedicated power-scan rotation experiment performed on TFTR in September 1988

  3. Neutron spectroscopy on TFTR [Tokamak Fusion Test Reactor

    International Nuclear Information System (INIS)

    Nishitani, T.; Strachan, J.D.

    1988-05-01

    This paper describes the use of an 3 He ionization chamber for neutron spectroscopy on TFTR during 1987. The ion temperature was measured using neutron spectroscopy for one set of ohmically heated plasmas. The deduced ion temperatures agreed to within 20% with those measured by other diagnostics. 11 refs., 11 figs., 1 tab

  4. Mechanical design of epithermal neutron diagnostic for TFTR

    International Nuclear Information System (INIS)

    Groo, R.C.

    1981-01-01

    The mechanical design of the Epithermal Neutron Diagnostic for TFTR is described. This fission detector system measures the time resolution of the neutron flux for folding into the Neutron Activation system and also provides continuous, wide range coverage of all expected fusion reaction rates

  5. Mechanical engineering problems in the TFTR neutral beam system

    International Nuclear Information System (INIS)

    Cannon, D.D.; Bryant, E.H.; Johnson, R.L.; Kim, J.; Queen, C.C.; Schilling, G.

    1975-01-01

    A conceptual design of a prototype beam line for the TFTR Neutral Beam System has been developed. The basic components have been defined, cost estimates prepared, and the necessary development programs identified. Four major mechanical engineering problems, potential solutions and the required development programs are discussed

  6. Measurements of TFTR D-T radiation shielding efficiency

    International Nuclear Information System (INIS)

    Kugel, H.W.; Ascione, G.; Elwood, S.; Gilbert, J.; Ku, L.P.; Levine, J.; Rule, K.; Azziz, N.; Goldhagen, P.; Hajnal, F.

    1994-11-01

    Measurements of neutron and gamma dose-equivalents were performed in the Test Cell, at the outer Test Cell wall, in nearby work areas, and out to the nearest property lines at a distance of 180 m. Argon ionization chambers, moderated 3 He proportional counters, and fission chamber detectors were used to obtain measurements of neutron and gamma dose-equivalents per D-T neutron during individual TFTR discharges. These measured neutron and gamma D-T dose-equivalents per TFTR neutron characterize the effects of local variations in material density resulting from the complex asymmetric site geometry. The measured dose-equivalents per TFTR D-T neutron and the cumulative neutron production were used to determine that the planned annual TFTR neutron production of 1 x 10 21 D-T neutrons is consistent with the design objective of limiting the total dose-equivalent at the property line, from all radiation sources and pathways, to less than 10 mrem per year

  7. Long Term Tritium Trapping in TFTR and JET

    International Nuclear Information System (INIS)

    Skinner, C.H.; Gentile, C.A.; Young, K.M.; Coad, J.P.; Hogan, J.T.; Penzhorn, R.-D.; Bekris, N.

    2001-01-01

    Tritium retention in TFTR [Tokamak Fusion Test Reactor] and JET [Joint European Torus] shows striking similarities and contrasts. In TFTR, 5 g of tritium were injected into circular plasmas over a 3.5 year period, mostly by neutral-beam injection. In JET, 35 g were injected into divertor plasmas over a 6 month campaign, mostly by gas puffing. In TFTR, the bumper limiter provided a large source of eroded carbon and a major part of tritium was co-deposited on the limiter and vessel wall. Only a small area of the co-deposit flaked off. In JET, the wall is a net erosion area, and co-deposition occurs principally in shadowed parts of the inner divertor, with heavy flaking. In both machines, the initial tritium retention, after a change from deuterium [D] to tritium [T] gas puffing, is high and is due to isotope exchange with deuterium on plasma-facing surfaces (dynamic inventory). The contribution of co-deposition is lower but cumulative, and is revealed by including periods of D fueling that reversed the T/D isotope exchange. Ion beam analysis of flakes from TFTR showed an atomic D/C ratio of 0.13 on the plasma facing surface, 0.25 on the back surface and 0.11 in the bulk. Data from a JET divertor tile showed a larger D/C ratio with 46% C, 30% D, 20% H and 4% O. Deuterium, tritium, and beryllium profiles have been measured and show a thin less than 50 micron co-deposited layer. Flakes retrieved from the JET vacuum vessel exhibited a high tritium release rate of 2e10 Bq/month/g. BBQ modeling of the effect of lithium on retention in TFTR showed overlapping lithium and tritium implantation and a 1.3x increase in local T retention

  8. Ideal MHD stability of high poloidal beta equilibria in TFTR

    International Nuclear Information System (INIS)

    Sabbagh, S.A.; Mauel, M.E.; Navratil, G.A.; Bell, M.G.; Budny, R.V.; Chance, M.S.; Fredrickson, E.D.; Jardin, S.C.; Manickam, J.; McCune, D.C.; McGuire, K.M.; Wieland, R.M.; Zarnstorff, M.C.; Phillips, M.W.; Hughes, M.H.; Kesner, J.

    1991-01-01

    Recent experiments in TFTR have expanded the operating space of the device to include plasmas with values of var-epsilon β p dia ≡ 2μ 0 var-epsilon perpendicular >/ p >> 2 as large as 1.6, and Troyon normalized diamagnetic beta β N dia ≡ β t perpendicular aB t /10 -8 I p as large as 4.7. At values of var-epsilon β p dia ≥ 1.3, a separatrix was observed to enter the vacuum vessel, producing a naturally diverted discharge. Plasmas with large values of var-epsilon β p dia were created with both the plasma current, I p , held constant and with I p decreased, or ramped down, before the start of neutral beam injection. A convenient characterization of the change in I p using experimental parameters can be defined by the ratio of I p before the ramp down, to I p during the neutral beam heating phase, F I p . The ideal MHD stability of these equilibria is investigated to determine their location in stability space, and to study the role of plasma current and pressure profile modification in the creation of these high var-epsilon β p and β N plasmas. The evolution of these plasmas is modelled from experimental data using the TRANSP code. Two-dimensional equilibria are computed from the TRANSP results and used as input to both high and low-n stability codes including PEST. The high var-epsilon β p equilibria, which generally have an oblate cross-sectional shape, are in the first stability region to high-n ballooning modes. At constant I p , these equilibria generally have maximum pressure gradients near the magnetic axis and are stable to n=1 modes without a stabilizing conducting wall. The effect of the current profile shape on the stability of low-n kink/ballooning modes and the requirements for these plasmas to access the second stability region are examined. 6 refs

  9. Probes for edge plasma studies of TFTR (invited)

    International Nuclear Information System (INIS)

    Manos, D.M.; Budny, R.V.; Kilpatrick, S.; Stangeby, P.; Zweben, S.

    1986-01-01

    Tokamak fusion test reactor (TFTR) probes are designed to study the interaction of the plasma with material surfaces such as the wall and limiters, and to study the transport of particles and energy between the core and edge. Present probe heads have evolved from prototypes in Princeton large torus (PLT), poloidal divertor experiment (PDX) [Princeton BETA experiment (PBX)], and the initial phase of TFTR operation. The newest heads are capable of making several simultaneous measurements and include Langmuir probes, heat flux probes, magnetic coils, rotating calorimeter fast ion probes, and sample exposure specimens. This paper describes these probe heads and presents some of the data they and their prototypes have acquired. The paper emphasizes measurement of transient plasma effects such as fast ion loss during auxiliary heating, the evolution of the edge plasma during heating, compression, and free expansion, and fluctuations in the edge plasma

  10. Charged fusion product and fast ion loss in TFTR

    International Nuclear Information System (INIS)

    Zweben, S.J.; Darrow, D.S.; Fredrickson, E.D.; Mynick, H.E.; White, R.B.; Biglari, H.; Bretz, N.; Budny, R.; Bush, C.E.; Chang, C.S.; Chen, L.; Cheng, C.Z.; Fu, G.Y.; Hammett, G.W.; Hawryluk, R.J.; Hosea, J.; Johnson, L.; Mansfield, D.; McGuire, K.; Medley, S.S.; Nazikian, R.; Owens, D.K.; Park, H.; Park, J.; Phillips, C.K.; Schivell, J.; Stratton, B.C.; Ulrickson, M.; Wilson, R.; Young, K.M.; Fisher, R.; McChesney, J.; Fonck, R.; McKee, G.; Tuszewski, M.

    1993-03-01

    Several different fusion product and fast ion loss processes have been observed in TFTR using an array of pitch angle, energy and time resolved scintillator detectors located near the vessel wall. For D-D fusion products (3 MeV protons and 1 MeV tritons) the observed loss is generally consistent with expected first-orbit loss for Ip I MA. However, at higher currents, Ip = 1.4--2.5 MA, an NM induced D-D fusion product loss can be up to 3-4 times larger than the first-orbit loss, particularly at high beam powers, P ≥ 25 MW. The MHD induced loss of 100 KeV neutron beam ions and ∼0.5 MeV ICRF minority tail tons has also been measured ≤ 459 below the outer midplane. be potential implications of these results for D-T alpha particle experiments in TFTR and ITER are described

  11. Studies of tritiated co-deposited Layers in TFTR

    International Nuclear Information System (INIS)

    Skinner, C.H.; Gentile, C.A.; Ascione, G.; Carpe, A.; Causey, R.A.; Hayashi, T.; Hogan, J.; Langish, S.W.; Nishi, M.F.; Shu, W.M.; Wampler, W.R.; Young, K.M.

    2000-01-01

    Plasma facing components in TFTR contain an important record of plasma wall interactions in reactor grade DT plasmas. Tiles, flakes, wall coupons, a stainless steel shutter and dust samples have been retrieved from the TFTR vessel for analysis. Selected samples have been baked to release tritium and assay the tritium content. The in-vessel tritium inventory is estimated to be 0.56 g and is consistent with the in-vessel tritium inventory derived from the difference between tritium fueling and tritium exhaust. The distribution of tritium on the limiter and vessel wall showed complex patterns of co-deposition. Relatively high concentrations of tritium were found at the top and bottom of the bumper limiter, as predicted by earlier BBQ modeling

  12. Studies of tritiated co-deposited layers in TFTR

    International Nuclear Information System (INIS)

    Skinner, C.H.; Gentile, C.A.; Ascione, G.; Carpe, A.; Causey, R.A.; Hayashi, T.; Hogan, J.; Langish, S.; Nishi, M.; Shu, W.M.; Wampler, W.R.; Young, K.M.

    2000-01-01

    Plasma facing components in TFTR contain an important record of plasma wall interactions in reactor grade DT plasmas. Tiles, flakes, wall coupons, a stainless steel shutter and dust samples have been retrieved from the TFTR vessel for analysis. Selected samples have been baked to release tritium and assay the tritium content. The in-vessel tritium inventory is estimated to be 0.56 g and is consistent with the in-vessel tritium inventory derived from the difference between tritium fueling and tritium exhaust. The distribution of tritium on the limiter and vessel wall showed complex patterns of co-deposition. Relatively high concentrations of tritium were found at the top and bottom of the bumper limiter, as predicted by earlier BBQ modeling

  13. Studies of tritiated co-deposited layers in TFTR

    International Nuclear Information System (INIS)

    Skinner, C.H.; Gentile, C.A.; Ascione, G.; Causey, R.A.; Hayaski, T.; Hogan, J.; Nishi, M.; Shu, W.M.; Wampler, William R.; Young, K.M.

    2000-01-01

    Plasma facing components in TFTR contain an important record of plasma wall interactions in reactor grade DT plasmas. Tiles, flakes, wall coupons and dust samples have been retrieved from the TFTR vessel for analysis. Selected samples have been baked to release tritium and assay the tritium content. The in-vessel tritium inventory is estimated to be 0.5 g and is consistent with the in-vessel tritium inventory derived from the difference between tritium fueling and tritium exhaust. Relatively high concentrations of tritium were found at the top and bottom of the bumper limiter, as predicted by earlier BBQ modeling. The distribution of tritium on the limiter and vessel wall showed complex patterns of co-deposition

  14. Expansion of the TFTR neutral beam computer system

    International Nuclear Information System (INIS)

    McEnerney, J.; Chu, J.; Davis, S.; Fitzwater, J.; Fleming, G.; Funk, P.; Hirsch, J.; Lagin, L.; Locasak, V.; Randerson, L.; Schechtman, N.; Silber, K.; Skelly, G.; Stark, W.

    1992-01-01

    Previous TFTR Neutral Beam computing support was based primarily on an Encore Concept 32/8750 computer within the TFTR Central Instrumentation, Control and Data Acquisition System (CICADA). The resources of this machine were 90% utilized during a 2.5 minute duty cycle. Both interactive and automatic processes were supported, with interactive response suffering at lower priority. Further, there were additional computing requirements and no cost effective path for expansion within the Encore framework. Two elements provided a solution to these problems: improved price performance for computing and a high speed bus link to the SELBUS. The purchase of a Sun SPARCstation and a VME/SELBUS bus link, allowed offloading the automatic processing to the workstation. This paper describes the details of the system including the performance of the bus link and Sun SPARCstation, raw data acquisition and data server functions, application software conversion issues, and experiences with the UNIX operating system in the mixed platform environment

  15. Neutron dosimetry for the TFTR Lithium-Blanket-Module program

    International Nuclear Information System (INIS)

    Harker, Y.D.; Tsang, F.Y.; Caffrey, A.J.; Homeyer, W.G.; Engholm, B.A.

    1981-01-01

    The Tokamak Fusion Test Reactor (TFTR) Lithium Blanket Module (LBM) program is a first-of-a-kind neutronics experiment involving a prototypical fusion reactor blanket module with a distributed neutron source from the plasma of the TFTR at Princeton Plasma Physics Laboratory. The objectives of the LBM program are: (1) to test the capabilities of neutron transport codes when applied to fusion test reactor blanket conditions, and (2) to obtain tritium breeding performance data on a typical design concept of a fusion-reactor blanket. This paper addresses the issues relative to the measurement of neutron fields in the LBM, presents the results of preliminary design studies concerning neutron measurements and also presents the results of blanket mockup experiments performed at the Idaho National Engineering Laboratory

  16. DT simulation of ICRF heated supershots in TFTR using TRANSP

    International Nuclear Information System (INIS)

    Goldfinger, R.C.; Batchelor, D.B.; Phillips, C.K.; Budny, R.; Hammett, G.W.; Hosea, J.C.; McCune, D.M.; Stevens, J.E.; Wilson, J.R.

    1993-01-01

    The principal goal of ion cyclotron range of frequency (ICRF) heating on the Tokamak Fusion Test Reactor (TFTR) is to enhance plasma performance during the deuterium-tritium (DT) physics phase of operations. Strongly centralized ICRF heating may play a critical role in obtaining high Q DT and high β α operation in TFTR, as well as in future fusion reactors. ICRF heating of a dilute minority species leads to the formation of an energetic ion population that, in turn, provides strong central electron heating. The corresponding rise in the central electron temperature translates into an increase in the slowing-down time of either neutral beam or alpha particles in the discharge. Preliminary DT simulations of the experimental results in deuterium-deuterium (DD) plasmas performed with the TRANSP code are presented in this paper

  17. ICRF sawtooth stabilization: Application on TFTR and CIT

    International Nuclear Information System (INIS)

    Hosea, J.C.; Phillips, C.K.; Stevens, J.E.; Wilson, J.R.; Bell, M.; Boivin, R.; Cavallo, A.; Colestock, P.; Fredrickson, E.; Hammett, G.; Hsuan, H.; Janos, A.; Jassby, D.; Jobes, F.; McGuire, K.; Mueller, D.; Nagayama, Y.; Owens, K.; Park, H.; Schmidt, G.; Stratton, B.; Taylor, G.; Wong, K.L.; Zweben, S.

    1991-03-01

    The use of ICRF heating to stabilize the core plasma sawtooth relaxations has been extended to TFTR where such stabilization has been produced at relatively low power in the L Mode regime at moderate density (P RF = 4 MW, 2.6 MW in helium and deuterium discharges, respectively, for the minority hydrogen ICRF heating regime with bar n e ∼2.5 x 10 13 cm -3 ). These results, as in the case of those obtained on JET, are qualitatively consistent with energetic ion stabilization of the m = 1, n = 1 ideal/resistive kink mode. The relevance of sawtooth stabilization to the primary regimes of interest on TFTR -- the high-Q supershot regime and the high density pellet injection regimes -- and on CIT -- the high density ICRF heated regime -- is considered in the context of the present theory and the projected ICRF power deposition characteristics. 35 refs., 11 figs

  18. Neutron diagnostics on TFTR utilizing the Campbelling technique

    International Nuclear Information System (INIS)

    England, A.C.; Hendel, H.W.; Nieschmidt, E.B.

    1986-01-01

    Modified commercial equipment installed on the tokamak fusion test reactor (TFTR) at Princeton Plasma Physics Laboratory (PPPL) utilizes Campbell's mean square voltage theorem to monitor the neutron source strength at neutron count rates orders of magnitude above the capability of the count rate mode. Campbelling uses the large amplitude fluctuations from neutron fission events in the detectors to discriminate against small amplitude γ ray and other noise events. Source strengths yielding equivalent count rates a factor of 5 greater than possible in the conventional count rate mode have been obtained to date. The concept of Campbelling is discussed and the particular application to TFTR is illustrated. Fundamental advantages are the extended useful range of the detectors by a factor of --10 4 and gamma rejection by a factor of --10 3 . Some results are shown and the neutron source strengths obtained are compared to those from conventional counting circuits and from other detectors whose outputs have not yet suffered counting losses

  19. Vacuum system transient simulator and its application to TFTR

    International Nuclear Information System (INIS)

    Sredniawski, J.

    1978-01-01

    The vacuum system transient simulator (VSTS) models transient gas transport throughout complex networks of ducts, valves, traps, vacuum pumps, and other related vacuum system components. VSTS is capable of treating gas models of up to 10 species, for all flow regimes from pure molecular to continuum. Viscous interactions between species are considered as well as non-uniform temperature of a system. Although this program was specifically developed for use on the Tokamak Fusion Test Reactor (TFTR) project at Princeton, it is a generalized tool capable of handling a broad range of vacuum system problems. During the TFTR engineering design phase, VSTS has been used in many applications. Two applications selected for presentation are: (1) torus vacuum pumping system performance between 400 Ci tritium pulses and (2) tritium backstreaming to neutral beams during pulses

  20. Vacuum system transient simulator and its application to TFTR

    International Nuclear Information System (INIS)

    Sredniawski, J.

    1977-01-01

    The vacuum system transient simulator (VSTS) models transient gas transport throughout complex networks of ducts, valves, traps, vacuum pumps, and other related vacuum system components. VSTS is capable of treating gas models of up to 10 species, for all flow regimes from pure molecular to continuum. Viscous interactions between species are considered as well as non-uniform temperature of a system. Although this program was specifically developed for use on the Tokamak Fusion Test Reactor (TFTR) project at Princeton, it is a generalized tool capable of handling a broad range of vacuum system problems. During the TFTR engineering design phase, VSTS has been used in many applications. Two applications selected for presentation are: torus vacuum pumping system performance between 400 Ci tritium pulses and tritium backstreaming to neutral beams during pulses

  1. A review of carbon blooms on JET and TFTR

    International Nuclear Information System (INIS)

    Ulrickson, M.

    1990-01-01

    Operation of JET and TFTR at high auxiliary heating power has resulted in the occurrence of phenomena called carbon blooms. The carbon bloom is characterized by a rapid increases in the emission of carbon spectral lines, the Z eff , the radiated power, and the plasma density. There is also a concurrent decrease in the neutron emission rate, stored energy, and plasma pressure. On both machines the source of the carbon is observed to be at localized (both toroidally and polidally) hot spots on either the divertor plates or limiters. The localized hot spots are due to one or more of the following: disruption damage spots, misalignment of tiles, and/or exposed edges of tiles. The occurrence of carbon blooms limits the performance of the highest input power plasmas on both machines. This paper reviews the carbon bloom phenomenon as it occurs on both JET and TFTR. (orig.)

  2. Power and particle balance during neutral beam injection in TFTR

    International Nuclear Information System (INIS)

    Pitcher, C.S.; Budny, R.V.; Hill, K.W.; Kilpatrick, S.J.; Manos, D.M.; Medley, S.S.; Ramsey, A.T.

    1991-05-01

    Detailed boundary plasma measurements on TFTR have been made during a NBI power scan in the range P tot = 1MW--20MW in the L-mode regime. The behavior of the plasma density left-angle n e right-angle, radiated power P rad , carbon and deuterium fluxes Γ C , Γ D , and Ζ eff can be summarized as, left-angle n e right-angle ∝ P tot 1/2 , P rad , Γ C , Γ D ∝ P tot , and Ζ eff ∼ constant. It is shown that central fuelling by the neutral beams plays a minor role in the particle balance of the discharge. More important is the NBI role in the power balance. The TFTR data during NBI originate primarily at the graphite limiter

  3. Heating and transport in TFTR D-T plasmas

    International Nuclear Information System (INIS)

    Zarnstorff, M.C.; Scott, S.D.

    1994-01-01

    The confinement and heating of supershot plasmas are significantly enhanced with tritium beam injection relative to deuterium injection in TFTR. The global energy confinement and local thermal transport are analyzed for deuterium and tritium fueled plasmas to quantify their dependence on the average mass of the hydrogenic ions. The radial profiles of the deuterium and tritium densities are determined from the DT fusion neutron emission profile

  4. Automatic and manual operation modes of the TFTR maintenance manipulator

    International Nuclear Information System (INIS)

    Boehme, G.; Gumb, L.; Lotz, E.; Mueller, G.; Selig, M.

    1987-01-01

    The remote in-vessel operations scheduled to maintain the TFTR at Princeton, NJ, USA, comprise inspection, calibration, cleaning and protective tile replacement. The environmental conditions inside the torus vessel are ultra high vacuum, moderate γ-radiation and 150 0 C temperature of the vessel structure. The Princeton Plasma Physics Laboratory (PPPL) and KfK are jointly developing a maintenance manipulator (MM) which can perform these tasks. (orig./HP)

  5. Observation of neoclassical transport in reverse shear plasmas on TFTR

    International Nuclear Information System (INIS)

    Efthimion, P.C.; Goeler, S. von; Houlberg, W.A.

    1999-01-01

    Perturbative experiments on TFTR have investigated the transport of multiple ion species in reverse shear (RS) plasmas. The profile evolutions of trace tritium and helium and intrinsic carbon indicate the formation of core particle transport barriers in enhanced reverse shear (ERS) plasmas. There is an order of magnitude reduction in the particle diffusivity inside the RS region. The diffusivities for these species in ERS plasmas agree with neoclassical theory. (author)

  6. Modification and final alignment of the TFTR bumper limiter

    International Nuclear Information System (INIS)

    McSmith, M.D.; Loesser, G.D.; Owens, D.K.

    1994-01-01

    During the past three Tokamak Fusion Test Reactor (TFTR) vacuum vessel machine openings, an extensive effort was undertaken to optimize the distribution of heating of the bumper limiter tiles. The optimization was achieved by locating the limiter tiles relative to the toroidal magnetic field and adjusting their position relative to the magnetic field rather than to fixed points in the vacuum vessel walls. This paper will discuss the results of these alignments as measured during operation with the limiter thermocouple system and subsequent visual inspection during this past TFTR vacuum vessel opening. During the most recent in-vessel inspection (January 1993), damage to the top and bottom rows of the bumper limiter tiles was noted. More tiles were damaged on the lower row than the upper row. Tiles on the right side of the bottom row and to a lesser extent tiles on the left side of the top row were damaged. The location of the damage corresponds to the plasma power flux direction. Theories explaining the asymmetric damage (bottom versus top) are summarized. Princeton Plasma Physics Laboratory (PPL) began a program to replace 223 of the originally installed tiles made from POCO AFX-5Q graphite. Of these 223 tiles, 151 were replaced with tiles made from carbon-fiber-composite (CFC) and 158 of these tiles were re-designed for installation on the top or bottom rows. The re-designed tiles have a tapered edge that reduces the angle of incidence of the power flux on the edge surface that was over-heating. This paper will review the in-vessel work and discuss the final modification of the TFTR bumper limiter to alleviate further damage at these locations prior to DT operation of TFTR

  7. Thermostructural and mechanical aspects of the TFTR plasma limiter design

    International Nuclear Information System (INIS)

    Condolff, R.; Fixler, S.

    1977-01-01

    This paper presents the preliminary mechanical and thermostructural aspects of the TFTR (TOKAMAK Fusion Test Reactor) plasma limiter design. The evolution of the limiter design is traced through the various stages from conceptual design to the present state. Results of parametric limiter blade studies are presented. Design criteria, requirements, design loads (mechanical and thermal), material considerations, and remote handling problems are described. The design approach used to achieve a satisfactory plasma limiter and blade is discussed

  8. Thermostructural and mechanical aspects of the TFTR plasma limiter design

    International Nuclear Information System (INIS)

    Condolff, R.; Fixler, S.

    1978-01-01

    This paper presents the preliminary mechanical and thermostructural aspects of the TFTR (TOKAMAK Fusion Test Reactor) plasma limiter design. The evolution of the limiter design is traced through the various stages from conceptual design to the present state. Results of parametric limiter blade studies are presented. Design criteria, requirements, design loads (mechanical and thermal), material considerations, and remote handling problems are described. The design approach used to achieve a satisfactory plasma limiter and blade is discussed

  9. Compound sawtooth study in ohmically heated TFTR plasmas

    International Nuclear Information System (INIS)

    Yamada, H.; McGuire, K.; Colchin, D.

    1985-09-01

    Compound sawtooth activity has been observed in ohmically heated, high current, high density TFTR plasmas. Commonly called ''double sawteeth,'' such sequences consist of a repetitive series of subordinate relaxations followed by a main relaxation with a different inversion radius. The period of such compound sawteeth can be as long as 100 msec. In other cases, however, no compound sawteeth or bursts of them can be observed in discharges with essentially the same parameters

  10. Extension of TFTR operations to higher toroidal field levels

    International Nuclear Information System (INIS)

    Woolley, R.D.

    1995-01-01

    For the past year, TFTR has sometimes operated at extended toroidal field (TF) levels. The extension to 5.6 Tesla (79 kA) was crucial for TFTR's November 1994 10.7 MW DT fusion power record. The extension to 6.0 Tesla (85 kA) was commissioned on 9 September 1995. There are several reasons that one could expect the TF coils to survive the higher stresses that develop at higher fields. They were designed to operate at 5.2 Tesla with a vertical field of 0.5 Tesla, whereas the actual vertical field needed for the plasma does not exceed 0.35 Tesla. Their design specification explicitly required they survive some pulses at 6.0 Tesla. TF coil mechanical analysis computer models available during coil design were crude, leading to conservative design. And design analyses also had to consider worst-case misoperations that TFTR's real time Coil Protection Calculators (CPCs) now positively prevent from occurring

  11. Design of a tritium pellet injector for TFTR

    International Nuclear Information System (INIS)

    Milora, S.L.; Gouge, M.J.; Fisher, P.W.; Combs, S.K.; Cole, M.J.; Wysor, R.B.; Fehling, D.T.; Foust, C.R.; Baylor, L.R.; Schmidt, G.L.; Barnes, G.W.; Persing, R.G.

    1991-01-01

    The TFTR tritium pellet injector (TPI) is designed to provide a tritium pellet fueling capability with pellet speeds in the 1- to 3 km/s-range for the TFTR D-T phase. The existing TFTR deuterium pellet injector is being modified at Oak Ridge National Laboratory to provide a fourshot, tritium-compatible, pipe-gun configuration with three upgraded single-stage pneumatic guns a two -stage light gas gun driver. The pipe gun concept has been qualified for tritium operation by the tritium proof-of-principle injector experiments conducted on the Tritium Systems Test Assembly at Los Alamos National Laboratory. In these experiments, tritium and D-T pellets were accelerated to speeds near 1.5 km/s. The TPI is being designed for pellet sizes in the range from 3.43 to 4.0 mm in diameter in arbitrarily programmable firing sequences at speeds up to approximately 1.5 km/s for the three single-stage drivers and 2.5 to 3 km/s for the two-stage driver. Injector operation will be controlled by a programmable logic controller. 7 refs., 4 figs

  12. Development of the TFTR neutral beam injection system

    International Nuclear Information System (INIS)

    Prichard, B.A. Jr.

    1977-01-01

    The TFTR Neutral Beam Lines are designed to inject 20 MW of 120 keV neutral deuterium atoms into the plasma. This is accomplished using 12 sources, 65 amperes each, mounted in 4 beam lines. The 120 kV sources and a prototype beam line are being developed. The implementation of these beam lines has required the development of several associated pieces of hardware. 200 kV switch tubes for the power supplies are being developed for modulation and regulation of the accelerating supplies. A 90 cm metallic seal gate valve capable of sealing against atmosphere in either direction is being developed for separating the torus and beam line vacuum systems. A 70 x 80 cm fast shutter valve is also being developed to limit tritium migration from the torus into the beam line. Internal to the beam line a calorimeter, ion dump and deflection magnet have been designed to handle three beams, and optical diagnostics utilizing the doppler broadening and doppler shift of light emitted from the accelerated beam are being developed. The control and monitoring of the 12 sources will be done via the TFTR computer control system (CICADA) as will other parts of the machine, and software is being developed to condition and operate the sources automatically. The prototype beam line is scheduled to begin operation in the fall of 1978 and all four production beam lines on TFTR in 1982

  13. High performance deuterium-tritium plasmas in TFTR

    International Nuclear Information System (INIS)

    Sabbagh, S.A.; Bell, M.G.

    1995-03-01

    Plasmas composed of nominally equal concentrations of deuterium and tritium (DT) have been created in TFTR with the goals of producing significant levels of fusion power and of examining the effects of DT fusion alpha particles. Conditioning of the limiter by the injection of lithium pellets has led to an approximate doubling of the energy confinement time, τ E , in supershot plasmas at high plasma current (I p ≤ 2.5 MA) and high heating power (P b ≤ 33 MW). Operation with DT typically results in an additional 20% increase in τ E . In the high poloidal beta, advanced tokamak regime in TFTR, confinement enhancement H triple-bond τ E /τ E ITER-89P > 4 has been obtained in a limiter H-mode configuration at moderate plasma current I p = 0.85 - 1.5 MA. By peaking the plasma current profile, β N dia triple-bond 10 8 tperpendicular > aB 0 /I p = 3 has been obtained in these plasmas, exceeding the β N limit for TFTR plasmas with lower internal inductance, l i . Confinement of alpha particles appears to be classical and losses due to collective effects have not been observed. While small fluctuations in fusion product loss were observed during ELMs, no large loss was detected in DT plasmas

  14. ORNL compact loop antenna design for TFTR and Tore Supra

    International Nuclear Information System (INIS)

    Taylor, D.J.; Baity, F.W.; Bryan, W.E.; Hoffman, D.J.; McIlwain, R.L.; Ray, J.M.

    1987-01-01

    The goal supplemental ion cyclotron resonance heating (ICRH) of fusion plasma is to deliver power at high efficiencies deep within the plasma. The technology for fast-wave ICRH has reached the point of requiring ''proof-of-performance'' demonstration of specific antenna configurations of specific antenna configurations and their mechanical adequacy for operating in a fusion environment. Oak Ridge National Laboratory (ORNL) has developed the compact loop antenna concept based on a resonant double loop (RDL) configuration for use in both Tokamak Fusion Test Reactor (TFTR) and the Tore Supra ICRH programs. A description and a comparison of the technologies developed in the two designs are presented. The electrical circuit and the mechanical philosophy employed are the same for both antennas, but different operating environments result in substantial differences in the design of specific components. The ORNL TFTR antenna is designed to deliver 4 MW over a 2-s pulse, and the ORNL Tore Supra antenna is designed for 4 MW and essentially steady-state conditions. The TFTR design embodies the first operations compact RDL antenna, and the Tore Supra antenna extends the technology to an operational duty cycle consistent with reactor-relevant applications. 7 refs., 5 figs

  15. EMI free fiber optic strain sensor system for TFTR

    International Nuclear Information System (INIS)

    Szuchy, N.C.; Caserta, A.L.; Ferrara, A.A.; Squires, R.W.; Sredniawski, J.J.

    1983-01-01

    In certain applications, structural components are subjected to loadings in high electromagnetic interference (EMI) environments. The mechanical responses of these components must be monitored under rapidly varying electromagnetic fields. A Fiber Optic Strain Sensor System (FOSSS) is an acceptable solution since it is immune to EMI. Grumman Aerospace Corporation initiated the development of a FOSSS that can be used in high EMI situations where resistive/electronic-based strain measurement systems would not be effective, such as on the Tokamak Fusion Test Reactor (TFTR) during plasma disruption. Tests have indicated that because of their increased sensitivity due to the size of the fiber optic (FO) transducer (1-in. 2 ) and responsiveness due to the areal changes of the FO sensor, the strain tracking capability of FO sensors are excellent. For the TFTR application a jacketed 400-micron fiber capable of operating in a 250 0 C temperature environment was used. Continuous 30 foot lengths of high-temperature FO cables were affixed to 304 LN SS tabs, forming an integrated strain sensor and pigtail unit. By fusion splicing 400-micron room temperature fibers to the pigtails, the required runs (approximately 200 feet) to the TFTR data acquisition room were made with minimum coupling attenuation. Development methodology is discussed and test data presented

  16. Finite element modeling of TFTR poloidal field coils

    International Nuclear Information System (INIS)

    Baumgartner, J.A.; O'Toole, J.A.

    1986-01-01

    The Tokamak Fusion Test Reactor (TFTR) Poloidal Field (PF) coils were originally analyzed to TFTR design conditions. The coils have been reanalyzed by PPPL and Grumman to determine operating limits under as-built conditions. Critical stress levels, based upon data obtained from the reanalysis of each PF coil, are needed for input to the TFTR simulation code algorithms. The primary objective regarding structural integrity has been to ascertain the magnitude and location of critical internal stresses in each PF coil due to various combinations of electromagnetic and thermally induced loads. For each PF coil, a global finite element model (FEM) of a coil sector is being analyzed to obtain the basic coil internal loads and displacements. Subsequent fine mesh local models of the coil lead stem and lead spur regions produce the magnitudes and locations of peak stresses. Each copper turn and its surrounding insulation are modeled using solid finite elements. The corresponding electromagnetic and thermal analyses are similarly modeled. A series of test beams were developed to determine the best combination of MSC/NASTRAN-type finite elements for use in PF coil analysis. The results of this analysis compare favorably with those obtained by the earlier analysis which was limited in scope

  17. Upgrade to the Tritium Remote Control and Monitoring System for TFTR D and D

    International Nuclear Information System (INIS)

    Sichta, P.; Oliaro, G.; Sengupta, S.

    2002-01-01

    Since 1988, the Tritium Remote Control and Monitoring System (TRECAMS) has performed crucial functions in support of D-T [deuterium-tritium] operations of the Tokamak Fusion Test Reactor (TFTR) at the Princeton Plasma Physics Laboratory (PPPL). Although plasma operations on TFTR were completed in 1997, the need for TRECAMS continued. During this period TRECAMS supported the TFTR tritium systems, the TFTR's Shutdown and Safing phase, and the TFTR Decontamination and Decommissioning (D and D) project. The most critical function of the TRECAMS in the post-TFTR era has been to provide a real-time indication of the airborne tritium levels in the tritium areas and the (HVAC) stacks. TRECAMS is a critical tool in conducting safe TFTR D and D tritium-line breaks and other tritium-related work activities. Beginning in 1998, the failure rate of the system's hardware sharply increased. Furthermore, the specialized knowledge required to maintain the original software and hardware was diminishing. It soon became apparent that a failure of the TRECAMS could significantly impact the TFTR D and D project's cost and schedule. To preclude this, the TRECAMS hardware and software was upgraded in the year 2000 to use modern components. This paper will describe that successful upgrade, including a review of the engineering processes and our operating experiences with the upgraded system

  18. Measurement of internal magnetic field pitch using Li pellet injection on TFTR (invited)

    International Nuclear Information System (INIS)

    Terry, J.L.; Marmar, E.S.; Howell, R.B.; Bell, M.; Cavallo, A.; Fredrickson, E.; Ramsey, A.; Schmidt, G.L.; Stratton, B.; Taylor, G.; Mauel, M.E.

    1990-01-01

    A diagnostic technique which measures the direction of the internal magnetic field pitch angle has been used successfully on TFTR. The technique requires the injection of high-speed Li pellets. The magnetic field direction is measured by observing the polarization direction of the intense visible line emission from Li + (λ∼5485 A, 1s2p 3 P 0,1,2 →1s2s 3 S 0 ) in the pellet ablation cloud. The presence of the large (primarily toroidal) magnetic field causes the line to be split due to the Zeeman effect, and the unshifted π component is polarized with its polarization direction parallel to the local magnetic field. In devices with sufficiently strong fields (B approx-gt 4.5 T), the Zeeman splitting of the line is large enough, relative to the linewidth of each Zeeman component, that enough residual polarization remains. Because the pellet moves about 1 cm before the Li + is ionized (τ ionization approx-lt 10 μs), the time history of the polarization direction (as the pellet penetrates from the outside toward the plasma center) yields the local magnetic field direction. In the TFTR experiment, spatial resolution of the measurement is typically ∼7 cm, limited by the requirement that a large number of photons must be collected in order to make the measurement of the polarization angle. Typically, the pitch of the field is measured with an accuracy of ±0.01 rad, limited by the photon statistics. The measurements of the internal field pitch angle, combined with external magnetic measurements, have been used in a code which finds the solution of the Grad--Shafranov equation, yielding the equilibrium which is the best fit to the measured inputs

  19. Overview of the first workshop on alpha particle physics in TFTR

    International Nuclear Information System (INIS)

    Zweben, S.J.; Biglari, H.

    1991-07-01

    The ''First Workshop on Alpha Physics in TFTR'' was held at the Princeton Plasma Physics Lab March 28--29, 1991. The motivation for this meeting was to clarify and strengthen the TFTR alpha physics program, and to increase the involvement of the fusion community outside PPPL in the TFTR D-T experiments. Therefore the meeting was sharply focused on alpha physics relevant to the upcoming TFTR D-T simulation, and was asked to devote half of his talk to specific TFTR issues. The Workshop consisted of 27 talks on: (1) experimental possibilities; (2) theoretical possibilities; (3) diagnostic possibilities; (4) relevance for future machines; and (5) discussion/summary session. This summary contains a brief sampling of the new results and ideas brought out by these talks, followed by two more general overviews of the status of experiment and theory

  20. Escaping 1 MeV tritons in TFTR

    International Nuclear Information System (INIS)

    Zweben, S.J.; Strachan, J.D.; Boivin, R.; Cavallo, A.; Fredrickson, E.D.; McGuire, K.; Mynick, H.E.; White, R.B.

    1989-01-01

    1 MeV tritons created by D-D reactions can simulate the 'single-particle' behavior expected with 3.5 MeV D-T alphas, since the gyroradii and slowing-down of these two particles are similar. This paper describes measurements of the flux of escaping 1 MeV tritons from the TFTR plasma during high power D 0 →D neutral beam injection, and shows that in most cases the observed triton loss is consistent with the classical (single-particle) first-orbit loss model. In this model tritons are lost if their first orbit intersects the wall due to their large banana width, while almost all tritons confined on their first orbit should stay confined until thermalized. The triton detectors are ZnS(Ag) scintillator screens housed in light-tight boxes located just outside the plasma boundary at the bottom of the TFTR vessel. They are particle 'pinhole' cameras which can resolve the triton flux vs. pitch angle (to ±5 o ), energy (to ±50 %), and time (to <20 μsec). The 2-D images of triton flux onto these scintillators are optically coupled to either an intensified TV camera or to photomultiplyer tubes for fast time resolution. The soft x-ray background in an earlier prototype has been eliminated. Although there are presently 8 such detectors in TFTR, this paper discusses results from only the detector located just below the vessel center (R=259 cm, r=102 cm). Note that the '1 MeV triton' signal discussed below also has about a 30 % contribution from 3 MeV protons; however, since these two particles have identical gyroradii they should behave alike. 5 refs., 5 figs

  1. Phenomenology of high density disruptions in the TFTR tokamak

    International Nuclear Information System (INIS)

    Fredrickson, E.D.; McGuire, K.M.; Bell, M.G.

    1993-01-01

    Studies of high density disruptions on TFTR, including a comparison of minor and major disruptions at high density, provide important new information regarding the nature of the disruption mechanism. Further, for the first time, an (m,n)=(1,1) 'cold bubble' precursor to high density disruptions has been experimentally observed in the electron temperature profile. The precursor to major disruptions resembles the 'vacuum bubble' model of disruptions first proposed by B.B. Kadomtsev and O.P. Pogutse (Sov. Phys. - JETP 38 (1974) 283). (author). Letter-to-the-editor. 25 refs, 3 figs

  2. Wall conditioning experiments on TFTR using impurity pellet injection

    International Nuclear Information System (INIS)

    Strachan, J.D.; Mansfield, D.K.; Bell, M.G.; Collins, J.; Ernst, D.; Hill, K.; Hosea, J.; Timberlake, J.; Ulrickson, M.; Terry, J.; Marmar, E.; Snipes, J.

    1994-01-01

    This work describes experiments intended to optimize the limiter conditioning for TFTR supershots. It is shown that deposition of thin layers of lithium on the limiters by impurity pellet injection changes the plasma-wall interaction and improves supershot performance. Series of up to ten Ohmic plasmas each with two lithium pellets were useful in pre-conditioning the limiter. Generally, plasma performance increased with the amount of lithium deposited up to the maximal amount which could be deposited. Experiments were performed with different materials being deposited (carbon, boron and lithium) and with different methods of deposition. ((orig.))

  3. Overview of the TFTR Lithium Blanket Module program

    International Nuclear Information System (INIS)

    Jassby, D.L.

    1986-01-01

    The LBM (Lithium Blanket Module) is an approximately cubic module, about 80 cm on each side, with construction representative of a helium-cooled lithium oxide fusion reactor blanket module. Measurements of neutron transport and tritium breeding in the LBM will be made in irradiation programs first with a point-neutron source, and subsequently with the D-D and D-T fusion-neutron sources of the TFTR. This paper summarizes the objectives of the LBM program, the design, development and construction of the LBM, and progress in the experimental tests

  4. Alpha particle loss in the TFTR DT experiments

    International Nuclear Information System (INIS)

    Zweben, S.J.; Darrow, D.S.; Herrmann, H.W.

    1995-01-01

    Alpha particle loss was measured during the TFTR DT experiments using a scintillator detector located at the vessel bottom in the ion grad-B drift direction. The DT alpha particle loss to this detector was consistent with the calculated first-orbit loss over the whole range of plasma current I=0.6-2.7 MA. In particular, the alpha particle loss rate per DT neutron did not increase significantly with fusion power up to 10.7 MW, indicating the absence of any new ''collective'' alpha particle loss processes in these experiments

  5. Transport of recycled deuterium to the plasma core in TFTR

    International Nuclear Information System (INIS)

    Skinner, C.H.; Bell, M.G.; Budny, R.V.; Jassby, D.L.; Park, H.; Ramsey, A.T.; Stotler, D.P.; Strachan, J.D.

    1997-10-01

    The authors report a study of the fueling of the plasma core by recycling in the Tokamak Fusion Test Reactor (TFTR). They have analyzed discharges fueled by deuterium recycled from the limiter and tritium-only neutral beam injection. In these plasmas, the DT neutron rate provides a measure of the deuterium influx into the core plasma. They find a reduced influx with plasmas using lithium pellet conditioning and with plasmas of reduced major (and minor) radius. Modeling with the DEGAS neutrals code shows that the dependence on radius can be related to the penetration of neutrals through the scrape-off layer

  6. ICRF-induced DD fusion product losses in TFTR

    International Nuclear Information System (INIS)

    Darrow, D.S.; Zweben, S.J.; Budny, R.V.

    1994-10-01

    When ICRF power is applied to TFTR plasmas in which there is no externally-supplied minority species, an enhanced loss of DD fusion products results. The characteristics of the loss are consistent with particles at or near the birth energy having their perpendicular velocity increased by the ICRF such that those near the passing/trapped boundary are carried into the first orbit loss cone. A rudimentary model of this process predicts losses of a magnitude similar to those seen. Extrapolations based upon this data for hypothetical ICRF ash removal from reactor plasmas suggest that the technique will not be energy efficient

  7. TAE Saturation of Alpha Particle Driven Instability in TFTR

    International Nuclear Information System (INIS)

    Berk, H.L.; Chen, Y.; Gorelenkov, N.N.; White, R.B.

    1998-01-01

    A nonlinear theory of kinetic instabilities near threshold [H.L. Berk, et al., Plasma Phys. Rep. 23, (1997) 842] is applied to calculate the saturation level of Toroidicity-induced Alfvn Eigenmodes (TAE) and be compared with the predictions of (delta)f method calculations [Y. Chen, Ph.D. Thesis, Princeton University, 1998]. Good agreement is observed between the predictions of both methods and the predicted saturation levels are comparable with experimentally measured amplitudes of the TAE oscillations in TFTR [D.J. Grove and D.M. Meade, Nucl. Fusion 25, (1985) 1167

  8. Design and analysis of the TFTR fixed limiters - 1

    International Nuclear Information System (INIS)

    Winkler, P.; Fixler, S.; Timlen, W.V.

    1981-01-01

    The operation of the Tokamak Fusion Test Reactor (TFTR) consists of two phases. In the first phase, the Tokamak systems will be tested and an ohmic heated plasma of 4 MW produced. The plasma limiter system for this phase consists of a set of movable and a set of fixed limiters. Because of the low power level during this phase, a design of passively cooled fixed limiters without tiles will satisfy the requirements. This limiter will be replaced by an actively cooled tile-covered axisymmetric limiter in the second phase. This paper discusses the design of the first phase fixed limiters only

  9. Tritium Decontamination of TFTR D-T Graphite Tiles Employing Ultra Violet Light and a Nd:YAG Laser

    International Nuclear Information System (INIS)

    Gentile, C.A.; Skinner, C.H.; Young, K.M.; Ciebiera, L.

    1999-01-01

    The use of an ultra violet (UV) light source (wavelength = 172 nm) and a Nd:YAG Laser for the decontamination of the Tokamak Fusion Test Reactor (TFTR) deuterium-tritium (D-T) tiles will be investigated at the Princeton Plasma Physics Laboratory (PPPL). The development of this form of tritium decontamination may be useful for future D-T burning fusion devices which employ carbon plasma-facing components on the first wall. Carbon tiles retain hydrogen isotopes, and the in-situ tritium decontamination of carbon can be extremely important in maintaining resident in-vessel tritium inventory to a minimum. A test chamber has been designed and fabricated at PPPL. The chamber has the ability to be maintained under vacuum, be baked to 200 *C, and provides sample ports for gas analyses. Tiles from TFTR that have been exposed to D-T plasmas will be placed within the chamber and exposed to either an UV light source or the ND:YAG Laser. The experiment will determine the effectiveness of these two techniques for the removal of tritium. In addition, exposure rates and scan times for the UV light source and/or Nd:YAG Laser will be determined for tritium removal optimization from D-T tiles

  10. Alpha diagnostics using pellet charge exchange: Results on TFTR and prospects for ITER

    International Nuclear Information System (INIS)

    Fisher, R.K.; Duong, H.H.; McChesney, J.M.

    1996-05-01

    Confinement of alpha particles is essential for fusion ignition and alpha physics studies are a major goal of the TFTR, JET, and ITER DT experiments, but alpha measurements remain one of the most challenging plasma diagnostic tasks. The Pellet Charge Exchange (PCX) diagnostic has successfully measured the radial density profile and energy distribution of fast (0.5 to 3.5 MeV) confined alpha particles in TFTR. This paper describes the diagnostic capabilities of PCX demonstrated on TFTR and discusses the prospects for applying this technique to ITER. Major issues on ITER include the pellet's perturbation to the plasma and obtaining satisfactory pellet penetration into the plasma

  11. Perspectives gained from ICRF physics studies on TFTR

    International Nuclear Information System (INIS)

    Phillips, C.K.; Bell, M.; Batha, S.

    1998-01-01

    The physics of ICRF heating and current drive has been studied on TFTR for over a decade. Following the early low power coupling studies, high power experiments resulted in sawtooth stabilization, the first observation of RF-driven excitation of toroidal Alfven eigenmodes, and the discovery of a mode conversion scenario for localized off-axis electron heating. The program culminated with the first studies of high power ICRF heating and profile control in tritium-rich high performance plasmas. A significant part of the concluding experiments centered on the potential of ICRF to drive sheared flows in order to suppress turbulence in the plasma core. Initial measurements taken with a novel poloidal velocity diagnostic suggest that localized sheared poloidal flows can be driven with ion Bernstein waves excited directly or else via mode conversion from a propagating fast magnetosonic wave. In this paper, recent results from TFTR on wave-based profile control techniques will be summarized along with suggestions for future studies elsewhere

  12. Measurement of TFTR D-T radiation shielding efficiency

    International Nuclear Information System (INIS)

    Kugel, H.W.; Ascione G.; Elwood, S.

    1994-01-01

    High power D-T fusion reactor designs presently exhibit complex geometric and material density configurations. Simulations of the radiation shielding required for safe operation and full compliance with all regulatory requirements must include sufficient margin to accommodate uncertainties in material properties and distributions, uncertainties in the final configurations, and uncertainties in approximations employing the homogenization of complex geometries. Measurements of radiation shielding efficiency performed in a realistic D-T tokamak environment can provide empirical guidance for simulating safe, efficient, and cost effective shielding systems for future high power fusion reactors. In this work, the authors present the results of initial measurements of the TFTR radiation shielding efficiency during high power D-T operations with record neutron yields. The TFTR design objective is to limit the total dose-equivalent at the nearest PPPL property lines from all radiation pathways to 10 mrem per calendar year. Compliance with this design objective over a calendar year requires measurements in the presence of typical site backgrounds of about 80 mrem per year

  13. Modeling of high power ICRF heating experiments on TFTR

    International Nuclear Information System (INIS)

    Phillips, C.K.; Wilson, J.R.; Bell, M.; Fredrickson, E.; Hosea, J.C.; Majeski, R.; Ramsey, A.; Rogers, J.H.; Schilling, G.; Skinner, C.; Stevens, J.E.; Taylor, G.; Wong, K.L.; Murakami, M.

    1993-01-01

    Over the past two years, ICRF heating experiments have been performed on TFTR in the hydrogen minority heating regime with power levels reaching 11.2 MW in helium-4 majority plasmas and 8.4 MW in deuterium majority plasmas. For these power levels, the minority hydrogen ions, which comprise typically less than 10% of the total electron density, evolve into la very energetic, anisotropic non-Maxwellian distribution. Indeed, the excess perpendicular stored energy in these plasmas associated with the energetic minority tail ions is often as high as 25% of the total stored energy, as inferred from magnetic measurements. Enhanced losses of 0.5 MeV protons consistent with the presence of an energetic hydrogen component have also been observed. In ICRF heating experiments on JET at comparable and higher power levels and with similar parameters, it has been suggested that finite banana width effects have a noticeable effect on the ICRF power deposition. In particular, models indicate that finite orbit width effects lead to a reduction in the total stored energy and of the tail energy in the center of the plasma, relative to that predicted by the zero banana width models. In this paper, detailed comparisons between the calculated ICRF power deposition profiles and experimentally measured quantities will be presented which indicate that significant deviations from the zero banana width models occur even for modest power levels (P rf ∼ 6 MW) in the TFTR experiments

  14. Measurements of tritium recycling and isotope exchange in TFTR

    International Nuclear Information System (INIS)

    Skinner, C.H.; Kamperschroer, J.; Mueller, D.; Nagy, A.; Stotler, D.P.

    1996-05-01

    Tritium Balmer-alpha (T α ) emission, along with H α and D α is observed in the current D-T experimental campaign in TFTR. The data are a measure of the fueling of the plasma by tritium accumulated in the TFTR limiter and the spectral profile maps neutral hydrogenic velocities. T α is relatively slow to appear in tritium neutral beam heated discharges, (T α /(H α + D α + T α ) = 11% after 8 tritium-only neutral beam discharges). In contrast, the T α fraction in a sequence of six discharges fueled with tritium puff,s increased to 44%. Larger transient increases (up to 75% T α ) were observed during subsequent tritium gas puffs. Analysis of the Doppler broadened spectral profiles revealed overall agreement with the dissociation, charge exchange, sputtering and reflection velocities predicted by the neutral Monte-Carlo code DEGAS with some deficiency in the treatment of dissociation products in the 10--100 eV range

  15. Tritium decontamination of TFTR carbon tiles employing ultra violet light

    International Nuclear Information System (INIS)

    Shu, W.M.; Ohira, S.; Gentile, C.A.; Oya, Y.; Nakamura, H.; Hayashi, T.; Iwai, Y.; Kawamura, Y.; Konishi, S.; Nishi, M.F.; Young, K.M.

    2001-01-01

    Tritium decontamination on the surface of Tokamak Fusion Test Reactor (TFTR) bumper limiter tiles used during the Deuterium-Deuterium (D-D) phase of TFTR operations was investigated employing an ultra violet light source with a mean wavelength of 172 nm and a maximum radiant intensity of 50 mW/cm 2 . The partial pressures of H 2 , HD, C and CO 2 during the UV exposure were enhanced more than twice, compared to the partial pressures before UV exposure. In comparison, the amount of O 2 decreased during the UV exposure and the production of a small amount of O 3 was observed when the UV light was turned on. Unlike the decontamination method of baking in air or oxygen, the UV exposure removed hydrogen isotopes from the tile to vacuum predominantly in forms of gases of hydrogen isotopes. The tritium surface contamination on the tile in the area exposed to the UV light was reduced after the UV exposure. The results show that the UV light with a wavelength of 172 nm can remove hydrogen isotopes from carbon-based tiles at the very surface

  16. Health physics and radioactive waste considerations for the TFTR

    International Nuclear Information System (INIS)

    Rule, K.; Gilbert, J.; Scott, J.

    1995-01-01

    The Tokamak Fusion Test Reactor (TFTR) began high power fusion operations, with tritium, in November of 1993. The operational health physics program involves maintenance on activated materials and tritium contaminated systems. Survey data and findings are collected on routine and special maintenance situations ranging from work on small volume piping to large volume neutral beam systems. The results of radiological measurements are described in relation to the differentiation of elemental tritium to tritium oxide in worker's breathing zones and the associated general work area. The contamination levels, airborne radioactivity, and oil concentrations are also compared. Measurements for gamma radiation are performed to determine personnel access requirements and for comparison to activation and decay models as a planning tools. TFTR presents many unusual challenges with regard to dismantling, packaging and disposal of its components and ancillary systems. A functional time phased radioactive waste generation schedule was developed to enhance project planning. This project will be the first demonstration of the decommissioning of a tritium fueled fusion test reactor

  17. Results obtained using the pellet charge exchange diagnostic on TFTR

    International Nuclear Information System (INIS)

    McChesney, J.M.; Fisher, R.K.; Parks, P.B.; Duong, H.H.; Mansfield, D.K.; Medley, S.S.; Roquemore, A.L.; Petrov, M.P.

    1994-05-01

    Experiments are underway on TFTR to measure the confined alpha particle distribution functions using small low-Z pellets injected into the plasma. Upon entering the plasma, the pellet ablates, forming a plasma ablation cloud, elongated in the magnetic field direction, that travels alongside the pellet. A small fraction of the fusion produced 3.5 MeV alpha particles incident on the cloud are converted to helium neutrals. By measuring the resultant helium neutrals escaping from the plasma by means of a mass and energy resolving charge exchange analyzer, the energy distribution of the alpha particles incident on the cloud can be inferred. Preliminary experiments to observe neutrals from the 100-1000 keV He tail produced during ICRF minority heating experiments were successful. However, no significant alpha particle signals have been observed during D-T operation on TFTR. The authors attribute this lack of signal to stochastic toroidal field ripple loss in the outer regions of the plasma. They are studying ways to improve the pellet penetration so that the pellet penetrates into the central regions of the plasma where ripple induced losses are small and the alpha population is high

  18. Configuration management of TFTR during final fabrication/assembly/installation

    International Nuclear Information System (INIS)

    Sabado, M.; Rappe, G.H.; Stern, E.; Wexler, H.

    1983-01-01

    In essence, configuration management consists of the establishment of a Baseline definition for each project phase, well documented, so that all project participants are conversant with it and the disciplined redefinition of the baseline as the project matures. This paper describes the methods by which the Baseline design for each phase of the TFTR program was updated. Definition was initiated through informal controls which became more formal as the design progressed. At the point where the design was essentially frozen, that is, released for procurement and manufacturing, a configuration change control procedure was instituted to continue on a routine basis both engineering and management review of all changes. Since the TFTR program is experimental in nature it was understood from the outset that desirable changes based on new analytical results and experimental results from other fusion programs could be injected into the design. The problem was one of maintaining the flexibility of providing a reasonable baseline definition, in order to allow the design to proceed yet avoiding the premature freezing of the design, in order to incorporate required changes at lowest cost

  19. Calibration issues of the TFTR multichannel neutron collimator

    International Nuclear Information System (INIS)

    Goeler, S. von; Johnson, L.C.; Bitter, M.; Efthimion, P.C.; Roquemore, A.L.

    1996-01-01

    The calibration procedures for the detectors in the Neutron Collimator are reviewed. The absolute calibration was performed for the NE451 detectors, in situ, by moving a DT neutron generator in the TFTR vacuum vessel across each sight line. This calibration was transferred to other detectors in the same channel. Four new sight lines have been installed at a different toroidal location, which view the plasma through the vacuum vessel port cover rather than through thinned windows. The new detectors are cross-calibrated to the NE451 detectors with a jog shot procedure, where the plasma is quickly shifted in major radius over a distance of 30 cm. The jog shot procedure shows that scattered neutrons account approximately for 30% of the signal of the new central channels. The neutron source strength from the collimator agrees within 10% with the source strength from global neutron monitors in the TFTR test cell. Detector non-linearity is discussed. Another special issue is the behavior of the detectors during T-puffs, where the DD/DT neutron ratio changes rapidly

  20. TFTR Inner Support Structure final assembly and installation

    International Nuclear Information System (INIS)

    Rocco, R.E.; Brown, G.; Carglia, G.; Heitzenroeder, P.; Koenig, F.; Mookerjee, S.; Raugh, J.

    1983-01-01

    The Inner Support Structure (ISS) of the TFTR provides a specific level of restraint to the net centering force and overturning moment produced by the Toroidal Field (TF) coils and to the vertical forces produced by the Inner Poloidal Field (PF) coils. This is accomplished consistent with the need for four radial dielectric breaks running the entire length of the ISS to prevent eddy current loops. A brief description of the major components, method of manufacture and material selection of the ISS and PF coils is presented. Particular attention is given to the integration of the PF coils and the ISS components into the total assembly and the installation of strain gauges and crack monitors on the ISS. The requirements of no gaps at the interfaces of the ISS teeth at all three horizontal planes is discussed. The problem encountered with achieving the no gap requirement and the successful resolution of this problem, including its impact on installation of the ISS, is also discussed. The installation of the ISS, including setting in position, preloading with TF coil clips, and final tensioning of the tension bars is discussed. A brief description of the lower and upper lead stem splicing operation is presented. Subsequent to the final assembly, electrical tests were performed prior to and after installation on the TFTR machine. An overview of the tests and their results is presented

  1. TFTR grounding scheme and ground-monitor system

    International Nuclear Information System (INIS)

    Viola, M.

    1983-01-01

    The Tokamak Fusion Test Reactor (TFTR) grounding system utilizes a single-point ground. It is located directly under the machine, at the basement floor level, and is tied to the building perimeter ground. Wired to this single-point ground, via individual 500 MCM insulated cables, are: the vacuum vessel; four toroidal field coil cases/inner support structure quadrants; umbrella structure halves; the substructure ring girder; radial beams and columns; and the diagnostic systems. Prior to the first machine operation, a ground-loop removal program was initiated. It required insulation of all hangers and supports (within a 35-foot radius of the center of the machine) of the various piping, conduits, cable trays, and ventilation systems. A special ground-monitor system was designed and installed. It actively monitors each of the individual machine grounds to insure that there are no inadvertent ground loops within the machine structure or its ground and that the machine grounds are intact prior to each pulse. The TFTR grounding system has proven to be a very manageable system and one that is easy to maintain

  2. An amplitude and phase control system for the TFTR rf heating sources

    International Nuclear Information System (INIS)

    Cutsogeorge, G.

    1989-04-01

    Feedback loops that control the amplitude and phase of the rf heating sources on TFTR are described. The method for providing arc protection is also discussed. Block diagrams and Bode plots are included. 6 figs

  3. Beta normal control of TFTR using fuzzy logic

    International Nuclear Information System (INIS)

    Lawson, J.E.; Bell, M.G.; Marsala, R.J.; Mueller, D.

    1995-01-01

    In TFTR plasmas heated by neutral beam injection, the fusion power yield increases rapidly with the plasma pressure. However, the pressure is limited by the onset of instabilities which may result in plasma disruptions that would have had an adverse effect on the performance of subsequent discharges and increase the risk of damage to internal components. The likelihood of disruption has been found to correlate with the normalized beta, defined as βN = 2 x 10 8 μ circle left angle p perpendicular to right angle a / BTIp where left angle p perpendicular to right angle is the volume-average plasma perpendicular pressure, a the mid-plane minor radius of the plasma, BT the toroidal magnetic field and Ip the plasma current. Other variables, such as the peaking of the plasma pressure and current profiles, have been found to influence the threshold of βN at which the probability of disruption begins to increase significantly. For TFTR plasmas with high fusion performance (TFTR ''supershots'') the probability of disruption has been found to increase rapidly for βN > 1.8. Since confinement in this regime is affected by plasma-wall interaction, which can vary from shot to shot, operation at high βN with preprogrammed heating power pulses can produce an unacceptably high risk of disruption. To reduce the risk of producing beta-limit disruptions during neutral beam heating experiments, a control system, the Neutral Beam Power Feedback System (NBPFS), has been developed to modulate the total heating power by switching individual neutral beam sources on and off in response to the evolution of the normalized beta so that the limit will not be exceeded. The value of βN is calculated in real time and transmitted to the NBPFS. The value of βN and its calculated time derivative are input to a fuzzy logic controller which implements a proportional-derivative control based on the difference between βN and a programmed reference level βNREF which can be programmed as a function

  4. Stack and area tritium monitoring systems for the tokamak fusion test reactor (TFTR)

    International Nuclear Information System (INIS)

    Pearson, G.G.; Meixler, L.D.; Sirsingh, R.A.P.

    1992-01-01

    This paper reports on the TFTR Tritium Stack and Area Monitoring Systems which have been developed to provide the required level of reliability in a cost effective manner consistent with the mission of the Tritium Handling System on TFTR. Personnel protection, environmental responsibility, and tritium containing system integrity have been the considerations in system design. During the Deuterium-Tritium (D-T) experiments on TFTR, tritium will be used for the first time as one of the fuels. Area monitors provide surveillance of the air in various rooms at TFTR. Stack monitors monitor the air at the TFTR test site that is exhausted through the HVAC systems, from the room exhaust stacks and the tritium systems process vents. The philosophies for the implementation of the Stack and Area Tritium Monitoring Systems at TFTR are to use hardwired controls wherever personnel protection is involved, and to take advantage of modern intelligent controllers to provide a distributed system to support the functions of tracking, displaying, and archiving concentration levels of tritium for all of the monitored areas and stacks

  5. Vacuum system for the tokamak fusion test reactor (TFTR)

    International Nuclear Information System (INIS)

    Lange, W.J.; Green, D.; Sink, D.A.

    1976-01-01

    The vacuum system for TFTR is described. Insofar as possible, conventional and ultrahigh vacuum (UHV) components and technology will be employed. Subassemblies will be prebaked in vacuum to reduce subsequent outgassing, and assembly will employ TIG welding and metal gaskets. It is not anticipated that the totally assembled torus with its numerous diagnostic appendages will be baked in situ to a high temperature, however a lower bakeout temperature (approximately 250 0 C) is under consideration. Final vacuum conditioning will be performed using discharge cleaning to obtain a specific outgassing rate of less than or = to 10 -10 Torr liter/sec cm 2 hydrogen isotopes and less than or = to 10 -12 Torr liter/sec cm 2 of other gases, and a base pressure of less than or = to 5 x 10 -8 Torr

  6. Neutronic design for the TFTR lithium blanket module

    International Nuclear Information System (INIS)

    Cheng, E.T.; Engholm, B.A.; Su, S.D.

    1981-01-01

    The preliminary design of a lithium blanket module (LBM) to be installed and tested in the TFTR has been performed under subcontract to PPPL and EPRI. The objectives of the LBM program are calculation and measurement of neutron fluences and tritium production in a breeding blanket module using state of art techniques, comparison of calculations with measurements, and acquisition of operational experience with a fusion reactor blanket module. The neutronic design of the LBM is one of the key areas of this program in which the LBM composition and geometry are optimized and the boundary material effects on the tritium production in the blanket module are explored. The concept of employing sintered Li/sub 2/O pellets in tubes is proposed for the blanket design

  7. TFTR horizontal high-resolution Bragg x-ray spectrometer

    International Nuclear Information System (INIS)

    Hill, K.W.; Bitter, M.; Tavernier, M.

    1984-11-01

    A bent quartz crystal spectrometer of the Johann type with a spectral resolution of lambda/Δlambda = 10,000 to 25,000 is used on TFTR to determine central plasma parameters from the spectra of heliumlike and lithiumlike metal impurity ions (Ti, Cr, Fe, and Ni). The spectra are observed along a central radial chord and are recorded by a position sensitive multiwire proportional counter with a spatial resolution of 250. Standard delay-line time-difference readout is employed. The data are histogrammed and stored in 64k of memory providing 128 time groups of 512-channel spectra. The central ion temperature and the toroidal plasma rotation are inferred from the Doppler broadening and Doppler shift of the K lines. The central electron temperature, the distribution of ionization states, and dielectronic recombination rates are obtained from satellite-to-resonance line ratios. The performance of the spectrometer is demonstrated by measurements of the Ti XXI K radiation

  8. Shielding calculations for the TFTR neutral beam injectors

    International Nuclear Information System (INIS)

    Santoro, R.T.; Lillie, R.A.; Alsmiller, R.G. Jr.; Barnes, J.M.

    1979-07-01

    Two-dimensional discrete ordinates calculations have been performed to determine the location and thickness of concrete shielding around the Tokamak Fusion Test Reactor (TFTR) neutral beam injectors. Two sets of calculations were performed: one to determine the dose equivalent rate on the roof and walls of the test cell building when no injectors are present, and one to determine the contribution to the dose equivalent rate at these locations from radiation streaming through the injection duct. Shielding the side and rear of the neutral beam injector with 0.305 and 0.61 m of concrete, respectively, and lining the inside of the test cell wall with an additional layer of concrete having a thickness of 0.305 m and a height above the axis of deuteron injection of 3.10 m are sufficient to maintain the biological dose equivalent rate outside the test cell to approx. 1 mrem/DT pulse

  9. Power loading on the first wall during disruptions in TFTR

    International Nuclear Information System (INIS)

    Janos, A.; Fredrickson, E.D.; McGuire, K.M.; Nagayama, Y.; Owens, D.K.; Wilfrid, E.

    1992-01-01

    Heating of the first wall of TFTR due to disruptions is investigated experimentally using an extensive array of thermocouples. By comparing results from discharges with and without disruptions, we extract effects due to the disruption alone. Disruptions preferentially heat the same areas which are heated during discharges without disruptions. Hot areas are inward protrusions or regions unshielded by neighboring areas. Peaking factors in the toroidal direction, defined as peak temperature divided by average toroidal temperature, as a function of poloidal angle, are calculated. For nondisruptive discharges, the peaking factor varies between 2 and 4. For the disruptive portion of a discharge only, the peaking factor near the midplane, where most of the energy is deposited, ranges from 3 to 5. Further away from the midplane, the peaking factor can reach 28, although the heat load is less in that region. (orig.)

  10. Measurements of edge density profile modifications during IBW on TFTR

    International Nuclear Information System (INIS)

    Hanson, G.R.; Bush, C.E.; Wilgen, J.B.

    1997-01-01

    Ion Bernstein wave (IBW) antennas are known to have substantial localized effects on the plasma edge. To allow better understanding and measurement of these effects, the TFTR edge reflectometer has been relocated to the new IBW antenna. This move was facilitated by the incorporation of a diagnostic access tube in the IBW antenna identical to the original diagnostic tube in the fast-wave (FW) antenna. This allowed the reflectometer launcher to simply be moved from the old FW antenna to the new IBW antenna. Only a moderate extension of the waveguide transmission line was required to reconnect the reflectometer to the launcher in its new location. Edge density profile modification during IBW experiments has been observed. Results from IBW experiments will be presented and contrasted to the edge density modifications previously observed during FW heating experiments

  11. TFTR Mirnov coil analysis at plasma start-up

    International Nuclear Information System (INIS)

    Harley, T.R.; Buchenauer, D.A.; Coonrod, J.; McGuire, K.M.

    1986-01-01

    The methods for finding poloidal and toroidal numbers of MHD oscillations from Mirnov coils are reviewed and modified. Examples of various MHD phenomena occurring during start-up on TFTR are illustrated. It is found that the MHD mode structure best fits a model with the toroidal correction included. A new algorithm which finds m,n numbers can accommodate toroidal effects which are manifested in the phase data. The algorithm can find m,n numbers with a given toroidal correction parameter lambda', (lambda' = 0 → cylindrical). This algorithm is also used to find the optimal value of lambda' automatically, eliminating the need for ''guesswork.'' The algorithm finds the best parameters to the fit much faster than more conventional computational techniques. 9 refs., 21 figs., 2 tabs

  12. Measurements of tritium retention and removal on TFTR

    International Nuclear Information System (INIS)

    Skinner, C.H.; Blanchard, W.; Kamperschroer, J.

    1996-05-01

    Recent experiments on the Tokamak Fusion Test Reactor (TFTR) have afforded an opportunity to measure the retention of tritium in a graphite limiter that is subject to erosion, codeposition and high neutron flux. The tritium was injected by both gas puff and neutral beams. The isotopic mix of hydrogenic recycling was measured spectroscopically and the tritium fraction T/(H+D+T) increased to as high as 75%. Some tritium was pumped out during the experimental run and some removed in a subsequent campaign using various clean-up techniques. While the short term retention of tritium was high, various conditioning techniques were successful in removing ∼ 8,000 Ci and restoring the tritium inventory to a level well below the administrative limit

  13. Designs for a TFTR full-power pumped limiter

    International Nuclear Information System (INIS)

    Budny, R.

    1986-10-01

    A pumped-limiter system which would provide increased particle control and enhance the performance of full-power discharges is being considered for TFTR. The system consists of two toroidal belts located near the Zirconium-Aluminium (ZrAl) getter panels. The limiter blades would be made of carbon/carbon composite in order to have a very thin profile, allowing a large fraction of the scrape-off flux to be pumped. Simulations of the plasma scrape-off and neutral transport indicate that the limiter pumping should reduce the recycling coefficient by 10 to 25%. Simulations of central plasma processes indicate that the lowered recycling could increase Q/sub fusion/ by more than 100%. This paper discusses the designs and the performance predictions for the system

  14. Thermal Response of Tritiated Codeposits from JET and TFTR to Transient Heat Pulses

    International Nuclear Information System (INIS)

    Skinner, C.H.; Bekrisl, N.; Coad, J.P.; Gentile, C.A.; Hassanein, A.; Reiswig, R.; Willms, S.

    2002-01-01

    High heat flux interactions with plasma-facing components have been studied at microscopic scales. The beam from a continuous wave neodymium laser was scanned at high speed over the surface of graphite and carbon fiber composite tiles that had been retrieved from TFTR (Tokamak Fusion Test Reactor) and JET (Joint European Torus) after D-T plasma operations. The tiles have a surface layer of amorphous hydrogenated carbon that was co-deposited during plasma operations, and laser scanning has released more than 80% of the co-deposited tritium. The temperature rise of the co-deposit was much higher than that of the manufactured material and showed an extended time history. The peak temperature varied dramatically (e.g., 1,436 C compared to >2,300 C), indicating strong variations in the thermal conductivity to the substrate. A digital microscope imaged the co-deposit before, during, and after the interaction with the laser and revealed 100-micron scale hot spots during the interaction. Heat pulse durations of order 100 ms resulted in brittle destruction and material loss from the surface, whilst a duration of =10 ms showed minimal changes to the co-deposit. These results show that reliable predictions for the response of deposition areas to off-normal events such as ELMs (edge-localized modes) and disruptions in next-step devices need to be based on experiments with tokamak generated co-deposits

  15. Periscope-camera system for visible and infrared imaging diagnostics on TFTR

    International Nuclear Information System (INIS)

    Medley, S.S.; Dimock, D.L.; Hayes, S.; Long, D.; Lowrence, J.L.; Mastrocola, V.; Renda, G.; Ulrickson, M.; Young, K.M.

    1985-05-01

    An optical diagnostic consisting of a periscope which relays images of the torus interior to an array of cameras is used on the Tokamak Fusion Test Reactor (TFTR) to view plasma discharge phenomena and inspect vacuum vessel internal structures in both visible and near-infrared wavelength regions. Three periscopes view through 20-cm-diameter fused-silica windows which are spaced around the torus midplane to provide a viewing coverage of approximately 75% of the vacuum vessel internal surface area. The periscopes have f/8 optics and motor-driven controls for focusing, magnification selection (5 0 , 20 0 , and 60 0 field of view), elevation and azimuth setting, mast rotation, filter selection, iris aperture, and viewing port selection. The four viewing ports on each periscope are equipped with multiple imaging devices which include: (1) an inspection eyepiece, (2) standard (RCA TC2900) and fast (RETICON) framing rate television cameras, (3) a PtSi CCD infrared imaging camera, (4) a 35 mm Nikon F3 still camera, or (5) a 16 mm Locam II movie camera with variable framing up to 500 fps. Operation of the periscope-camera system is controlled either locally or remotely through a computer-CAMAC interface. A description of the equipment and examples of its application are presented

  16. Periscope-camera system for visible and infrared imaging diagnostics on TFTR

    International Nuclear Information System (INIS)

    Medley, S.S.; Dimock, D.L.; Hayes, S.; Long, D.; Lowrance, J.L.; Mastrocola, V.; Renda, G.; Ulrickson, M.; Young, K.M.

    1985-01-01

    An optical diagnostic consisting of a periscope which relays images of the torus interior to an array of cameras is used on the Tokamak Fusion Test Reactor (TFTR) to view plasma discharge phenomena and inspect the vacuum vessel internal structures in both the visible and near-infrared wavelength regions. Three periscopes view through 20-cm-diam fused-silica windows which are spaced around the torus midplane to provide a viewing coverage of approximately 75% of the vacuum vessel internal surface area. The periscopes have f/8 optics and motor-driven controls for focusing, magnification selection (5 0 , 20 0 , and 60 0 field of view), elevation and azimuth setting, mast rotation, filter selection, iris aperture, and viewing port selection. The four viewing ports on each periscope are equipped with multiple imaging devices which include: (1) an inspection eyepiece, (2) standard (RCA TC2900) and fast (RETICON) framing rate television cameras, (3) a PtSi CCD infrared imaging camera, (4) a 35-mm Nikon F3 still camera, or (5) a 16-mm Locam II movie camera with variable framing rate up to 500 fps. Operation of the periscope-camera system is controlled either locally or remotely through a computer-CAMAC interface. A description of the equipment and examples of its application are presented

  17. Physics of high performance deuterium-tritium plasmas in TFTR

    International Nuclear Information System (INIS)

    McGuire, K.M.; Batha, S.

    1996-11-01

    During the past two years, deuterium-tritium (D-T) plasmas in the Tokamak Fusion Test Reactor (TFTR) have been used to study fusion power production, isotope effects associated with tritium fueling, and alpha-particle physics in several operational regimes. The peak fusion power has been increased to 10.7 MW in the supershot mode through the use of increased plasma current and toroidal magnetic field and extensive lithium wall conditioning. The high-internal-inductance (high-I i ) regime in TFTR has been extended in plasma current and has achieved 8.7 MW of fusion power. Studies of the effects of tritium on confinement have now been carried out in ohmic, NBI- and ICRF- heated L-mode and reversed-shear plasmas. In general, there is an enhancement in confinement time in D-T plasmas which is most pronounced in supershot and high-I i discharges, weaker in L-mode plasmas with NBI and ICRF heating and smaller still in ohmic plasmas. In reversed-shear discharges with sufficient deuterium-NBI heating power, internal transport barriers have been observed to form, leading to enhanced confinement. Large decreases in the ion heat conductivity and particle transport are inferred within the transport barrier. It appears that higher heating power is required to trigger the formation of a transport barrier with D-T NBI and the isotope effect on energy confinement is nearly absent in these enhanced reverse-shear plasmas. Many alpha-particle physics issues have been studied in the various operating regimes including confinement of the alpha particles, their redistribution by sawteeth, and their loss due to MHD instabilities with low toroidal mode numbers. In weak-shear plasmas, alpha-particle destabilization of a toroidal Alfven eigenmode has been observed

  18. Operation of TFTR neutral beams with heavy ions

    International Nuclear Information System (INIS)

    Kamperschroer, J.H.; Stevenson, T.N.; Wright, K.E.; Dudek, L.E.; Grisham, L.R.; Newman, R.A.; O'Connor, T.E.; Oldaker, M.E.; von Halle, A.; Williams, M.D.

    1991-07-01

    High Z neutral atoms have been injected into TFTR plasmas in an attempt to enhance plasma confinement through modification of the edge electric field. TFTR ion sources have extracted 9 A of 62 keV Ne + for up to 0.2 s during injection into deuterium plasmas, and for 0.5 s during conditioning pulses. Approximately 400 kW of Ne 0 have been injected from each of two ion sources. Operation was at full bending magnet current, with the Ne + barely contained on the ion dump. Beamline design modifications to permit operation up to 120 keV with krypton or xenon are described. Such ions are too massive to be deflected up to the ion dump. The plan, therefore, is to armor those components receiving these ions. Even with this armor, modest increases in the bending magnet current capability are necessary to safely reach 120 kV with Kr or Xe. Information relevant to heavy ion operation was also acquired when several ion sources were inadvertently operated with water contamination. Spectroscopic analysis of certain pathological pulses indicate that up to 6% of the extracted ions were water. After dissociation in the neutralizer, water yields oxygen ions which, as with Ne, Kr, and Xe, are under-deflected by the magnet. Damage to a calorimeter scraper, due to the focal properties of the magnet, has resulted. A magnified power density of 6 KW/cm 2 for 2 s, from ∼ 90 kW of O + , is the suspected cause. 11 refs., 4 figs

  19. D-T radiation effects on TFTR diagnostics

    International Nuclear Information System (INIS)

    Ramsey, A.T.

    1994-10-01

    For a 50%-50% deuterium-tritium plasma, the neutron production is 80x higher and the total energy release is 200x higher than the same plasma composed only of deuterium. With this increase in radiation, diagnostics which see only negligible amounts of noise during DD operation may find themselves overwhelmed during DT. The neutrons are not only more numerous, but have 6x as much energy, which causes the calculated 2.4x increase in the gamma flux per neutron near TFTR. We report here the effects of this increased radiation on the TFTR diagnostic set. The most noticeable effects are luminescence and transmission losses in fiber optic signal cables. In addition, a plastic fiber near the torus became unusably opaque after a few DT discharges. Silicon detectors show signs of neutron interactions as well as gamma response, and microchannel electron multipliers show an increased background due to the gamma flux. Bolometers show n and γ heating, and the Thomson scattering intensifier gate spark gap was unreliable until the gas pressure was adjusted. All of these effects were anticipated, and in some cases shielding or compensation techniques were used. Compensation fibers work satisfactorily at these radiation levels, and the rapid fall-off of the radiation as one moves away from the machine makes relocation of fibers and other sensitive components very useful. Conventional shielding designs worked when streaming through signal penetrations was properly dealt with. In coming DT campaigns and the generation of new tokamaks, such problems will be more severe. JET anticipates higher dose levels per shot during DT; TPX has 1000 s pulses and ITER presents a particularly difficult challenge. We shall discuss the implications of our results for diagnostics on these machines

  20. TFTR ultrahigh-vacuum pumping system incorporating mercury diffusion pumps

    International Nuclear Information System (INIS)

    Sink, D.A.; Sniderman, M.

    1976-06-01

    The TFTR vacuum vessel will have a system of four 61 cm diameter mercury diffusion pumps to provide a base pressure in the 10 -8 to 10 -9 Torr range as well as a low impurity level within the vessel. The system, called the Torus Vacuum Pumping System (TVPS), will be employed with the aid of an occasional 250 0 C bakeout in situ as well as periodic applications of aggressive discharge cleaning. The TVPS is an ultrahigh-vacuum (UHV) system using no elastomers as well as being a closed system with respect to tritium or any tritiated gases. The backing system employing approximately 75 all-metal isolation valves is designed with the features of redundancy and flexibility employed in a variety of ways to meet the fundamental requirements and functions enumerated for the TVPS. Since the design, is one which is a modification of the conceptual design of the TVPS, those features which have changed are discussed. Calculations are presented for the major performance parameters anticipated for the TVPS and include conductances, effective pumping speeds, base pressures, operating parameters, getter pump parameters, and calculations of time constants associated with leak checking. Modifications in the vacuum pumping system for the guard regions on the twelve bellows sections are presented so that it is compatible with the main TVPS. The bellows pumping system consists of a mechanical pump unit, a zirconium aluminum getter pump unit and a residual gas analyzer. The control and management of the TVPS is described with particular attention given to providing both manual and automatic control at a local station and at the TFTR Central Control. Such operations as testing, maintenance, leak checking, startup, bakeout, and various other operations are considered in some detail. Various aspects related to normal pulsing, discharge cleaning, non-tritium operations and tritium operations are also taken into consideration. A cost estimate is presented

  1. Meteorological data summaries for the TFTR from March 1984 to February 1985

    International Nuclear Information System (INIS)

    Kolibal, J.; Ku, L.P.; Liew, S.L.; Pierce, C.

    1985-06-01

    This report reviews the first year of meteorological data gathered for the Tokamak Fusion Test Reactor (TFTR) at Princeton Plasma Physics Laboratory (PPPL) from March 1, 1984 to February 28, 1985. The meteorological station at TFTR is located at D-Site, to the east of the motor generator building as shown in Fig. 1. The station consists of a 60 m tower which is instrumented at 10, 30, and 60 m along with the associated equipment for data acquisition and logging. Instrumentation for the tower consists of measuring the temperature, wind speed, wind direction, dew point, and the standard deviation of the horizontal wind direction. The purpose of the station is to gather site specific meteorological data to assess atmospheric transport and dispersion for TFTR

  2. Evolution of the electron temperature profile of ohmically heated plasmas in TFTR

    International Nuclear Information System (INIS)

    Taylor, G.; Efthimion, P.C.; Arunasalam, V.

    1985-08-01

    Blackbody electron cyclotron emission was used to ascertain and study the evolution and behavior of the electron temperature profile in ohmically heated plasmas in the Tokamak Fusion Test Reactor (TFTR). The emission was measured with absolutely calibrated millimeter wavelength radiometers. The temperature profile normalized to the central temperature and minor radius is observed to broaden substantially with decreasing limiter safety factor q/sub a/, and is insensitive to the plasma minor radius. Sawtooth activity was seen in the core of most TFTR discharges and appeared to be associated with a flattening of the electron temperature profile within the plasma core where q less than or equal to 1. Two types of sawtooth behavior were identified in large TFTR plasmas (minor radius, a less than or equal to 0.8 m) : a typically 35 to 40 msec period ''normal'' sawtooth, and a ''compound'' sawtooth with 70 to 80 msec period

  3. 120-keV beam direct conversion system for TFTR injectors

    International Nuclear Information System (INIS)

    Hamilton, G.W.

    1976-01-01

    Several practical motivations exist for the development of beam direct conversion systems that are compatible with the injection systems of large experiments such as the Tokamak Fusion Test Reactor (TFTR). We present a preliminary design in which we analyze the most acute problems involved in scaling up existing designs and apparatus to fulfill TFTR requirements. Some of the questions addressed are the requirements for electron suppression, gas pumping, compactness, and power densities. A new idea is presented that allows for the handling of higher beam power. The gross savings in the capital cost of injector power supplies for the TFTR will be about $7.2 million, but the net savings will be somewhat less than this. This preliminary design has not yet revealed fundamental limitations with respect to the development of beam energy-recovery systems operating at high levels of current, voltage, and power densities

  4. TFTR neutral beam control and monitoring for DT operations

    International Nuclear Information System (INIS)

    O'Connor, T.; Kamperschroer, J.; Chu, J.

    1995-01-01

    Record fusion power output has recently been obtained in TFTR with the injection of deuterium and tritium neutral beams. This significant achievement was due in part to the controls, software, and data processing capabilities added to the neutral beam system for DT operations. Chief among these improvements was the addition of SUN workstations and large dynamic data storage to the existing Central Instrumentation Control and Data Acquisition (CICADA) system. Essentially instantaneous look back over the recent shot history has been provided for most beam waveforms and analysis results. Gas regulation controls allowing remote switchover between deuterium and tritium were also added. With these tools, comparison of the waveforms and data of deuterium and tritium for four test conditioning pulses quickly produced reliable tritium setpoints. Thereafter, all beam conditioning was performed with deuterium, thus saving the tritium supply for the important DT injection shots. The lookback capability also led to modifications of the gas system to improve reliability and to control ceramic valve leakage by backbiasing. Other features added to improve the reliability and availability of DT neutral beam operations included master beamline controls and displays, a beamline thermocouple interlock system, a peak thermocouple display, automatic gas inventory and cryo panel gas loading monitoring, beam notching controls, a display of beam/plasma interlocks, and a feedback system to control beam power based on plasma conditions

  5. Confinement studies of ohmically heated plasmas in TFTR

    International Nuclear Information System (INIS)

    Efthimion, P.C.; Bretz, N.L.; Bell, M.G.

    1985-03-01

    Systematic scans of density in large deuterium plasmas (a = 0.83 m) at several values of plasma current and toroidal magnetic field strength indicate that the total energy confinement time, tau/sub E/, is proportional to the line-average density anti n/sub e/ and the limiter q. Confinement times of approx. 0.3 s have been observed for anti n/sub e/ = 2.8 x 10 19 m -3 . Plasma size scaling experiments with plasmas of minor radii a = 0.83, 0.69, 0.55, and 0.41 m at constant limiter q reveal a confinement dependence on minor radius. The major-radius dependence of tau/sub E/, based on a comparison between TFTR and PLT results, is consistent with R 2 scaling. From the power balance, the thermal diffusivity chi/sub e/ is found to be significantly less than the INTOR value. In the a = 0.41 m plasmas, saturation of confinement is due to neoclassical ion conduction (chi/sub i/ neoclassical >> chi/sub e/)

  6. ICRF heating and current drive experiments on TFTR

    International Nuclear Information System (INIS)

    Rogers, J.H.; Hosea, J.C.; Phillips, C.K.

    1996-01-01

    Recent experiments in the Ion Cyclotron Range of Frequencies (ICRF) at TFTR have focused on the RF physics relevant to advanced tokamak D-T reactors. Experiments performed either tested confinement in reactor relevant plasmas or tested specific ICRF heating scenarios under consideration for reactors. H-minority heating was used to supply identical heating sources for matched D-T and D only L-mode plasmas to determine the species scaling for energy confinement. Second harmonic tritium heating was performed with only thermal tritium ions in an L-mode target plasma, verifying a possible start-up scenario for the International Thermonuclear Experimental Reactor (ITER). Direct electron heating in Enhanced Reverse Shear (ERS) plasmas has been found to delay the back transition out of the ERS state. D-T mode conversion of the fast magnetosonic wave to an Ion Berstein Wave (IBW) for off-axis heating and current drive has been successfully demonstrated for the first time. Parasitic Li 7 cyclotron damping limited the fraction of the power going to the electrons to less than 30%. Similar parasitic damping by Be 9 could be problematic in ITER. Doppler shifted fundamental resonance heating of beam ions and alpha particles has also been observed

  7. Operating experience with TFTR's Tritium Storage and Delivery System

    International Nuclear Information System (INIS)

    Voorhees, D.R.

    1995-01-01

    The Tritium Storage and Delivery System (TSDS) at TFTR was fabricated at Monsanto Mound Lab in the late 1970's and delivered to PPPL in the early 1980's. Commissioning progressed slowly and was finally completed in 1992 following a series of Preoperational tests and Integrated Systems tests. Those tests included thorough leak testing of glove boxes and process piping, electrical interlocks and controls, instrumentation calibrations, volume determinations and verification of uranium bed capacity. The system accepted tritium in dilute form in May of 1993 and began serious usage of pure tritium in November 1993. As the throughput of high purity tritium increased, shortcomings of the system became evident and extensive repairs were implemented. System leakage and material compatibility were the primary causes of the problems. To date, the system has received, stored and delivered over 500 kCi of tritium and is performing very well. The dedicated quadrupole mass spectrometer and beta scintillator system has been analyzing tritium bearing and pure gas streams for over 3 years with minimal downtime

  8. Cryogenic supplies for the TFTR neutral beam line cryopanels

    International Nuclear Information System (INIS)

    Pinter, G.

    1977-01-01

    Cryocondensing panels will be used for the Neutral Beam Lines of the TFTR to satisfy a pumping speed requirement of 2.5 x 10 6 l/s. The cryocondensing panels are fed by liquid helium (LHe), boiling at selectable temperatures of 4.5 0 K or 3.8 0 K. Liquid nitrogen (LN 2 ) panels and chevrons thermally shield the LHe panel. The closed-loop LHe supply system and the open loop LN 2 system are discussed. The helium refrigerator of minimum 1070-W capacity, together with its distribution system, and the nitrogen distribution system in the ton/hour LN 2 range is presented. Problems and their solutions in connection with the LHe system, including the distribution over a distance of 500 feet of large quantities of liquid/gas mixtures with load variations over the range of about 3 : 1, and the economies of various types of distribution lines (passive, pumped, shielded, combined), are described. The system design passed the preliminary phase. Design features and auxiliary equipment to assure dispersion of large quantities of nitrogen into the atmosphere and to permit operation under degraded cryogenic helium refrigerator performance are also discussed in Design Considerations

  9. TFTR 60 GHz alpha particle collective Thomson Scattering diagnostic

    International Nuclear Information System (INIS)

    Machuzak, J.S.; Woskov, P.P.; Gilmore, J.; Bretz, N.L.; Park, H.K.; Bindslev, H.

    1995-03-01

    A 60 GHz gyrotron collective Thomson Scattering alpha particle diagnostic has been implemented for the D-T period on TFM. Gyrotron power of 0.1-1 kW in pulses of up to 1 second can be launched in X-mode. Efficient corrugated waveguides are used with antennaes and vacuum windows of the TFTR Microwave Scattering system. A multichannel synchronous detector receiver system and spectrum analyzer acquire the scattered signals. A 200 Megasample/sec digitizer is used to resolve fine structure in the frequency spectrum. By scattering nearly perpendicular to the magnetic field, this experiment will take advantage of an enhancement of the scattered signal which results from the interaction of the alpha particles with plasma resonances in the lower hybrid frequency range. Significant enhancements are expected, which will make these measurements possible with gyrotron power less than 1 kW, while maintaining an acceptable signal to noise ratio. We hope to extract alpha particle density and velocity distribution functions from the data. The D and T fuel densities and temperatures may also be obtainable by measurement of the respective ion cyclotron harmonic frequencies

  10. Explosion potential of neutral-beam source cryopumps for TFTR

    International Nuclear Information System (INIS)

    Graham, W.G.; Lim, T.H.; Ruby, L.

    1977-12-01

    The explosion potential of the test cryopump became a paramount issue in the safety analysis required for the reactor experiment. The administrative limit for loading of the cryopump with normal hydrogen or deuterium is that amount of gas which will produce a partial pressure of 13 torr at a total pressure of 1 atmosphere, i.e., a 1.7% mixture by volume. At atmospheric pressure, combustion can occur for mixtures in the range 4.0 to 75%. It is important to know whether, in a leak-up-to-air accident, when the partial pressure will range from 100% to 1.7%, an explosion can occur. For the test cryopump (250l), loaded to the administrative limit, the energy of combustion would amount to 9.21 x 10 5 J, or 21.9 g of T.N.T. equivalent. However, for a TFTR beamline (73,000l), the corresponding numbers are 2.69 x 10 7 J, or 6.39 x 10 3 g of T.N.T. equivalent

  11. Pitch angle resolved measurements of escaping charged fusion products in TFTR

    International Nuclear Information System (INIS)

    Zweben, S.J.

    1989-01-01

    Measurements of the flux of charged fusion products escaping from the TFTR plasma have been made with a new type of detector which can resolve the particle flux vs. pitch angle, energy, and time. The design of this detector is described, and results from the 1987 TFTR run are presented. These results are roughly consistent with predictions from a simple first-orbit particle loss model with respect to the pitch angle, energy, time, and plasma current dependence of the signals. 11 refs., 9 figs

  12. Characteristics of radiated power for various TFTR [Tokamak Fusion Test Reactor] regimes

    International Nuclear Information System (INIS)

    Bush, C.E.; Schivell, J.; McNeill, D.H.

    1988-04-01

    Power loss studies were carried out to determine the impurity radiation and energy transport characteristics of various TFTR operation and confinement regimes including L-Mode, detached plasma, co-only neutral beam injection (energetic ion regime), and the enhanced confinement (''supershot'') regime. Combined bolometric, spectroscopic, and infrared photometry measurements provide a picture of impurity behavior and power accounting in TFTR. The purpose of this paper is to make a survey of the various regimes with the aim of determining the radiated power signatures of each. 10 refs., 6 figs., 1 tab

  13. Four-channel ZnS scintillator measurements of escaping tritons in TFTR

    International Nuclear Information System (INIS)

    Zweben, S.J.

    1988-10-01

    A four-channel scintillation detector capable of measuring tritons, protons, and alphas escaping from a tokamak plasma was operated during the 1986 run period of the Tokamak Fusion Test Reactor (TFTR). Signals consistent with the expected 1 MeV triton behavior have been observed during deuterium operation. Backgrounds associated with neutrons, gammas, and soft x-rays have been evaluated in situ. Such a detector should be capable of measuring escaping alphas during the D/T phase of TFTR. 16 refs., 10 figs

  14. Pitch angle resolved measurements of escaping charged fusion products in TFTR

    Energy Technology Data Exchange (ETDEWEB)

    Zweben, S.J.

    1989-01-01

    Measurements of the flux of charged fusion products escaping from the TFTR plasma have been made with a new type of detector which can resolve the particle flux vs. pitch angle, energy, and time. The design of this detector is described, and results from the 1987 TFTR run are presented. These results are roughly consistent with predictions from a simple first-orbit particle loss model with respect to the pitch angle, energy, time, and plasma current dependence of the signals. 11 refs., 9 figs.

  15. Four-channel ZnS scintillator measurements of escaping tritons in TFTR

    Energy Technology Data Exchange (ETDEWEB)

    Zweben, S.J.

    1988-10-01

    A four-channel scintillation detector capable of measuring tritons, protons, and alphas escaping from a tokamak plasma was operated during the 1986 run period of the Tokamak Fusion Test Reactor (TFTR). Signals consistent with the expected 1 MeV triton behavior have been observed during deuterium operation. Backgrounds associated with neutrons, gammas, and soft x-rays have been evaluated in situ. Such a detector should be capable of measuring escaping alphas during the D/T phase of TFTR. 16 refs., 10 figs.

  16. Feasability study of using the TFTR Thomson scattering system for q profile measurements

    International Nuclear Information System (INIS)

    Brizard, A.; Grewk, B.; Johnson, D.; LeBlanc, B.

    1986-01-01

    The results of a study made to determine the possibility of using the TFTR 76 channels Thomson scattering system to measure the direction of local magnetic fields in a tokamak plasma are presented. As this is a local measurement, this technique can in principle yield q profiles without the need of any de-convolution. The effect of the TFTR geometrical configuration and its various components on the expected measurement accuracy is discussed. The authors find that the measurement of q values within the inner half of the plasma should be possible, with only minor modification to the present TVTS system

  17. Fokker-Planck Modelling of Delayed Loss of Charged Fusion Products in TFTR

    International Nuclear Information System (INIS)

    Edenstrasser, J.W.; Goloborod'ko, V.Ya.; Reznik, S.N.; Yavorskij, V.A.; Zweben, S.

    1998-01-01

    The results of a Fokker-Planck simulation of the ripple-induced loss of charged fusion products in the Tokamak Fusion Test Reactor (TFTR) are presented. It is shown that the main features of the measured ''delayed loss'' of partially thermalized fusion products, such as the differences between deuterium-deuterium and deuterium-tritium discharges, the plasma current and major radius dependencies, etc., are in satisfactory agreement with the classical collisional ripple transport mechanism. The inclusion of the inward shift of the vacuum flux surfaces turns out to be necessary for an adequate and consistent explanation of the origin of the partially thermalized fusion product loss to the bottom of TFTR

  18. TFTR radiation contour and shielding efficiency measurements during D-D operations

    International Nuclear Information System (INIS)

    Kugel, H.W.; Ascione, G.; Elwood, S.; Gilbert, J.; Hwang, D.; Lewis, M.; Levine, J.; Ku, L.P.; Rule, K.; Hajnal, F.

    1994-11-01

    Extensive neutron and gamma radiation contour, shielding efficiency, and spectral measurements were performed during high power TFTR D-D operations at the tokamak Test Cell inner walls, ceiling, roof, and outer walls, in nearby control rooms, work areas, and personnel pathways, outdoors along the site fence at 125 m, and out to the nearest property lines at 180 m. The results confirmed that the efficiency of the basic radiation shielding was sufficient to allow the TFTR D-T experimental plan, and provide empirical guidance for simulating the radiation fields of future fusion reactors

  19. Review of recent D-T experiments from TFTR

    International Nuclear Information System (INIS)

    Hawryluk, R.J.; Adler, H.; Alling, P.; Ancher, C.; Anderson, H.; Anderson, J.W.; Arunasalam, V.; Ascione, G.; Ashcroft, D.; Barnes, G.; Bateman, G.

    1995-01-01

    An extensive set of deuterium-tritium (D-T) experiments has been carried out on the Tokamak Fusion Test Reactor (TFTR), using nearly equal concentrations of deuterium and tritium. The fusion power has been increased to 9.3 MW, using 34 MW of neutral-beam heating, in a supershot discharge and to 6.7 MW in a high-pp discharge following a current rampdown. Extensive lithium pellet injection has increased the confinement time to 0.27 s and enabled higher current operation in both supershot and high-pp discharges. The energy confinement time, τ E , was observed to increase in D-T, relative to D plasmas, by 20% and the n i (0)Ti(0)τ E product by 55%. The improvement in thermal confinement was caused primarily by a decrease in ion heat conductivity in both supershot and limiter-H-mode discharges. ICRF heating of a D-T plasma, using the second harmonic of tritium, has been demonstrated. First measurements of the confined alpha particles have been performed and found to be in good agreement with TRANSP simulations. Initial measurements of the alpha ash profile have been compared with simulations using particle transport coefficients from He gas puffing experiments. The loss of alpha particles to a detector at the bottom of the vessel is well described by the first-orbit loss mechanism. No loss due to alpha-particle-driven instabilities has yet been observed. The TFIR experiments were able to challenge and confirm several of the underlying assumptions of the ITER design

  20. High-Q plasmas in the TFTR tokamak

    International Nuclear Information System (INIS)

    Jassby, D.L.; Barnes, C.W.; Bell, M.G.; Bitter, M.; Boivin, R.; Bretz, N.L.; Budny, R.V.; Bush, C.E.; Dylla, H.F.; Efthimion, P.C.; Fredrickson, E.D.; Hawryluk, R.J.; Hill, K.W.; Hosea, J.; Hsuan, H.; Janos, A.C.; Jobes, F.C.; Johnson, D.W.; Johnson, L.C.; Kamperschroer, J.; Kieras-Phillips, C.; Kilpatrick, S.J.; LaMarche, P.H.; LeBlanc, B.; Mansfield, D.K.; Marmar, E.S.; McCune, D.C.; McGuire, K.M.; Meade, D.M.; Medley, S.S.; Mikkelsen, D.R.; Mueller, D.; Owens, D.K.; Park, H.K.; Paul, S.F.; Pitcher, S.; Ramsey, A.T.; Redi, M.H.; Sabbagh, S.A.; Scott, S.D.; Snipes, J.; Stevens, J.; Strachan, J.D.; Stratton, B.C.; Synakowski, E.J.; Taylor, G.; Terry, J.L.; Timberlake, J.R.; Towner, H.H.; Ulrickson, M.; von Goeler, S.; Wieland, R.M.; Williams, M.; Wilson, J.R.; Wong, K.; Young, K.M.; Zarnstorff, M.C.; Zweben, S.J.

    1991-01-01

    In the Tokamak Fusion Test Reactor (TFTR) [Plasma Phys. Controlled Fusion 26, 11 (1984)], the highest neutron source strength S n and D--D fusion power gain Q DD are realized in the neutral-beam-fueled and heated ''supershot'' regime that occurs after extensive wall conditioning to minimize recycling. For the best supershots, S n increases approximately as P 1.8 b . The highest-Q shots are characterized by high T e (up to 12 keV), T i (up to 34 keV), and stored energy (up to 4.7 MJ), highly peaked density profiles, broad T e profiles, and lower Z eff . Replacement of critical areas of the graphite limiter tiles with carbon-fiber composite tiles and improved alignment with the plasma have mitigated the ''carbon bloom.'' Wall conditioning by lithium pellet injection prior to the beam pulse reduces carbon influx and particle recycling. Empirically, Q DD increases with decreasing pre-injection carbon radiation, and increases strongly with density peakedness [n e (0)/left-angle n e right-angle] during the beam pulse. To date, the best fusion results are S n =5x10 16 n/sec, Q DD =1.85x10 -3 , and neutron yield=4.0x10 16 n/pulse, obtained at I p =1.6--1.9 MA and beam energy E b =95--103 keV, with nearly balanced co- and counter-injected beam power. Computer simulations of supershot plasmas show that typically 50%--60% of S n arises from beam--target reactions, with the remainder divided between beam--beam and thermonuclear reactions, the thermonuclear fraction increasing with P b

  1. High speed, locally controlled data acquisition system for TFTR

    International Nuclear Information System (INIS)

    Feng, H.K.; Bradish, G.J.

    1983-01-01

    A high speed, locally controlled, data acquisition and transmission system has been developed by the CICADA (Central Instrumentation Control and Data Acquisition) Group for extracting certain timecritical data during a TFTR pulse and passing it to the control room, 1000 feet distant, to satisfy realtime requirements of frequently sampled variables. The system is designed to utilize any or all of the standard CAMAC (Computer Automated Measurement and Control) modules now employed on the CAMAC links for retrieval of the main body of data, but to operate them in a much faster manner than in a standard CAMAC system. To do this, a pre-programmable ROM sequencer is employed as a controller to transmit commands to the modules at intervals down to one microsecond, replacing the usual CAMAC dedicated computer, and increasing the command rate by an order of magnitude over what could be sent down a Branch Highway. Data coming from any number of channels originating within a single CAMAC ''crate'' is then time-multiplexed and transmitted over a single conductor pair in bi-phase at a 2.5 MHz bit rate using Manchester coding techniques. Benefits gained from this approach include: Reduction in the number of conductors required, elimination of line-to-line skew found in parallel transmission systems, and the capability of being transformer coupled or transmitted over a fiber optic cable to avoid safety hazards and ground loops. The main application for this system so far has been as the feedback path in this closed loop control of currents through the Tokamak's field coils. The paper will treat the system's various applications

  2. Measurements of charged fusion product diffusion in TFTR

    Energy Technology Data Exchange (ETDEWEB)

    Boivin, R.L.

    1991-12-01

    The single particle confinement of charged fusion products, namely the 1 MeV triton and the 3 MeV proton, has been studied using a detector located near the outer midplane of TFTR. The detector, which measure the flux of escaping particles, is composed of a scintillator (ZnS(Ag)) and a system of collimating apertures, which permit pitch angle, energy and time resolution. It is mounted on a movable probe which can be inserted 25 cm into the vacuum vessel. Measurements indicate a level of losses higher than expected from a first-orbit loss mechanism alone. The primary candidate for explaining the observed anomalous losses is the toroidal field (TF) stochastic ripple diffusion, theoretically discovered by Goldston, White and Boozer. This loss mechanism is expected to be localized near the outer midplane where, at least at high current ({approx gt} 1.0 MA) it would locally dominate over first-orbit losses. Calculations made with a mapping particle orbit code (MAPLOS) show a semi-quantitative agreement with the measurements. The predominant uncertainties in the numerical simulations were found to originate from the modeling of the first wall geometry and also from the assumed plasma current and source profiles. Direct measurements of the diffusion rate were performed by shadowing the detector with a second movable probe used as an obstacle. The diffusion rate was also measured by moving the detector behind the radius of the RF limiters, located on the outer wall. Comparisons of these experimental results with numerical simulations, which include diffusive mechanisms, indicate a quantitative agreement with the TF stochastic ripple diffusion model.

  3. Measurements of charged fusion product diffusion in TFTR

    Energy Technology Data Exchange (ETDEWEB)

    Boivin, Rejean Louis [Princeton Univ., NJ (United States)

    1991-12-01

    The single particle confinement of charged fusion products, namely the 1 MeV triton and the 3 MeV proton, has been studied using a detector located near the outer midplane of TFTR. The detector, which measure the flux of escaping particles, is composed of a scintillator [ZnS(Ag)] and a system of collimating apertures, which permit pitch angle, energy and time resolution. It is mounted on a movable probe which can be inserted 25 cm into the vacuum vessel. Measurements indicate a level of losses higher than expected from a first-orbit loss mechanism alone. The primary candidate for explaining the observed anomalous losses is the toroidal field (TF) stochastic ripple diffusion, theoretically discovered by Goldston, White and Boozer. This loss mechanism is expected to be localized near the outer midplane where, at least at high current (≳ 1.0 MA) it would locally dominate over first-orbit losses. Calculations made with a mapping particle orbit code (MAPLOS) show a semi-quantitative agreement with the measurements. The predominant uncertainties in the numerical simulations were found to originate from the modeling of the first wall geometry and also from the assumed plasma current and source profiles. Direct measurements of the diffusion rate were performed by shadowing the detector with a second movable probe used as an obstacle. The diffusion rate was also measured by moving the detector behind the radius of the RF limiters, located on the outer wall. Comparisons of these experimental results with numerical simulations, which include diffusive mechanisms, indicate a quantitative agreement with the TF stochastic ripple diffusion model.

  4. Measurements of charged fusion product diffusion in TFTR

    International Nuclear Information System (INIS)

    Boivin, R.L.

    1991-12-01

    The single particle confinement of charged fusion products, namely the 1 MeV triton and the 3 MeV proton, has been studied using a detector located near the outer midplane of TFTR. The detector, which measure the flux of escaping particles, is composed of a scintillator [ZnS(Ag)] and a system of collimating apertures, which permit pitch angle, energy and time resolution. It is mounted on a movable probe which can be inserted 25 cm into the vacuum vessel. Measurements indicate a level of losses higher than expected from a first-orbit loss mechanism alone. The primary candidate for explaining the observed anomalous losses is the toroidal field (TF) stochastic ripple diffusion, theoretically discovered by Goldston, White and Boozer. This loss mechanism is expected to be localized near the outer midplane where, at least at high current (approx-gt 1.0 MA) it would locally dominate over first-orbit losses. Calculations made with a mapping particle orbit code (MAPLOS) show a semi-quantitative agreement with the measurements. The predominant uncertainties in the numerical simulations were found to originate from the modeling of the first wall geometry and also from the assumed plasma current and source profiles. Direct measurements of the diffusion rate were performed by shadowing the detector with a second movable probe used as an obstacle. The diffusion rate was also measured by moving the detector behind the radius of the RF limiters, located on the outer wall. Comparisons of these experimental results with numerical simulations, which include diffusive mechanisms, indicate a quantitative agreement with the TF stochastic ripple diffusion model

  5. Studies of the permeation and diffusion of tritium and hydrogen in TFTR

    International Nuclear Information System (INIS)

    Garber, H.J.

    1975-10-01

    This report documents the main features of studies conducted on the permeation and diffusion of tritium and hydrogen through the stainless steel sections comprising the vacuum vessel of TFTR. The overall conclusion of these studies is that tritium releases to the environment resulting from TFTR operations under normal conditions will be very small, less than one curie per year. A basis is described for predicting the magnitudes of the applicable transport properties for tritium-austenitic stainless steel systems as derived from a survey of the technical literature on tritium transport. The key characteristics of the TFTR vacuum vessel that are involved in the permeation and diffusion calculations are given. Information is given regarding the contemplated plasma scenarios and associated required gas injection quantities. Various issues involved in the bakeout of the vacuum vessel are discussed; focussing principally on the problems associated with in-situ bakeout and related means to reduce outgassing from the TFTR vessel and vacuum pumping system hardware. The anticipated tritium releases are studied considering the diffusion transients

  6. Facility for the testing of the TFTR prototype neutral beam injector

    Energy Technology Data Exchange (ETDEWEB)

    Haughian, J.M.

    1977-07-01

    The design of the prototype neutral beam injection system for TFTR is nearing completion at the Lawrence Livermore Laboratory. This paper describes some of the features of the facility at the Lawrence Berkeley Laboratory where this prototype will be assembled and tested.

  7. Facility for the testing of the TFTR prototype neutral beam injector

    International Nuclear Information System (INIS)

    Haughian, J.M.

    1977-07-01

    The design of the prototype neutral beam injection system for TFTR is nearing completion at the Lawrence Livermore Laboratory. This paper describes some of the features of the facility at the Lawrence Berkeley Laboratory where this prototype will be assembled and tested

  8. Transport simulations TFTR: Theoretically-based transport models and current scaling

    International Nuclear Information System (INIS)

    Redi, M.H.; Cummings, J.C.; Bush, C.E.; Fredrickson, E.; Grek, B.; Hahm, T.S.; Hill, K.W.; Johnson, D.W.; Mansfield, D.K.; Park, H.; Scott, S.D.; Stratton, B.C.; Synakowski, E.J.; Tang, W.M.; Taylor, G.

    1991-12-01

    In order to study the microscopic physics underlying observed L-mode current scaling, 1-1/2-d BALDUR has been used to simulate density and temperature profiles for high and low current, neutral beam heated discharges on TFTR with several semi-empirical, theoretically-based models previously compared for TFTR, including several versions of trapped electron drift wave driven transport. Experiments at TFTR, JET and D3-D show that I p scaling of τ E does not arise from edge modes as previously thought, and is most likely to arise from nonlocal processes or from the I p -dependence of local plasma core transport. Consistent with this, it is found that strong current scaling does not arise from any of several edge models of resistive ballooning. Simulations with the profile consistent drift wave model and with a new model for toroidal collisionless trapped electron mode core transport in a multimode formalism, lead to strong current scaling of τ E for the L-mode cases on TFTR. None of the theoretically-based models succeeded in simulating the measured temperature and density profiles for both high and low current experiments

  9. Plasma-wall interaction: Recent TFTR results and implications on design and construction of limiters

    International Nuclear Information System (INIS)

    Owens, D.K.; Ulrickson, M.A.

    1987-01-01

    The first wall of the Tokamak Fusion Test Reactor (TFTR) consists of a water cooled toroidal belt limiter, a cooled moveable limiter, and cooled protective plates to shield the vacuum vessel from neutral beam shinethrough. Each of these systems consists of Inconel support plates covered with graphite tiles. In addition, there are Inconel and stainless steel bellows cover plates to protect the bellows and the surface pumping system which provides enhanced pumping in the torus and also serves to protect the bellows. These systems are described and the design requirements, simulations and actual thermal and mechanical loads reviewed. The normal and off-normal operating conditions which were considered in the design of the TFTR components include thermal loading during normal and disruptive plasma operation, eddy-current induced mechanical forces and arcing. The failures which have occurred are generally associated with thermal stress rather than mechanical failure due to disruption induced eddy currents. The models which were developed to design the TFTR hardware appear to have worked well as the performance of these systems has generally been satisfactory at loads approaching design limits. The implications of the TFTR experience for reactor design are discussed

  10. Measurement of ion profiles in TFTR neutral beamlines

    International Nuclear Information System (INIS)

    Kamperschroer, J.H.; Grisham, L.R.; Kugel, H.W.; O'Connor, T.E.; Stevenson, T.N.; von Halle, A.; Williams, M.D.

    1992-02-01

    A technique is described whereby the ion dumps inside the TFTR Neutral Beam Test Stand were used to measure thermal profiles of the full-, half-, and third-energy ions. 136 thermocouples were installed on the full-energy ion dump, allowing full beam contours. Additional linear arrays across the widths of the half- and third-energy ion dumps provided a measure of the shape, in the direction parallel to the grid rails, of the half- and third-energy ions, and, hence, of the molecular ions extracted from the source. As a result of these measurements it was found that the magnet was more weakly focusing, by a factor of two, than expected, explaining past overheating of the full-energy ion dump. Hollow profiles on the half- and third-energy ion dumps were observed, suggesting that extraction of D 2 + and D 3 + are primarily from the edge of the ion source. If extraction of half-energy ions is from the edge of the accelerator, a divergence parallel to the grid rails of 0.6 degrees ±0.1 degrees results. It is postulated that a nonuniform gas profile near the accelerator is the cause of the hollow partial-energy ion profiles; the pressure being depressed over the accelerator by particles passing through this highly transparent structure. Primary electrons reaching the accelerator produce nonuniform densities of D 2 + through the ionization of this across the full-energy dump was examined as a means of reducing the power density. By unbalancing the current in the two coils of the magnet, on a shot by shot basis, by up to 2:1 ratio, it was possible to move the centerline of the full-energy ion beam sideways by ∼12.5 cm. The adoption of such a technique, with a ramp of the coil imbalance from 2:1 to 1:2 over a beam pulse, could reduce the power density by a factor of ≥1.5

  11. Confinement studies of neutral beam heated discharges in TFTR

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, M.; Arunasalam, V.; Bell, J.D.; Stauffer, F.; Bell, M.G.; Bitte, M.; Blanchard, W.R.; Boody, F.; Britz, N.

    1985-11-01

    The TFTR tokamak has reached its original machine design specifications (I/sub p/ = 2.5 MA and B/sub T/ = 5.2T). Recently, the D/sup 0/ neutral beam heating power has been increased to 6.3 MW. By operating at low plasma current (I/sub p/ approx. = 0.8 MA) and low density anti n/sub e/ approx. = 1 x 10/sup 19/m/sup -3/), high ion temperatures (9 +- keV) and rotation speeds (7 x 10/sup 5/ m/s) have been achieved during injection. At the opposite extreme, pellet injection into high current plasmas has been used to increase the line-average density to 8 x 10/sup 19/m/sup -3/ and the central density to 1.6 x 10/sup 20/m/sup -3// This wide range of operating conditions has enabled us to conduct scaling studies of the global energy confinement time in both ohmically and beam heated discharges as well as more detailed transport studies of the profile dependence. In ohmic discharges, the energy confinement time is observed to scale linearly with density only up to anti n/sub e/ approx. 4.5 x 10/sup 19/m/sup -3/ and then to increase more gradually, achieving a maximum value of approx. 0.45 s. In beam heated discharges, the energy confinement time is observed to decrease with beam power and to increase with plasma current. With P/sub b/ = 5.6 MW, anti n/sub e/ = 4.7 x 10/sup 19/m/sup -3/, I/sub p/ = 2.2 MA and B/sub T = 4.7T, the gross energy confinement time is 0.22 s and T/sub i/(0) = 4.8 keV. Despite shallow penetration of D/sup 0/ beams (at the beam energy less than or equal to 80 keV with low species yield), tau/sub E/(a) values are as large as those for H/sup 0/ injection, but central confinement times are substantially greater. This is a consequence of the insensitivity of the temperature and safety factor profile shapes to the heating profile. The radial variation of tau/sub E/ is even more pronounced with D/sup 0/ injection into high density pellet-injected plasmas. 25 refs.

  12. Deuterium-tritium TFTR plasmas in the high poloidal beta regime

    International Nuclear Information System (INIS)

    Sabbagh, S.A.; Mauel, M.E.; Navratil, G.A.

    1995-03-01

    Deuterium-tritium plasmas with enhanced energy confinement and stability have been produced in the high poloidal beta, advanced tokamak regime in TFTR. Confinement enhancement H triple-bond τ E /τ E ITER-89P > 4 has been obtained in a limiter H-mode configuration at moderate plasma current I p = 0.85 - 1.46 MA. By peaking the plasma current profile, β N dia triple-bond 10 8 tperpendicular > aB 0 /I p = 3 has been obtained in these plasma,s exceeding the β N limit for TFTR plasmas with lower internal inductance, l i . Fusion power exceeding 6.7 MW with a fusion power gain Q DT = 0.22 has been produced with reduced alpha particle first orbit loss provided by the increased l i

  13. New Monte Carlo results for the TFTR/Lithium Blanket Module system

    International Nuclear Information System (INIS)

    Engholm, B.A.

    1985-01-01

    Neutronics analysis results from Phase II of the TFTR Lithium Blanket Module (LBM) program are reported. Principal activities were analyses of new coverplate and protective plate designs; updating of the MCNP Monte Carlo model of TFTR/LBM; and performing new reference calculations for D-D and D-T plasmas. The new protective plate was found to reduce LBM responses by 20%. Updating the model included a new tally structure in which the LBM is divided into 92 volume elements corresponding to foil locations. A new version of the MCNP surface-source routine was used, along with the latest pointwise cross sections. All flux, tritium and foil responses are stored at NMFECC and are available for comparison with measurements, when the experimental program gets underway

  14. Special remote tooling developed and utilized to tighten TFTR TF coil casing bolts

    International Nuclear Information System (INIS)

    Burgess, T.W.; Walton, G.R.; Meighan, T.G.; Paul, B.L.

    1993-01-01

    Special tooling has been developed and used to tighten toroidal field (TF) coil casing bolts that have loosened from years of Tokamak Fusion Test Reactor (TFTR) operation. Due to their location, many of the TF casing bolts cannot be directly accessed or viewed; their condition was first discovered during unrelated inspections in 1988. Engineering solutions were, sought until 1992, when a remotely operated wrench concept was successfully demonstrated on a TF coil mockup. The concept was developed into several working tools that have successfully been applied to tighten several thousand TF casing bolts during recent scheduled outages. This effort has improved the integrity and reliability of the TF coil system in preparing for the final experimental phase of the TFTR. This paper discusses the design and application of this tooling

  15. TFTR neutral beam D-T gas injection system operational experiences of the first two years

    International Nuclear Information System (INIS)

    Oldaker, M.E.; Lawson, J.E.; Stevenson, T.N.; Kamperschroer, J.H.

    1995-01-01

    The TFTR Neutral Beam Tritium Gas Injection System (TGIS) has successfully performed tritium operations since December 1993. TGIS operation has been reliable, with no leaks to the secondary containment to date. Notable operational problems include throughput leaks on fill, exit and piezoelectric valves. Repair of a TGIS requires replacement of the assembly, involving TFTR downtime and extensive purging, since the TGIS assembly is highly contaminated with residual tritium, and is located within secondary containment. Modifications to improve reliability and operating range include adjustable reverse bias voltage to the piezoelectric valves, timing and error calculation changes to tune the PLC and hardwired timing control, and exercising piezoelectric valves without actually pulsing gas prior to use after extended inactivity. A pressure sensor failure required the development of an open loop piezoelectric valve drive control scheme, using a simple voltage ramp to partially compensate for declining plenum pressure. Replacement of TGIS's have been performed, maintaining twelve system tritium capability as part of scheduled project maintenance activity

  16. Theory-based transport simulations of TFTR L-mode temperature profiles

    International Nuclear Information System (INIS)

    Bateman, G.

    1991-01-01

    The temperature profiles from a selection of TFTR L-mode discharges are simulated with the 1-1/2-D BALDUR transport code using a combination of theoretically derived transport models, called the Multi-Mode Model. The present version of the Multi-Mode Model consists of effective thermal diffusivities resulting from trapped electron modes and ion temperature gradient (η i ) modes, which dominate in the core of the plasma, together with resistive ballooning modes, which dominate in the periphery. Within the context of this transport model and the TFTR simulations reported here, the scaling of confinement with heating power comes from the temperature dependence of the η i and trapped electron modes, while the scaling with current comes mostly from resistive ballooning modes. 24 refs., 16 figs., 3 tabs

  17. In-situ calibration of TFTR [Tokamak Fusion Test Reactor] neutron detectors

    International Nuclear Information System (INIS)

    Hendel, H.W.; Palladino, R.W.; Barnes, C.W.; Diesso, M.; Felt, J.S.; Jassby, D.L.; Johnson, L.C.; Ku, L.P.; Liu, Q.P.; Motley, R.W.; Murphy, H.B.; Murphy, J.; Nieschmidt, E.B.; Roberts, J.A.; Saito, T.; Strachan, J.D.; Waszazak, R.J.; Young, K.

    1990-03-01

    We report results of the TFTR fission detector calibration performed in December 1988. A NBS-traceable, remotely controlled 252 Cf neutron source was moved toroidally through the TFTR vacuum vessel. Detection efficiencies for two 235 U detectors were measured for 930 locations of the neutron point source in toroidal scans at 16 different major radii and vertical heights. These scans effectively simulated the volume-distributed plasma neutron source, and the volume-integrated detection efficiency was found to be insensitive to plasma position. The Campbell mode is useful due to its large overlap with the count rate mode and large dynamic range. The resulting absolute plasma neutron source calibration has an uncertainty of ± 13%. 21 refs., 23 figs., 4 tabs

  18. Simulation of α-particle redistribution due to sawteeth on TFTR

    International Nuclear Information System (INIS)

    Yi Zhao; White, R.B.

    1996-01-01

    In recent Deuterium-Tritium experiments on the Tokamak Fusion Test Reactor (TFTR), both the Pellet Charge Exchange (PCX) and the alpha Charge Exchange Recombination Spectroscopy (α-CHERS) diagnostics indicate that sawtooth oscillations can cause significant broadening of the fusion alpha radial density profile. The authors investigate this sawtooth mixing phenomenon by applying a Hamiltonian guiding center approach. A model of time evolution of the Kadomtsev-type sawtooth is constructed. The presence of more than one mode in the nonlinear stage of the sawtooth crash is necessary to cause significant broadening of the alpha density profile. Use of numerical equilibria allows us to perform detailed comparisons with TFTR experimental data. The results are in reasonable agreement with α-CHERS and show a broadening of alpha particles similar to that seen in PCX measurements

  19. Study of optically thin electron cyclotron emission from TFTR using a Michelson interferometer

    International Nuclear Information System (INIS)

    Stauffer, F.J.; Boyd, D.A.

    1986-01-01

    The TFTR Michelson interferometer, which is used as an electron temperature diagnostic, has a spectral range of 75-540 GHz. This range is adequate for measuring at least the first three cyclotron harmonics, and it spans both optically thick and thin portions of the ECE spectrum. During the most recent opening of the TFTR vacuum vessel, a concave, carbon reflector was installed on the back wall of the vessel, opposite the light collecting optic of the Michelson system. The reflector is designed to prevent the observation of optically thin ECE that originates from a location that is outside the field of view of the light collecting optic. If this is achieved, it should be possible to derive the electron density profile from measurements of either the extraordinary mode third harmonic or the ordinary mode second harmonic. An analysis of ECE spectra that have been measured before and after installation of the reflector is presented

  20. Analysis of erosion and transport of carbon impurity in the TFTR inner bumper limiter region

    International Nuclear Information System (INIS)

    Hua, T.Q.; Brooks, J.N.

    1992-01-01

    Carbon sputtering and transport on the TFTR inner graphite bumper limiter is investigated with the impurity transport code REDEP. Analysis is carried out for a series of ohmic discharges in TFTR. Predictions for Z eff in the core plasma agree well with in-situ experimental measurements. Run-away self-sputtering of carbon is predicted at low densities and high edge plasma temperatures when the limiter surface was purged of deuterium. Surface erosion and deposition is analyzed. In general, redeposition reduces the peak erosion by about a factor of five. Analysis is also carried out for a typical neutral beam heated discharge with a noncircular plasma. Spatial surface erosion and deposition profiles are compared qualitatively with beta backscattering measurements of metal deposition found on the limiter

  1. Tritium processing and management during D-T experiments on TFTR

    International Nuclear Information System (INIS)

    La Marche, P.H.; Anderson, J.L.; Gentile, C.A.; Hawryluk, R.J.; Hosea, J.; Kalish, M.; Kozub, T.; Murray, H.; Nagy, A.; Raftopoulos, S.

    1994-11-01

    TFTR performance has surpassed many of the previous tokamak records. This has been made possible by the use of tritium as fuel for DT plasma discharges. Stable operations of tritium systems provide for safe, routine DT operation of TFTR. In the preparation for DT operation, in the commissioning of the tritium systems and in the operation of the Nuclear Facility several key lessons have been learned. They include: the facility must take the lead in interpreting the applicable regulations and orders and then seek regulator approval; the use of ultra high vacuum technology in tritium system design and construction simplifies and enhances operations and maintenance; and central facility control under a single supervisory position is crucial to safely orchestrate operational and maintenance activities

  2. Enhanced D-T supershot performance at high current using extensive lithium conditioning in TFTR

    International Nuclear Information System (INIS)

    Mansfield, D.K.; Strachan, J.D.; Bell, M.G.; Scott, S.D.; Budny, R.; Bell, R.E.; Bitter, M.; Darrow, D.S.; Fredrickson, E.; Grek, B.

    1995-05-01

    A substantial improvement in supershot fusion plasma performance has been realized by combining the enhanced confinement due to tritium fueling with the enhanced confinement due to extensive Li conditioning of the TFTR limiter. This combination has resulted in not only significantly higher global energy confinement times than had previously been obtained in high current supershots, but also the highest ratio of central fusion output power to input power observed to date

  3. Expansion of parameter space for Toroidal Alfven Eigenmode experiments in TFTR

    International Nuclear Information System (INIS)

    Wong, K.L.; Wilson, J.R.; Chang, Z.Y.; Fredrickson, E.; Hammett, G.W.; Bush, C.; Nazikian, R.; Phillips, C.K.; Snipes, J.; Taylor, G.

    1993-05-01

    Several techniques were used to excite toroidal Alfven Eigenmodes in the Tokamak Fusion Test Reactor (TFTR) at magnetic fields above 10 kG. These involve pellet injection to raise the plasma density, variation of plasma current to change the energetic ion orbit and the q-profile, and ICRF heating to produce energetic hydrogen ions at velocities comparable to 3.5 MeV alpha particles. These experimental results are presented and relevance to fusion reactors are discussed

  4. Analysis of momentum and impurity confinement in TFTR. [Annual report, 1989

    Energy Technology Data Exchange (ETDEWEB)

    1988-12-31

    The accomplishments to date of this research in collaboration with PPPL are the following: (1) full access capability to the TFTR data system has been achieved at Georgia Tech; (2) procedures to enable PPPL codes to be used in conjunction with ``in house`` programs for data analysis have been developed; (3) evaluation of the experimental data has been performed; and (4) a preliminary comparison of several momentum transport theories against experimental measurements has been performed.

  5. Design and fabrication of an ion accelerator for TFTR-type neutral beam systems

    International Nuclear Information System (INIS)

    Paterson, J.A.; Duffy, T.J.; Haughian, J.M.; Biagi, L.A.; Yee, D.P.

    1977-10-01

    The design of the prototype 120-keV, 65-A, 0.5-sec ion accelerator for TFTR-type beam systems is described. Details of the manufacture of the constituent parts are given along with descriptions of the major components of the accelerator. Included are the molybdenum grid structures, molybdenum shields, stainless steel hats and the epoxy insulator. Specific manufacturing problems are discussed along with the results of tests to determine the voltage holding capabilities of the assembly

  6. Construction of the facility for the testing of the TFTR Neutral Beam Injector

    International Nuclear Information System (INIS)

    Haughian, J.; Lou, K.; Roth, D.

    1979-11-01

    The prototype for the TFTR Neutral Beam Injection System has been assembled at the Lawrence Berkeley Laboraory, and is presently under test. Some of the construction features of the shielding enclosure, the cryogenic supply system, control and computer area, and the auxiliary vacuum and utility supply system are described. In addition, the paper describes the target chamber, its beam dump and cryopanels, and the duct that connects the target chamber to the injector vessel

  7. Assessment of eddy current effects on compression experiments in the TFTR tokamak

    International Nuclear Information System (INIS)

    Wong, K.L.; Park, W.

    1986-05-01

    The eddy current induced on the TFTR vacuum vessel during compression experiments is estimated based on a cylindrical model. It produces an error magnetic field that generates magnetic islands at the rational magnetic surfaces. The widths of these islands are calculated and found to have some effect on electron energy confinement. However, resistive MHD simulation results indicate that the island formation process can be slowed down by plasma rotation

  8. Fusion reactivity, confinement, and stability of neutral-beam heated plasmas in TFTR and other tokamaks

    International Nuclear Information System (INIS)

    Park, Hyeon, K.

    1996-05-01

    The hypothesis that the heating beam fueling profile shape connects the edge condition and improved core confinement and fusion reactivity is extensively studied on TFTR and applied to other tokamaks. The derived absolute scalings based on beam fueling profile shape for the stored energy and neutron yield can be applied to the deuterium discharges at different major radii in TFTR. These include Supershot, High poloidal beta, L-mode, and discharges with a reversed shear (RS) magnetic configuration. These scalings are also applied to deuterium-tritium discharges. The role of plasma parameters, such as plasma current, Isdo2(p), edge safety factor, qsdo5(a), and toroidal field, Bsdo2(T), in the performance and stability of the discharges is explicitly studied. Based on practical and externally controllable plasma parameters, the limitation and optimization of fusion power production of the present TFTR is investigated and a path for a discharge condition with fusion power gain, Q > 1 is suggested based on this study. Similar physics interpretation is provided for beam heated discharges on other major tokamaks

  9. MSC/NASTRAN ''expert'' techniques developed and applied to the TFTR poloidal field coils

    International Nuclear Information System (INIS)

    O'Toole, J.A.

    1986-01-01

    The TFTR poloidal field (PF) coils are being analyzed by PPPL and Grumman using MSC/NASTRAN as a part of an overall effort to establish the absolute limiting conditions of operation for TFTR. Each of the PF coils will be analyzed in depth, using a detailed set of finite element models. Several of the models developed are quite large because each copper turn, as well as its surrounding insulation, was modeled using solid elements. Several of the finite element models proved large enough to tax the capabilities of the National Magnetic Fusion Energy Computer Center (NMFECC), specifically disk storage space. To allow the use of substructuring techniques with their associated data bases for the larger models, it became necessary to employ certain infrequently used MSC/NASTRAN ''expert'' techniques. The techniques developed used multiple data bases and data base sets to divide each problem into a series of computer runs. For each run, only the data required was kept on active disk space, the remainder being placed in inactive ''FILEM'' storage, thus, minimizing active disk space required at any time and permitting problem solution using the NMFECC. A representative problem using the TFTR OH-1 coil global model provides an example of the techniques developed. The special considerations necessary to obtain proper results are discussed

  10. Estimated neutron-activation data for TFTR. Part II. Biological dose rate from sample-materials activation

    International Nuclear Information System (INIS)

    Ku, L.; Kolibal, J.G.

    1982-06-01

    The neutron induced material activation dose rate data are summarized for the TFTR operation. This report marks the completion of the second phase of the systematic study of the activation problem on the TFTR. The estimations of the neutron induced activation dose rates were made for spherical and slab objects, based on a point kernel method, for a wide range of materials. The dose rates as a function of cooling time for standard samples are presented for a number of typical neutron spectrum expected during TFTR DD and DT operations. The factors which account for the variations of the pulsing history, the characteristic size of the object and the distance of observation relative to the standard samples are also presented

  11. Parametric analysis of neutron streaming through major penetrations in the 0.914 m TFTR test cell floor

    International Nuclear Information System (INIS)

    Ku, L.P.; Liew, S.L.; Kolibal, J.G.

    1985-09-01

    Neutron streaming through penetrations in the 0.914 m TFTR test cell floor has two distinct features: (1) the oblique angle of incidence; and (2) the high order of anisotropy in the angular distribution for incident neutrons with energies > 10 keV. The effects of these features on the neutron streaming into the TFTR basement were studied parametrically for isolated penetrations. Variations with respect to the source energies, angular distributions, and sizes of the penetrations were made. The results form a data base from which the spatial distribution of the neutron flux in the basement due to multiple penetrations may be evaluated

  12. Analysis of electron cyclotron emission spectra of high electron temperature, supershot plasmas in TFTR

    International Nuclear Information System (INIS)

    Taylor, G.; Arunasalam, V.; Efthimion, P.C.; Grek, B.

    1993-01-01

    A primary objective of the TFTR program since 1986 has been the study and optimization of deuterium Supershot plasmas. These plasmas are predominantly heated by 90-110 keV neutral deuterium beams (P NBI /P OH >30), central ion temperatures are ∝30 keV and central electron temperatures from ECE (T ECE ) often exceed 10 keV. Central electron temperature data measured with a TV Thomson scattering (TVTS) system (T TVTS ) during the period 1987-1990 have been compared with data from three different ECE instruments on TFTR. Although T ECE ∝T TVTS for temperatures below 6 keV, there is a systematically increasing disagreement at higher electron temperatures, with T ECE ∝1.2 T TVTS for T TVTS in the range 9-10 keV. Recent theoretical work on the ECE radiation temperature of non-equilibrium plasmas indicates that for a bi-Maxwellian electron velocity distribution with a ratio of tail to bulk electron density η, a bulk temperature T b , and a hot tail temperature T h , the perpendicular ECE radiation temperature is given by T ECE ∝T b {1+η(T h /T b )}, for η ECE would be enhanced over T TVTS by a factor which depends on η and T h . This paper investigates whether the discrepancy between T TVTS and T ECE seen in TFTR Supershots at high electron temperatures is due to the presence of a hot electron tail component. The extraordinary mode ECE spectrum at the second, third and fourth harmonics is measured on the horizontal midplane by an absolutely calibrated ECE Michelson interferometer. This ECE spectrum is compared with the output from a time-independent transport code with relativistic opacity which solves the three-dimensional ECE radiation transport in a toroidally symmetric, two-dimensional geometry and uses measured electron density and temperature profiles from the TVTS system. (orig.)

  13. Fusion power production from TFTR plasmas fueled with deuterium and tritium

    International Nuclear Information System (INIS)

    Strachan, J.D.; Adler, H.; Alling, P.

    1994-03-01

    Peak fusion power production of 6.2 ± 0.4 MW has been achieved in TFTR plasmas heated by deuterium and tritium neutral beams at a total power of 29.5 MW. These plasmas have an inferred central fusion alpha particle density of 1.2 x 10 17 m -3 without the appearance of either disruptive MHD events or detectable changes in Alfven wave activity. The measured loss rate of energetic alpha particles agreed with the approximately 5% losses expected from alpha particles which are born on unconfined orbits

  14. MeV ion loss during 3He minority heating in TFTR

    International Nuclear Information System (INIS)

    Zweben, S.J.; Hammett, G.; Boivin, R.; Phillips, C.; Wilson, R.

    1992-01-01

    The loss of MeV ions during 3 He ICRH minority heating experiments has been measured using scintillator detectors near the wall of TFTR. The observed MeV ion losses to the bottom (90 degrees poloidal) detector are generally consistent with the expected first-orbit loss of D- 3 He alpha particle fusion products, with an inferred global reaction rate up to ∼10 16 reactions/sec. A qualitatively similar but unexpectedly large loss occurs 45 degrees poloidally below the outer midplane. This additional loss might be due to ICRH tail ions or to ICRH wave-induced loss of previously confined fusion products

  15. QA support for TFTR reliability improvement program in preparation for DT operation

    International Nuclear Information System (INIS)

    Parsells, R.F.; Howard, H.P.

    1987-01-01

    As TFTR approaches experiments in the Q=1 regime, machine reliability becomes a major variable in achieving experimental objectives. This paper describes the methods used to quantify current reliability levels, levels required for D-T operations, proposed methods for reliability growth and improvement, and tracking of reliability performance in that growth. Included in this scope are data collection techniques and short comings, bounding current reliability on the upper end, and requirements for D-T operations. Problem characterization through Pareto diagrams provides insight into recurrent failure modes and the use of Duane plots for charting of reliability changes both cumulative and instantaneous, is explained and demonstrated

  16. The effect of ICRF antenna phasing on metal impurities in TFTR

    International Nuclear Information System (INIS)

    Stevens, J.E.; Bush, C.; Colestock, P.L.; Oak Ridge National Lab., TN; AN Ukrainskoj SSR, Kharkov

    1989-07-01

    ICRF power levels of up to 2.8 MW were achieved during the 1988 experimental run on TFTR. Metal impurity concentrations (Ti, Cr, Fe, Ni) and Z eff were monitored during ICRF heating by x-ray pulse height analysis and uv spectroscopy. Antenna phasing was the key variable affecting ICRF performance. No increase in metallic impurities was observed for P rf approx lt 2.8 MW with the antenna straps 0-Π, while a measurable increase in titanium (Faraday screen material) was observed for P rf approx gt 1.0 MW with 0-0 phasing. 18 refs., 8 figs

  17. Development of remote welding equipment and techniques for the TFTR vacuum vessel

    International Nuclear Information System (INIS)

    Masson, L.S.; Watts, K.D.; Larson, R.A.; Aldrich, W.C.

    1980-01-01

    In the event that the TFTR vacuum vessel is damaged or one of the toroidal field coils fails after the system has become substantially activated, it is necessary to remotely remove and replace the damaged section of the vessel using remote handling procedures. This paper describes a welding system developed through the final design stage to perform the remote welding necessary during the replacement operation. Information is presented describing the vessel configuration, the replacement sequence, the welding system requirements, welder configuration, supporting systems, the weld development program and future development requirements

  18. Observations of neutral beam and ICRF tail ion losses due to Alfven modes in TFTR

    International Nuclear Information System (INIS)

    Darrow, D.S.; Zweben, S.J.; Chang, Z.

    1996-04-01

    Fast ion losses resulting from MHD modes at the Alfven frequency, such as the TAE, have been observed in TFTR. The modes have been driven both by neutral beam ions, at low B T , and by H-minority ICRF tail ions at higher B T . The measurements indicate that the loss rate varies linearly with the mode amplitude, and that the fast ion losses during the mode activity can be significant, e.g. up to 10% of the input power is lost in the worst case

  19. Unifying role of radial electric field shear in the confinement trends of transitionless regimes in TFTR

    International Nuclear Information System (INIS)

    Ernst, D.R.; Beer, M.; Batha, S.

    2001-01-01

    Turbulence suppression by radial electric field shear (E r ) is shown to be important in the enhanced confinement of TFTR supershot plasmas. Simulations of supershot ion temperature profiles are performed using an existing parameterization of transport due to toroidal ion temperature gradient modes, extended to include suppression by E r shear. New spectroscopic measurements of E r differ significantly from prior neoclassical estimates. Supershot temperature profiles appear to be consistent with a criterion describing near-complete turbulence suppression by intrinsically generated E r shear. Helium spoiling and xenon puffing experiments are simulated to illustrate the role of E r shear in the confinement changes observed. (author)

  20. Unifying role of radial electric field shear in the confinement trends of transitionless regimes in TFTR

    International Nuclear Information System (INIS)

    Ernst, D.R.; Beer, M.; Batha, S.

    1999-01-01

    Turbulence suppression by radial electric field shear (E r ) is shown to be important in the enhanced confinement of TFTR supershot plasmas. Simulations of supershot ion temperature profiles are performed using an existing parameterization of transport due to toroidal ion temperature gradient modes, extended to include suppression by E r shear. New spectroscopic measurements of E r differ significantly from prior neoclassical estimates. Supershot temperature profiles appear to be consistent with a criterion describing near-complete turbulence suppression by intrinsically generated E r shear. Helium spoiling and xenon puffing experiments are simulated to illustrate the role of E r shear in the confinement changes observed. (author)

  1. Applying neural networks to control the TFTR neutral beam ion sources

    International Nuclear Information System (INIS)

    Lagin, L.

    1992-01-01

    This paper describes the application of neural networks to the control of the neutral beam long-pulse positive ion source accelerators on the Tokamak Fusion Test Reactor (TFTR) at Princeton University. Neural networks were used to learn how the operators adjust the control setpoints when running these sources. The data sets used to train these networks were derived from a large database containing actual setpoints and power supply waveform calculations for the 1990 run period. The networks learned what the optimum control setpoints should initially be set based uon desired accel voltage and perveance levels. Neural networks were also used to predict the divergence of the ion beam

  2. Measurements of DT alpha particle loss near the outer midplane of TFTR

    International Nuclear Information System (INIS)

    Zweben, S.J.; Darrow, D.S.; Herrmann, H.W.; Redi, M.H.; Schivell, J.; White, R.B.

    1995-07-01

    Measurements of DT alpha particle loss to the outer midplane region of TFTR have been made using a radially movable scintillator detector. The conclusion from this data is that mechanisms determining the DT alpha loss to the outer midplane are not substantially different from those for DD fusion products. Some of these results are compared with a simplified theoretical model for TF ripple-induced alpha loss, which is expected to be the dominant classical alpha loss mechanism near the outer midplane. An example of plasma-driven MHD-induced alpha particle loss is shown, but no signs of any ''collective'' alpha instability-induced alpha loss have yet been observed

  3. Some features of the disruption instability in reversed shear TFTR plasmas

    International Nuclear Information System (INIS)

    Semenov, I.B.; Mirnov, S.V.; McGuire, K.M.

    1999-01-01

    The behaviour of MHD perturbations before and during disruptions in TFTR reversed shear plasmas with q min ∼ 2 was analysed. In the q min region, tearing modes, wavelike modes, and mixed tearing plus wavelike modes are followed by disruption. Sometimes a helical snake (helix) appears at the X point of the q min island. The local outward electron energy transport near the X point can be explained by the development of 'positive' magnetic islands (islands with positive current perturbations). It is proposed that the disruption is initiated when the X point of the magnetic islands coincides in one toroidal position near the torus equator. (author)

  4. The high density and high βpol disruption mechanism on TFTR

    International Nuclear Information System (INIS)

    Fredrickson, E.D.; Manickam, J.; McGuire, K.M.; Monticello, D.; Nagayama, Y.; Park, W.; Taylor, G.

    1992-01-01

    Studies of disruptions on TFTR have been extended to include high density disruptions as well as the high β pol disruptions. The data strongly suggests that the (m,n)=(1,1) mode plays an important role in both types of disruptions. Further, for the first time, it is unambiguously shown, using a fast electron cyclotron emission (ECE) instrument for the electron temperature profile measurements, that the (m,n)=(1,1) precursor to the high density disruptions has a 'cold bubble' structure. The precursor to the major disruption at high density resembles the 'vacuum bubble' model of disruptions first proposed by Kadomtsev and Pogutse. (author) 2 refs., 2 figs

  5. TFTR bumper limiter and final protective plate engineering, fabrication and assembly

    International Nuclear Information System (INIS)

    Helmich, R.C.; Snook, P.G.; Loesser, G.D.; Reilly, T.B.; Trachsel, C.A.

    1986-01-01

    The inner vacuum vessel wall of the Tokamak Fusion Test Reactor (TFTR) is protected from plasma impingement by a bumper limiter and from neutral beam bombardment by protective plates. Engineering problems and solutions relating to Inconel 718, such as welding, machining in the annealed or age-hardened condition, selection of feeds, speeds and the need for rigid tooling are discussed. Vacuum furnace brazing of the 5/16'' Inconel 600 cooling tubing to the backing plates in both horizontal and vertical sections are shown. A detailed description of the plate and tile fabrication and assembly, with manufacturing and management techniques is outlined in this paper

  6. The effect of toroidal field ripple on confined alphas in TFTR D-T plasmas

    International Nuclear Information System (INIS)

    Duong, H.H.; Medley, S.S.

    1996-05-01

    The Pellet Charge Exchange (PCX) diagnostic on the Tokamak Fusion Test Reactor (TFTR) presently measures trapped alpha distribution functions with very small pitch angle (v parallel /v ∼ 0.05) at the midplane. The measured PCX alpha signal exhibits a depletion region near the outboard region. Results of the alpha energy spectra and radial profile suggest stochastic ripple diffusion is the cause of the depletion. Comparison of the ripple stochastization boundary with Goldston-White-Boozer theory also shows the correct functional dependence on alpha energy and q-profile

  7. Loss of alpha-like MeV fusion products from TFTR

    International Nuclear Information System (INIS)

    Zweben, S.J.; Boivin, R.L.; Diesso, M.; Hayes, S.E.; Hendel, H.W.; Park, H.; Strachan, J.D.

    1990-03-01

    A detailed comparison between the observed and expected loss of alpha-like MeV fusion products in TFTR is presented. The D-D fusion products (mainly the 1 MeV triton) were measured with an 2-D imaging scintillation detector. The expected first-orbit loss was calculated with a simple Lorentz orbit code. In almost all cases the measured loss was consistent with the expected first-orbit loss model. Exceptions are noted for small major radius plasmas and during strong MHD activity. 37 refs., 28 figs

  8. Vacuum system design and tritium inventory for the TFTR charge exchange diagnostic

    International Nuclear Information System (INIS)

    Medley, S.S.

    1979-05-01

    The charge exchange diagnostic for the TFTR is comprised of two analyzer systems which contain a total of twenty independent mass/energy analyzers and one diagnostic neutral beam tentatively rated at 80 keV, 15 A. The associated vacuum systems were analyzed using the Vacuum System Transient Simulator (VSTS) computer program which models the transient transport of multi-gas species through complex networks of ducts, valves, traps, vacuum pumps, and other related vacuum system components. In addition to providing improved design performance at reduced cost, the analysis yields estimates for the exchange of tritium from the torus to the diagnostic components and of the diagnostic working gases to the torus

  9. Flaking of co-deposited hydrogenated carbon layers on the TFTR limiter

    International Nuclear Information System (INIS)

    Skinner, C.H.; Gentile, C.A.; Menon, M.M.; Barry, R.E.

    1999-01-01

    Flaking of co-deposited layers on the inner limiter tiles was recently observed in TFTR. This phenomenon was unexpected and has occurred since the termination of plasma operations on 4 April 1997. Flaking affects approximately 15% of the observable tiles and appears on isotropic graphite but not on carbon fibre composite tiles. Photographic images of the flakes and precise measurements of the limiter geometry are reported. The mobilizability of tritium retained in co-deposited layers is an important factor in safety analyses of future DT reactors. A programme to analyse the flakes and tiles is underway. (author). Letter-to-the-editor

  10. Enhanced loss of fusion products during mode conversion heating in TFTR

    International Nuclear Information System (INIS)

    Darrow, D.S.; Majeski, R.; Fisch, N.J.; Heeter, R.F.; Herrmann, H.W.; Herrmann, M.C.; Zarnstorff, M.C.; Zweben, S.J.

    1995-07-01

    Ion Bernstein waves (IBWS) have been generated by mode conversion of ion cyclotron range of frequency (ICRF) fast waves in TFTR. The loss rate of fusion products in these discharges can be large, up to 10 times the first orbit loss rate. The losses are observed at the passing/trapped boundary, indicating that passing particles are being moved onto loss orbits either by increase of their v perpendicular due to the wave, by outward transport in minor radius, or both. The lost particles appear to be DD fusion produced tritons heated to ∼1.5 times their birth energy

  11. Enhanced loss of fast ions during mode conversion ion Bernstein wave heating in TFTR

    International Nuclear Information System (INIS)

    Darrow, D.S.; Majeski, R.; Fisch, N.J.; Heeter, R.F.; Herrmann, H.W.; Herrmann, M.C.; Zarnstorff, M.C.; Zweben, S.J.

    1995-12-01

    A strong interaction of fast ions with ion Bernstein waves has been observed in TFTR. It results in a large increase in the fast ion loss rate, and heats the lost particles to several MeV. The lost ions are observed at the passing/trapped boundary and appear to be either DD fusion produced tritons or accelerated D neutral beam ions. Under some conditions, enhanced loss of DT alpha particles is also seen. The losses provide experimental support for some of the elements required for alpha energy channeling

  12. Model of alpha particle diffusion in the outer limiter shadow of TFTR

    International Nuclear Information System (INIS)

    Wang, S.; Academia Sinica, Hefei, Anhui; Zweben, S.J.

    1996-05-01

    A new code, Monte Carlo Collisional Stochastic Orbit Retracing (MCCSOR), has been developed to model the alpha particle loss signal as measured by the outer midplane scintillator detector in TFTR. The shadowing effects due to the outer limiters and the detector itself have been included, along with a pitch angle scattering and stochastic ripple diffusion. Shadowing by the outer limiters has a strong effect on both the magnitude and pitch angle distribution of the calculated loss. There is at least qualitative agreement between the calculated results and the experimental data

  13. Operation of the repeating pneumatic injector on TFTR and design of an 8-shot deuterium pellet injector

    International Nuclear Information System (INIS)

    Combs, S.K.; Milora, S.L.; Foust, C.R.

    1985-01-01

    The repeating pneumatic hydrogen pellet injector, which was developed at the Oak Ridge National Laboratory (ORNL), has been installed and operated on the Tokamak Fusion Test Reactor (TFTR). The injector combines high-speed extruder and pneumatic acceleration technologies to propel frozen hydrogen isotope pellets repetitively at high speeds. The pellets are transported to the plasma in an injection line that also serves to minimize the gas loading on the torus; the injection line incorporates a fast shutter valve and two stages of guide tubes with intermediate vacuum pumping stations. A remote, stand-alone control and data acquisition system is used for injector and vacuum system operation. In early pellet fueling experiments on TFTR, the injector has been used to deliver deuterium pellets at speeds ranging from 1.0 to 1.5 km/s into plasma discharges. First, single large (nominal 4-mm-dia) pellets provided high densities in TFTR (1.8 x 10 14 cm -3 on axis); after conversion to smaller (nominal 2.7-mm-dia) pellets, up to five pellets were injected at 0.25-s intervals into a plasma discharge, giving a line-averaged density of 1 x 10 14 cm -3 . Operating characteristics and performance of the injector in initial tests on TFTR are presented

  14. Use of the TFTR prototype charge exchange neutral analyzer for fast He3++ diagnostics during ICRF heating on PLT

    International Nuclear Information System (INIS)

    Medley, S.S.

    1981-07-01

    The Charge Exchange Neutral Analyzer (CENA) for TFTR is designed to measure singly charged ion species of atomic mass A = 1, 2, and 3 simultaneously with up to 75 energy channels per mass and an energy range of 0.5 3 charge exchange neutrals makes the analyzer of particular interest for recently proposed fast He 3 ++ diagnostics during ICRF heating on PLT

  15. Achieving high fusion reactivity in high poloidal beta discharges in TFTR

    International Nuclear Information System (INIS)

    Manuel, M.E.; Navratil, G.A.; Sabbagh, S.A.; Batha, S.; Bell, M.G.; Bell, R.; Budny, R.V.; Bush, C.E.; Cavallo, A.; Chance, M.S.; Cheng, C.Z.; Efthimion, P.C.; Fredrickson, E.D.; Fu, G.Y.; Hawryluk, R.J.; Janos, A.C.; Jassby, D.L.; Levinton, F.; Mikkelsen, D.R.; Manickam, J.; McCune, D.C.; McGuire, K.M.; Medley, S.S.; Mueller, D.; Nagayama, Y.; Owens, D.K.; Park, H.K.; Ramsey, A.T.; Stratton, B.C.; Synakowski, E.J.; Taylor, G.; Wieland, R.M.; Yamada, M.; Zarnstorff, M.C.: Zweben, S.; Kesner, J.; Marmar, E.; Snipes, J.; Terry, J.

    1993-04-01

    High poloidal beta discharges have been produced in TFTR that achieved high fusion reactivities at low plasma currents. By rapidly decreasing the plasma current just prior to high-power neutral beam injection, relatively peaked current profiles were created having high l i > 2, high Troyon-normalized beta, βN > 3, and high poloidal beta. β p ≥ 0.7 R/a. The global energy confinement time after the current ramp was comparable to supershots, and the combination of improved MHD stability and good confinement produced a new high εβ p high Q DD operating mode for TFTR. Without steady-state current profile control, as the pulse lengths of high βp discharges were extended, l i decreased, and the improved stability produced immediately after by the current ramp deteriorated. In four second, high εβ p discharges, the current profile broadened under the influence of bootstrap and beam-drive currents. When the calculated voltage throughout the plasma nearly vanished, MHD instabilities were observed with β N as low as 1.4. Ideal MHD stability calculations showed this lower beta limit to be consistent with theoretical expectations

  16. Measurements with vertically viewing charge exchange analyzers during ion cyclotron range of frequencies heating in TFTR

    International Nuclear Information System (INIS)

    Kaita, R.; Hammett, G.W.; Gammel, G.; Goldston, R.J.; Medley, S.S.; Scott, S.D.; Young, K.M.

    1988-01-01

    The utility of charge exchange neutral particle analyzers for studying energetic ion distributions in high-temperature plasmas has been demonstrated in a variety of tokamak experiments. Power deposition profiles have been estimated in the Princeton large torus (PLT) from particle measurements as a function of energy and angle during heating in the ion cyclotron range of frequencies (ICRF) and extensive studies of this heating mode are planned for the upcoming operational period in the tokamak fusion test reactor (TFTR). Unlike the horizontally scanning analyzer on PLT, the TFTR system consists of vertical sightlines intersecting a poloidal cross section of the plasma. A bounce-averaged Fokker--Planck program, which includes a quasilinear operator to calculate ICRF-generated energetic ions, is used to simulate the charge exchange flux expected during fundamental hydrogen heating. These sightlines also cross the trajectory of a diagnostic neutral beam (DNB), and it may be possible to observe the fast ion tail during 3 He minority heating, if the DNB is operated in helium for double charge exchange neutralization

  17. Simulation of mode converted ion Bernstein wave - beam deuteron interactions on TFTR

    Science.gov (United States)

    Herrmann, Mark; Fisch, Nathaniel

    1998-11-01

    Experiments on TFTR have documented strong interactions between mode converted ion Bernstein waves (MCIBW) and beam deuterons(D. S. Darrow et al.), Nucl. Fusion 36, 509 (1996).^,(N. J. Fisch et al.), IAEA, Vol. 1, p. 271 (1996). This is of particular interest in the study of α channelling, since the most promising scenarios(M. C. Herrmann and N. J. Fisch, Phys. Rev. Lett. 79), 1495 (1997). rely on a suitable combination of MCIBW and Alfvén eigenmodes to achieve the cooling of the α particles. Collisional effects, realistic wave fields, and a detailed model of the wave-particle interaction have been added to the Monte Carlo simulations which are used to simulate α channelling in order to model TFTR experiments(M. C. Herrmann, Ph.D. thesis, Princeton University, 1998.). The results are found to be in qualitative agreement with the data. In addition, the simulation is used, in conjunction with the data, to demonstrate the existence of the k_\\|-flip of the MCIBW, and to infer a diffusion coefficient for the beam deuterons interacting with the wave. This diffusion coefficient significantly exceeds what would be expected on the basis of quasilinear theory with the fields specified by 1 D ray tracing of the MCIBW.

  18. A Michelson interferometer/polarimeter on the Tokamak Fusion Test Reactor (TFTR)

    International Nuclear Information System (INIS)

    Park, H.K.; Mansfield, D.K.; Johnson, L.C.; Ma, C.H.

    1987-01-01

    A multichannel interferometer/polarimeter for the Tokamak Fusion Test Reactor (TFTR) has been developed in order to study the time dependent plasma current density (J/sub p/) and electron density (n/sub e/) profile simultaneously. The goal of the TFTR is demonstration of breakeven via dueuterium and tritium (DT) plasma. In order to be operated and maintained during DT operation phase, the system is designed based on the Michelson geometry which possesses intrinsic standing wave problems. So far, there has been no observable signals due to these standing waves. However, a standing wave resulted from the beam path design to achieve a optimum use of the laser power was found. This standing wave has not prevented initial 10 channel interferometer operation. However, a single channel polarimeter test indicated this standing wave was fatal for Faraday notation measurements. Techniques employing 1/2 wave plates and polarizers have been applied to eliminate this standing wave problem. The completion of 10 channel Faraday rotation measurements may be feasible in the near future

  19. Measurement of loss of DT fusion products using scintillator detectors in TFTR

    International Nuclear Information System (INIS)

    Darrow, D.S.; Herrmann, H.W.; Johnson, D.W.; Marsala, R.J.; Palladino, R.W.; Zweben, S.J.

    1995-03-01

    A poloidal array of MeV ion loss probes previously used to measure DD fusion product loss has been upgraded to measure the loss of alpha particles from DT plasmas in TFTR. The following improvements to the system have been made in preparation for the use of tritium in TFTR: (1) relocation of detectors to a neutronshielded enclosure in the basement to reduce neutron-induced background signals; (2) replacement of ZnS:Cu (P31) scintillators in the probes with the Y 3 Al 5 0 12 :Ce(P46) variety to minimize damage and assure linearity at the fluxes anticipated from DT plasmas; and (3) shielding of the fiber optic bundles which carry the fight from the probes to the detectors to reduce neutron- and gamma-induced light within them. In addition to the above preparations, the probes have been absolutely calibrated for alpha particles by using the Van de Graaf accelerator at Los Alamos National Laboratory. Alpha particle losses from DT plasmas have been observed, and losses at the detector 901 below the midplane are consistent with first orbit loss

  20. Simulations of enhanced reversed shear TFTR discharges with lower hybrid current drive

    International Nuclear Information System (INIS)

    Kesner, J.; Bateman, G.

    1996-01-01

    The BALDUR based BBK code permits predictive simulations of time-dependent tokamak discharges and has the capability to include neutral beam heating, pellet injection, bootstrap currents and lower hybrid current drive. BALDUR contains a theory based multi-regime transport model and previous work has shown excellent agreement with both L-mode and supershot TFTR discharges. These simulations reveal that core transport is dominated by η i and trapped electron modes and the outer region by resistive ballooning. We simulate enhanced reverse shear discharges by beginning with a supershot simulation with a reversed shear profile. Similarly to the TFTR experiments the reversed shear profile is obtained through the programming of the current during startup and the freezing in of these profiles by subsequent heating. At the time of transition into the enhanced confinement regime we turn off the η i and trapped-electron mode transport. We examine the further modification of the plasma current profile that can be obtained with the application of lower hybrid current drive. The results of these simulations will be discussed

  1. Foil deposition alpha collector probe for TFTR's D-T phase

    International Nuclear Information System (INIS)

    Hermann, H.W.; Darrow, D.S.; Timberlake, J.; Zweben, S.J.; Chong, G.P.; Pitcher, C.S.; Macaulay-Newcombe, R.G.

    1995-03-01

    A new foil deposition alpha collector sample probe has been developed for TFTR's D-T phase. D-T fusion produced alpha particles escaping from the plasma are implanted in nickel foils located in a series of collimating ports on the detector. The nickel foils are removed from the tokamak after exposure to one or more plasma discharges and analyzed for helium content. This detector is intended to provide improved alpha particle energy resolution and pitch angle coverage over existing lost alpha detectors, and to provide an absolutely calibrated cross-check with these detectors. The ability to resolve between separate energy components of alpha particle loss is estimated to be ∼ 20%. A full 360 degree of pitch angle coverage is provided for by 8 channels having an acceptance range of ∼ 53 degree per channel. These detectors will be useful in characterizing classical and anomalous alpha losses and any collective alpha instabilities that may be excited during the D-T campaign of TFTR

  2. Electron temperature profiles in high power neutral-beam-heated TFTR [Tokamak Fusion Test Reactor] plasmas

    International Nuclear Information System (INIS)

    Taylor, G.; Grek, B.; Stauffer, F.J.; Goldston, R.J.; Fredrickson, E.D.; Wieland, R.M.; Zarnstorff, M.C.

    1987-09-01

    In 1986, the maximum neutral beam injection (NBI) power in the Tokamak Fusion Test Reactor (TFTR) was increased to 20 MW, with three beams co-parallel and one counter-parallel to I/sub p/. TFTR was operated over a wide range of plasma parameters; 2.5 19 19 m -3 . Data bases have been constructed with over 600 measured electron temperature profiles from multipoint TV Thomson scattering which span much of this parameter space. We have also examined electron temperature profile shapes from electron cyclotron emission at the fundamental ordinary mode and second harmonic extraordinary mode for a subset of these discharges. In the light of recent work on ''profile consistency'' we have analyzed these temperature profiles in the range 0.3 < (r/a) < 0.9 to determine if a profile shape exists which is insensitive to q/sub cyl/ and beam-heating profile. Data from both sides of the temperature profile [T/sub e/(R)] were mapped to magnetic flux surfaces [T/sub e/(r/a)]. Although T/sub e/(r/a), in the region where 0.3 < r/a < 0.9 was found to be slightly broader at lower q/sub cyl/, it was found to be remarkably insensitive to β/sub p/, to the fraction of NBI power injected co-parallel to I/sub p/, and to the heating profile going from peaked on axis, to hollow. 10 refs., 8 figs

  3. Structural analysis of TFTR toroidal field coil conceptual design

    International Nuclear Information System (INIS)

    Smith, R.A.

    1975-10-01

    The conceptual design evaluation of the V-shaped toroidal field coils on the Tokamak Fusion Test Reactor has been performed by detailed structural analysis with the finite element method. The innovation provided by this design and verified in this work is the capability to support toroidal field loads while simultaneously performing the function of twist restraint against the device axial torques resulting from the vertical field loads. The evaluations made for the conceptual design provide predictions for coil deflections and stresses. The results are available for the separate effects from toroidal fields, poloidal fields, and the thermal expansion of the coils as well as for the superposition of the primary loads and the primary plus thermal loads

  4. Ion cyclotron emission due to collective instability of fusion products and beam ions in TFTR and JET

    International Nuclear Information System (INIS)

    Dendy, R.O.; McClements, K.G.; Lashmore Davies, C.N.; Cottrell, G.A.; Majeski, R.; Cauffman, S.

    1995-01-01

    Ion cyclotron emission (ICE) has been observed from neutral beam heated TFTR and JET tritium experiments at sequential cyclotron harmonics of both fusion products and beam ions. The emission originates from the outer midplane plasma, where fusion products and beam ions are likely to have a drifting ring-type velocity-space distribution that is anisotropic and sharply peaked. Fusion product driven ICE can be attributed to the magnetoacoustic cyclotron instability, which involves the excitation of obliquely propagating waves on the fast Alfven/ion Bernstein branch at cyclotron harmonics of the fusion products. Differences between ICE observations in JET and TFTR appear to reflect the sensitivity of the instability growth rate to the ratio υ birth /c A , where υ birth is the fusion product birth speed and c A is the local Alfven speed: for fusion products in the outer midplane edge of TFTR supershots, υ birth A ; for alpha particles in the outer midplane edge of JET, the opposite inequality applies. If sub-Alfvenic fusion products are isotropic or have undergone even a moderate degree of thermalization, the magnetoacoustic instability cannot occur. In contrast, the super-Alfvenic alpha particles that are present in the outer midplane of JET can drive the magnetoacoustic cyclotron instability even if they are isotropic or have a relatively broad distribution of speeds. These conclusions may account for the observation that fusion product driven ICE in JET persists for longer than fusion product driven ICE in TFTR. A separate mechanism is proposed for the excitation of beam driven ICE in TFTR: electrostatic ion cyclotron harmonic waves, supported by strongly sub-Alfvenic beam ions, can be destabilized by a low concentration of such ions with a very anrrow spread of velocities in the parallel direction. 25 refs, 14 figs

  5. Ion cyclotron emission due to collective instability of fusion products and beam ions in TFTR and JET

    International Nuclear Information System (INIS)

    Dendy, R.O.; Clements, K.G.; Lashmore-Davies, C.N.; Cottrell, G.A.; Majeski, R.; Cauffman, S.

    1995-06-01

    Ion cyclotron emission (ICE) has been observed from neutral beam-heated TFTR and JET tritium experiments at sequential cyclotron harmonics of both fusion products and beam ions. The emission originates from the outer mid-plane plasma, where fusion products and beam ions are likely to have a drifting ring-type velocity-space distribution which is anisotropic and sharply peaked. Fusion product-driven ICE in both TFTR and JET can be attributed to the magnetoacoustic cyclotron instability, which involves the excitation of obliquely propagating waves on the fast Alfven/ion Bernstein branch at cyclotron harmonics of the fusion products. Differences between ICE observations in JET and TFTR appear to reflect the sensitivity of the instability growth rate to the ratio υ birth /c A , where υ birth is the fusion product birth speed and c A is the local Alfven speed:for fusion products in the outer midplane edge of TFTR, υ birth A ; for alpha-particles in the outer midplane edge of JET, the opposite inequality applies. If sub-Alfvenic fusion products are isotropic or have undergone even a moderate degree of thermalization, the magnetoacoustic instability cannot occur. In contrast, the super-Alfvenic alpha-particles which are present in the outer mid-plane of JET can drive the magnetoacoustic cyclotron instability even if they are isotropic or have a relatively broad distribution of speeds. These conclusions may account for the observation that fusion product-driven ICE in JET persists for longer than fusion product-driven ICE in TFTR. (Author)

  6. Interrupter and hybrid-switch testing for fusion devices

    International Nuclear Information System (INIS)

    Parsons, W.M.; Warren, R.W.; Honig, E.M.; Lindsay, J.D.G.; Bellamo, P.; Cassel, R.L.

    1979-01-01

    This paper discusses recent and ongoing switch testing for fusion devices. The first part describes testing for the TFTR ohmic-heating circuit. In this set of tests, which simulated the stresses produced during a plasma initiation pulse, circuit breakers were required to interrupt a current of 24 kA with an associated recovery voltage of 25 kV. Two interrupter systems were tested for over 1000 operations each, and both appear to satisfy TFTR requirements. The second part discusses hybrid-switch development for superconducting coil protection. These switching systems must be capable of carrying large currents on a continuous basis as well as performing interruption duties. The third part presents preliminary results on an early-counterpulse technique applied to vacuum interrupters. Implementation of this technique has resulted in large increases in interruptible current as well as a marked reduction in contact erosion

  7. A survey of reflectometry techniques with applications to TFTR

    International Nuclear Information System (INIS)

    Collazo, I.; Stacey, W.M.; Wilgen, J.; Hanson, G.; Bigelow, T.; Thomas, C.E.; Bretz, N.

    1993-12-01

    This report presents a review of reflectometry with particular attention to eXtraordinary mode (X-mode) reflectometry using the novel technique of dual frequency differential phase. The advantage of using an X-mode wave is that it can probe the edge of the plasma with much higher resolution and using a much smaller frequency range than with the Ordinary mode (O-Mode). The general problem with previous full phase reflectometry techniques is that of keeping track of the phase (on the order of 1000 fringes) as the frequency is swept over the band. The dual frequency phase difference technique has the advantage that since it is keeping track of the phase difference of two frequencies with a constant frequency separation, the fringe counting is on the order of only 3 to 5 fringes. This fringe count, combined with the high resolution of the X-mode wave and the small plasma access requirements of reflectometry, make X-mode reflectometry a very attractive diagnostic for today's experiments and future fusion devices

  8. Three-dimensional Monte Carlo calculations of the neutron and γ-ray fluences in the TFTR diagnostic basement and comparisons with measurements

    International Nuclear Information System (INIS)

    Liew, S.L.; Ku, L.P.; Kolibal, J.G.

    1985-10-01

    Realistic calculations of the neutron and γ-ray fluences in the TFTR diagnostic basement have been carried out with three-dimensional Monte Carlo models. Comparisons with measurements show that the results are well within the experimental uncertainties

  9. Selected topics on surface effects in fusion devices: neutral-beam injectors and beam-direct converters

    International Nuclear Information System (INIS)

    Kaminsky, M.

    1978-01-01

    Neutral-beam injectors are being used for the heating and fueling of plasmas in existing devices such as PLT (Princeton), ISX (Oak Ridge) and 2XIIB (Lawrence Livermore Laboratory) and will be used in devices such as TFTR (Princeton), MX (Livermore) and Doublet III (Gulf Atomic). For example, TFTR has been designed to receive a total of 20 MW of 120-keV deuterium atoms in pulses of 0.5-sec duration from 12 neutral beam injectors; for the MX experiment it is planned to inject a total of 750A (equivalent) of deuterium atoms with a mean energy of 56 keV in 0.5-sec pulses. The interaction of energetic deuterium atoms with exposed surfaces of device components such as beam dumps, beam-direct-convertors collectors, beam calorimeters, and armor plates, cause a variety of surface effects which affect deleteriously the operation of such devices. Some of the major effects will be discussed

  10. Charge-exchange neutral hydrogen measurements in TFTR using Pd-MOS microsensors

    International Nuclear Information System (INIS)

    Bastasz, R.; Kilpatrick, S.J.; Ruzic, D.N.

    1991-06-01

    An array of Pd-metal-oxide semiconductor (Pd-MOS) diodes has been used to monitor the fluence and energy of charge-exchange neutral hydrogen isotopes striking the wall of the Tokamak Fusion Test Reactor (TFTR). The array was positioned 4 cm behind the graphite-tiled wall at the toroidal midplane and exposed to several hundred plasma discharges. Hydrogen isotopes striking the Pd-MOS diodes were detected by measuring the leakage current, which is affected by the presence of these species at the Pd/SiO 2 interface. It was found that the midplane flux strongly increased for neutral-beam heated plasmas and correlated with co-injected neutral beam power. The majority of the neutral flux was <50 eV in energy but its energy distribution extended to above 500 eV. 20 refs., 4 figs

  11. Long- and short-term trends in vessel conditioning of TFTR [Tokamak Fusion Test Reactor

    International Nuclear Information System (INIS)

    LaMarche, P.H.; Dylla, H.F.; Bell, M.G.

    1986-10-01

    We have investigated trends in the conditioning of the Tokamak Fusion Test Reactor (TFTR) vacuum vessel during the May 1984 to April 1985 run period. The initial conditioning of the vessel, consisting of glow discharge cleaning (GDC) and pulse discharge cleaning (PDC) in concert with a 150 0 C vessel bakeout, is necessary to assure plasma operation after atmospheric venting. A long-term conditioning process, ascribed to limiter conditioning, effectively improves operational conditions during the course of the run. Over several thousand high power plasma discharges, the improvement was documented by using standard parameter (fiducial) plasma discharges. Several techniques demonstrated short-term improvements in vessel conditioning during this time period, including: Cr gettering and programming the plasma position relative to the limiter contact area

  12. Implementation of the α-CHERS diagnostic for D-T operation of TFTR

    International Nuclear Information System (INIS)

    McKee, G.R.; Fonck, R.J.; Stratton, F.K.

    1995-01-01

    The α-CHERS diagnostic is a high throughput charge exchange recombination spectroscopy diagnostic designed to measure the density profile and time evolution of 0-500 keV alpha particles during D-T operation of TFTR. Following successful tests with a prototype (α-CHERS system, an improved, multi-channel system has been installed for D-T Operation. Three spatial channels may be observed simultaneously, and the spectral resolution of 0.5 nm permits increased alpha energy resolution and improved impurity line identification. More efficient coupling optics between the spectrometer and CCD detectors have increased the light throughput, and radiation shielding has been installed around the detectors and spectrometers to eliminate the neutron/gamma ray noise observed in high power D-D plasmas

  13. Anomalous delayed loss of trapped D-D fusion products in TFTR

    International Nuclear Information System (INIS)

    Zweben, S.J.; Darrow, D.S.; Fredrickson, E.D.; Mynick, H.E.

    1993-02-01

    A new anomalous delayed loss of D-D fusion products has been measured at the bottom of the TFRR vessel. This loss is delayed by ∼ 0.2 sec with respect to the usual prompt first-orbit loss, and has a correspondingly lower energy, i.e. about half the fusion product birth energy. This loss process dominates the total fusion product loss measured 90 degrees below the midplane for plasma currents. I≥ 1.8 MA and major radii near R=2.45 m, e.g. for recent TFTR supershots. This delayed feature can occur without large coherent MED activity, although it can be strongly modulated by such activity. Several possible causes for this phenomenon are discussed, but no clear explanation for this delayed loss has yet been found

  14. Simulations of alpha parameters in a TFTR DT supershot with high fusion power

    International Nuclear Information System (INIS)

    Budny, R.V.; Bell, M.G.; Janos, A.C.

    1995-07-01

    A TFTR supershot with a plasma current of 2.5 MA, neutral beam heating power of 33.7 MW, and a peak DT fusion power of 7.5 MW is studied using the TRANSP plasma analysis code. Simulations of alpha parameters such as the alpha heating, pressure, and distributions in energy and v parallel /v are given. The effects of toroidal ripple and mixing of the fast alpha particles during the sawteeth observed after the neutral beam injection phase are modeled. The distributions of alpha particles on the outer midplane are peaked near forward and backward v parallel /v. Ripple losses deplete the distributions in the vicinity of v parallel /v ∼-0.4. Sawtooth mixing of fast alpha particles is computed to reduce their central density and broaden their width in energy

  15. Localized MHD activity near transport barriers in JT-60U and TFTR

    International Nuclear Information System (INIS)

    Manickam, J.

    2001-01-01

    Localized MHD activity observed in JT-60U and TFTR near transport barriers with their associated large pressure gradients is investigated. Stability analysis of equilibria modeling the experiments supports an identification of this MHD as being due to an ideal MHD n=1 instability. The appearance of the instability depends on the local pressure gradient, local shear in the q profile and the proximity of rational surfaces where q∼m/n and m and n are the poloidal and toroidal mode numbers respectively. The mode width is shown to depend on the local value of q, and is larger when q is smaller. In addition the role of the edge current density in coupling the internal mode to the plasma edge and of the energetic particles which can drive fishbone like modes is investigated. (author)

  16. Structural analysis of TFTR vacuum vessel bellows and bellows cover sections

    International Nuclear Information System (INIS)

    Driesen, G.

    1975-10-01

    A structural evaluation of the bellows and bellows cover sections was undertaken in order to confirm the structural integrity of these TFTR vacuum vessel components in the prescribed operating environment. The evaluations investigate component stability, stress, and deflection behavior. The products of this investigation appearing in this report include; (1) Structural verification of the vacuum bellows as currently defined in an operating environment of one atmosphere external pressure and 93 0 C (200 0 F) uniform temperature. (2) The establishment of a structurally adequate design configuration for the bellows cover section. (3) The presentation of a parametric study which indicates the effects of varying some bellows cover section parameters in order to obtain acceptable variations of this design configuration. (4) A verification of bellows and bellows cover section integrity to preclude a fatigue type failure for reactor startup and shutdown cyclic life in the design environment

  17. ICRF antenna modifications and additions for TFTR: Relevance to BPX/ITER projections

    International Nuclear Information System (INIS)

    Hosea, J.; Phillips, C.K.; Raftopoulos, S.; Stevens, J.; Wilson, J.R.

    1991-01-01

    The TFTR Bay L and M antennas have been modified to improve their power handling capability. In particular, the Bay L antenna, which exhibited a lower than expected loading resistance, now has a configuration similar to that of Bay M -- slotted walls and septum -- and together with Bay M is expected to support 7 MW operations. The in situ loading enhancement achieved for the Modified Bay L design will serve to quantify models for the coupling effects of slots. Also, comparisons with Bay M loading performance will elucidate wave spectrum and antenna location (relative to in-vessel structures) effects. Two new antennas, with single/double row shields slanted at 6 degree (along B) are to be added in the near future to augment the power capability to ∼12.5 MW. The relevance of the four antenna array features to quantifying BPX/ITER antenna characteristic projections for heating and current drive is discussed. 8 refs., 5 figs

  18. Distributed process control system for remote control and monitoring of the TFTR tritium systems

    International Nuclear Information System (INIS)

    Schobert, G.; Arnold, N.; Bashore, D.; Mika, R.; Oliaro, G.

    1989-01-01

    This paper reviews the progress made in the application of a commercially available distributed process control system to support the requirements established for the Tritium REmote Control And Monitoring System (TRECAMS) of the Tokamak Fusion Test REactor (TFTR). The system that will discussed was purchased from Texas (TI) Instruments Automation Controls Division), previously marketed by Rexnord Automation. It consists of three, fully redundant, distributed process controllers interfaced to over 1800 analog and digital I/O points. The operator consoles located throughout the facility are supported by four Digital Equipment Corporation (DEC) PDP-11/73 computers. The PDP-11/73's and the three process controllers communicate over a fully redundant one megabaud fiber optic network. All system functionality is based on a set of completely integrated databases loaded to the process controllers and the PDP-11/73's. (author). 2 refs.; 2 figs

  19. Dielectronic satellite spectra of hydrogenlike iron from TFTR [Tokamak Fusion Test Reactor

    International Nuclear Information System (INIS)

    Decaux, V.; Bitter, M.; Hsuan, H.; von Goeler, S.; Hill, K.W.; Hulse, R.A.; Taylor, G.; Park, H.; Bhalla, C.P.

    1990-08-01

    Spectra of hydrogenlike iron, Fe26, have been observed from Tokamak Fusion Test Reactor (TFTR) plasmas with a high-resolution crystal spectrometer. The experimental arrangement permits simultaneous observation of the Fe26 Ly-α 1 and Ly-α 2 lines and the associated dielectronic satellites, which are due to transitions 1snl-2pnl' with n ≥ 2, as well as the heliumlike 1s 2 ( 1 S 0 )-1s4p( 1 P 1 )and both hydrogenlike Ly-β 1 and Ly-β 2 lines from chromium. Relative wavelengths and line intensities can be determined very accurately. The spectral data are in very good agreement with theoretical calculations. The observed spectra have also been used to estimate the total dielectronic recombination rate coefficient of Fe26. 30 refs., 4 figs., 3 tabs

  20. Analysis of the TFTR toroidal field power supply and its interactions with other loads

    International Nuclear Information System (INIS)

    Newell, W.E.

    1976-01-01

    The rectifiers which supply the four major pulsed loads of the Tokamak Fusion Test Reactor (TFTR) share two flywheel generators. Thus there is a possibility of significant interaction between these rectifiers by way of the notched voltage waveforms which they create at the generator terminals. This paper presents an analysis of the build up of current in the toroidal field (TF) coil, which is the largest load. From this analysis, the notched waveform caused by the TF rectifier is derived and its effect on the other rectifiers is investigated. It is concluded that with the present conceptual design parameters, the external effects of the interactions are likely to be small. However, the internal control circuits of the rectifiers must be carefully designed to minimize those effects

  1. Recent progress on MHD-induced loss of D-D fusion products in TFTR

    International Nuclear Information System (INIS)

    Zweben, S.J.; Darrow, D.S.; Budny, R.V.; Cheng, C.Z.; Fredrickson, E.D.; Herrmann, H.; Mynick, H.E.; Schivell, J.

    1993-08-01

    This paper reviews the recent progress made toward understanding the MHD-induced loss of D-D fusion products which has been seen on TFTR since 1988. These measurements have been made using the ''lost alpha'' diagnostic, which is described briefly. The largest MHD- induced loss occurs with coherent 3/2 or 2/1 MHD activity (kink/tearing modes), which can cause up to ∼3--5 times the first-orbit loss at I∼1.6--1.8 MA, roughly a ∼20--30% global los of D-D fusion products. Modeling of these MHD-induced losses has progressed to the point where the basic loss mechanism can be accounted for qualitatively, but the experimental results can not yet be understood quantitatively. Several alpha loss codes are being developed to improve the quantitative comparison between experiment and theory

  2. Design of the calorimeter and beam dump for the TFTR prototype neutral beam injector

    International Nuclear Information System (INIS)

    Stone, R.R.; Haughian, J.M.

    1977-01-01

    A calorimeter has been designed for use with the TFTR prototype neutral beam injection system. It consists of three vees each having two 18.8-mm-thick (0.75 in.) copper plates at a 6-deg angle, relative to the beam centerline. The maximum power density on a plate with this arrangement will be 2.0 kW/cm 2 , resulting in a front surface temperature rise of about 420 0 C. A support and retraction system moves the calorimeter in and out of the beam centerline. Various factors used in the selection of the absorber plate material will be discussed and also some experimental test results will be presented

  3. Technique for measuring the losses of alpha particles to the wall in TFTR

    International Nuclear Information System (INIS)

    England, A.C.

    1984-03-01

    It is proposed to measure the losses of alpha particles to the wall in the Tokamak Fusion Test Reactor (TFTR) or any large deuterium-tritium (D-T) burning tokamak by a nuclear technique. For this purpose, a chamber containing a suitable fluid would be mounted near the wall of the tokamak. Alpha particles would enter the chamber through a thin window and cause nuclear reactions in the fluid. The material would then be transported through a tube to a remote, low-background location for measurement of the activity. The most favorable reaction suggested here is 10 B(α,n) 13 N, although 14 N(α,γ) 18 F and others may be possible. The system, the sensitivity, the probe design, and the sources of error are described

  4. Conceptual thermal-mechanical design of the TFTR first wall armor against neutral beam impingement

    International Nuclear Information System (INIS)

    Chi, J.W.H.; Flaherty, R.

    1976-01-01

    The Tokamak Fusion Test Reactor (TFTR) is designed to operate in a pulsed mode with relatively low duty cycles. Each pulse consists of a short plasma heat-up period, a reaction period, followed by a relatively long cooldown period. Plasma heating is accomplished by ohmic heating by a current induced change in the magnetically linked ohmic heating coils, followed by neutral beam injection for further preheat and the initiation of fusion reactions. During normal operation, the bulk of the neutral beam energy will be absorbed by the plasma, while the remainder will impinge on the vacuum vessel wall. The amount of thermal energy deposited on an unprotected wall is expected to be excessive, limiting the frequency of pulses and requiring frequent wall replacement. A faulted condition would cause penetration of an unprotected wall. As a consequence, a wall armoring (or liner) concept was developed to protect the vacuum vessel wall and to permit ease of liner replacement

  5. Installation and early operation of a complex low inventory cryogenic distillation system for the Princeton TFTR

    International Nuclear Information System (INIS)

    Busigin, A.; Busigin, C.J.; Robins, J.R.; Woodall, K.B.; Bellamy, D.G.; Fong, C.; Kalyanam, K.; Sood, S.K.

    1995-01-01

    A low inventory Tritium Purification System (TPS) has just been installed at the Princeton Plasma Physics Laboratory (PPPL). The TPS was designed specifically for PPPL, based on their specifications for exhaust gases. The generic design, however, can easily be modified to accept a large variety of input conditions. The Princeton system is designed to have a total tritium inventory of approximately 0.5 g while producing pure product streams consisting of H 2 , D 2 , and T 2 . The purpose of the system is to separate and recycle unburnt tritium from the TFTR and to produce hydrogen and deuterium streams that are free of tritium. These streams can be disposed by stacking, thus eliminating the need to create large volume waste streams that are contaminated with tritium and that must be managed for permanent disposal. This paper will discuss the installation, the modifications and preliminary results of operation of this system at Princeton. 2 refs., 3 figs

  6. ICRF heating and transport of deuterium-tritium plasmas in TFTR

    International Nuclear Information System (INIS)

    Rogers, J.H.; Schilling, G.; Stevens, J.E.; Taylor, G.; Wilson, J.R.; Bell, M.G.; Budny, R.V.; Bretz, N.L.; Darrow, D.; Fredrickson, E.

    1995-02-01

    This paper describes results of the first experiments utilizing high-power ion cyclotron range of frequency (ICRF) to heat deuterium-tritium (D-T) plasmas in reactor-relevant regimes on the Tokamak Fusion Test Reactor (TFTR). Results from these experiments have demonstrated efficient core, second harmonic, tritium beating of D-T supershot plasmas with tritium concentrations ranging from 6%-40%. Significant direct ion heating on the order of 60% of the input radio frequency (rf) power has been observed. The measured deposition profiles are in good agreement with two-dimensional modeling code predictions. Energy confinement in an rf-heated supershot is at least similar to that without rf, and possibly better in the electron channel. Efficient electron heating via mode conversion of fast waves to ion Bernstein waves (IBW) has been demonstrated in ohmic, deuterium-deuterium and DT-neutral beam injection plasmas with high concentrations of minority 3 He (n 3He /n e = 15% - 30%). By changing the 3 He concentration or the toroidal field strength, the location of the mode-conversion radius was varied. The power deposition profile measured with rf power modulation indicated that up to 70% of the power can be deposited on electrons at an off-axis position. Preliminary results with up to 4 MW coupled into the plasma by 90-degree phased antennas showed directional propagation of the mode-converted IBW. Analysis of heat wave propagation showed no strong inward thermal pinch in off-axis heating of an ohmically-heated target plasma in TFTR

  7. TFTR Ion Cyclotron Range of Frequencies (ICRF) experimental data analysis collaboration. Annual progress report, December 1, 1993--November 30, 1994

    International Nuclear Information System (INIS)

    Sharer, J.E.; Bettenhausen, M.; Lam, N.; Sund, R.

    1994-08-01

    The research performed under this grant during the past year has concentrated on coupling, heating, and current drive issues for TFTR. The authors have developed a code and submitted for publication a open-quotes 3-Dclose quotes coupling analysis of the TFIR ICRF cavity-backed coil antennas to plasma edge profiles including the Faraday shield blade angle and fast wave coupling for heating and current drive. They have also carried out TFTR ICRF full-wave field solutions and heating analyses for the second harmonic tritium supershot, and the effects of fusion alpha particle and tritium ion tail populations on the ICRF absorption. They have also published a paper on the effects of alpha particle absorption on fundamental deuterium ion cyclotron absorption incorporating self-consistent deuterium tails and fusion reactivity. Research progress, publications, and conference presentations are summarized in this report

  8. Transport simulations of TFTR experiments to test theoretical models for χe and χi

    International Nuclear Information System (INIS)

    Redi, M.H.; Bateman, G.

    1990-08-01

    1-1/2-d BALDUR transport code predictions using recent theoretically-based models for thermal and particle transport are compared to measured profiles of electron plasma density and electron and ion temperatures for TFTR ohmic, L-mode and supershot discharges. The profile consistent drift wave model is found to overestimate ion temperatures at high heating powers, so that a third mode or loss process is needed in addition to drift wave transport (TEM, η i ) and an edge loss model. None of several versions of local multiple mode models, using the 1989 Carreras-Diamond resistive ballooning model, gives T e , T i within 20% for all three TFTR regimes studied. 36 refs., 7 figs., 4 tabs

  9. MIRI: A multichannel far-infrared laser interferometer for electron density measurements on TFTR [Tokamak Fusion Test Reactor

    International Nuclear Information System (INIS)

    Mansfield, D.K.; Park, H.K.; Johnson, L.C.; Anderson, H.M.; Chouinard, R.; Foote, V.S.; Ma, C.H.; Clifton, B.J.

    1987-07-01

    A ten-channel far-infrared laser interferometer which is routinely used to measure the spatial and temporal behavior of the electron density profile on the TFTR tokamak is described and representative results are presented. This system has been designed for remote operation in the very hostile environment of a fusion reactor. The possible expansion of the system to include polarimetric measurements is briefly outlined. 13 refs., 8 figs

  10. Layout of the manipulator-arm (boom) for the TFTR fusion reactor (Princeton, USA) under UHV-conditions

    International Nuclear Information System (INIS)

    Klaubert, J.

    1987-01-01

    This presentation shows the main criteria for the layout of the manipulator - arm and the antechamber - vessel of the TFTR - FUSION - REACTOR at Princeton University, PLASMA PHYSICS LABORATORY (USA). The main problem during layout of a manipulator system like the TFTR - Boom has been the limitation of the vertical deflections due to deadweight of the construction. The design problem is rather a deformation problem and a problem of stability than a stress problem. The way of optimizing the ratio between stiffness and deadweight is the most important part during the complete design - process. Additional earthquake requirements need further investigations for a satisfying layout (horizontal forces, weak-axis of moment of inertia). The details of the construction (welding, connections etc.) have to be designed in respect to UHV - requirements --> no holes and no fillet welds (outgasing - rate.) are allowed. All weldings have to be designed as bevel-welds. This manipulator system is designed for working in a plane system (two degrees of freedom). A manipulator system with the same operating capabilities in a three degree of freedom system needs larger cross sections for the different beam-elements than those of the discussed TFTR - BOOM

  11. Measurement of the nonaxisymmetric heat load distribution on the first wall of TFTR due to locked modes

    International Nuclear Information System (INIS)

    Janos, A.C.; Fredrickson, E.; McGuire, K.M.; Nagayama, Y.; Owens, D.K.

    1992-01-01

    The first wall of TFTR is covered in large part (23%) by an inner-wall bumper limiter which is the primary power handling structure in TFTR. The limiter is comprised of more than 2000 tiles, and is instrumented with a large number (>100) of thermocouples in a two-dimensional (2D) array, primarily for protection of the wall. While only about 5% of the tiles are monitored, this thermocouple system is nevertheless capable of mapping details in the nonaxisymmetric, as well as symmetric, heat load patterns encountered under different conditions. In particular, helical heating patterns are observed in discharges which have locked modes. The helical patterns clearly match the expected trajectories based on the m/n mode numbers obtained from Mirnov coils (m/n=2/1 and 4/1), so that the thermocouple system can and was used to identify the existence and mode number of a locked mode. While TFTR discharges rarely suffer from locked modes, locked modes always alter the heating pattern. The locked modes are found to very significantly redistribute the heat load for both ohmic and NBI heated discharges. Locked modes can make what were the coldest areas into the hottest areas, and vice versa. Locked modes also can alter the heat pattern resulting from the frequent disruptions which occur as a result of a locked mode

  12. Neutron sawtooth behavior in the PLT, DIII-D, and TFTR tokamaks

    International Nuclear Information System (INIS)

    Lovberg, J.A.; Heidbrink, W.W.; Strachan, J.D.; Zaveryaev, V.S.

    1988-10-01

    The effect of the sawtooth instability on the 2.5 MeV neutron emission in the PLT, DIII-D, and TFTR tokamaks is studied. In thermonuclear plasmas, the instability typically results in a 20% reduction in emission. The time evolution of the thermonuclear neutron signal suggests that the sawtooth crash consists of four phases. First, the electron density profile flattens rapidly (in /approximately/30μsec on PLT) but, in some cases, there is little associated change in neutron emission, suggesting that most reacting ions remain confined in the sawtooth region but do not completely mix. After the electron sawtooth, the ions continue to mix, resulting in a /approximately/10% reduction in neutron emission in /approximately/0.5 msec. The emission then decays more slowly during the final two phases. Thermalization of reacting ions on a /approximately/3/tau//sub ii/ time scale accounts for only /approximately/20% of the slow drop. Most of the slow drop seems to be caused by loss of ion energy from the mixing region (an ion heat pulse). 36 refs., 15 figs., 1 tabs

  13. Thermal and hydraulic analyses of TFTR cooling water system and magnetic field coils

    International Nuclear Information System (INIS)

    Lee, A.Y.

    1975-10-01

    The TFTR toroidal field coils, ohmic heating, hybrid and equilibrium field coils are cooled by water from the machine area cooling water system. The system has the following major equipment and capacities: flow rate of 3600 gpm; ballast tank volume of 5500 gal; pumps of 70.4 m head; chiller refrigeration rating of 3300 tons and connecting pipe of 45.7 cm I.D. The performance of the closed loop system was analyzed and found to be adequate for the thermal loads. The field coils were analyzed with detailed thermal and hydraulic models, including a simulation of the complete water cooling loop. Under the nominal operating mode of one second of toroidal field flat top time and 300 seconds of pulse cycle time, the maximum temperature for the TF coils is 53 0 C; for the OH coils 46 0 C and for the EF coils 39 0 C, which are well below the coil design limit of 120 0 C. The maximum TF coil coolant temperature is 33 0 C which is below the coolant design limit of 100 0 C. The overall pressure loss of the system is below 6.89 x 10 5 Pa (100 psi). With the given chiller refrigeration capacity, the TF coils can be operated to yield up to 4 seconds of flat top time. The TF coils can be operated on a steady state basis at up to 20% of the pulsed duty design current rating of 7.32 kA/coil

  14. Structural analysis of TFTR TF coils and support structure for 6 Tesla operation

    International Nuclear Information System (INIS)

    Zatz, I.J.; Cargulia, G.; Lontai, L.

    1995-01-01

    The Tokamak Fusion Test Reactor (TFTR), which has been on line since December 1982, has successfully operated at its design Toroidal Field (TF) of 5.2 Tesla. Analysis of test data has indicated that the measured peak D-D neutron power in supershots may be scaled to the fourth power of TF field. Increasing the TF field to 6 Tesla provides the opportunity to explore the possibility of improving the D-T fusion yield, with the use of tritium. This increase in TF field from 5.2 to 6.0 Tesla increases the centering force by 33% and the out-of-plane force by 15% over previous peak operating levels. To examine the impact of the increase in loads on the TF coil, case and supporting structure, finite element analyses (FEA) were performed with and without the presence of loose bolts in the TF case. Note that the loose bolts comprise a fraction of the total number of bolts fastening the TF case sidewalls to the inner and outer rings of the case. Extensive analysis was performed using the FEA results in conjunction with supplementary calculations. Results are presented for the TF case, bolts, copper conductors, insulation, and supporting structure which indicate that the TF coils can successfully operate at 6 Tesla for a reasonable number of pulses

  15. Helium, iron and electron particle transport and energy transport studies on the TFTR tokamak

    International Nuclear Information System (INIS)

    Synakowski, E.J.; Efthimion, P.C.; Rewoldt, G.; Stratton, B.C.; Tang, W.M.; Grek, B.; Hill, K.W.; Hulse, R.A.; Johnson, D.W.; Mansfield, D.K.; McCune, D.; Mikkelsen, D.R.; Park, H.K.; Ramsey, A.T.; Redi, M.H.; Scott, S.D.; Taylor, G.; Timberlake, J.; Zarnstorff, M.C.

    1993-03-01

    Results from helium, iron, and electron transport on TFTR in L-mode and Supershot deuterium plasmas with the same toroidal field, plasma current, and neutral beam heating power are presented. They are compared to results from thermal transport analysis based on power balance. Particle diffusivities and thermal conductivities are radially hollow and larger than neoclassical values, except possibly near the magnetic axis. The ion channel dominates over the electron channel in both particle and thermal diffusion. A peaked helium profile, supported by inward convection that is stronger than predicted by neoclassical theory, is measured in the Supershot The helium profile shape is consistent with predictions from quasilinear electrostatic drift-wave theory. While the perturbative particle diffusion coefficients of all three species are similar in the Supershot, differences are found in the L-Mode. Quasilinear theory calculations of the ratios of impurity diffusivities are in good accord with measurements. Theory estimates indicate that the ion heat flux should be larger than the electron heat flux, consistent with power balance analysis. However, theoretical values of the ratio of the ion to electron heat flux can be more than a factor of three larger than experimental values. A correlation between helium diffusion and ion thermal transport is observed and has favorable implications for sustained ignition of a tokamak fusion reactor

  16. Gas utilization in TFTR [Tokamak Fusion Test Reactor] neutral beam injectors

    International Nuclear Information System (INIS)

    Kamperschroer, J.H.; Gammel, G.M.; Kugel, H.W.; Grisham, L.R.; Stevenson, T.N.; von Halle, A.; Williams, M.D.

    1987-08-01

    Measurements of gas utilization in a test TFTR neutral beam injector have been performed to study the feasibility of running tritium neutral beams with existing ion sources. Gas consumption is limited by the restriction of 50,000 curies of T 2 allowed on site. It was found that the gas efficiency of the present long-pulse ion sources is higher than it was with previous short-pulse sources. Gas efficiencies were studied over the range of 35 to 55%. At the high end of this range the neutral fraction of the beam fell below that predicted by room temperature molecular gas flow. This is consistent with observations made on the JET injectors, where it has been attributed to beam heating of the neutralizer gas and a concomitant increase in conductance. It was found that a working gas isotope exchange from H 2 to D 2 could be accomplished on the first beam shot after changing the gas supply, without any intermediate preconditioning. The mechanism believed responsible for this phenomenon is heating of the plasma generator walls by the arc and a resulting thermal desorption of all previously adsorbed and implanted gas. Finally, it was observed that an ion source conditioned to 120 kV operation could produce a beam pulse after a waiting period of fourteen hours by preceding the beam extraction with several hi-pot/filament warm-up pulses, without any gas consumption. 18 refs., 7 figs., 2 tabs

  17. Operation of a TFTR ion source with a ground potential gas feed into the neutralizer

    International Nuclear Information System (INIS)

    Kamperschroer, J.H.; Dudek, L.E.; Grisham, L.R.; Newman, R.A.; O'Connor, T.E.; Stevenson, T.N.; von Halle, A.; Williams, M.D.; Wright, K.E.

    1991-01-01

    TFTR long pulse ion sources have been operated with gas fed only into the neutralizer. Gas for the plasma generator entered through the accelerator rather than directly into the arc chamber. This modification has been proposed for tritium beam operation to locate control electronics at ground potential and to simplify tritium plumbing. Source operation with this configuration and with the nominal gas system that feeds gas into both the ion source and the center of the neutralizer are compared. Comparison is based upon accelerator grid currents, beam composition, and neutral power delivered to the calorimeter. Charge exchange in the accelerator can be a significant loss mechanism in both systems at high throughput. A suitable operating point with the proposed system was found that requires 30% less gas than used presently. The extracted D + , D + 2 , and D + 3 fractions of the beam were found to be a function of the gas throughput; at similar throughputs, the two gas feed systems produced similar extracted ion fractions. Operation at the proposed gas efficient point results in a small reduction (relative to the old high throughput mode) in the extracted D + fraction of the beam from 77% to 71%, with concomitant changes in the D + 2 fraction from 18% to 26%, and 6% to 3% for D + 3 . The injected power is unchanged, ∼2.2 MW at 95 kV

  18. Helium, Iron and Electron Particle Transport and Energy Transport Studies on the TFTR Tokamak

    Science.gov (United States)

    Synakowski, E. J.; Efthimion, P. C.; Rewoldt, G.; Stratton, B. C.; Tang, W. M.; Grek, B.; Hill, K. W.; Hulse, R. A.; Johnson, D .W.; Mansfield, D. K.; McCune, D.; Mikkelsen, D. R.; Park, H. K.; Ramsey, A. T.; Redi, M. H.; Scott, S. D.; Taylor, G.; Timberlake, J.; Zarnstorff, M. C. (Princeton Univ., NJ (United States). Plasma Physics Lab.); Kissick, M. W. (Wisconsin Univ., Madison, WI (United States))

    1993-03-01

    Results from helium, iron, and electron transport on TFTR in L-mode and Supershot deuterium plasmas with the same toroidal field, plasma current, and neutral beam heating power are presented. They are compared to results from thermal transport analysis based on power balance. Particle diffusivities and thermal conductivities are radially hollow and larger than neoclassical values, except possibly near the magnetic axis. The ion channel dominates over the electron channel in both particle and thermal diffusion. A peaked helium profile, supported by inward convection that is stronger than predicted by neoclassical theory, is measured in the Supershot The helium profile shape is consistent with predictions from quasilinear electrostatic drift-wave theory. While the perturbative particle diffusion coefficients of all three species are similar in the Supershot, differences are found in the L-Mode. Quasilinear theory calculations of the ratios of impurity diffusivities are in good accord with measurements. Theory estimates indicate that the ion heat flux should be larger than the electron heat flux, consistent with power balance analysis. However, theoretical values of the ratio of the ion to electron heat flux can be more than a factor of three larger than experimental values. A correlation between helium diffusion and ion thermal transport is observed and has favorable implications for sustained ignition of a tokamak fusion reactor.

  19. Diffusion of alpha-like MeV ions in TFTR

    International Nuclear Information System (INIS)

    Boivin, R.L.; Zweben, S.J.; Chang, C.S.; Hammett, G.; Mynick, H.E.; White, R.B.

    1991-01-01

    Single particle confinement of alpha particles is of crucial importance in reactor-grade tokamaks like BPX and ITER. Besides the well-known process of first-orbit losses, mechanisms that could lead to significant loss of alpha particles are turbulence-induced diffusion and toroidal field ripple stochastic diffusion. These two mechanisms have been separately studied in TFTR using two different detectors (one at the bottom of the machine and the other near the outer midplane) which can detect escaping charged fusion products, namely the 1 MeV triton and the 3 MeV proton in D-D plasmas (and also the 3.5 MeV alpha in D-T). The main difficulty in this type of experiment lies in the necessity of distinguishing the diffusion process from the always-present first-orbit loss-process. In this paper, we show how these two processes can be distinguished using the pitch-angle discrimination of the detectors. The pitch-angle is defined here as the angle of the particle trajectory with respect to the toroidal direction and so is a measure of the ion magnetic moment, μ. Results obtained at the midplane would be the first reported evidence of TF ripple diffusion in a tokamak. (author) 3 refs., 2 figs

  20. Multiple track Doppler-shift spectroscopy system for TFTR neutral beam injectors

    International Nuclear Information System (INIS)

    Kamperschroer, J.H.; Kugel, H.W.; Reale, M.A.

    1986-09-01

    A Doppler-shift spectroscopy system has been installed on the TFTR neutral beam injection system to measure species composition during both conditioning and injection pulses. Two intensified vidicon detectors and two spectrometers are utilized in a system capable of resolving data from up to twelve ion sources simultaneously. By imaging the light from six ion sources onto one detector, a cost-effective system has been achieved. Fiber optics are used to locate the diagnostic in an area remote from the hazards of the tokamak test cell allowing continuous access, and eliminating the need for radiation shielding of electronic components. Automatic hardware arming and interactive data analysis allow beam composition to be computed between tokamak shots for use in analyzing plasma heating experiments. Measurements have been made using lines of sight into both the neutralizer and the drift duct. Analysis of the data from the drift duct is both simpler and more accurate since only neutral particles are present in the beam at this location. Comparison of the data taken at these two locations reveals the presence of partially accelerated particles possessing an estimated 1/e half-angle divergence of 15 0 and accounting for up to 30% of the extracted power

  1. Overcurrent protection for the TFTR neutral beam sources during spark down

    International Nuclear Information System (INIS)

    Praeg, W.F.

    1979-01-01

    The accelerating grid of a neutral beam source (NBS) of the Tokamak Fusion Test Reactor (TFTR) operates at 120 kV and 65 A. The capacitance to ground between the switch tube (ST) and the NBS is C 1 approx. 5 nF (approx. 36 J). The arc and filament power supplies for the NBS float at 120 kV and have a capacitance to ground of C 2 approx. 2 nF (approx. 14 J). When the NBS sparks to ground, C 2 begins to discharge immediately. The ST impedance limits the fault current from the high voltage (HV) power supply to approx. 100 A until it disconnects the power source 1 begins to discharge. During spark down, fault currents are limited with a saturated time-delay transformer (STDT) connected between the ST and the NBS and with a snubber, which is in the arc and filament power leads, in connection with a spark gap. Alternatively, STDT's can be used for the HV and for the arc and filament power leads. This paper presents design details and experimental results of the overcurrent protection circuits

  2. A labview approach to instrumentation for the TFTR bumper limiter alignment project

    International Nuclear Information System (INIS)

    Skelly, G.N.; Owens, D.K.

    1992-01-01

    This paper reports on a project recently undertaken to measure the alignment of the TFTR bumper limiter in relation to the toroidal magnetic field axis. The process involved the measurement of the toroidal magnetic field, and the positions of the tiles that make up the bumper limiter. The basis for the instrument control and data acquisition system was National Instrument's LabVIEW 2. LabVIEW is a graphical programming system for developing scientific and engineering applications on a Macintosh. For this project, a Macintosh IIci controlled the IEEE-488 GPIB programmable instruments via an interface box connected to the SCSI port of the computer. With LabVIEW, users create graphical software modules called virtual instruments instead of writing conventional text-based code. To measure the magnetic field, the control system acquired data from two nuclear magnetic resonance magnetometers while the torroidal field coils were pulsed. To measure the position of the tiles on the limiter, an instrumented mechanical arm was used inside the vessel

  3. The TFTR 40 MW neutral beam injection system and DT operations

    International Nuclear Information System (INIS)

    Stevenson, T.; O'Connor, T.; Garzotto, V.

    1995-01-01

    Since December 1993, TFTR has performed DT experiments using tritium fuel provided mainly by neutral beam injection. Significant alpha particle populations and reactor-like conditions have been achieved at the plasma core, and fusion output power has risen to a record 10.7 MW using a record 40 MW NB heating. Tritium neutral beams have injected into over 480 DT plasmas and greater than 500 kCi have been processed through the neutral beam gas, cryo, and vacuum systems. Beam tritium injections, as well as tritium feedstock delivery and disposal, have now become part of routine operations. Shot reliability with tritium is about 90% and is comparable to deuterium shot reliability. This paper describes the neutral beam DT experience including the preparations, modifications, and operating techniques that led to this high level of success, as well as the critical differences in beam operations encountered during DT operations. Also, the neutral beam maintenance and repair history during DT operations, the corrective actions taken, and procedures developed for handling tritium contaminated components are discussed in the context of supporting a continuous DT program

  4. Ion temperature gradient driven transport in a density modification experiment on the TFTR tokamak

    International Nuclear Information System (INIS)

    Horton, W.; Lindberg, D.; Kim, J.Y.; Dong, J.Q.; Hammett, G.W.; Scott, S.D.; Zarnstorff, M.C.; Hamaguchi, S.

    1991-07-01

    TFTR profiles from a supershot density-modification experiment are analyzed for their local and ballooning stability to toroidal η i -modes in order to understand the initially puzzling results showing no increase in X i when a pellet is used to produce an abrupt and large increase in the η i parameter. The local stability analysis assumes that k parallel = 1/qR and ignores the effects of shear, but makes no assumption on the magnitude of k parallel v ti /ω. The ballooning stability analysis determines a self-consistent linear spectrum of k parallel's including the effect of shear and toroidicity, but it expands in k parallel v ti /ω ≤ 1, which is a marginal assumption for this experiment. Nevertheless, the two approaches agree well and show that the mixing length estimate of the transport rate does not change appreciably during the density-modification and has a value close to or less than the observed X i , in contrast to most previous theories which predicted X i 's which were over an order-of-magnitude too large. However, we are still unable to explain the observed increase X i (r) with minor radius by adding the effects of the finite beta drift - MHD mode coupling, the slab-like mode, or the trapped electron response. The experimental tracking 0.2 e /X i i and trapped-electron driving mechanisms are operating. 4 refs., 5 figs., 5 tabs

  5. The relationship between turbulence measurements and transport in different heating regimes in TFTR

    International Nuclear Information System (INIS)

    Bretz, N.L.; Mazzucato, E.; Nazikian, R.; Paul, S.F.; Hammett, G.; Rewoldt, G.; Tang, W.M.; Zarnstorff, M.C.

    1992-01-01

    The scaling of broad band density fluctuations in the confinement zone of TFTR measured by microwave scattering, beam emission spectroscopy (BES), and reflectometry show a relationship between these fluctuations and energy transport measured from power balance calculations. In L-mode plasmas scattering and BES indicates that the density fluctuation level, δn 2 , in the confinement zone for 0.2 aux and I p in a way that is consistent with variations in energy transport. Fluctuation levels measured with all systems increase strongly toward the edge in all heating regimes following increases in energy transport coefficients. Measurements using BES have shown that poloidal and radial correlation lengths in the confinement zone of L-mode and supershot plasmas fall in the range of 1 to 2 cm. with a wave structure which has k max ∼ 1 cm -1 (k perpendicular ps ∼ 0.2) in the poloidal direction and k max approaching zero in the radial direction. A simple estimate of the diffusion coefficient based on a measured radial correlation length and correlation time indicates good agreement with power balance calculations. Similar estimates using reflectometry give radial coherence lengths at 10 to 20 kHz in low density ohmic and supershot plasmas of between I and 2 cm

  6. Absolute calibration of TFTR neutron detectors for D-T plasma operation

    International Nuclear Information System (INIS)

    Jassby, D.L.; Johnson, L.C.; Roquemore, A.L.; Strachan, J.D.; Johnson, D.W.; Medley, S.S.; Young, K.M.

    1995-03-01

    The two most sensitive TFTR fission-chamber detectors were absolutely calibrated in situ by a D-T neutron generator (∼5 x 10 7 n/s) rotated once around the torus in each direction, with data taken at about 45 positions. The combined uncertainty for determining fusion neutron rates, including the uncertainty in the total neutron generator output (±9%), counting statistics, the effect of coil coolant, detector stability, cross-calibration to the current mode or log Campbell mode and to other fission chambers, and plasma position variation, is about ±13%. The NE-451 (ZnS) scintillators and 4 He proportional counters that view the plasma in up to 10 collimated sightlines were calibrated by scanning. the neutron generator radially and toroidally in the horizontal midplane across the flight tubes of 7 cm diameter. Spatial integration of the detector responses using the calibrated signal per unit chord-integrated neutron emission gives the global neutron source strength with an overall uncertainty of ±14% for the scintillators and ±15% for the 4 He counters

  7. Measurements of DT and DD neutron yields by neutron activation on TFTR

    International Nuclear Information System (INIS)

    Barnes, C.W.; Larson, A.R.; LeMunyan, G.

    1994-01-01

    A variety of elemental foils have been activated by neutron fluence from TFTR under conditions with the DT neutron yield per shot ranging from 10 12 to over 10 18 , and with the DT/(DD+DT) neutron ratio varying from 0.5% (from triton burnup) to unity. Linear response over this large dynamic range is obtained by reducing the mass of the foils and increasing the cooling time, all while accepting greatly improved counting statistics. Effects on background gamma-ray lines from foil-capsule-material contaminants. and the resulting lower limits on activation foil mass, have been determined. DT neutron yields from dosimetry standard reactions on aluminum, chromium, iron, nickel, zirconium, and indium are in agreement within the ±9% (one-sigma,) accuracy of the measurements: also agreeing are yields from silicon foils using the ACTL library cross-section. While the ENDF/B-V library has too low a cross-section. Preliminary results from a variety of other threshold reactions are presented. Use of the 115 In(n,n) 115m In reaction (0.42 times as sensitive to DT neutrons as DD neutrons) in conjunction with pure-DT reactions allows a determination of the DT/(DD+DT) ratio in trace tritium or low-power tritium beam experiments

  8. Measurements of DT and DD neutron yields by neutron activation on TFTR

    International Nuclear Information System (INIS)

    Barnes, C.W.; Larson, A.R.; LeMunyan, G.

    1995-03-01

    A variety of elemental foils have been activated by neutron fluence from TFTR under conditions with the DT neutron yield per shot ranging from 10 12 to over 10 18 , and with the DT/(DD+DT) neutron ratio varying from 0.5% (from triton burnup) to unity. Linear response over this large dynamic range is obtained by reducing the mass of the foils and increasing the cooling time, all while accepting greatly improved counting statistics. Effects on background gamma-ray lines from foil-capsule-material contaminants, and the resulting lower limits on activation foil mass, have been determined. DT neutron yields from dosimetry standard reactions on aluminum, chromium, iron, nickel, zirconium, and indium are in agreement within the ±9% (one-sigma) accuracy of the measurements; also agreeing are yields from silicon foils using the ACTL library cross-section, while the ENDF/B-V library has too low a cross-section. Preliminary results from a variety of other threshold reactions are presented. Use of the 115 In(n.n') 115m In reaction (0.42 times as sensitive to DT neutrons as DD neutrons) in conjunction with pure-DT reactions allows a determination of the DT/(DD+DT) ratio in trace tritium or low-power tritium beam experiments

  9. Control system implementation for a complex low inventory cryogenic distillation system for Princeton TFTR

    International Nuclear Information System (INIS)

    Busigin, A.; Busigin, C.J.; Adamek, F.; Woodall, K.B.; Robins, J.R.; Bellamy, D.G.; Fong, C.; Kalyanam, K.M.; Sood, S.K.

    1995-01-01

    The TFTR Tritium Purification System (TPS) is based on a Pd/Ag diffuser front-end for separating hydrogen isotopes from inert gas, and a four column cryogenic distillation cascade for separation of hydrogen isotopes. The system has a tritium inventory of approximately 0.5 g while successfully producing pure H 2 , D 2 and T 2 products. The system has recently been built and successfully commissioned with protium and deuterium. Stable automatic control of the cascade has been demonstrated even when feed rate and composition varied. The automatic control scheme maintained stable column inventories and excellent H 2 and D 2 product qualities. The control system employed new control concepts such as real time analysis of mid-column composition using temperature and pressure data for feedback control. Very stable column inventory control was achieved by automatic adjustment of inter-column flows (feed forward and feed back). This paper discusses the control system design and presents performance test results. (orig.)

  10. Mechanical design of the folded waveguide for PBX-M and TFTR

    International Nuclear Information System (INIS)

    Fogelman, C.H.; Bigelow, T.S.; Yugo, J.J.

    1995-01-01

    The folded waveguide (FWG) antenna is an advanced Cyclotron Range of Frequencies launcher being designed at Oak Ridge National Laboratory in collaboration with Princeton Plasma Physics Laboratory. The FWG offers a drastic increase in radio frequency (RF) power density over typical loop antennas. It also results in internal electric fields of much lower magnitude near the plasma. It is scheduled for installation on either the Tokamak Fusion Test Reactor (TFTR) or the Princeton Beta Experiment-Modified (PBX-M) tokamak in January 1996. The design objective is to provide an FWG that can withstand the thermal loads and disruption scenarios and meet the space constants of both machines. The design is also intended to be prototypical for the International Thermonuclear Experimental Reactor (ITER). The FWG is fully retractable, and maintenance operations can be performed while the vessel remains under vacuum. The FWG can operate in fast-wave mode, or it can be retracted, rotated 90 degrees, and reengaged for the ion-Bernstein wave launch. The polarizing plate completely covers the front of the antenna, except for slots cut at every other gap between with plates of other configurations such as a 0-π dipole plate

  11. Cryosorption of helium on argon frost TFTR [Tokamak Fusion Test Reactor] neutral beamlines

    International Nuclear Information System (INIS)

    Kamperschroer, J.H.; Cropper, M.B.; Dylla, H.F.

    1989-11-01

    Helium pumping on argon frost has been investigated on TFTR neutral beam injectors and shown to be viable for limited helium beam operation. Maximum pumping speeds are ∼ 25% less than those measured for pumping of deuterium. Helium pumping efficiency is low, > 20 argon atoms are required to pump each helium atom. Adsorption isotherms are exponential and exhibit a two-fold increase in adsorption capacity as the cryopanel temperature is reduced from 4.3 K to 3.7 K. Pumping speed was found to be independent of cryopanel temperature over the temperature range studied. After pumping a total of 2000 torr-l of helium, the beamline base pressure rose to 2x10 -5 torr from an initial value of 10 -8 torr. Accompanying this three order of magnitude increase in pressure was a modest 40% decrease in pumping speed. The introduction of 168 torr-l of deuterium prior to helium injection reduced the pumping speed by a factor of two with no decrease in adsorption capacity. 29 refs., 7 figs

  12. Design of TFTR movable limiter blades for ohmic and neutral-beam-heated plasmas

    International Nuclear Information System (INIS)

    Doll, D.W.; Ulrickson, M.A.; Cecchi, J.L.; Citrolo, J.C.; Weissenburger, D.; Bialek, J.

    1981-10-01

    A new set of movable limiter blades has been designed for TFTR that will meet both the requirements of the 4 MW ohmic heated and the 33 MW neutral beam heated plasmas. This is accomplished with three limiter blades each having and elliptical shape along the toroidal direction. Heat flux levels are acceptable for both ohmic heated and pre-strong compression plasmas. The construction consists of graphite tiles attached to cooled backing plates. The tiles have an average thickness of approx. 4.7 cm and are drawn against the backing plate with spring loaded fasteners that are keyed into the graphite. The cooled backing plate provides the structure for resisting disruption and fault induced loads. A set of rollers attached to the top and bottom blades allow them to be expanded and closed in order to vary the plasma surface for scaling experiments. Water cooling lines penetrate only the mid-plane port cover/support plate in such a way as to avoid bolted water connections inside the vacuum boundary and at the same time allow blade movement. Both the upper and lower blades are attached to the mid-plane limiter blade through pivots. Pivot connections are protected against arcing with an alumina coating and a shunt bar strap. Remote handling is considered throughout the design

  13. Local transport barrier formation and relaxation in reverse-shear plasmas on the TFTR tokamak

    International Nuclear Information System (INIS)

    Synakowski, E.J.; Beer, M.A.

    1997-02-01

    The roles of turbulence stabilization by sheared E x B flow and Shafranov-shift gradients are examined for TFTR. Enhanced Reverse-Shear plasmas. Both effects in combination provide the basis of a positive-feedback model that predicts reinforced turbulence suppression with increasing pressure gradient. Local fluctuation behavior at the onset of ERS confinement is consistent with this framework. The power required for transitions into the ERS regime are lower when high power neutral beams are applied earlier in the current profile evolution, consistent with the suggestion that both effects play a role. Separation of the roles of E x B and Shafranov shift effects was performed by varying the E x B shear through changes in the toroidal velocity with nearly-steady-state pressure profiles. Transport and fluctuation levels increase only when E x B shearing rates are driven below a critical value that is comparable to the fastest linear growth rates of the dominant instabilities. While a turbulence suppression criterion that involves the ratio of shearing to linear growth rates is in accord with many of these results, the existence of hidden dependencies of the criterion is suggested in experiments where the toroidal field was varied. The forward transition into the ERS regime has also been examined in strongly rotating plasmas. The power threshold is higher with unidirectional injection than with balanced injection

  14. A comparison of hydrogen vs. helium glow discharge effects on fusion device first-wall conditioning

    International Nuclear Information System (INIS)

    Dylla, H.F.

    1989-09-01

    Hydrogen- and deuterium-fueled glow discharges are used for the initial conditioning of magnetic fusion device vacuum vessels following evacuation from atmospheric pressure. Hydrogenic glow discharge conditioning (GDC) significantly reduces the near-surface concentration of simple adsorbates, such as H 2 O, CO, and CH 4 , and lowers ion-induced desorption coefficients by typically three orders of magnitude. The time evolution of the residual gas production observed during hydrogen-glow discharge conditioning of the carbon first-wall structure of the TFTR device is similar to the time evolution observed during hydrogen GDC of the initial first-wall configuration in TFTR, which was primarily stainless steel. Recently, helium GDC has been investigated for several wall-conditioning tasks on a number of tokamaks including TFTR. Helium GDC shows negligible impurity removal with stainless steel walls. For impurity conditioning with carbon walls, helium GDC shows significant desorption of H 2 O, CO, and CO 2 ; however, the total desorption yield is limited to the monolayer range. In addition, helium GDC can be used to displace hydrogen isotopes from the near-surface region of carbon first-walls in order to lower hydrogenic retention and recycling. 38 refs., 6 figs

  15. Eddy current analysis in fusion devices

    International Nuclear Information System (INIS)

    Turner, L.R.

    1988-06-01

    In magnetic fusion devices, particularly tokamaks and reversed field pinch (RFP) experiments, time-varying magnetic fields are in intimate contact with electrically conducting components of the device. Induced currents, fields, forces, and torques result. This note reviews the analysis of eddy current effects in the following systems: Interaction of a tokamak plasma with the eddy currents in the first wall, blanket, and shield (FWBS) systems; Eddy currents in a complex but two-dimensional vacuum vessel, as in TFTR, JET, and JT-60; Eddy currents in the FWBS system of a tokamak reactor, such as NET, FER, or ITER; and Eddy currents in a RFP shell. The cited studies are chosen to be illustrative, rather than exhaustive. 42 refs

  16. First evidence of collective alpha particle effect on TAE modes in the TFTR D-T experiment

    International Nuclear Information System (INIS)

    Wong, K.L.; Schmidt, G.; Batha, S.H.

    1995-08-01

    The alpha particle effect on the excitation of toroidal Alfven eigenmodes (TAE) was investigated in deuterium-tritium (d-t) plasmas in the Tokamak Fusion Test Reactor (TFTR). RF power was used to position the plasma near the instability threshold, and the alpha particle effect was inferred from the reduction of RF power threshold for TAE instability in d-t plasmas. Initial calculations indicate that the alpha particles contribute 10--30% of the total drive in a d-t plasma with 3 MW of peak fusion power

  17. Measurements of the toroidal plasma rotation velocity in TFTR major-radius compression experiments with auxiliary neutral beam heating

    International Nuclear Information System (INIS)

    Bitter, M.; Wong, K.L.; Scott, S.; Hsuan, H.; Grek, B.; Johnson, D.; Tait, G.

    1990-01-01

    The time history of the central toroidal plasma rotation velocity in Tokamak Fusion Test Reactor (TFTR) experiments [Phys. Rev. Lett. 55, 2587 (1985)] with auxiliary heating by neutral deuterium beam injection and major-radius compression has been measured from the Doppler shift of the emitted Ti XXI Kα line radiation. The experiments were conducted for neutral beam powers in the range 2.1--3.8 MW and line-averaged densities in the range 1.8--3.0x10 19 m -2 . The observed rotation velocity increase during compression is consistent with theoretical estimates

  18. Application of sensitivity analysis to a quantitative assessment of neutron cross-section requirements for the TFTR: an interim report

    International Nuclear Information System (INIS)

    Gerstl, S.A.W.; Dudziak, D.J.; Muir, D.W.

    1975-09-01

    A computational method to determine cross-section requirements quantitatively is described and applied to the Tokamak Fusion Test Reactor (TFTR). In order to provide a rational basis for the priorities assigned to new cross-section measurements or evaluations, this method includes quantitative estimates of the uncertainty of currently available data, the sensitivity of important nuclear design parameters to selected cross sections, and the accuracy desired in predicting nuclear design parameters. Perturbation theory is used to combine estimated cross-section uncertainties with calculated sensitivities to determine the variance of any nuclear design parameter of interest

  19. High poloidal beta equilibria in TFTR limited by a natural inboard poloidal field null

    International Nuclear Information System (INIS)

    Sabbagh, S.A.; Gross, R.A.; Mauel, M.E.; Navratil, G.A.; Bell, M.G.; Bell, R.; Bitter, M.; Bretz, N.L.; Budny, R.V.; Bush, C.E.; Chance, M.S.; Efthimion, P.C.; Fredrickson, E.D.; Hatcher, R.; Hawryluk, R.J.; Hirshman, S.P.; Janos, A.C.; Jardin, S.C.; Jassby, D.L.; Manickam, J.; McCune, D.C.; McGuire, K.M.; Medley, S.S.; Mueller, D.; Nagayama, Y.; Owens, D.K.; Okabayashi, M.; Park, H.K.; Ramsey, A.T.; Stratton, B.C.; Synakowski, E.J.; Taylor, G.; Wieland, R.M.; Zarnstorff, M.C.; Kesner, J.; Marmar, E.S.; Terry, J.L.

    1991-07-01

    Recent operation of the Tokamak Fusion Test Reactor TFTR, has produced plasma equilibria with values of Λ triple-bond β p eq + l i /2 as large as 7, εβ p dia triple-bond 2μ 0 ε /much-lt B p much-gt 2 as large as 1.6, and Troyon normalized diamagnetic beta, β N dia triple-bond 10 8 t perpendicular>aB 0 /I p as large as 4.7. When εβ p dia approx-gt 1.25, a separatrix entered the vacuum chamber, producing a naturally diverted discharge which was sustained for many energy confinement times, τ E . The largest values of εβ p and plasma stored energy were obtained when the plasma current was ramped down prior to neutral beam injection. The measured peak ion and electron temperatures were as large as 24 keV and 8.5 keV, respectively. Plasma stored energy in excess of 2.5 MJ and τ E greater than 130 msec were obtained. Confinement times of greater than 3 times that expected from L-mode predictions have been achieved. The fusion power gain. Q DD , reached a values of 1.3 x 10 -3 in a discharge with I p = 1 MA and εβ p dia = 0.85. A large, sustained negative loop voltage during the steady state portion of the discharge indicates that a substantial non-inductive component of I p exists in these plasmas. Transport code analysis indicates that the bootstrap current constitutes up to 65% of I p . Magnetohydrodynamic (MHD) ballooning stability analysis shows that while these plasmas are near, or at the β p limit, the pressure gradient in the plasma core is in the first region of stability to high-n modes. 24 refs., 10 figs

  20. Neutron and hard x-ray measurements during pellet deposition in TFTR

    Energy Technology Data Exchange (ETDEWEB)

    Heidbrink, W.W.; Milora, S.L.; Schmidt, G.L.; Schneider, W.; Ramsey, A.

    1986-06-01

    Measurements of neutrons and hard x rays are made with a pair of plastic scintillators during injection of deuterium pellets into deuterium TFTR plasmas. Three cases are investigated. During ohmic heating in plasmas with few runaway electrons, the neutron emission does not increase when a pellet is injected, indicating that strong acceleration of the pellet ions does not occur. In ohmic plasmas with low but detectable levels of runaway electrons, an x-ray burst is observed on a detector near the pellet injector as the pellet ablates, while a detector displaced 126/sup 0/ toroidally from the injector does not measure a synchronous burst. Reduced pellet penetration correlates with the presence of x-ray emission, suggesting that the origin of the burst is bremsstrahlung from runaway electrons that strike the solid pellet. In deuterium beam-heated discharges, an increase in the d-d neutron emission is observed when the pellet ablates. In this case, the increase is due to fusion reactions between beam ions and the high density neutral and plasma cloud produced by ablation of the pellet; this localized density perturbation equilibrates in about 700 ..mu..sec. Analysis of the data indicates that the density propagates without forming a sharp shock front with a rapid initial propagation velocity (greater than or equal to 2 x 10/sup 7/ cm/sec) that subsequently decreases to around 3 x 10/sup 6/ cm/sec. Modelling suggests that the electron heat flux into the pellet cloud is much less than the classical Spitzer value.

  1. Confined trapped-alpha behavior in TFTR deuterium-tritium plasmas

    International Nuclear Information System (INIS)

    Medley, S.S.; Budny, R.V.; Redi, M.H.; Roquemore, A.L.; White, R.B.; Petrov, M.P.; Gorelenkov, N.N.

    1997-10-01

    Confined trapped-alpha energy spectra and differential radial density profiles in TFTR D-T plasmas are obtained with the Pellet Charge-eXchange (PCX) diagnostic which measures high energy (E α = 0.5--3.5 MeV), trapped alphas (v parallel /v = - 0.048) at a single time slice (Δt ∼ 1 msec) with a spatial resolution of Δr ∼ 5 cm. Tritons produced in D-D plasmas and RF-driven ion tails (H, 3 He or T) were also observed and energetic tritium ion tail measurements will be discussed. PCX alpha and triton energy spectra extending up to their birth energies were measured in the core of MHD-quiescent discharges where the expected classical slowing down and pitch angle scattering effects are not complicated by stochastic ripple diffusion and sawtooth activity. Both the shape of the measured alpha and triton energy distributions and their density ratios are in good agreement with TRANSP predictions, indicating that the PCX measurements are consistent with classical thermalization of the fusion-generated alphas and tritons. From calculations, these results set an upper limit on possible anomalous radial diffusion for trapped alphas of D α ≤ 0.01 m 2 s -1 . Outside the core, where the trapped alphas are influenced by stochastic ripple diffusion effects, the PCX measurements are consistent with the functional dependence of the Goldston-White-Boozer stochastic ripple threshold on the alpha energy and the q-profile. In the presence of strong sawtooth activity, the PCX diagnostic observes significant redistribution of the alpha signal radial profile wherein alphas are depleted in the core and redistributed to well outside the q = 1 radius, but apparently not beyond the energy-dependent stochastic ripple loss boundary

  2. ICRF heating and transport of deuterium-tritium plasmas in TFTR

    International Nuclear Information System (INIS)

    Murakami, M.; Batchelor, D.B.; Bush, C.E.

    1994-01-01

    This paper describes results of the first experiments utilizing high-power ion cyclotron range of frequency (ICRF) to heat deuterium-tritium (D-T) plasmas in reactor-relevant regimes on the Tokamak Fusion Test Reactor (TFTR). Results from these experiments have demonstrated efficient core, second harmonic, tritium heating of D-T supershot plasmas with tritium concentrations ranging from 6%--40%. Significant direct ion heating on the order of 60% of the input radio frequency (rf) power has been observed. The measured deposition profiles are in good agreement with two-dimensional modeling code predictions. Confinement in an rf-heated supershot is at least similar to that without rf, and possibly better in the electron channel. Efficient electron heating via mode conversion of fast waves to ion Bernstein waves (IBW) has been demonstrated in ohmic, deuterium-deuterium and DT-neutral beam injection plasmas with high concentrations of minority 3 He (n 3 He /n e > 10%). By changing the 3 He concentration or the toroidal field strength, the location of the mode-conversion radius was varied. The power deposition profile measured with rf power modulation showed that up to 70% of the power can be deposited on electrons at an off-axis position. Preliminary results with up to 4 MW coupled into the plasma by 90-degree phased antennas showed directional propagation of the mode-converted IBW. Heat wave propagation showed no strong inward thermal pinch in off-axis heating of an ohmically-heated (OH) target plasma in TFIR

  3. Temporal behavior of neutral particle fluxes in TFTR [Tokamak Fusion Test Reactor] neutral beam injectors

    International Nuclear Information System (INIS)

    Kamperschroer, J.H.; Gammel, G.M.; Roquemore, A.L.

    1989-09-01

    Data from an E parallel B charge exchange neutral analyzer (CENA), which views down the axis of a neutral beamline through an aperture in the target chamber calorimeter of the TFTR neutral beam test facility, exhibit two curious effects. First, there is a turn-on transient lasting tens of milliseconds having a magnitude up to three times that of the steady-state level. Second, there is a 720 Hz, up to 20% peak-to-peak fluctuation persisting the entire pulse duration. The turn-on transient occurs as the neutralizer/ion source system reaches a new pressure equilibrium following the effective ion source gas throughput reduction by particle removal as ion beam. Widths of the transient are a function of the gas throughput into the ion source, decreasing as the gas supply rate is reduced. Heating of the neutalizer gas by the beam is assumed responsible, with gas temperature increasing as gas supply rate is decreased. At low gas supply rates, the transient is primarliy due to dynamic changes in the neutralizer line density and/or beam species composition. Light emission from the drift duct corroborate the CENA data. At high gas supply rates, dynamic changes in component divergence and/or spatial profiles of the source plasma are necessary to explain the observations. The 720 Hz fluctuation is attributed to a 3% peak-to-peak ripple of 720 Hz on the arc power supply amplified by the quadratic relationship between beam divergence and beam current. Tight collimation by CENA apertures cause it to accept a very small part of the ion source's velocity space, producing a signal linearly proportional to beam divergence. Estimated fluctuations in the peak power density delivered to the plasma under these conditions are a modest 3--8% peak to peak. The efffects of both phenomena on the injected neutral beam can be ameliorated by careful operion of the ion sources. 21 refs., 11 figs., 2 tabs

  4. End points in discharge cleaning on TFTR (Tokamak Fusion Test Reactor)

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, D.; Dylla, H.F.; Bell, M.G.; Blanchard, W.R.; Bush, C.E.; Gettelfinger, G.; Hawryluk, R.J.; Hill, K.W.; Janos, A.C.; Jobes, F.C.

    1989-07-01

    It has been found necessary to perform a series of first-wall conditioning steps prior to successful high power plasma operation in the Tokamak Fusion Test Reactor (TFTR). This series begins with glow discharge cleaning (GDC) and is followed by pulse discharge cleaning (PDC). During machine conditioning, the production of impurities is monitored by a Residual Gas Analyzer (RGA). PDC is made in two distinct modes: Taylor discharge cleaning (TDC), where the plasma current is kept low (15--50 kA) and of short duration (50 ms) by means of a relatively high prefill pressure and aggressive PDC, where lower prefill pressure and higher toroidal field result in higher current (200--400 kA) limited by disruptions at q(a) /approx/ 3 at /approx/ 250 ms. At a constant repetition rate of 12 discharges/minute, the production rate of H/sub 2/O, CO, or other impurities has been found to be an unreliable measure of progress in cleaning. However, the ability to produce aggressive PDC with substantial limiter heating, but without the production of x-rays from runaway electrons, is an indication that TDC is no longer necessary after /approx/ 10/sup 5/ pulses. During aggressive PDC, the uncooled limiters are heated by the plasma from the bakeout temperature of 150/degree/C to about 250/degree/C over a period of three to eight hours. This limiter heating is important to enhance the rate at which H/sub 2/O is removed from the graphite limiter. 14 refs., 3 figs., 1 tab.

  5. End points in discharge cleaning on TFTR [Tokamak Fusion Test Reactor

    International Nuclear Information System (INIS)

    Mueller, D.; Dylla, H.F.; Bell, M.G.

    1989-07-01

    It has been found necessary to perform a series of first-wall conditioning steps prior to successful high power plasma operation in the Tokamak Fusion Test Reactor (TFTR). This series begins with glow discharge cleaning (GDC) and is followed by pulse discharge cleaning (PDC). During machine conditioning, the production of impurities is monitored by a Residual Gas Analyzer (RGA). PDC is made in two distinct modes: Taylor discharge cleaning (TDC), where the plasma current is kept low (15--50 kA) and of short duration (50 ms) by means of a relatively high prefill pressure and aggressive PDC, where lower prefill pressure and higher toroidal field result in higher current (200--400 kA) limited by disruptions at q(a) approx 3 at approx 250 ms. At a constant repetition rate of 12 discharges/minute, the production rate of H 2 O, CO, or other impurities has been found to be an unreliable measure of progress in cleaning. However, the ability to produce aggressive PDC with substantial limiter heating, but without the production of x-rays from runaway electrons, is an indication that TDC is no longer necessary after approx 10 5 pulses. During aggressive PDC, the uncooled limiters are heated by the plasma from the bakeout temperature of 150 degree C to about 250 degree C over a period of three to eight hours. This limiter heating is important to enhance the rate at which H 2 O is removed from the graphite limiter. 14 refs., 3 figs., 1 tab

  6. Transport simulations of ohmic TFTR experiments with profile-consistent microinstability-based models for chi/sub e/ and chi/sub i/

    International Nuclear Information System (INIS)

    Redi, M.H.; Tang, W.M.; Efthimion, P.C.; Mikkelsen, D.R.; Schmidt, G.L.

    1987-03-01

    Transport simulations of ohmically heated TFTR experiments with recently developed profile-consistent microinstability models for the anomalous thermal diffusivities, chi/sub e/ and chi/sub i/, give good agreement with experimental data. The steady-state temperature profiles and the total energy confinement times, tau/sub e/, were found to agree for each of the ohmic TFTR experiments simulated, including three high radiation cases and two plasmas fueled by pellet injection. Both collisional and collisionless models are tested. The trapped-electron drift wave microinstability model results are consistent with the thermal confinement of large plasma ohmic experiments on TFTR. We also find that transport due to the toroidal ion temperature gradient (eta/sub i/) modes can cause saturation in tau/sub E/ at the highest densities comparable to that observed on TFTR and equivalent to a neoclassical anomaly factor of 3. Predictions based on stabilized eta/sub i/-mode-driven ion transport are found to be in agreement with the enhanced global energy confinement times for pellet-fueled plasmas. 33 refs., 26 figs., 4 tabs

  7. Deposition of lithium on a plasma edge probe in TFTR -- Behavior of lithium-painted walls interacting with edge plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Hirooka, Y. [Univ. of California, San Diego, La Jolla, CA (United States); Ashida, K. [Toyama Univ. (Japan); Kugel, H. [Princeton Univ., NJ (United States)] [and others

    1998-05-01

    Recent observations have indicated that lithium pellet injection wall conditioning plays an important role in achieving the enhanced supershot regime in TFTR. However, little is understood about the behavior of lithium-coated limiter walls, interacting with edge plasmas. In the final campaign of TFTR, a cylindrical carbon fiber composite probe was inserted into the boundary plasma region and exposed to ohmically-heated deuterium discharges with lithium pellet injection. The ion-drift side probe surface exhibits a sign of codeposition of lithium, carbon, oxygen, and deuterium, whereas the electron side essentially indicates high-temperature erosion. It is found that lithium is incorporated in these codeposits in the form of oxide at the concentration of a few percent. In the electron side, lithium has been found to penetrate deeply into the probe material, presumably via rapid diffusion through interplane spaces in the graphite crystalline. Though it is not conclusive, materials mixing in the carbon and lithium system appears to be a key process in successful lithium wall conditioning.

  8. The effect of oxygen on the release of tritium during baking of TFTR D-T tiles

    Energy Technology Data Exchange (ETDEWEB)

    Shu, W.M. E-mail: shu@tpl.tokai.jaeri.go.jp; Gentile, C.A.; Skinner, C.H.; Langish, S.; Nishi, M.F

    2002-11-01

    A series of tests involving 10 h baking under the current ITER design conditions (240 deg. C with 933 Pa O{sub 2}) was performed using a cube of a carbon fiber composite tile that had been used in Tokamak Fusion Test Reactor (TFTR) during its deuterium-tritium burning operation. The removal rate of the codeposits was about 3 {mu}m/h near the surface and 0.9 {mu}m/h in the deeper region. Total amount of tritium released from the cube during 10 h baking was 202 MBq, while remaining tritium in the cube after baking was 403 MBq. Thus 10 h baking at 240 deg. C with 933 Pa O{sub 2} removed 1/3 of tritium from the cube. After 10 h baking, the tritium concentration on the cube surface also dropped by about 1/3. In addition, some tritium was released from another cube of the tile during baking at 240 deg. C in pure Ar, and a rapid increase of tritium release was observed when the purging gas was shifted from pure Ar to Ar-1%O{sub 2}. When a whole TFTR tile was baked in air at 350 deg. C for 1 h and then at 500 deg. C for 1 h, the ratios of tritium released were 53 and 47%, respectively. Oxygen reacted with carbon to produce carbon monoxide during baking in air.

  9. The effect of oxygen on the release of tritium during baking of TFTR D-T tiles

    International Nuclear Information System (INIS)

    Shu, W.M.; Gentile, C.A.; Skinner, C.H.; Langish, S.; Nishi, M.F.

    2002-01-01

    A series of tests involving 10 h baking under the current ITER design conditions (240 deg. C with 933 Pa O 2 ) was performed using a cube of a carbon fiber composite tile that had been used in Tokamak Fusion Test Reactor (TFTR) during its deuterium-tritium burning operation. The removal rate of the codeposits was about 3 μm/h near the surface and 0.9 μm/h in the deeper region. Total amount of tritium released from the cube during 10 h baking was 202 MBq, while remaining tritium in the cube after baking was 403 MBq. Thus 10 h baking at 240 deg. C with 933 Pa O 2 removed 1/3 of tritium from the cube. After 10 h baking, the tritium concentration on the cube surface also dropped by about 1/3. In addition, some tritium was released from another cube of the tile during baking at 240 deg. C in pure Ar, and a rapid increase of tritium release was observed when the purging gas was shifted from pure Ar to Ar-1%O 2 . When a whole TFTR tile was baked in air at 350 deg. C for 1 h and then at 500 deg. C for 1 h, the ratios of tritium released were 53 and 47%, respectively. Oxygen reacted with carbon to produce carbon monoxide during baking in air

  10. Design and operation of the pellet charge exchange diagnostic for measurement of energetic confined alphas and tritons on TFTR

    International Nuclear Information System (INIS)

    Medley, S.S.; Duong, H.H.

    1996-05-01

    Radially-resolved energy and density distributions of the energetic confined alpha particles in D-T experiments on TFTR are being measured by active neutral particle analysis using low-Z impurity pellet injection. When injected into a high temperature plasma, an impurity pellet (e.g. Lithium or Boron) rapidly ablates forming an elongated cloud which is aligned with the magnetic field and moves with the pellet. This ablation cloud provides a dense target with which the alpha particles produced in D-T fusion reactions can charge exchange. A small fraction of the alpha particles incident on the pellet ablation cloud will be converted to helium neutrals whose energy is essentially unchanged by the charge transfer process. By measuring the resultant helium neutrals escaping from the plasma using a mass and energy resolving charge exchange analyzer, this technique offers a direct measurement of the energy distribution of the incident high-energy alpha particles. Other energetic ion species can be detected as well, such as tritons generated in D-D plasmas and H or He 3 RF-driven minority ion tails. The diagnostic technique and its application on TFTR are described in detail

  11. Multichord time-resolved electron temperature measurements by the x-ray absorber-foil method on TFTR

    International Nuclear Information System (INIS)

    Kiraly, J.; Bitter, M.; Efthimion, P.

    1985-09-01

    Absorber foils have been installed in the TFTR X-Ray Imaging System to permit measurement of the electron temperature along 10 to 30 chords spaced at 5-12.5 cm with a time resolution of less than 100 μs. The technique uses the ratio of x-ray fluxes transmitted through two different foils. The ratio depends mainly on electron temperature. Simulations show that strong impurity line radiation can distort this ratio. To correct for these effects, special beryllium-scandium filters are employed to select the line-free region between 2 and 4.5 keV. Other filter pairs allow corrections for Fe L and Ni L line radiation as well as Ti K and Ni K emission. Good accuracy is also obtained with simple beryllium filters, provided that impurity corrections are incorporated in the analysis, taking line intensities from the x-ray pulse-height analysis diagnostic. A description of modeling calculations and a comparison of temperature values from this diagnostic with data from the x-ray pulse height analysis, the electron cyclotron emission, and the Thomson scattering diagnostics are presented. Several applications of the absorber foil electron temperature diagnostic on TFTR are discussed

  12. Multichord time-resolved electron temperature measurements by the x-ray absorber-foil method on TFTR

    Energy Technology Data Exchange (ETDEWEB)

    Kiraly, J.; Bitter, M.; Efthimion, P.; von Goeler, S.; Grek, B.; Hill, K.W.; Johnson, D.; McGuire, K.; Sauthoff, N.; Sesnic, S.

    1985-09-01

    Absorber foils have been installed in the TFTR X-Ray Imaging System to permit measurement of the electron temperature along 10 to 30 chords spaced at 5-12.5 cm with a time resolution of less than 100 ..mu..s. The technique uses the ratio of x-ray fluxes transmitted through two different foils. The ratio depends mainly on electron temperature. Simulations show that strong impurity line radiation can distort this ratio. To correct for these effects, special beryllium-scandium filters are employed to select the line-free region between 2 and 4.5 keV. Other filter pairs allow corrections for Fe L and Ni L line radiation as well as Ti K and Ni K emission. Good accuracy is also obtained with simple beryllium filters, provided that impurity corrections are incorporated in the analysis, taking line intensities from the x-ray pulse-height analysis diagnostic. A description of modeling calculations and a comparison of temperature values from this diagnostic with data from the x-ray pulse height analysis, the electron cyclotron emission, and the Thomson scattering diagnostics are presented. Several applications of the absorber foil electron temperature diagnostic on TFTR are discussed.

  13. Measurements of confined alphas and tritons in the MHD quiescent core of TFTR plasmas using the pellet charge exchange diagnostic

    International Nuclear Information System (INIS)

    Medley, S.S.; Budny, R.V.; Mansfield, D.K.

    1996-05-01

    The energy distributions and radial density profiles of the fast confined trapped alpha particles in DT experiments on TFTR are being measured in the energy range 0.5--3.5 MeV using a Pellet Charge eXchange (PCX) diagnostic. A brief description of the measurement technique which involves active neutral particle analysis using the ablation cloud surrounding an injected impurity pellet as the neutralizer is presented. This paper focuses on alpha and triton measurements in the core of MHD quiescent TFTR discharges where the expected classical slowing down and pitch angle scattering effects are not complicated by stochastic ripple diffusion and sawtooth activity. In particular, the first measurement of the alpha slowing down distribution up to the birth energy, obtained using boron pellet injection, is presented. The measurements are compared with predictions using either the TRANSP Monte-Carlo code and/or a Fokker-Planck Post-TRANSP processor code, which assumes that the alphas and tritons are well confined and slow down classically. Both the shape of the measured alpha and triton energy distributions and their density ratios are in good agreement with the code calculations. The authors conclude that the PCX measurements are consistent with classical thermalization of the fusion-generated alphas and tritons

  14. Alpha-Driven MHD and MHD-Induced Alpha Loss in TFTR DT Experiments

    Science.gov (United States)

    Chang, Zuoyang

    1996-11-01

    Theoretical calculation and numerical simulation indicate that there can be interesting interactions between alpha particles and MHD activity which can adversely affect the performance of a tokamak reactor (e.g., ITER). These interactions include alpha-driven MHD, like the toroidicity-induced-Alfven-eigenmode (TAE) and MHD induced alpha particle losses or redistribution. Both phenomena have been observed in recent TFTR DT experiments. Weak alpha-driven TAE activity was observed in a NBI-heated DT experiment characterized by high q0 ( >= 2) and low core magnetic shear. The TAE mode appears at ~30-100 ms after the neutral beam turning off approximately as predicted by theory. The mode has an amplitude measured by magnetic coils at the edge tildeB_p ~1 mG, frequency ~150-190 kHz and toroidal mode number ~2-3. It lasts only ~ 30-70 ms and has been seen only in DT discharges with fusion power level about 1.5-2.0 MW. Numerical calculation using NOVA-K code shows that this type of plasma has a big TAE gap. The calculated TAE frequency and mode number are close to the observation. (2) KBM-induced alpha particle loss^1. In some high-β, high fusion power DT experiments, enhanced alpha particle losses were observed to be correlated to the high frequency MHD modes with f ~100-200 kHz (the TAE frequency would be two-times higher) and n ~5-10. These modes are localized around the peak plasma pressure gradient and have ballooning characteristics. Alpha loss increases by 30-100% during the modes. Particle orbit simulations show the added loss results from wave-particle resonance. Linear instability analysis indicates that the plasma is unstable to the kinetic MHD ballooning modes (KBM) driven primarily by strong local pressure gradients. ----------------- ^1Z. Chang, et al, Phys. Rev. Lett. 76 (1996) 1071. In collaberation with R. Nazikian, G.-Y. Fu, S. Batha, R. Budny, L. Chen, D. Darrow, E. Fredrickson, R. Majeski, D. Mansfield, K. McGuire, G. Rewoldt, G. Taylor, R. White, K

  15. Study of the mass and energy resolution of the E parallel B charge exchange analyzer for TFTR

    International Nuclear Information System (INIS)

    Kaita, R.; Medley, S.S.

    1979-09-01

    The charge exchange diagnostic for TFTR requires simultaneous multispecie (H + , D + , γ + ) analysis of particles in the energy range of 0.5 - 150 keV. The analyzer design chosen to provide this capability employs a wide gap semi-circular region of superimposed parallel electric and magnetic fields to accomplish mass and energy resolution, respectively. Combined with a large area, multi-anode microchannel plate detector, this arrangement will enable the energy distributions of protons, deuterions, and tritons to be measured concurrently as a function of time during each discharge. A computer simulation program for calculating ion trajectories through the analyzer was written that includes a realistic model of the magnetic and electrostatic fringe fields. This report presents the results of a study of the proposed E parallel B analyzer, and it reveals that the fringe fields are not detrimental to the performance of the analyzer

  16. Development of large high-voltage pressure insulators for the Princeton TFTR [Tokamak Fusion Test Reactor] flexible transmission lines

    International Nuclear Information System (INIS)

    Scalise, D.T.; Fong, E.; Haughian, J.; Prechter, R.

    1986-10-01

    Specially formulated insulator materials with improved strength and high-voltage properties were developed and used for critical components of the flexible transmission lines to the TFTR neutral beam ion sources. These critical components are plates which support central conductors as they exit the high-voltage power supply and enter the ion source enclosure. Each plate acts both as a high-voltage insulator and as a pressure barrier to the SF 6 insulating gas. The original plate was made of commercial glass-epoxy laminate which limited the plate voltage capacity. The newly developed insulator is made of specially-formulated cycloalphatic Di-epoxide whose isotropic properties exhibit increased arc resistance. It is cast in one piece with skirts which greatly increase the breakdown voltage. This paper discusses the design, fabrication and testing of the new insulator

  17. TFTR lithium blanket module program. Final design report. Volume VII. LBM instrumentation and Program of Experiments and Analysis

    International Nuclear Information System (INIS)

    Harker, Y.D.; Tsang, F.Y.; Jassby, D.L.

    1983-07-01

    The Program of Experiments and Analysis comprises 3 spheres of activity: (1) measurements of neutron fluence and flux spectra inside and around the LBM, and of tritium production in the LBM central zone; (2) neutronic-code modeling and analysis of the TFTR/LBM system to predict the quantities measured in (1); (3) comparisons of the predicted and measured quantities, and improvements of the code modeling and analysis and the experimental techniques, in order to resolve any discrepancy between prediction and measurement. The measurement techniques are discussed. Section 5 of this volume discusses the strategy for carrying out the measurement program, for making comparisons with the neutronics code predictions, and for resolving discrepancies

  18. Measurements of the toroidal plasma rotation velocity in TFTR major-radius compression experiments with auxiliary neutral beam heating

    International Nuclear Information System (INIS)

    Bitter, M.; Scott, S.; Wong, K.L.

    1986-07-01

    The time history of the central toroidal plasma rotation velocity in Tokamak Fusion Test Reactor (TFTR) experiments with auxiliary heating by neutral deuterium beam injection and major-radius compression has been measured from the Doppler shift of the emitted TiXXI-Kα line radiation. The experiments were conducted for neutral beam powers in the range from 2.1 to 3.8 MW and line-averaged densities in the range from 1.8 to 3.0 x 10 19 m -2 . The observed rotation velocity increase during compression is in agreement with results from modeling calculations which assume classical slowing-down of the injected fast deuterium ions and momentum damping at the rate established in the precompression plasma

  19. The roles of electric field shear and Shafranov shift in sustaining high confinement in enhanced reversed shear plasmas on the TFTR tokamak

    International Nuclear Information System (INIS)

    Synakowski, E.J.; Beer, M.A.

    1997-02-01

    The relaxation of core transport barriers in TFTR Enhanced Reversed Shear plasmas has been studied by varying the radial electric field using different applied torques from neutral beam injection. Transport rates and fluctuations remain low over a wide range of radial electric field shear, but increase when the local E x B shearing rates are driven below a threshold comparable to the fastest linear growth rates of the dominant instabilities. Shafranov-shift-induced stabilization alone is not able to sustain enhanced confinement

  20. Engineering study of the neutral beam and rf heating systems for DIII-D, MFTF-B, JET, JT-60 and TFTR

    International Nuclear Information System (INIS)

    Lindquist, W.B.; Staten, S.H.

    1987-01-01

    An engineering study was performed on the rf and neutral beam heating systems implemented for DIII-D, MFTF-B, JET, JT-60 and TFTR. Areas covered include: methodology used to implement the systems, technology, cost, schedule, performance, problems encountered and lessons learned. Systems are compared and contrasted in the areas studied. Summary statements were made on common problems and lessons learned. 3 refs., 6 tabs

  1. Difference in electron thermal diffusivity and profile between interior and exterior of TFTR L-mode plasmas

    International Nuclear Information System (INIS)

    Hiroe, S.; Johnson, D.W.; Goldston, R.J.

    1990-01-01

    The local properties such as scale lengths of the electron density (L n e ), temperature (L T e ), and pressure (L p e ), and the electron thermal diffusivity χ e (r) (m 2 /s) for r/a > 0.3 have been studied for TFTR L-mode discharges under the assumption of χ e = χ i . The scale lengths and the electron thermal diffusivity in the interior 0.3 e can be expressed as (with correlation coefficient R = 0.61), χ e (r) = 1.44 x 10 18 (r/a) 1.0 T e (r) 0.1 q(r) 0.1 /n e 0.9 (r). In the exterior region (0.55 e can be described as (with R = 0.68), χ e (r) = 2.3 x 10 3 (r/a) 1.7 T e (r) 0.7 q(r) 0.8 /n e 0.2 (r). It is interesting to note the negative n e dependence of χ e in the interior and the positive T e dependence of χ e in the exterior

  2. Operations analysis of the unscheduled summer machine opening of the Tokamak Fusion Test Reactor (TFTR) at the Princeton Plasma Physics Laboratory

    International Nuclear Information System (INIS)

    Viola, M.E.; McCann, J.

    1985-01-01

    During experimental operation, a problem developed with the mechanical integrity of the TFTR surface pumping system neutralizer plates that required a vacuum vessel entry for repairs. This problem, coupled with several less significant machine internal problems that had been developing, forced the decision to make an unscheduled vacuum vessel entry. An extended machine outage at that time would have had a severe impact on the experimental schedule. Therefore, the goal was to make repairs and return the vacuum vessel to a clean condition as quickly as possible. The total time required between the end of regularly scheduled activity and restoration of the machine capability to routinely obtain 1 MA disruption-free plasma was 12 days

  3. TFTR plasma feedback systems

    International Nuclear Information System (INIS)

    Efthimion, P.; Hawryluk, R.J.; Hojsak, W.; Marsala, R.J.; Mueller, D.; Rauch, W.; Tait, G.D.; Taylor, G.; Thompson, M.

    1985-01-01

    The Tokamak Fusion Test Reactor employs feedback control systems for four plasma parameters, i.e. for plasma current, for plasma major radius, for plasma vertical position, and for plasma density. The plasma current is controlled by adjusting the rate of change of current in the Ohmic Heating (OH) coil system. Plasma current is continuously sensed by a Rogowski coil and its associated electronics; the error between it and a preprogrammed reference plasma current history is operated upon by a ''proportional-plusintegral-plus-derivative'' (PID) control algorithm and combined with various feedforward terms, to generate compensating commands to the phase-controlled thyristor rectifiers which drive current through the OH coils. The plasma position is controlled by adjusting the currents in Equilibrium Field and Horizontal Field coil systems, which respectively determine the vertical and radial external magnetic fields producing J X B forces on the plasma current. The plasma major radius position and vertical position, sensed by ''B /sub theta/ '' and ''B /sub rho/ '' magnetic flux pickup coils with their associated electronics, are controlled toward preprogrammed reference histories by allowing PID and feedforward control algorithms to generate commands to the EF and HF coil power supplies. Plasma density is controlled by adjusting the amount of gas injected into the vacuum vessel. Time-varying gains are used to combine lineaveraged plasma density measurements from a microwave interferometer plasma diagnostic system with vacuum vessel pressure measurements from ion gauges, with various other measurements, and with preprogrammed reference histories, to determine commands to piezoelectric gas injection valves

  4. TFTR tritium handling concepts

    International Nuclear Information System (INIS)

    Garber, H.J.

    1976-01-01

    The Tokamak Fusion Test Reactor, to be located on the Princeton Forrestal Campus, is expected to operate with 1 to 2.5 MA tritium--deuterium plasmas, with the pulses involving injection of 50 to 150 Ci (5 to 16 mg) of tritium. Attainment of fusion conditions is based on generation of an approximately 1 keV tritium plasma by ohmic heating and conversion to a moderately hot tritium--deuterium ion plasma by injection of a ''preheating'' deuterium neutral beam (40 to 80 keV), followed by injection of a ''reacting'' beam of high energy neutral deuterium (120 to 150 keV). Additionally, compressions accompany the beam injections. Environmental, safety and cost considerations led to the decision to limit the amount of tritium gas on-site to that required for an experiment, maintaining all other tritium in ''solidified'' form. The form of the tritium supply is as uranium tritide, while the spent tritium and other hydrogen isotopes are getter-trapped by zirconium--aluminum alloy. The issues treated include: (1) design concepts for the tritium generator and its purification, dispensing, replenishment, containment, and containment--cleanup systems; (2) features of the spent plasma trapping system, particularly the regenerable absorption cartridges, their integration into the vacuum system, and the handling of non-getterables; (3) tritium permeation through the equipment and the anticipated releases to the environment; (4) overview of the tritium related ventilation systems; and (5) design bases for the facility's tritium clean-up systems

  5. Tritium analysis at TFTR

    International Nuclear Information System (INIS)

    Voorhees, D.R.; Rossmassler, R.L.; Zimmer, G.

    1995-01-01

    The tritium analytical system at TFRR is used to determine the purity of tritium bearing gas streams in order to provide inventory and accountability measurements. The system includes a quadrupole mass spectrometer and beta scintillator originally configured at Monsanto Mound Research Laboratory in the late 1970's and early 1980's. The system was commissioned and tested between 1991 and 1992 and is used daily for analysis of calibration standards, incoming tritium shipments, gases evolved from uranium storage beds and measurement of gases returned to gas holding tanks. The low resolution mass spectrometer is enhanced by the use of a metal getter pump to aid in resolving the mass 3 and 4 species. The beta scintillator complements the analysis as it detects tritium bearing species that often are not easily detected by mass spectrometry such as condensable species or hydrocarbons containing tritium. The instruments are controlled by a personal computer with customized software written with a graphical programming system designed for data acquisition and control. A discussion of the instrumentation, control systems, system parameters, procedural methods, algorithms, and operational issues will be presented. Measurements of gas holding tanks and tritiated water waste streams using ion chamber instrumentation are discussed elsewhere

  6. Photovoltaic device

    Energy Technology Data Exchange (ETDEWEB)

    Reese, Jason A; Keenihan, James R; Gaston, Ryan S; Kauffmann, Keith L; Langmaid, Joseph A; Lopez, Leonardo; Maak, Kevin D; Mills, Michael E; Ramesh, Narayan; Teli, Samar R

    2017-03-21

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device with a multilayered photovoltaic cell assembly and a body portion joined at an interface region and including an intermediate layer, at least one interconnecting structural member, relieving feature, unique component geometry, or any combination thereof.

  7. Photovoltaic device

    Science.gov (United States)

    Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.

    2015-06-02

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device with a multilayered photovoltaic cell assembly and a body portion joined at an interface region and including an intermediate layer, at least one interconnecting structural member, relieving feature, unique component geometry, or any combination thereof.

  8. Photovoltaic device

    Science.gov (United States)

    Reese, Jason A.; Keenihan, James R.; Gaston, Ryan S.; Kauffmann, Keith L.; Langmaid, Joseph A.; Lopez, Leonardo C.; Maak, Kevin D.; Mills, Michael E.; Ramesh, Narayan; Teli, Samar R.

    2015-09-01

    The present invention is premised upon an improved photovoltaic device ("PV device"), more particularly to an improved photovoltaic device (10) with a multilayered photovoltaic cell assembly (100) and a body portion (200) joined at an interface region (410) and including an intermediate layer (500), at least one interconnecting structural member (1500), relieving feature (2500), unique component geometry, or any combination thereof.

  9. Sealing device

    Science.gov (United States)

    Garcia-Crespo, Andres Jose

    2013-12-10

    A sealing device for sealing a gap between a dovetail of a bucket assembly and a rotor wheel is disclosed. The sealing device includes a cover plate configured to cover the gap and a retention member protruding from the cover plate and configured to engage the dovetail. The sealing device provides a seal against the gap when the bucket assemply is subjected to a centrifugal force.

  10. Microfluidic Device

    Science.gov (United States)

    Tai, Yu-Chong (Inventor); Zheng, Siyang (Inventor); Lin, Jeffrey Chun-Hui (Inventor); Kasdan, Harvey L. (Inventor)

    2017-01-01

    Described herein are particular embodiments relating to a microfluidic device that may be utilized for cell sensing, counting, and/or sorting. Particular aspects relate to a microfabricated device that is capable of differentiating single cell types from dense cell populations. One particular embodiment relates a device and methods of using the same for sensing, counting, and/or sorting leukocytes from whole, undiluted blood samples.

  11. Gauging device

    International Nuclear Information System (INIS)

    Qurnell, F.D.; Patterson, C.B.

    1979-01-01

    A gauge supporting device for measuring say a square tube comprises a pair of rods or guides in tension between a pair of end members, the end members being spaced apart by a compression member or members. The tensioned guides provide planes of reference for measuring devices moved therealong on a carriage. The device is especially useful for making on site dimensional measurements of components, such as irradiated and therefore radioactive components, that cannot readily be transported to an inspection laboratory. (UK)

  12. Fusion devices

    International Nuclear Information System (INIS)

    Fowler, T.K.

    1977-01-01

    Three types of thermonuclear fusion devices currently under development are reviewed for an electric utilities management audience. Overall design features of laser fusion, tokamak, and magnetic mirror type reactors are described and illustrated. Thrusts and trends in current research on these devices that promise to improve performance are briefly reviewed. Twenty photographs and drawings are included

  13. BRAKE DEVICE

    Science.gov (United States)

    O'Donnell, T.J.

    1959-03-10

    A brake device is described for utilization in connection with a control rod. The device comprises a pair of parallelogram link mechanisms, a control rod moveable rectilinearly therebetween in opposite directions, and shoes resiliently supported by the mechanism for frictional engagement with the control rod.

  14. PLASMA DEVICE

    Science.gov (United States)

    Gow, J.D.; Wilcox, J.M.

    1961-12-26

    A device is designed for producing and confining highenergy plasma from which neutrons are generated in copious quantities. A rotating sheath of electrons is established in a radial electric field and axial magnetic field produced within the device. The electron sheath serves as a strong ionizing medium to gas introdueed thereto and also functions as an extremely effective heating mechanism to the resulting plasma. In addition, improved confinement of the plasma is obtained by ring magnetic mirror fields produced at the ends of the device. Such ring mirror fields are defined by the magnetic field lines at the ends of the device diverging radially outward from the axis of the device and thereafter converging at spatial annular surfaces disposed concentrically thereabout. (AFC)

  15. Broadband measurements of electron cyclotron emission in TFTR [Tokamak Fusion Test Reactor] using a quasi-optical light collection system and a polarizing Michelson interferometer

    International Nuclear Information System (INIS)

    Stauffer, F.J.; Boyd, D.A.; Cutler, R.C.; Diesso, M.; McCarthy, M.P.; Montague, J.; Rocco, R.

    1988-04-01

    For the past three years, a Fourier transform spectrometer diagnostic system, employing a fast-scanning polarizing Michelson interferometer, has been operating on the TFTR tokamak at Princeton Plasma Physics Laboratory. It is used to measure the electron cyclotron emission spectrum over the range 2.5 to 18 cm/sup /minus/1/ (75-540 GHz) with a resolution of 0.123 cm/sup /minus/1/(3.7 GHz), at a rate of 72 spectra per second. The quasi-optical system for collecting the light and transporting it through the interferometer to the detector has been designed using the concepts of both Gaussian and geometrical optics in order to produce a system that is efficient over the entire spectral range. The commerical Michelson interferometer was custom-made for this project and is at the state of the art for this type of specialized instrument. Various pre-installation and post-installation tests of the optical system and the interferometer were performed and are reported here. An error propagation analysis of the absolute calibration process is given. Examples of electron cyclotron emission spectra measured in two polarization directions are given, and electron temperature profiles derived from each of them are compared. 34 refs., 17 figs

  16. Sealing devices

    International Nuclear Information System (INIS)

    Coulson, R.A.

    1980-01-01

    A sealing device for minimising the leakage of toxic or radioactive contaminated environments through a biological shield along an opening through which a flexible component moves that penetrates the shield. The sealing device comprises an outer tubular member which extends over a length not less than the maximum longitudinal movement of the component along the opening. An inner sealing block is located intermediate the length of the component by connectors and is positioned in the bore of the outer tubular member to slide in the bore and effect a seal over the entire longitudinal movement of the component. The cross-section of the device may be circular and the block may be of polytetrafluoroethylene or of nylon impregnated with molybdenum or may be metallic. A number of the sealing devices may be combined into an assembly for a plurality of adjacent longitudinally movable components, each adapted to sustain a tensile load, providing the various drives of a master-slave manipulator. (author)

  17. Ferroelectric devices

    CERN Document Server

    Uchino, Kenji

    2009-01-01

    Updating its bestselling predecessor, Ferroelectric Devices, Second Edition assesses the last decade of developments-and setbacks-in the commercialization of ferroelectricity. Field pioneer and esteemed author Uchino provides insight into why this relatively nascent and interdisciplinary process has failed so far without a systematic accumulation of fundamental knowledge regarding materials and device development.Filling the informational void, this collection of information reviews state-of-the-art research and development trends reflecting nano and optical technologies, environmental regulat

  18. Guide device

    International Nuclear Information System (INIS)

    Brammer, C.M. Jr.

    1977-01-01

    Disclosed is a fuel handling guide tube centering device for use in nuclear reactors during fuel assembly handling operations. The device comprises an outer ring secured to the flange of a nuclear reactor pressure vessel, a rotatable table rotatably coupled to the outer ring, and a plurality of openings through the table. Truncated locating cones are positioned in each of the openings in the table, and the locating cones center the guide tube during fuel handling operations. The openings in the table are located such that each fuel assembly in the nuclear core may be aligned with one of the openings by a suitable rotation of the table. The locating cones thereby provide alignment between the fuel handling mechanism located in the guide tube and the individual fuel assemblies of the cone. The need for a device to provide alignment is especially critical for floating nuclear power plants, where wave motion may exist during fuel handling operations. 5 claims, 4 figures

  19. Challenges for Plasma Diagnostic in a Next Step Device (FIRE)

    International Nuclear Information System (INIS)

    Young, Kenneth M.

    2002-01-01

    The physics program of any next-step tokamak such as FIRE [Fusion Ignition Research Experiment] sets demands for plasma measurement which are at least as comprehensive as on present tokamaks, with the additional capabilities needed for control of the plasma and for understanding the effects of the alpha-particles. The diagnostic instrumentation must be able to provide the fine spatial and temporal resolution required for the advanced tokamak plasma scenarios. It must also be able to overcome the effects of neutron- and gamma-induced electrical noise in ceramic components or detectors, and fluorescence and absorption in optical components. There are practical engineering issues of minimizing radiation streaming while providing essential diagnostic access to the plasma. Many diagnostics will require components at or close to the first wall, e.g., ceramics and MI cable for magnetic diagnostics and mirrors for optical diagnostics; these components must be mounted to operate, and survive, i n fluxes which require special material selection. A better set of diagnostics of alpha-particles than that available for the TFTR [Tokamak Fusion Test Reactor] is essential; it must be qualified well before moving into D-T [deuterim-tritium] experiments. A start has been made to assessing the potential implementation of key diagnostics for the FIRE device. The present status is described

  20. Medical Devices

    NARCIS (Netherlands)

    Verkerke, Gijsbertus Jacob; Mahieu, H.F.; Geertsema, A.A.; Hermann, I.F.; van Horn, J.R.; Hummel, J. Marjan; van Loon, J.P.; Mihaylov, D.; van der Plaats, A.; Schraffordt Koops, H.; Schutte, H.K.; Veth, R.P.H.; de Vries, M.P.; Rakhorst, G.; Shi, Donglu

    2004-01-01

    The development of new medical devices is a very time-consuming and costly process. Besides the time between the initial idea and the time that manufacturing and testing of prototypes takes place, the time needed for the development of production facilities, production of test series, marketing,

  1. Electrochemical device

    Science.gov (United States)

    Grimes, Patrick G.; Einstein, Harry; Bellows, Richard J.

    1988-01-12

    A tunnel protected electrochemical device features channels fluidically communicating between manifold, tunnels and cells. The channels are designed to provide the most efficient use of auxiliary power. The channels have a greater hydraulic pressure drop and electrical resistance than the manifold. This will provide a design with the optimum auxiliary energy requirements.

  2. Assistive Devices

    Science.gov (United States)

    If you have a disability or injury, you may use a number of assistive devices. These are tools, products or types of equipment that help you perform tasks and activities. They may help you move around, see, communicate, eat, or get ...

  3. Detection device

    Science.gov (United States)

    Smith, J.E.

    1981-02-27

    The present invention is directed to a detection device comprising: (1) an entrance chamber; (2) a central chamber; and (3) an exit chamber. The central chamber includes an ionizing gas, anode, and means for connecting the anode with an external power supply and pulse counter.

  4. Cooling device in thermonuclear device

    International Nuclear Information System (INIS)

    Honda, Tsutomu.

    1988-01-01

    Purpose: To prevent loss of cooling effect over the entire torus structure directly after accidental toubles in a cooling device of a thermonuclear device. Constitution: Coolant recycling means of a cooling device comprises two systems, which are alternately connected with in-flow pipeways and exit pipeways of adjacent modules. The modules are cooled by way of the in-flow pipeways and the exist pipeways connected to the respective modules by means of the coolant recycling means corresponding to the respective modules. So long as one of the coolant recycling means is kept operative, since every one other modules of the torus structure is still kept cooled, the heat generated from the module put therebetween, for which the coolant recycling is interrupted, is removed by means of heat conduction or radiation from the module for which the cooling is kept continued. No back-up emergency cooling system is required and it can provide high economic reliability. (Kamimura, M.)

  5. Thermonuclear device

    International Nuclear Information System (INIS)

    Tezuka, Masaru.

    1993-01-01

    Protrusions and recesses are formed to a vacuum vessel and toroidal magnetic coils, and they are engaged. Since the vacuum vessel is generally supported firmly by a rack or the like by support legs, the toroidal magnetic field coils can be certainly supported against tumbling force. Then, there can be attained strong supports for the toroidal magnetic field coils, in addition to support by wedges on the side of inboard and support by share panels on the side of outboard, capable of withstanding great electromagnetic forces which may occur in large-scaled next-generation devices. That is, toroidal magnetic field coils excellent from a view point of deformation and stress can be obtained, to provide a thermonuclear device of higher reliability. (N.H.)

  6. Thermonuclear device

    International Nuclear Information System (INIS)

    Oosaki, Osamu; Masuda, Kenju.

    1980-01-01

    Purpose: To provide excellent electric properties and high reliability in a thermonuclear device by improving a current collecting board connected to a coil device. Constitution: A current collecting board element perforated with an opening for enserting a connecting terminal is sized to be inserted into a plating tank, and is surface treated in the plating tank. Only the current collecting board element preferably surface treated is picked up. A plurality of such current collecting board elements are connected and welded to form a large current collecting board. In this manner, the current collecting board having several m 2 to several ten order m 2 in area can be obtained as preferably surface treated at the connecting terminal hole. The current collecting board element can be determined in shape with the existing facility without increasing the size of a surface treating tank. (Kamimura, M.)

  7. Thermonuclear device

    International Nuclear Information System (INIS)

    Yagi, Yasuomi; Takahashi, Ken; Hashimoto, Hiroshi.

    1984-01-01

    Purpose: To improve the plasma confining performances by bringing the irregular magnetic fields nearly to zero and decreasing the absolute value of the irregular magnetic fields at every positions. Constitution: The winding direction of a plurality of coil elements, for instance, double pan cake coils of toroidal coils in a torus type or mirror type thermonuclear device are reversed to each other in their laminating direction, whereby the irregular magnetic fields due to the coil-stepped portions in each toroidal coils are brought nearly to zero. This enables to bring the average irregular magnetic fields as a whole in the thermonuclear device nearly to zero, as well as, decrease the absolute value of the irregular magnetic fields in each positions. Thus, the plasma confining performances can be improved. (Moriyama, K.)

  8. "Distinvar" device

    CERN Multimedia

    CERN PhotoLab

    1965-01-01

    The alignment of one of the accelerator magnets being checked by the AR Division survey group. A "distinvar" device, invented by the group, using calibrated invar wires stretched between the fixed survey pillar (on the left) and a fixed point on the magnet. In two days it is thus possible to measure the alignment of the 100 magnets with an accuracy better than 1/10.

  9. Latching device

    Science.gov (United States)

    Ulrich, G. W. (Inventor)

    1975-01-01

    A latching device is suited for use in establishing a substantially motionless connection between a stationary receiver and a movable latching mechanism. The latching mechanism includes a pivotally supported restraining hook continuously urged into a capturing relationship with the receiver, characterized by a spring-biased pawl having a plurality of aligned teeth. The teeth are seated in the surface of the throat of the hook and positionable into restraining engagement with a rigid restraining shoulder projected from the receiver.

  10. Tritium Issues in Next Step Devices

    International Nuclear Information System (INIS)

    C.H. Skinner; G. Federici

    2001-01-01

    Tritium issues will play a central role in the performance and operation of next-step deuterium-tritium (DT) burning plasma tokamaks and the safety aspects associated with tritium will attract intense public scrutiny. The orders-of-magnitude increase in duty cycle and stored energy will be a much larger change than the increase in plasma performance necessary to achieve high fusion gain and ignition. Erosion of plasma-facing components will scale up with the pulse length from being barely measurable on existing machines to centimeter scale. Magnetic Fusion Energy (MFE) devices with carbon plasma-facing components will accumulate tritium by co-deposition with the eroded carbon and this will strongly constrain plasma operations. We report on a novel laser-based method to remove co-deposited tritium from carbon plasma-facing components in tokamaks. A major fraction of the tritium trapped in a co-deposited layer during the deuterium-tritium (DT) campaign on the Tokamak Fusion Test Reactor (TFTR) was released by heating with a scanning laser beam. This technique offers the potential for tritium removal in a next-step DT device without the use of oxidation and the associated deconditioning of the plasma-facing surfaces and expense of processing large quantities of tritium oxide. The operational lifetime of alternative materials such as tungsten has significant uncertainties due to melt layer loss during disruptions. Production of dust and flakes will need careful monitoring and minimization, and control and accountancy of the tritium inventory will be critical issues. Many of the tritium issues in Inertial Fusion Energy (IFE) are similar to MFE, but some, for example those associated with the target factory, are unique to IFE. The plasma-edge region in a tokamak has greater complexity than the core due to lack of poloidal symmetry and nonlinear feedback between the plasma and wall. Sparse diagnostic coverage and low dedicated experimental run time has hampered the

  11. Tritium Issues in Next Step Devices

    Energy Technology Data Exchange (ETDEWEB)

    C.H. Skinner; G. Federici

    2001-09-05

    Tritium issues will play a central role in the performance and operation of next-step deuterium-tritium (DT) burning plasma tokamaks and the safety aspects associated with tritium will attract intense public scrutiny. The orders-of-magnitude increase in duty cycle and stored energy will be a much larger change than the increase in plasma performance necessary to achieve high fusion gain and ignition. Erosion of plasma-facing components will scale up with the pulse length from being barely measurable on existing machines to centimeter scale. Magnetic Fusion Energy (MFE) devices with carbon plasma-facing components will accumulate tritium by co-deposition with the eroded carbon and this will strongly constrain plasma operations. We report on a novel laser-based method to remove co-deposited tritium from carbon plasma-facing components in tokamaks. A major fraction of the tritium trapped in a co-deposited layer during the deuterium-tritium (DT) campaign on the Tokamak Fusion Test Reactor (TFTR) was released by heating with a scanning laser beam. This technique offers the potential for tritium removal in a next-step DT device without the use of oxidation and the associated deconditioning of the plasma-facing surfaces and expense of processing large quantities of tritium oxide. The operational lifetime of alternative materials such as tungsten has significant uncertainties due to melt layer loss during disruptions. Production of dust and flakes will need careful monitoring and minimization, and control and accountancy of the tritium inventory will be critical issues. Many of the tritium issues in Inertial Fusion Energy (IFE) are similar to MFE, but some, for example those associated with the target factory, are unique to IFE. The plasma-edge region in a tokamak has greater complexity than the core due to lack of poloidal symmetry and nonlinear feedback between the plasma and wall. Sparse diagnostic coverage and low dedicated experimental run time has hampered the

  12. Alpha heating in toroidal devices

    International Nuclear Information System (INIS)

    Miley, G.H.

    1978-01-01

    Ignition (or near-ignition) by alpha heating is a key objective for the achievement of economic fusion reactors. While good confinement of high-energy alphas appears possible in larger reactors, near-term tokamak-type ignition experiments as well as some concepts for small reactors (e.g., the Field-Reversed Mirror or FRM) potentially face marginal situations. Consequently, there is a strong motivation to develop methods to evaluate alpha losses and heating profiles in some detail. Such studies for a TFTR-size tokamak and for a small FRM are described here

  13. Damping device

    International Nuclear Information System (INIS)

    Banks, E.L. Jr.; Dowell, T.P.

    1976-01-01

    The description is given of a damper which includes a pair of telescopic components interconnected by relative linear movement one in relation to the other, by a screw and ball nut device, with a braking surface on one of the components, a brake engaging the braking surface, an inertia mass entrained by the other components, non-deformable and distinct brake actuating gear, independently mobile in relation to the other braking system and fixed and controlled by the inertia mass, positively to engage the braking surface. This damper is for retaining the parts of a nuclear power station so that can withstand earthquakes [fr

  14. Thermonuclear device

    International Nuclear Information System (INIS)

    Inoue, Toyokazu; Murata, Toru.

    1983-01-01

    Purpose: To shield superconducting coils for use in the generation of magnetic field against neutron irradiation thereby preventing tritium contamination. Constitution: The thermonuclear device comprises, in its inside, a vacuum container for containing plasmas, superconducting coils disposed to the outside of the vacuum container and neutron absorbers disposed between the super-conducting coils and the vacuum container. since neutrons issued from the plasma are absorbed by neutron absorbers and not irradiated to the superconducting coils, generation of tritium due to the reaction between 3 He in the liquid helium as the coolants for the super-conducting coils and the neutrons is prevented. (Aizawa, K.)

  15. Strainer device

    International Nuclear Information System (INIS)

    Mokuya, Kenji.

    1975-01-01

    Object: To provide a strainer device, which is adapted to facilitate flushing and is particularly suited for installation in the cooling system of a liquid metal cooled fast breeding reactor. Structure: A casing accommodating a strainer and a blind plate for the selection of a flow path is provided at a suitable portion of the duct line. The blind plate is adapted to be rotated by an opening and closing means consisting of a rod. bellows, shaft and so forth. At the time of flushing, the duct line is sealed by the blind plate. (Nakamura, S.)

  16. Scalable devices

    KAUST Repository

    Krüger, Jens J.

    2014-01-01

    In computer science in general and in particular the field of high performance computing and supercomputing the term scalable plays an important role. It indicates that a piece of hardware, a concept, an algorithm, or an entire system scales with the size of the problem, i.e., it can not only be used in a very specific setting but it\\'s applicable for a wide range of problems. From small scenarios to possibly very large settings. In this spirit, there exist a number of fixed areas of research on scalability. There are works on scalable algorithms, scalable architectures but what are scalable devices? In the context of this chapter, we are interested in a whole range of display devices, ranging from small scale hardware such as tablet computers, pads, smart-phones etc. up to large tiled display walls. What interests us mostly is not so much the hardware setup but mostly the visualization algorithms behind these display systems that scale from your average smart phone up to the largest gigapixel display walls.

  17. Thermonuclear device

    International Nuclear Information System (INIS)

    Honda, Takuro; Maki, Koichi.

    1997-01-01

    The present invention provides a thermonuclear device, in which integrity of a measuring device is kept, the reactor wall temperature and wear of armour materials are monitored accurately even under intense radiation rays, so that the flow rate of coolants and plasma power can be controlled by using the signals. Infrared rays generated from the surface of the armour materials disposed on a first wall are detected to measure the reactor wall temperature. Coolant flow rate and plasma power are controlled based on the obtained reactor wall temperature. In addition, infrared rays generated from the back of the armour materials are detected to obtain the surface temperature in order to avoid intense radiation rays from plasmas. The coolant flow rate and the plasma power are controlled based on the obtained temperature on the surface of the reactor thereby controlling the temperature of the first wall and the armour material to 300degC or lower in a case of the first wall made of stainless steel and 1000degC or lower in a case of the armour material made of graphite. (I.S.)

  18. Thermonuclear device

    International Nuclear Information System (INIS)

    Kuriyama, Masaaki; Yamamoto, Masahiro; Furuyama, Masayuki; Saito, Ryusei.

    1981-01-01

    Purpose: To enable the efficient and rapid cooling of a vacuum vessel by cooling with gas when the temperature of the vacuum vessel is higher than the boiling point of water and cooling with water when the temperature is lower than the boiling point of water. Constitution: A cooling pipe is provided through an insulating pipe on the outer periphery of a vacuum vessel. The cooling pipe communicates through a cooling gas valve and a coolant valve with a cooling gas supply device and a coolant supply device, and a heat exchanger is disposed at the pipe. When the vessel is higher than the boiling point of the coolant the coolant valve is closed and the cooling gas valve is opened and gas is supplied to cool the vessel. The gas is recoverd through a heat exchanger. On the other hand, when the temperature of vessel is lower than the boiling point of the coolant, the gas valve is closed, the coolant valve is opened, and the vessel is cooled with coolant. The vacuum vessel can be cooled for short time employing both the gas and the coolant together. (Yoshino, Y.)

  19. Thermonuclear device

    International Nuclear Information System (INIS)

    Takano, Hirohisa; Nakamoto, Kazunari; Hanai, Satoshi.

    1984-01-01

    Purpose: To provide coils of high mechanical strength for use at the center of a torus type thermonuclear device. Constitution: A plurality of copper plates having cooling holes and bolt holes and insulation paper sheets of the same shape are prepared. The copper plate is different from the insulation paper sheet only in that the position-phase angle of the opening portion is larger by 15 - 30 0 . The copper plates and the insulation paper sheets are alternately stacked by a required number of turns while displacing the angle, and then clamped by bolts to form a mechanically strong coil with no metallurgical joining. Further, since the insulation paper sheets are not present in the radial direction and only one insulation paper sheet is inserted for each turn in the direction of the coil height, the space occupied by the coil can be decreased. According to this invention, the magnetic flux density at the center of the device can be increased as compared with the conventional case to thereby apply a higher voltage on the side of plasmas. (Moriyama, K.)

  20. Irradiation device

    International Nuclear Information System (INIS)

    Suzuki, Toshimitsu.

    1989-01-01

    In an irradiation device for irradiating radiation rays such as electron beams to pharmaceuticals, etc., since the distribution of scanned electron rays was not monitored, the electron beam intensity could be determined only indirectly and irradiation reliability was not satisfactory. In view of the above, a plurality of monitor wires emitting secondary electrons are disposed in the scanning direction near a beam take-out window of a scanning duct, signals from the monitor wires are inputted into a display device such as a cathode ray tube, as well as signals from the monitor wires at the central portion are inputted into counting rate meters to measure the radiation dose as well. Since secondary electrons are emitted when electron beams pass through the monitor wires and the intensity thereof is in proportion with the intensity of incident electron beams, the distribution of the radiation dose can be monitored by measuring the intensity of the emitted secondary electrons. Further, uneven irradiation, etc. can also be monitored to make the radiation of irradiation rays reliable. (N.H.)

  1. Practical microwave electron devices

    CERN Document Server

    Meurant, Gerard

    2013-01-01

    Practical Microwave Electron Devices provides an understanding of microwave electron devices and their applications. All areas of microwave electron devices are covered. These include microwave solid-state devices, including popular microwave transistors and both passive and active diodes; quantum electron devices; thermionic devices (including relativistic thermionic devices); and ferrimagnetic electron devices. The design of each of these devices is discussed as well as their applications, including oscillation, amplification, switching, modulation, demodulation, and parametric interactions.

  2. Thermonuclear device

    International Nuclear Information System (INIS)

    Furuyama, Masayuki.

    1979-01-01

    Purpose: To provide the subject device wherein a conductive short-circuiting ring is installed in the vicinity of the bonded part of bellows and thick portion of vacuum vessel in the small circumferential direction of torus, thereby to reduce the electromagnetic force generated at the bellows. Constitution: A conductive short-circuiting ring is provided in the vicinity of the connected part of a thick portion and bellows portion. By this organization, a saddle type current generated at the thick portion by a vertical magnetic field flows through the short-circuiting ring because the resistance at a part where the short-circuiting ring is provided is reduced, and the current flowing through the bellows is remarkably reduced. For this reason, the electromagnetic force generated at the bellows is reduced thereby to prevent the bellows from being destroyed by the electromagnetic force. (Yoshihara, H.)

  3. Electrophoresis device

    Science.gov (United States)

    Rhodes, P. H.; Snyder, R. S. (Inventor)

    1982-01-01

    A device for separating cellular particles of a sample substance into fractionated streams of different cellular species includes a casing having a distribution chamber, a separation chamber, and a collection chamber. The electrode chambers are separated from the separation chamber interior by means of passages such that flow variations and membrane variations around the slotted portion of the electrode chamber do not enduce flow perturbations into the laminar buffer curtain flowing in the separation chamber. The cellular particles of the sample are separated under the influence of the electrical field and the separation chamber into streams of different cellular species. The streams of separated cells enter a partition array in the collection chamber where they are fractionated and collected.

  4. Thermonuclear device

    International Nuclear Information System (INIS)

    Suzuki, Shohei

    1988-01-01

    Purpose: To obtain high voltage withstanding current introduction terminals not suffering from the effects of the reduction in the creeping voltage withstanding property by the application of magnetic fields. Constitution: This invention concerns a current introduction terminal for supplying electric current to coils for use in a thermonuclear device, etc. The conductor of the current introduction terminal on the side of vacuum is completely covered with solid insulator. This can eliminate the portion of securing the creeping withstanding voltage. The voltage withstanding characteristics of the solid insulator covering the portion of the conductor on the side of vacuum has a constant value irrespective of the atmosphere or the absence or presence of magnetic fields. Accordingly, the voltage withstanding characteristics of the current introduction terminal on the side of vacuum are determined by the property of the solid insulator, which is not reduced by the application of magnetic fields. (Ikeda, J.)

  5. Safety device of thermonuclear device

    International Nuclear Information System (INIS)

    Aoki, Isao; Ueda, Shuzo; Seki, Yasushi; Sakurai, Akiko; Kasahara, Fumio; Obara, Atsushi; Yamauchi, Michinori.

    1997-01-01

    The present invention provides a safety device against an event of intrusion of coolants in a vacuum vessel. Namely, a coolant supply system comprises cooling tubes for supplying coolants to main reactor structure components including a vacuum vessel. A detection means detects leakage of coolants in the vacuum vessel. A coolant supply control means controls the supply of coolants to the main reactor structural components based on the leakage detection signals of the detection means. A stagnated material discharging means discharges stagnated materials in the main reactor structural components caused by the leakage of coolants. The leakage of coolants (for example, water) in the vacuum vessel can thus be detected by the water detection device in the vacuum vessel. A control value of a coolant supply means is closed by the leakage detection signals. The supply of coolants to the main reactor structural components is restricted to suppress the leakage. The stagnated materials are discharged to a tank by way of a water draining valve. (I.S.)

  6. Low-Z coating as a first wall of nuclear fusion devices

    International Nuclear Information System (INIS)

    Shikama, Tatsuo; Okada, Masatoshi

    1984-01-01

    The tokamak nuclear fusion devices of the largest scale in the world, TFTR in USA and JET in Europe, started the operation from the end of 1982 to 1983. Also in Japan, the tokamak JT-60 is scheduled to begin the operation in 1985. One of the technological obstacles is the problem of first walls facing directly to plasma and subjected to high particle loading and thermal loading. Moreover, first walls achieve the active role of controlling impurities in plasma and recycling hydrogen isotopes. It is impossible to find a single material which satisfies all these requirements. The compounding of materials can create a material having new function, but also has the meaning of expanding the range of material selection. One of the material compounding methods is surface coating. In this paper, as the materials for first walls, the characteristics of low Z materials are discussed from the design examples of actual takamak nuclear fusion devices. The outline of first walls is explained. High priority is given to the impurity control in plasma, and in view of plasma energy emissivity and the rate of self sputtering, low Z material coating seems to be the solution. The merits and the problems of such low Z material coating are discussed. (Kako, I.)

  7. Progress of research and development of nuclear fusion and development of large nuclear fusion device technology

    International Nuclear Information System (INIS)

    1994-01-01

    In the last several years, the results of tokamak experiments were conspicuous, and the progress of plasma confinement performance, transport mechanism, divertors and impurities, helium transport and exhaust, electric current drive, magnetic field ripple effect and high speed particle transport and DT experiment are reported. The other confinement methods than tokamak, the related theories and reactor technology are described. The conceptual design of ITER was carried out by the cooperation of Japan, USA, EC and the former USSR. The projects of developing nuclear fusion in various countries, the design and the required research and development of ITER, the reconstruction and the required research and development of JT-60, JET and TFTR, the design and the required research and development of large helical device, the state of research and development of laser nuclear fusion and inversion magnetic field pinch nuclear fusion, the activities and roles of industrial circles in large nuclear fusion device technology, and the long term perspective of the technical development of nuclear fusion are described. (K.I.)

  8. Thermonuclear device

    International Nuclear Information System (INIS)

    Suzuki, Shohei.

    1980-01-01

    Purpose: To improve the plasma confining efficiency in a thermonuclear device having magnet coils using super-conducting wires by decreasing the uneven magnetic field resulted from current supply terminals and wirings. Constitution: Current introduction terminals of magnet coils using superconducting wires are short circuitted with a superconducting short circuit wire. Upon supplying current to the coils, the resistance of the coils is rendered superconductive and the resistance of the short circuit wire is rendered normally conductive heated by a heater and the switch is closed. In this case, most parts of the current are flown through the resistance of the coils and the switch is opened when the current arrives at a predetermined value to render the resistance of the short circuit wire superconductive. Then, the current transfers from the thyristor power source to the resistance of the short circuit wire, whereby the resistance of the coils and that of the short circuit wire from a permanent current loop. In this conditions, since current flows through the short circuit wire and the coils and not to the current introduction terminals, no uniform magnetic field is generated. (Kawakami, Y.)

  9. Reluctance device

    International Nuclear Information System (INIS)

    Claridge, A.N.; Smith, A.J.

    1983-01-01

    A reluctance device comprises two or more phases, each of which has a rotor mounted for rotation within a tubular member and an annular stator positioned externally of the tubular member. The rotor and the internal surface of the tubular member are each provided with aligned, axially spaced apart annular arrays of teeth, the teeth on the rotor confronting those on the tubular member in radially spaced apart relationship. The stator encloses a coil which, when electrically energised, creates a plurality of magnetic flux paths each of which extends radially between the rotor and stator via the confronting teeth and the tubular member, and axially along both the rotor and the portion of the stator located radially outwardly of the coil. The portion of the tubular member intermediate the teeth thereon is provided with a non-magnetic insert in order to resist the axial passage of magnetic flux therethrough. In one of the claims, the tubular member comprises a portion of a nuclear reactor which is adapted to contain a reactor control rod, the rotor constituting a portion of the drive mechanism for the control rod contained in operation within the tubular member. (author)

  10. Protection device for a thermonuclear device

    International Nuclear Information System (INIS)

    Kawashima, Shuichi.

    1986-01-01

    Purpose: To exactly detect the void coefficients of coolants even under high magnetic fields thereby detect the overheat of a thermonuclear device at an early stage. Constitution: The protecting device of this invention comprises a laser beam generation device, a laser beam detection device and an accident detection device. The laser generation device always generates laser beams, which are permeated through coolants and detected by the laser beam detection device, the optical amount of which is transmitted to the accident detection device. The accident detection device judges the excess or insufficiency of the detected optical amount with respect to the optical amount of the laser beams under the stationary state as a reference and issues an accident signal. Since only the optical cables that do not undergo the effect of the magnetic fields are exposed to high magnetic fields in the protection device of this invention, a high reliability can be maintained. (Kamimura, M.)

  11. TFTR tritium inventory accountability system

    International Nuclear Information System (INIS)

    Saville, C.; Ascione, G.; Elwood, S.; Nagy, A.; Raftopoulos, S.; Rossmassler, R.; Stencel, J.; Voorhees, D.; Tilson, C.

    1995-01-01

    This paper discusses the program, PPPL (Princeton Plasma Physics Laboratory) Material Control and Accountability Plan, that has been implemented to track US Department of Energy's tritium and all other accountable source material. Specifically, this paper details the methods used to measure tritium in various systems at the Tokamak Fusion Test Reactor; resolve inventory differences; perform inventory by difference inside the Tokamak; process and measure plasma exhaust and other effluent gas streams; process, measure and ship scrap or waste tritium on molecular sieve beds; and detail organizational structure of the Material Control and Accountability group. In addition, this paper describes a Unix-based computerized software system developed at PPPL to account for all tritium movements throughout the facility. 5 refs., 2 figs

  12. Performance of the TFTR bolometers

    International Nuclear Information System (INIS)

    Schivell, J.

    1985-01-01

    For the past year we have been making use of a horizontally viewing 19-channel array and a bolometer which views a narrow cross-sectional slice of the plasma. More recently, we have also obtained results from a second, vertically viewing array. Software has been developed to translate the data from general plasma and array locations to plasma minor radius and to do the Abel inversion with an antisymmetrical term included. Experience has been obtained on the noise and response-time characteristics, as well as the accuracy of total radiated power and radial profiles. Representative cases of radiated power profiles and local power balance are presented, as well as comparisons with other measurements of impurity concentration and trends with electron density and limiter coating. Although most of the ohmic-heating input power leaves by radiation, most of this loss occurs near the outer part of the plasma. Also, the behavior of power profiles during neutral beam injection and disruptions is discussed briefly

  13. Medical Device Safety

    Science.gov (United States)

    A medical device is any product used to diagnose, cure, or treat a condition, or to prevent disease. They ... may need one in a hospital. To use medical devices safely Know how your device works. Keep ...

  14. Implantable electronic medical devices

    CERN Document Server

    Fitzpatrick, Dennis

    2014-01-01

    Implantable Electronic Medical Devices provides a thorough review of the application of implantable devices, illustrating the techniques currently being used together with overviews of the latest commercially available medical devices. This book provides an overview of the design of medical devices and is a reference on existing medical devices. The book groups devices with similar functionality into distinct chapters, looking at the latest design ideas and techniques in each area, including retinal implants, glucose biosensors, cochlear implants, pacemakers, electrical stimulation t

  15. Encoding technique for high data compaction in data bases of fusion devices

    International Nuclear Information System (INIS)

    Vega, J.; Cremy, C.; Sanchez, E.; Portas, A.; Dormido, S.

    1996-01-01

    At present, data requirements of hundreds of Mbytes/discharge are typical in devices such as JET, TFTR, DIII-D, etc., and these requirements continue to increase. With these rates, the amount of storage required to maintain discharge information is enormous. Compaction techniques are now essential to reduce storage. However, general compression techniques may distort signals, but this is undesirable for fusion diagnostics. We have developed a general technique for data compression which is described here. The technique, which is based on delta compression, does not require an examination of the data as in delayed methods. Delta values are compacted according to general encoding forms which satisfy a prefix code property and which are defined prior to data capture. Several prefix codes, which are bit oriented and which have variable code lengths, have been developed. These encoding methods are independent of the signal analog characteristics and enable one to store undistorted signals. The technique has been applied to databases of the TJ-I tokamak and the TJ-IU torsatron. Compaction rates of over 80% with negligible computational effort were achieved. Computer programs were written in ANSI C, thus ensuring portability and easy maintenance. We also present an interpretation, based on information theory, of the high compression rates achieved without signal distortion. copyright 1996 American Institute of Physics

  16. Hip supporting device

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention relates to a device for limiting movements in one or more anatomical joints, such as a device for limiting movement in the human hip joint after hip replacement surgery. This is provided by a device for limiting movement in the human hip joint, said device comprising: at least...

  17. FLUIDICS DEVICE FOR ASSAY

    DEFF Research Database (Denmark)

    2007-01-01

    The present invention relates to a device for use in performing assays on standard laboratory solid supports whereon chemical entities are attached. The invention furthermore relates to the use of such a device and a kit comprising such a device. The device according to the present invention is a...

  18. Power source device for thermonuclear device

    International Nuclear Information System (INIS)

    Ozaki, Akira.

    1992-01-01

    The present invention provides a small sized and economical power source device for a thermonuclear device. That is, the device comprises a conversion device having a rated power determined by a power required during a plasma current excitation period and a conversion device having a rated power determined by a power required during a plasma current maintaining period, connected in series to each other. Then, for the former conversion device, power is supplied from an electric power generator and, for the latter, power is supplied from a power system. With such a constitution, during the plasma electric current maintaining period for substantially continuous operation, it is possible to conduct bypassing paired operation for the former conversion device while the electric power generator is put under no load. Further, since a short period rated power may be suffice for the former conversion device and the electric power generator having the great rated power required for the plasma electric current excitation period, they can be reduced in the size and made economical. On the other hand, since the power required for the plasma current maintaining period is relatively small, the capacity of the continuous rated conversion device may be small, and the power can be received from the power system. (I.S.)

  19. Implantable Medical Devices

    Science.gov (United States)

    ... Artery Disease Venous Thromboembolism Aortic Aneurysm More Implantable Medical Devices Updated:Sep 16,2016 For Rhythm Control ... a Heart Attack Introduction Medications Surgical Procedures Implantable Medical Devices • Life After a Heart Attack • Heart Attack ...

  20. Devices for hearing loss

    Science.gov (United States)

    ... the sounds you want to hear. Assistive listening devices bring certain sounds directly to your ears. This can ... a small room or on a stage. Other devices can bring the sound from your TV, radio, or music ...

  1. Novel Magnetic Devices

    National Research Council Canada - National Science Library

    Schuller, Ivan

    2007-01-01

    ...: ballistic magnetoresistance, magnetic field proximity effect and spin drag. These three phenomena would then be exploited for the design of novel device architectures and to investigate the physical principles behind these devices...

  2. Smart devices are different

    DEFF Research Database (Denmark)

    Stisen, Allan; Blunck, Henrik; Bhattacharya, Sourav

    2015-01-01

    research results. This is due to variations in training and test device hardware and their operating system characteristics among others. In this paper, we systematically investigate sensor-, device- and workload-specific heterogeneities using 36 smartphones and smartwatches, consisting of 13 different...... device models from four manufacturers. Furthermore, we conduct experiments with nine users and investigate popular feature representation and classification techniques in HAR research. Our results indicate that on-device sensor and sensor handling heterogeneities impair HAR performances significantly...

  3. Heterostructures and quantum devices

    CERN Document Server

    Einspruch, Norman G

    1994-01-01

    Heterostructure and quantum-mechanical devices promise significant improvement in the performance of electronic and optoelectronic integrated circuits (ICs). Though these devices are the subject of a vigorous research effort, the current literature is often either highly technical or narrowly focused. This book presents heterostructure and quantum devices to the nonspecialist, especially electrical engineers working with high-performance semiconductor devices. It focuses on a broad base of technical applications using semiconductor physics theory to develop the next generation of electrical en

  4. Rooting an Android Device

    Science.gov (United States)

    2015-09-01

    1. Overview The purpose of this document is to demonstrate how to gain administrative privileges on an Android device. The term “rooting” is...is applicable for the Samsung Galaxy S3 as well as many other Android devices, but there are several steps involved in rooting an Android device (as...root access has been granted. 4. Conclusion This document serves as a tutorial on how to grant user administrative privilege to an Android device by

  5. Photovoltaic device and method

    Science.gov (United States)

    Cleereman, Robert J; Lesniak, Michael J; Keenihan, James R; Langmaid, Joe A; Gaston, Ryan; Eurich, Gerald K; Boven, Michelle L

    2015-01-27

    The present invention is premised upon an improved photovoltaic device ("PVD") and method of use, more particularly to an improved photovoltaic device with an integral locator and electrical terminal mechanism for transferring current to or from the improved photovoltaic device and the use as a system.

  6. Radioactive waste processing device

    International Nuclear Information System (INIS)

    Inaguma, Masahiko; Takahara, Nobuaki; Hara, Satomi.

    1996-01-01

    In a processing device for filtering laundry liquid wastes and shower drains incorporated with radioactive materials, a fiber filtration device is disposed and an activated carbon filtration device is also disposed subsequent to the fiber filtration device. In addition, a centrifugal dewatering device is disposed for dewatering spent granular activated carbon in the activated carbon filtration device, and a minute filtering device is disposed for filtering the separated dewatering liquid. Filtrates filtered by the minute filtration device are recovered in a collecting tank. Namely, at first, suspended solid materials in laundry liquid wastes and shower drains are captured, and then, ingredients concerning COD are adsorbed in the activated carbon filtration device. The radioactive liquid wastes of spent granular activated carbon in the activated carbon filtration device are reduced by dewatering them by the centrifugal dewatering device, and then the granular activated carbon is subjected to an additional processing. Further, it is separated by filtration using the minute filtration device and removed as cakes. Since the filtrates are recovered to the collecting tank and filtered again, the water quality of the drains is not degraded. (N.H.)

  7. Inspection device in liquid

    International Nuclear Information System (INIS)

    Nagaoka, Etsuo.

    1996-01-01

    The present invention provides an inspection device in PWR reactor core in which inspection operations are made efficient by stabilizing a posture of the device in front-to-back, vertical and left-to-right directions by a simple structure. When the device conducts inspection while running in liquid, the front and the back directions of the device main body are inspected using a visual device while changing the posture by operating a front-to-back direction propulsion device and a right-to-left direction propulsion device, and a vertical direction propulsion device against to rolling, pitching and yawing of the device main body. In this case, a spherical magnet moves freely in the gravitational direction in a vibration-damping fluid in a non-magnetic spherical shell following the change of the posture of the device main body, in which the vibrations due to the movement of the spherical magnet is settled by the vibration-damping fluid thereby stabilizing the posture of the device main body. At a typical inspection posture, the settling effect is enhanced by the attraction force between the spherical magnets in the spherical shell and each of magnetic force-attracted magnetic members disposed to the outer circumference of the shell, and the posture of the device main body can be confirmed in front-to-back, right-to-left and vertical directions by each of the posture confirming magnetic sensors. (N.H.)

  8. Containment and surveillance devices

    International Nuclear Information System (INIS)

    Campbell, J.W.; Johnson, C.S.; Stieff, L.R.

    The growing acceptance of containment and surveillance as a means to increase safeguards effectiveness has provided impetus to the development of improved surveillance and containment devices. Five recently developed devices are described. The devices include one photographic and two television surveillance systems and two high security seals that can be verified while installed

  9. Radiation emitting devices act

    International Nuclear Information System (INIS)

    1970-01-01

    This Act, entitled the Radiation Emitting Devices Act, is concerned with the sale and importation of radiation emitting devices. Laws relating to the sale, lease or import, labelling, advertising, packaging, safety standards and inspection of these devices are listed as well as penalties for any person who is convicted of breaking these laws

  10. Solar panel foundation device

    Energy Technology Data Exchange (ETDEWEB)

    Hawley, W.W.

    1983-03-29

    A transportable solar panel foundation device which has a bottom member, at least one upstanding side member, and an essentially open top. The side members are angled to permit nesting of a plurality of the foundation devices, and reinforcement pads are carried by the foundation device to support legs for one or more solar panels.

  11. Articulating feedstock delivery device

    Science.gov (United States)

    Jordan, Kevin

    2013-11-05

    A fully articulable feedstock delivery device that is designed to operate at pressure and temperature extremes. The device incorporates an articulating ball assembly which allows for more accurate delivery of the feedstock to a target location. The device is suitable for a variety of applications including, but not limited to, delivery of feedstock to a high-pressure reaction chamber or process zone.

  12. Radiation emitting devices regulations

    International Nuclear Information System (INIS)

    1970-01-01

    The Radiation Emitting Devices Regulations are the regulations referred to in the Radiation Emitting Devices Act and relate to the operation of devices. They include standards of design and construction, standards of functioning, warning symbol specifications in addition to information relating to the seizure and detention of machines failing to comply with the regulations. The radiation emitting devices consist of the following: television receivers, extra-oral dental x-ray equipment, microwave ovens, baggage inspection x-ray devices, demonstration--type gas discharge devices, photofluorographic x-ray equipment, laser scanners, demonstration lasers, low energy electron microscopes, high intensity mercury vapour discharge lamps, sunlamps, diagnostic x-ray equipment, ultrasound therapy devices, x-ray diffraction equipment, cabinet x-ray equipment and therapeutic x-ray equipment

  13. Smart portable rehabilitation devices

    Directory of Open Access Journals (Sweden)

    Leahey Matt

    2005-07-01

    Full Text Available Abstract Background The majority of current portable orthotic devices and rehabilitative braces provide stability, apply precise pressure, or help maintain alignment of the joints with out the capability for real time monitoring of the patient's motions and forces and without the ability for real time adjustments of the applied forces and motions. Improved technology has allowed for advancements where these devices can be designed to apply a form of tension to resist motion of the joint. These devices induce quicker recovery and are more effective at restoring proper biomechanics and improving muscle function. However, their shortcoming is in their inability to be adjusted in real-time, which is the most ideal form of a device for rehabilitation. This introduces a second class of devices beyond passive orthotics. It is comprised of "active" or powered devices, and although more complicated in design, they are definitely the most versatile. An active or powered orthotic, usually employs some type of actuator(s. Methods In this paper we present several new advancements in the area of smart rehabilitation devices that have been developed by the Northeastern University Robotics and Mechatronics Laboratory. They are all compact, wearable and portable devices and boast re-programmable, real time computer controlled functions as the central theme behind their operation. The sensory information and computer control of the three described devices make for highly efficient and versatile systems that represent a whole new breed in wearable rehabilitation devices. Their applications range from active-assistive rehabilitation to resistance exercise and even have applications in gait training. The three devices described are: a transportable continuous passive motion elbow device, a wearable electro-rheological fluid based knee resistance device, and a wearable electrical stimulation and biofeedback knee device. Results Laboratory tests of the devices

  14. Smart portable rehabilitation devices.

    Science.gov (United States)

    Mavroidis, Constantinos; Nikitczuk, Jason; Weinberg, Brian; Danaher, Gil; Jensen, Katherine; Pelletier, Philip; Prugnarola, Jennifer; Stuart, Ryan; Arango, Roberto; Leahey, Matt; Pavone, Robert; Provo, Andrew; Yasevac, Dan

    2005-07-12

    The majority of current portable orthotic devices and rehabilitative braces provide stability, apply precise pressure, or help maintain alignment of the joints with out the capability for real time monitoring of the patient's motions and forces and without the ability for real time adjustments of the applied forces and motions. Improved technology has allowed for advancements where these devices can be designed to apply a form of tension to resist motion of the joint. These devices induce quicker recovery and are more effective at restoring proper biomechanics and improving muscle function. However, their shortcoming is in their inability to be adjusted in real-time, which is the most ideal form of a device for rehabilitation. This introduces a second class of devices beyond passive orthotics. It is comprised of "active" or powered devices, and although more complicated in design, they are definitely the most versatile. An active or powered orthotic, usually employs some type of actuator(s). In this paper we present several new advancements in the area of smart rehabilitation devices that have been developed by the Northeastern University Robotics and Mechatronics Laboratory. They are all compact, wearable and portable devices and boast re-programmable, real time computer controlled functions as the central theme behind their operation. The sensory information and computer control of the three described devices make for highly efficient and versatile systems that represent a whole new breed in wearable rehabilitation devices. Their applications range from active-assistive rehabilitation to resistance exercise and even have applications in gait training. The three devices described are: a transportable continuous passive motion elbow device, a wearable electro-rheological fluid based knee resistance device, and a wearable electrical stimulation and biofeedback knee device. Laboratory tests of the devices demonstrated that they were able to meet their design

  15. Fluid circulation control device

    International Nuclear Information System (INIS)

    Benard, Henri; Henocque, Jean.

    1982-01-01

    Horizontal fluid circulation control device, of the type having a pivoting flap. This device is intended for being fitted in the pipes of hydraulic installation, particularly in a bleed and venting system of a nuclear power station shifting radioactive or contaminated liquids. The characteristic of this device is the cut-out at the top of the flap to allow the air contained in the pipes to flow freely [fr

  16. Mobile Device Encryption Systems

    OpenAIRE

    Teufl , Peter; Zefferer , Thomas; Stromberger , Christof

    2013-01-01

    Part 4: Software Security; International audience; The initially consumer oriented iOS and Android platforms, and the newly available Windows Phone 8 platform start to play an important role within business related areas. Within the business context, the devices are typically deployed via mobile device management (MDM) solutions, or within the bring-your-own-device (BYOD) context. In both scenarios, the security depends on many platform security functions, such as permission systems, manageme...

  17. Temperature indicating device

    International Nuclear Information System (INIS)

    Angus, J.P.; Salt, D.

    1988-01-01

    A temperature indicating device comprises a plurality of planar elements some undergoing a reversible change in appearance at a given temperature the remainder undergoing an irreversible change in appearance at a given temperature. The device is useful in indicating the temperature which an object has achieved as well as its actual temperature. The reversible change is produced by liquid crystal devices. The irreversible change is produced by an absorbent surface carrying substances e.g. waxes which melt at predetermined temperatures and are absorbed by the surface; alternatively paints may be used. The device is used for monitoring processes of encapsulation of radio active waste. (author)

  18. Ion trap device

    Science.gov (United States)

    Ibrahim, Yehia M.; Smith, Richard D.

    2016-01-26

    An ion trap device is disclosed. The device includes a series of electrodes that define an ion flow path. A radio frequency (RF) field is applied to the series of electrodes such that each electrode is phase shifted approximately 180 degrees from an adjacent electrode. A DC voltage is superimposed with the RF field to create a DC gradient to drive ions in the direction of the gradient. A second RF field or DC voltage is applied to selectively trap and release the ions from the device. Further, the device may be gridless and utilized at high pressure.

  19. Recoil transporter devices

    International Nuclear Information System (INIS)

    Madhavan, N.

    2005-01-01

    The study of sparsely produced nuclear reaction products in the direction of intense primary beam is a challenging task, the pursuit of which has given rise to the advent or several types of selective devices. These range from a simple parallel plate electrostatic deflector to state-of-the-art electromagnetic separators. There is no single device which can satisfy all the requirements of an ideal recoil transporter, simultaneously. An overview of such devices and their building blocks is presented, which may help in the proper choice of the device as per the experimental requirements. (author)

  20. Establishment Registration & Device Listing

    Data.gov (United States)

    U.S. Department of Health & Human Services — This searchable database contains establishments (engaged in the manufacture, preparation, propagation, compounding, assembly, or processing of medical devices...

  1. Virtual Training Devices Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Virtual Training Devices (VTD) Laboratory at the Life Cycle Software Engineering Center, Picatinny Arsenal, provides a software testing and support environment...

  2. High heat flux device of thermonuclear device

    International Nuclear Information System (INIS)

    Tachikawa, Nobuo.

    1994-01-01

    The present invention provides an equipments for high heat flux device (divertor) of a thermonuclear device, which absorbs thermal deformation during operation, has a high installation accuracy, and sufficiently withstands for thermal stresses. Namely, a heat sink member is joined to a structural base. Armour tiles are joined on the heat sink member. Cooling pipes are disposed between the heat sink member and the armour tiles. With such a constitution, the heat sink member using a highly heat conductive material having ductility, such as oxygen free copper, the cooling pipes using a material having excellent high temperature resistance and excellent elongation, such as aluminum-dispersed reinforced copper, and the armour tiles are completely joined on the structural base. Therefore, when thermal deformation tends to cause in the high heat flux device such as a divertor, cooling pipes cause no plastic deformation because of their high temperature resistance, but the heat sink member such as a oxygen free copper causes plastic deformation to absorb thermal deformation. As a result, the high heat flux device such as a divertor causes no deformation. (I.S.)

  3. Repairing method and device for thermonuclear device

    International Nuclear Information System (INIS)

    Sakurai, Akiko; Masumoto, Hiroshi; Tachikawa, Nobuo.

    1995-01-01

    The present invention provides a method of and a device for repairing a first wall and a divertor disposed in a vacuum vessel of a thermonuclear device. Namely, an armour tile of the divertor secured, by a brazing material, in a vacuum vessel of the thermonuclear device in which high temperature plasmas of deuterium and tritium are confined to cause fusion reaction is induction-heated or heated by microwaves to melt the brazing material. Only the armour tile is thus exchanged by its attachment/detachment. This device comprises, in the vacuum vessel, an armour tile attaching/detaching manipulator and a repairing manipulator comprising a heating manipulator having induction heating coils at the top end thereof. Induction heating coils are connected to an AC power source. According to the present invention, the armour tile is exchanged without taking the divertor out of the vacuum vessel. Therefore, cutting of a divertor cooling tube for taking the divertor out of the vacuum vessel and re-welding of the divertor for attaching it to the vacuum vessel again are no more necessary. (I.S.)

  4. Partial Device Fingerprints

    NARCIS (Netherlands)

    Ciere, M.; Hernandez Ganan, C.; van Eeten, M.J.G.

    2017-01-01

    In computing, remote devices may be identified by means of device fingerprinting, which works by collecting a myriad of clientside attributes such as the device’s browser and operating system version, installed plugins, screen resolution, hardware artifacts, Wi-Fi settings, and anything else

  5. Unconventional Quantum Computing Devices

    OpenAIRE

    Lloyd, Seth

    2000-01-01

    This paper investigates a variety of unconventional quantum computation devices, including fermionic quantum computers and computers that exploit nonlinear quantum mechanics. It is shown that unconventional quantum computing devices can in principle compute some quantities more rapidly than `conventional' quantum computers.

  6. Magnetic sensor device

    NARCIS (Netherlands)

    2009-01-01

    The present invention provides a sensor device and a method for detg. the presence and/or amt. of target moieties in a sample fluid, the target moieties being labeled with magnetic or magnetizable objects. The sensor device comprises a magnetic field generating means adapted for applying a retention

  7. Process control device

    International Nuclear Information System (INIS)

    Hayashi, Toshifumi; Kobayashi, Hiroshi.

    1994-01-01

    A process control device comprises a memory device for memorizing a plant operation target, a plant state or a state of equipments related with each other as control data, a read-only memory device for storing programs, a plant instrumentation control device or other process control devices, an input/output device for performing input/output with an operator, and a processing device which conducts processing in accordance with the program and sends a control demand or a display demand to the input/output device. The program reads out control data relative to a predetermined operation target, compares and verify them with actual values to read out control data to be a practice premise condition which is further to be a practice premise condition if necessary, thereby automatically controlling the plant or requiring or displaying input. Practice presuming conditions for the operation target can be examined succesively in accordance with the program without constituting complicated logical figures and AND/OR graphs. (N.H.)

  8. EPICS GPIB device support

    International Nuclear Information System (INIS)

    Winans, J.

    1993-01-01

    A GPIB device support module is used to provide access to the operating parameters of a GPIB device. GPIB devices may be accessed via National Instruments 1014 cards or via Bitbus Universal Gateways. GPIB devices typically have many parameters, each of which may be thought of in terms of the standard types of database records available in EPICS. It is the job of the device support module designer to decide how the mapping of these parameters will be made to the available record types. Once this mapping is complete, the device support module may be written. The writing of the device support module consists primarily of the construction of a parameter table. This table is used to associate the database record types with the operating parameters of the GPIB instrument. Other aspects of module design include the handling of SRQ events and errors. SRQ events are made available to the device support module if so desired. The processing of an SRQ event is completely up to the designer of the module. They may be ignored, tied to event based record processing, or anything else the designer wishes. Error conditions may be handled in a similar fashion

  9. Positioning devices for patients

    International Nuclear Information System (INIS)

    Heavens, M.

    1981-01-01

    It has been suggested that it is very important to position patients reproducibly at different stages of radiotherapy treatment planning and treatment, or similar procedures. Devices have been described for positioning a patient's upper and lower thorax. This invention provides reproducible positioning for a female patient's breasts, for example in planning treatment of and treating breast tumours. The patient is placed prone, using for example an upper thorax device. A support device is placed central to and beneath her breasts to partially displace them outwards. The device may be triangular in section with one apex contacting the chest wall at the sternum. Restraining straps may be provided to hold the breasts against the support device. Means may be provided to take a healthy breast from the path of radiation through the tumour. (author)

  10. Safety rod driving device

    International Nuclear Information System (INIS)

    Murakami, Kiyonobu; Kurosaki, Akira.

    1988-01-01

    Purpose: To rapidly insert safety rods for a criticality experiment device into a reactor core container to stop the criticality reaction thereby prevent reactivity accidents. Constitution: A cylinder device having a safety rod as a cylinder rod attached with a piston at one end is constituted. The piston is elevated by pressurized air and attracted and fixed by an electromagnet which is a stationary device disposed at the upper portion of the cylinder. If the current supply to the electromagnet is disconnected, the safety rod constituting the cylinder rod is fallen together with the piston to the lower portion of the cylinder. Since the cylinder rod driving device has neither electrical motor nor driving screw as in the conventional device, necessary space can be reduced and the weight is decreased. In addition, since the inside of the nuclear reactor can easily be shielded completely from the external atmosphere, leakage of radioactive materials can be prevented. (Horiuchi, T.)

  11. Compound semiconductor device modelling

    CERN Document Server

    Miles, Robert

    1993-01-01

    Compound semiconductor devices form the foundation of solid-state microwave and optoelectronic technologies used in many modern communication systems. In common with their low frequency counterparts, these devices are often represented using equivalent circuit models, but it is often necessary to resort to physical models in order to gain insight into the detailed operation of compound semiconductor devices. Many of the earliest physical models were indeed developed to understand the 'unusual' phenomena which occur at high frequencies. Such was the case with the Gunn and IMPATI diodes, which led to an increased interest in using numerical simulation methods. Contemporary devices often have feature sizes so small that they no longer operate within the familiar traditional framework, and hot electron or even quantum­ mechanical models are required. The need for accurate and efficient models suitable for computer aided design has increased with the demand for a wider range of integrated devices for operation at...

  12. Metallic spintronic devices

    CERN Document Server

    Wang, Xiaobin

    2014-01-01

    Metallic Spintronic Devices provides a balanced view of the present state of the art of metallic spintronic devices, addressing both mainstream and emerging applications from magnetic tunneling junction sensors and spin torque oscillators to spin torque memory and logic. Featuring contributions from well-known and respected industrial and academic experts, this cutting-edge work not only presents the latest research and developments but also: Describes spintronic applications in current and future magnetic recording devicesDiscusses spin-transfer torque magnetoresistive random-access memory (STT-MRAM) device architectures and modelingExplores prospects of STT-MRAM scaling, such as detailed multilevel cell structure analysisInvestigates spintronic device write and read optimization in light of spintronic memristive effectsConsiders spintronic research directions based on yttrium iron garnet thin films, including spin pumping, magnetic proximity, spin hall, and spin Seebeck effectsProposes unique solutions for ...

  13. Device for cutting protrusions

    Science.gov (United States)

    Bzorgi, Fariborz M [Knoxville, TN

    2011-07-05

    An apparatus for clipping a protrusion of material is provided. The protrusion may, for example, be a bolt head, a nut, a rivet, a weld bead, or a temporary assembly alignment tab protruding from a substrate surface of assembled components. The apparatus typically includes a cleaver having a cleaving edge and a cutting blade having a cutting edge. Generally, a mounting structure configured to confine the cleaver and the cutting blade and permit a range of relative movement between the cleaving edge and the cutting edge is provided. Also typically included is a power device coupled to the cutting blade. The power device is configured to move the cutting edge toward the cleaving edge. In some embodiments the power device is activated by a momentary switch. A retraction device is also generally provided, where the retraction device is configured to move the cutting edge away from the cleaving edge.

  14. Baking exhaustion device in thermonuclear device

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, Mitsunori.

    1987-02-02

    Purpose: To rapidly remove tritium and impurity from the vacuum region in the access port of the baking exhaustion device in a thermonuclear device. Constitution: Each of the gaps at the boundary between a fixed shielding member and a blanket module and at the boundary between the blanket and a divertor is made extremely small so as to minimize the neutron streaming from plasmas. Accordingly, in the case of evacuating the vacuum region in the access port, the gap conductance is extremely poor and the exhaustion speed is low. Then, baking pipeways for flowing high temperature fluids are embedded to the surface layer at the position facing to the vacuum region and the plasma evacuation duct and the vacuum region are connected with an evacuation duct of the access port. By flowing high temperature fluids in the pipeways and conducting evacuation, baking exhaustion can be carried out rapidly. (Kamimura, M.).

  15. Plasma facing device of thermonuclear device

    International Nuclear Information System (INIS)

    Sumita, Hideo; Ioki, Kimihiro.

    1993-01-01

    The present invention improves integrity of thermal structures of a plasma facing device. That is, in the plasma facing device, an armour block portion from a metal cooling pipe to a carbon material comprises a mixed material of the metal as the constituent material of the cooling pipe and ceramics. Then, the mixing ratio of the composition is changed continuously or stepwise to suppress peakings of remaining stresses upon production and thermal stresses upon exertion of thermal loads. Accordingly, thermal integrity of the structural materials can further be improved. In this case, a satisfactory characteristic can be obtained also by using ceramics instead of carbon for the mixed material, and the characteristic such as heat expansion coefficient is similar to that of the armour tile. (I.S.)

  16. Position measuring device

    International Nuclear Information System (INIS)

    Maeda, Kazuyuki; Takahashi, Shuichi; Maruyama, Mayumi

    1998-01-01

    The present invention provides a device capable of measuring accurate position and distance easily even at places where operator can not easily access, such as cell facilities for vitrifying radioactive wastes. Referring to a case of the vitrifying cell, an objective equipment settled in the cell is photographed by a photographing device. The image is stored in a position measuring device by way of an image input device. After several years, when the objective equipment is exchanged, a new objective equipment is photographed by a photographing device. The image is also stored in the position measuring device. The position measuring device compares the data of both of the images on the basis of pixel unit. Based on the image of the equipment before the exchange as a reference, extent of the displacement of the installation position of the equipment on the image after the exchange caused by installation error and manufacturing error is determined to decide the position of the equipment after exchange relative to the equipment before exchange. (I.S.)

  17. Incore instrumentation device

    International Nuclear Information System (INIS)

    Fujita, Kazuhiko.

    1996-01-01

    A position of a detector is detected by a driving device, and the detected values are sampled by a newly disposed central processing unit for sampling the detected values depending on the sampling position of the detected values. Since the sampling position of the detected values is detected by the driving device, the sampling position for the detection values does not rely on the speed of the driving motor of the driving device. The load on the central processing device for controlling the device is lowered by newly disposing the central processing unit for sampling detected values. When the values for the position of the detector counted after conversion to digital values reach the digital values corresponding to the detection value sampling position outputted from the central processing unit for controlling the device, a counted value comparison circuit causes the central processing unit for controlling the device to sample the detection values outputted from the detector. Then, the processing speed can be increased without interruption processings, which can save the central processing unit for sampling detection values. In addition, software can be simplified and loads can be lowered. (N.H.)

  18. Fuel pattern recognition device

    International Nuclear Information System (INIS)

    Sato, Tomomi.

    1995-01-01

    The device of the present invention monitors normal fuel exchange upon fuel exchanging operation carried out in a reactor of a nuclear power plant. Namely, a fuel exchanger is movably disposed to the upper portion of the reactor and exchanges fuels. An exclusive computer receives operation signals of the fuel exchanger during operation as inputs, and outputs reactor core fuel pattern information signals to a fuel arrangement diagnosis device. An underwater television camera outputs image signals of a fuel pattern in the reactor core to an image processing device. If there is any change in the image signals for the fuel pattern as a result of the fuel exchange operation of the fuel exchanger, the image processing device outputs the change as image signals to the fuel pattern diagnosis device. The fuel pattern diagnosis device compares the pattern information signals from the exclusive computer with the image signals from the image processing device, to diagnose the result of the fuel exchange operation performed by the fuel exchanger and inform the diagnosis by means of an image display. (I.S.)

  19. Diamond semiconducting devices

    International Nuclear Information System (INIS)

    Polowczyk, M.; Klugmann, E.

    1999-01-01

    Many efforts to apply the semiconducting diamond for construction of electronic elements: resistors, thermistors, photoresistors, piezoresistors, hallotrons, pn diodes, Schottky diodes, IMPATT diodes, npn transistor, MESFETs and MISFETs are reviewed. Considering the possibilities of acceptor and donor doping, electrical resistivity and thermal conductivity of diamond as well as high electric-field breakdown points, that diamond devices could be used at about 30-times higher frequency and more then 8200 times power than silicon devices. Except that, due to high heat resistant of diamond, it is concluded that diamond devices can be used in environment at high temperature, range of 600 o C. (author)

  20. Fundamentals of semiconductor devices

    CERN Document Server

    Lindmayer, Joseph

    1965-01-01

    Semiconductor properties ; semiconductor junctions or diodes ; transistor fundamentals ; inhomogeneous impurity distributions, drift or graded-base transistors ; high-frequency properties of transistors ; band structure of semiconductors ; high current densities and mechanisms of carrier transport ; transistor transient response and recombination processes ; surfaces, field-effect transistors, and composite junctions ; additional semiconductor characteristics ; additional semiconductor devices and microcircuits ; more metal, insulator, and semiconductor combinations for devices ; four-pole parameters and configuration rotation ; four-poles of combined networks and devices ; equivalent circuits ; the error function and its properties ; Fermi-Dirac statistics ; useful physical constants.

  1. Electronic devices and circuits

    CERN Document Server

    Pridham, Gordon John

    1972-01-01

    Electronic Devices and Circuits, Volume 3 provides a comprehensive account on electronic devices and circuits and includes introductory network theory and physics. The physics of semiconductor devices is described, along with field effect transistors, small-signal equivalent circuits of bipolar transistors, and integrated circuits. Linear and non-linear circuits as well as logic circuits are also considered. This volume is comprised of 12 chapters and begins with an analysis of the use of Laplace transforms for analysis of filter networks, followed by a discussion on the physical properties of

  2. Evolution of atherectomy devices.

    Science.gov (United States)

    Al Khoury, G; Chaer, R

    2011-08-01

    Percutaneous atherectomy provides an alternative approach to the endovascular treatment of peripheral atherosclerotic occlusive disease beyond angioplasty and stenting, and has the theoretical advantage of lesion debulking and minimizing barotrauma to the vessel wall. Atherectomy has evolved greatly during the last decade, with currently four FDA approved devices for the treatment of peripheral arterial disease. Several reports have focused on the initial technical success rates, and demonstrated the safety and short as well as mid-term efficacy of atherectomy devices. This article will review the evolution of current atherectomy devices and the associated literature.

  3. Introduction to Semiconductor Devices

    Science.gov (United States)

    Brennan, Kevin F.

    2005-03-01

    This volume offers a solid foundation for understanding the most important devices used in the hottest areas of electronic engineering today, from semiconductor fundamentals to state-of-the-art semiconductor devices in the telecommunications and computing industries. Kevin Brennan describes future approaches to computing hardware and RF power amplifiers, and explains how emerging trends and system demands of computing and telecommunications systems influence the choice, design and operation of semiconductor devices. In addition, he covers MODFETs and MOSFETs, short channel effects, and the challenges faced by continuing miniaturization. His book is both an excellent senior/graduate text and a valuable reference for practicing engineers and researchers.

  4. Proton therapy device

    International Nuclear Information System (INIS)

    Tronc, D.

    1994-01-01

    The invention concerns a proton therapy device using a proton linear accelerator which produces a proton beam with high energies and intensities. The invention lies in actual fact that the proton beam which is produced by the linear accelerator is deflected from 270 deg in its plan by a deflecting magnetic device towards a patient support including a bed the longitudinal axis of which is parallel to the proton beam leaving the linear accelerator. The patient support and the deflecting device turn together around the proton beam axis while the bed stays in an horizontal position. The invention applies to radiotherapy. 6 refs., 5 figs

  5. Nanoelectronic device applications handbook

    CERN Document Server

    Morris, James E

    2013-01-01

    Nanoelectronic Device Applications Handbook gives a comprehensive snapshot of the state of the art in nanodevices for nanoelectronics applications. Combining breadth and depth, the book includes 68 chapters on topics that range from nano-scaled complementary metal-oxide-semiconductor (CMOS) devices through recent developments in nano capacitors and AlGaAs/GaAs devices. The contributors are world-renowned experts from academia and industry from around the globe. The handbook explores current research into potentially disruptive technologies for a post-CMOS world.These include: Nanoscale advance

  6. Physics of photonic devices

    CERN Document Server

    Chuang, Shun Lien

    2009-01-01

    The most up-to-date book available on the physics of photonic devices This new edition of Physics of Photonic Devices incorporates significant advancements in the field of photonics that have occurred since publication of the first edition (Physics of Optoelectronic Devices). New topics covered include a brief history of the invention of semiconductor lasers, the Lorentz dipole method and metal plasmas, matrix optics, surface plasma waveguides, optical ring resonators, integrated electroabsorption modulator-lasers, and solar cells. It also introduces exciting new fields of research such as:

  7. Output hardcopy devices

    CERN Document Server

    Durbeck, Robert

    1988-01-01

    Output Hardcopy Devices provides a technical summary of computer output hardcopy devices such as plotters, computer output printers, and CRT generated hardcopy. Important related technical areas such as papers, ribbons and inks, color techniques, controllers, and character fonts are also covered. Emphasis is on techniques primarily associated with printing, as well as the plotting capabilities of printing devices that can be effectively used for computer graphics in addition to their various printing functions. Comprised of 19 chapters, this volume begins with an introduction to vector and ras

  8. A gauge device

    International Nuclear Information System (INIS)

    Qurnell, F.D.; Patterson, C.B.

    1982-01-01

    A readily transportable device of relative light weight comprising a pair of tensioned guides for providing accurate and stable reference planes. An embodiment comprises a pair of rods or guides in tension between a pair of end members, the end members being spaced apart by a pair of arcuate compression members. The tensioned guides provide planes of reference for measuring devices moved therealong adjacent to a component to be measured. The device is especially useful for making on-site dimensional measurements of components, such as irradiated and therefore radioactive components, that cannot readily be transported to an inspection laboratory. (author)

  9. Compound semiconductor device physics

    CERN Document Server

    Tiwari, Sandip

    2013-01-01

    This book provides one of the most rigorous treatments of compound semiconductor device physics yet published. A complete understanding of modern devices requires a working knowledge of low-dimensional physics, the use of statistical methods, and the use of one-, two-, and three-dimensional analytical and numerical analysis techniques. With its systematic and detailed**discussion of these topics, this book is ideal for both the researcher and the student. Although the emphasis of this text is on compound semiconductor devices, many of the principles discussed will also be useful to those inter

  10. Digital communication device

    DEFF Research Database (Denmark)

    2005-01-01

    The invention concerns a digital communication device like a hearing aid or a headset. The hearing aid or headset has a power supply, a signal processing device, means for receiving a wireless signal and a receiver or loudspeaker, which produces an audio signal based on a modulated pulsed signal...... point is provided which is in electrical contact with the metal of the metal box and whereby this third connection point is connected to the electric circuitry of the communication device at a point having a stable and well defined electrical potential. In this way the electro-and magnetic radiation...

  11. Powering biomedical devices

    CERN Document Server

    Romero, Edwar

    2013-01-01

    From exoskeletons to neural implants, biomedical devices are no less than life-changing. Compact and constant power sources are necessary to keep these devices running efficiently. Edwar Romero's Powering Biomedical Devices reviews the background, current technologies, and possible future developments of these power sources, examining not only the types of biomedical power sources available (macro, mini, MEMS, and nano), but also what they power (such as prostheses, insulin pumps, and muscular and neural stimulators), and how they work (covering batteries, biofluids, kinetic and ther

  12. Sodium aerosol recovering device

    International Nuclear Information System (INIS)

    Fujimori, Koji; Ueda, Mitsuo; Tanaka, Kazuhisa.

    1997-01-01

    A main body of a recovering device is disposed in a sodium cooled reactor or a sodium cooled test device. Air containing sodium aerosol is sucked into the main body of the recovering device by a recycling fan and introduced to a multi-staged metal mesh filter portion. The air about against each of the metal mesh filters, and the sodium aerosol in the air is collected. The air having a reduced sodium aerosol concentration circulates passing through a recycling fan and pipelines to form a circulation air streams. Sodium aerosol deposited on each of the metal mesh filters is scraped off periodically by a scraper driving device to prevent clogging of each of the metal filters. (I.N.)

  13. Incore monitoring device

    International Nuclear Information System (INIS)

    Tai, Ichiro; Shirayama, Shin-pei; Nozaki, Shin-ichi.

    1978-01-01

    Purpose: To provide an incore monitoring device wherein both radiation monitoring and acoustic monitoring are carried out simultaneously by one detector, whereby installation of the device and signal pick-up are facilitated. Incore conditions are accurately grasped. Constitution: When a neutron is irradiated in a state where a DC voltage is applied between the electrode and the vessel in the device, an ionization current is occured by (n.γ) reaction of the transformed substance as in an ionization chamber, Accordingly, a voltage drop occurs at both ends of the resistor of the radiation signal processing system, as a result of which a neutron flux can be detected. Further, when a sound is generated in the reactor, the monitoring device bottom wall which formed by a piezoelectric element detects the sound-waves. This output signal is picked up by the acoustic signal processing system to judge the generation of sound. (Aizawa, K.)

  14. Authenticated sensor interface device

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, Jody Rustyn; Poland, Richard W.

    2018-05-01

    A system and method for the secure storage and transmission of data is provided. A data aggregate device can be configured to receive secure data from a data source, such as a sensor, and encrypt the secure data using a suitable encryption technique, such as a shared private key technique, a public key encryption technique, a Diffie-Hellman key exchange technique, or other suitable encryption technique. The encrypted secure data can be provided from the data aggregate device to different remote devices over a plurality of segregated or isolated data paths. Each of the isolated data paths can include an optoisolator that is configured to provide one-way transmission of the encrypted secure data from the data aggregate device over the isolated data path. External data can be received through a secure data filter which, by validating the external data, allows for key exchange and other various adjustments from an external source.

  15. Plant abnormality inspection device

    International Nuclear Information System (INIS)

    Takenaka, Toshio.

    1990-01-01

    The present invention concerns a plant abnormality inspection device for conducting remote or automatic patrolling inspection in a plant and, more particularly, relates to such a device as capable of detecting abnormal odors. That is, the device comprises a moving device for moving to a predetermined position in the plant, a plurality of gas sensors for different kind of gases to be inspected mounted thereon, a comparator for comparing the concentration of a gas detected by the gas sensor with the normal gas concentration at the predetermined position and a judging means for judging the absence or presence of abnormality depending on the combination of the result of the comparison and deliverying a signal if the state is abnormal. As a result, a slight amount of gas responsible to odors released upon abnormality of the plant can be detected by a plurality of gas sensors for different kinds gases to rapidly and easily find abnormal portions in the plant. (I.S.)

  16. Geometry and Cloaking Devices

    Science.gov (United States)

    Ochiai, T.; Nacher, J. C.

    2011-09-01

    Recently, the application of geometry and conformal mappings to artificial materials (metamaterials) has attracted the attention in various research communities. These materials, characterized by a unique man-made structure, have unusual optical properties, which materials found in nature do not exhibit. By applying the geometry and conformal mappings theory to metamaterial science, it may be possible to realize so-called "Harry Potter cloaking device". Although such a device is still in the science fiction realm, several works have shown that by using such metamaterials it may be possible to control the direction of the electromagnetic field at will. We could then make an object hidden inside of a cloaking device. Here, we will explain how to design invisibility device using differential geometry and conformal mappings.

  17. Reactor noise monitoring device

    International Nuclear Information System (INIS)

    Yamanaka, Hiroto.

    1990-01-01

    The present invention concerns a reactor noise monitoring device by detecting abnormal sounds in background noises. Vibration sounds detected by accelerometers are applied to a loose parts detector. The detector generates high alarm if there are sudden impact sounds in the background noises and applies output signals to an accumulation device. If there is slight impact sounds in the vicinity of any of the accelerometers, the accumulation device accumulates the abnormal sounds assumed to be generated from an identical site while synchronizing the waveforms for all of the channels. Then, the device outputs signals in which the background noises are cancelled, as detection signals. Therefore, S/N ratio can be improved and the abnormal sounds contained in the background noises can be detected, to thereby improve the accuracy for estimating the position where the abnormal sounds are generated. (I.S.)

  18. Marine Sanitation Devices (MSDs)

    Science.gov (United States)

    Marine sanitation devices treat or retain sewage from vessels, and have performance standards set by the EPA. This page provides information on MSDs, including who must use an MSD, states' roles, types of MSDs and standards.

  19. MDR (Medical Device Reporting)

    Data.gov (United States)

    U.S. Department of Health & Human Services — This database allows you to search the CDRH's database information on medical devices which may have malfunctioned or caused a death or serious injury during the...

  20. Tokapole II device

    International Nuclear Information System (INIS)

    Sprott, J.G.

    1978-05-01

    A discussion is given of the design and operation of the Tokapole II device. The following topics are considered: physics considerations, vacuum vessel, poloidal field, ring and support design, toroidal field, vacuum system, initial results, and future plans