WorldWideScience

Sample records for alcator c-mod research

  1. Alcator C-Mod Tokamak

    Data.gov (United States)

    Federal Laboratory Consortium — Alcator C-Mod at the Massachusetts Institute of Technology is operated as a DOE national user facility. Alcator C-Mod is a unique, compact tokamak facility that uses...

  2. Overview of recent Alcator C-Mod research

    International Nuclear Information System (INIS)

    Marmar, E.S.

    2002-01-01

    Experiments have been carried out to investigate the triggering and control of ITBs, using multiple frequency ICRF tools. It is found that the ITBs can be reliably triggered using off-axis ICRF minority heating; the addition of on-axis heating at a second frequency can be used for control of the particle transport, leading to quasi-steady operation. Cross-field particle transport in the SOL been shown to be very rapid in Alcator C-Mod usually dominating over the parallel transport into the divertor with very important implications for our understanding of particle recycling and ash removal. Detailed explorations of the quasi-coherent mode (QCM) that appears to be responsible for particle transport across the EDA H-mode barrier have revealed that the QCM has a magnetic component, and comparisons with MHD stability calculations are consistent with the hypothesis that it is due to a resistive ballooning instability. In preparation for long-pulse discharges which will be sustained non-inductively we have produced discharges up to 3 seconds in length confirming that all systems can be operated for at least 5-second shots, which corresponds to about 5 current relaxation times at 5 keV. (author)

  3. Twenty Years of Research on the Alcator C-Mod Tokamak

    Science.gov (United States)

    Greenwald, Martin

    2013-10-01

    Alcator C-Mod is a compact, high-field tokamak, whose unique design and operating parameters have produced a wealth of new and important results since its start in 1993, contributing data that extended tests of critical physical models into new parameter ranges and into new regimes. Using only RF for heating and current drive with innovative launching structures, C-Mod operates routinely at very high power densities. Research highlights include direct experimental observation of ICRF mode-conversion, ICRF flow drive, demonstration of Lower-Hybrid current drive at ITER-like densities and fields and, using a set of powerful new diagnostics, extensive validation of advanced RF codes. C-Mod spearheaded the development of the vertical-target divertor and has always operated with high-Z metal plasma facing components--an approach adopted for ITER. C-Mod has made ground-breaking discoveries in divertor physics and plasma-material interactions at reactor-like power and particle fluxes and elucidated the critical role of cross-field transport in divertor operation, edge flows and the tokamak density limit. C-Mod developed the I-mode and EDA H-mode regimes which have high performance without large ELMs and with pedestal transport self-regulated by short-wavelength electromagnetic waves. C-Mod has carried out pioneering studies of intrinsic rotation and found that self-generated flow shear can be strong enough to significantly modify transport. C-Mod made the first quantitative link between pedestal temperature and H-mode performance, showing that the observed self-similar temperature profiles were consistent with critical-gradient-length theories and followed up with quantitative tests of nonlinear gyrokinetic models. Disruption studies on C-Mod provided the first observation of non-axisymmetric halo currents and non-axisymmetric radiation in mitigated disruptions. Work supported by U.S. DoE

  4. 20 years of research on the Alcator C-Mod tokamak

    International Nuclear Information System (INIS)

    Greenwald, M.; Baek, S.; Barnard, H.; Beck, W.; Bonoli, P.; Brunner, D.; Burke, W.; Ennever, P.; Ernst, D.; Faust, I.; Fiore, C.; Fredian, T.; Gao, C.; Golfinopoulos, T.; Granetz, R.; Hartwig, Z.; Hubbard, A.; Hughes, J.; Hutchinson, I.; Irby, J.

    2014-01-01

    The object of this review is to summarize the achievements of research on the Alcator C-Mod tokamak [Hutchinson et al., Phys. Plasmas 1, 1511 (1994) and Marmar, Fusion Sci. Technol. 51, 261 (2007)] and to place that research in the context of the quest for practical fusion energy. C-Mod is a compact, high-field tokamak, whose unique design and operating parameters have produced a wealth of new and important results since it began operation in 1993, contributing data that extends tests of critical physical models into new parameter ranges and into new regimes. Using only high-power radio frequency (RF) waves for heating and current drive with innovative launching structures, C-Mod operates routinely at reactor level power densities and achieves plasma pressures higher than any other toroidal confinement device. C-Mod spearheaded the development of the vertical-target divertor and has always operated with high-Z metal plasma facing components—approaches subsequently adopted for ITER. C-Mod has made ground-breaking discoveries in divertor physics and plasma-material interactions at reactor-like power and particle fluxes and elucidated the critical role of cross-field transport in divertor operation, edge flows and the tokamak density limit. C-Mod developed the I-mode and the Enhanced Dα H-mode regimes, which have high performance without large edge localized modes and with pedestal transport self-regulated by short-wavelength electromagnetic waves. C-Mod has carried out pioneering studies of intrinsic rotation and demonstrated that self-generated flow shear can be strong enough in some cases to significantly modify transport. C-Mod made the first quantitative link between the pedestal temperature and the H-mode's performance, showing that the observed self-similar temperature profiles were consistent with critical-gradient-length theories and followed up with quantitative tests of nonlinear gyrokinetic models. RF research highlights include direct experimental

  5. 20 years of research on the Alcator C-Mod tokamaka)

    Science.gov (United States)

    Greenwald, M.; Bader, A.; Baek, S.; Bakhtiari, M.; Barnard, H.; Beck, W.; Bergerson, W.; Bespamyatnov, I.; Bonoli, P.; Brower, D.; Brunner, D.; Burke, W.; Candy, J.; Churchill, M.; Cziegler, I.; Diallo, A.; Dominguez, A.; Duval, B.; Edlund, E.; Ennever, P.; Ernst, D.; Faust, I.; Fiore, C.; Fredian, T.; Garcia, O.; Gao, C.; Goetz, J.; Golfinopoulos, T.; Granetz, R.; Grulke, O.; Hartwig, Z.; Horne, S.; Howard, N.; Hubbard, A.; Hughes, J.; Hutchinson, I.; Irby, J.; Izzo, V.; Kessel, C.; LaBombard, B.; Lau, C.; Li, C.; Lin, Y.; Lipschultz, B.; Loarte, A.; Marmar, E.; Mazurenko, A.; McCracken, G.; McDermott, R.; Meneghini, O.; Mikkelsen, D.; Mossessian, D.; Mumgaard, R.; Myra, J.; Nelson-Melby, E.; Ochoukov, R.; Olynyk, G.; Parker, R.; Pitcher, S.; Podpaly, Y.; Porkolab, M.; Reinke, M.; Rice, J.; Rowan, W.; Schmidt, A.; Scott, S.; Shiraiwa, S.; Sierchio, J.; Smick, N.; Snipes, J. A.; Snyder, P.; Sorbom, B.; Stillerman, J.; Sung, C.; Takase, Y.; Tang, V.; Terry, J.; Terry, D.; Theiler, C.; Tronchin-James, A.; Tsujii, N.; Vieira, R.; Walk, J.; Wallace, G.; White, A.; Whyte, D.; Wilson, J.; Wolfe, S.; Wright, G.; Wright, J.; Wukitch, S.; Zweben, S.

    2014-11-01

    The object of this review is to summarize the achievements of research on the Alcator C-Mod tokamak [Hutchinson et al., Phys. Plasmas 1, 1511 (1994) and Marmar, Fusion Sci. Technol. 51, 261 (2007)] and to place that research in the context of the quest for practical fusion energy. C-Mod is a compact, high-field tokamak, whose unique design and operating parameters have produced a wealth of new and important results since it began operation in 1993, contributing data that extends tests of critical physical models into new parameter ranges and into new regimes. Using only high-power radio frequency (RF) waves for heating and current drive with innovative launching structures, C-Mod operates routinely at reactor level power densities and achieves plasma pressures higher than any other toroidal confinement device. C-Mod spearheaded the development of the vertical-target divertor and has always operated with high-Z metal plasma facing components—approaches subsequently adopted for ITER. C-Mod has made ground-breaking discoveries in divertor physics and plasma-material interactions at reactor-like power and particle fluxes and elucidated the critical role of cross-field transport in divertor operation, edge flows and the tokamak density limit. C-Mod developed the I-mode and the Enhanced Dα H-mode regimes, which have high performance without large edge localized modes and with pedestal transport self-regulated by short-wavelength electromagnetic waves. C-Mod has carried out pioneering studies of intrinsic rotation and demonstrated that self-generated flow shear can be strong enough in some cases to significantly modify transport. C-Mod made the first quantitative link between the pedestal temperature and the H-mode's performance, showing that the observed self-similar temperature profiles were consistent with critical-gradient-length theories and followed up with quantitative tests of nonlinear gyrokinetic models. RF research highlights include direct experimental

  6. The alcator C-MOD control system

    International Nuclear Information System (INIS)

    Bosco, J.; Fairfax, S.

    1992-01-01

    The Alcator C-MOD experiment includes over 30 engineering and diagnostic subsystems. The control system hardware and software is a mixture of custom and commercial products which includes sensors, signal conditioners, hard-wired controls, programmable logic controllers, displays, a hybrid analog/digital computer, networked personal computers, and networked VAX workstations. This paper describes the computer-based portions of the control system. The control system coordinates all C-MOD systems including power, vacuum, heating and cooling, access control, plasma shape and position control, and diagnostics. Programmable logic controllers (PLC's) are located near each subsystem. The control room is isolated by fiber optics. Functions that are essential to personnel or equipment safety (e.g. access control) are implemented in hardwired logic and monitored but not controlled by the PLC's. The initial configuration will include over 25 Allen-Bradley PLC-5 units. The PLCs in each subsystem are connected to personal computers (PC's) in the control room. The PC's provide graphical displays and operator interface. The Pc's are networked and share process data with each other and with a master control console and a large mimic panel

  7. The physics and engineering of Alcator C-Mod

    International Nuclear Information System (INIS)

    Hutchinson, I.H.; Becker, H.; Bonoli, P.

    1988-08-01

    Alcator C-Mod is a new tokamak under construction at M.I.T. that promises to play an important and flexible role in the international fusion research effort. The physics and engineering features of the tokamak are described, giving an overview of the machine and plasma configurations. On the basis of empirical scaling laws, we predict the plasma confinement performance to be near DT equivalent breakeven. The planned experimental program is addressed to many of the vital physics questions still uncertain in high-performance tokamak plasma behaviour as well as to the investigation of innovative approaches to tokamak improvement. 17 refs., 17 figs., 3 tabs

  8. Gas jet disruption mitigation studies on Alcator C-Mod

    International Nuclear Information System (INIS)

    Granetz, R.; Whyte, D.G.; Izzo, V.A.; Biewer, T.; Reinke, M.L.; Terry, J.; Bader, A.; Bakhtiari, M.; Jernigan, T.; Wurden, G.

    2006-01-01

    Damaging effects of disruptions are a major concern for Alcator C-Mod, ITER and future tokamak reactors. High-pressure noble gas jet injection is a mitigation technique which potentially satisfies the operational requirements of fast response time and reliability, while still being benign to subsequent discharges. Disruption mitigation experiments using an optimized gas jet injection system are being carried out on Alcator C-Mod to study the physics of gas jet penetration into high pressure plasmas, as well as the ability of the gas jet impurities to convert plasma energy into radiation on timescales consistent with C-Mod's fast quench times, and to reduce halo currents given C-Mod's high-current density. The dependence of impurity penetration and effectiveness on noble gas species (He, Ne, Ar, Kr) is also being studied. It is found that the high-pressure neutral gas jet does not penetrate deeply into the C-Mod plasma, and yet prompt core thermal quenches are observed on all gas jet shots. 3D MHD modelling of the disruption physics with NIMROD shows that edge cooling of the plasma triggers fast growing tearing modes which rapidly produce a stochastic region in the core of the plasma and loss of thermal energy. This may explain the apparent effectiveness of the gas jet in C-Mod despite its limited penetration. The higher-Z gases (Ne, Ar, Kr) also proved effective at reducing halo currents and decreasing thermal deposition to the divertor surfaces. In addition, noble gas jet injection proved to be benign for plasma operation with C-Mod's metal (Mo) wall, actually improving the reliability of the startup in the following discharge

  9. The LHCD Launcher for Alcator C-Mod - Design, Construction, Calibration and Testing

    International Nuclear Information System (INIS)

    Hosea, J.; Beals, D.; Beck, W.; Bernabei, S.; Burke, W.; Childs, R.; Ellis, R.; Fredd, E.; Greenough, N.; Grimes, M.; Gwinn, D.; Irby, J.; Jurczynski, S.; Koert, P.; Kung, C.C.; Loesser, G.D.; Marmar, E.; Parker, R.; Rushinski, J.; Schilling, G.; Terry, D.; Vieira, R.; Wilson, J.R.; Zaks, J.

    2005-01-01

    MIT and PPPL have joined together to fabricate a high-power lower hybrid current drive (LHCD) system for supporting steady-state AT regime research on Alcator C-Mod. The goal of the first step of this project is to provide 1.5 MW of 4.6 GHz rf [radio frequency] power to the plasma with a compact launcher which has excellent spectral selectivity and fits into a single C-Mod port. Some of the important design, construction, calibration and testing considerations for the launcher leading up to its installation on C-Mod are presented here

  10. The LHCD launcher for Alcator C-Mod-Design, construction, calibration and testing

    International Nuclear Information System (INIS)

    Hosea, J.; Beals, D.; Beck, W.; Bernabei, S.; Burke, W.; Childs, R.; Ellis, R.; Fredd, E.; Greenough, N.; Grimes, M.; Gwinn, D.; Irby, J.; Jurczynski, S.; Koert, P.; Kung, C.C.; Loesser, G.D.; Marmar, E.; Parker, R.; Rushinski, J.; Schilling, G.; Terry, D.; Vieira, R.; Wilson, J.R.; Zaks, J.

    2005-01-01

    MIT and PPPL have joined together to fabricate a high-power lower hybrid current drive (LHCD) system for supporting steady-state AT regime research on Alcator C-Mod. The goal of the first step of this project is to provide 1.5 MW of 4.6 GHz rf power to the plasma with a compact launcher which has excellent spectral selectivity and fits into a single C-Mod port. Some of the important design, construction, calibration and testing considerations for the launcher leading up to its installation on C-Mod are presented here

  11. Edge Ion Heating during ICRH in Alcator C-Mod

    Science.gov (United States)

    Rost, J. C.; Boivin, R. L.; Porkolab, M.; Reardon, J.; Takase, Y.

    1997-11-01

    Observations of edge ion heating during ICRF injection on Alcator C-Mod have been made using a toroidally and poloidally scanning charge-exchange neutral particle analyzer. The ion tails create a large flux of charge-exchange neutrals (hydrogen and deuterium), at suprathermal energies, with a short rise time (exchange data from different poloidal sightlines taken during toroidal field ramps shows that the ion tails are generated near the radius of the antenna-protection limiter. Experimental estimates of the spatial dependence of the RF power going to the tails are made for one toroidal field value.

  12. Conceptual design Alcator C-MOD magnetic systems

    International Nuclear Information System (INIS)

    Schultz, J.H.; Becker, H.; Fertl, K.; Gwinn, D.; Montgomery, D.B.; Pierce, N.T.; Pillsbury, R.D. Jr.; Thome, R.J.

    1986-01-01

    The conceptual designs of the magnetic systems for Alcator C-MOD, a proposed tokamak at M.I.T., are described, including the toroidal magnet, the poloidal field coils and the cryogenic system. The toroidal magnet is constructed from rectangular plates, connected by sliding joints. Toroidal magnet forces are contained by a steel superstructure. Poloidal coil system options are largely or wholly inside the TF magnet, in order to control plasmas with high current, strong shaping, and expanded boundaries. All magnets are cryocooled by the natural circulation of boiling liquid nitrogen. 3 refs., 5 figs

  13. Edge Turbulence Imaging on NSTX and Alcator C-Mod

    International Nuclear Information System (INIS)

    S.J. Zweben; R.A. Maqueda; J.L. Terry; B. Bai; C.J. Boswell; C.E. Bush; D. D'Ippolito; E.D. Fredrickson; M. Greenwald; K. Hallatschek; S. Kaye; B. LaBombard; R. Maingi; J. Myra; W.M. Nevins; B.N. Rogers; D.P. Stotler; J. Wilgen; and X.Q. Xu

    2002-01-01

    Edge turbulence images have been made using an ultra-high speed CCD camera on both NSTX and Alcator C-Mod. In both cases, the D-alpha or HeI (587.6 nm) line emission from localized deuterium or helium gas puffs was viewed along a local magnetic field line near the outer midplane. Fluctuations in this line emission reflect fluctuations in electron density and/or electron temperature through the atomic excitation rates, which can be modeled using the DEGAS-2 code. The 2-D structure of the measured turbulence can be compared with theoretical simulations based on 3-D fluid models

  14. Neutral particle dynamics in the Alcator C-Mod tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Niemczewski, Artur P. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    1995-08-01

    This thesis presents an experimental study of neutral particle dynamics in the Alcator C-Mod tokamak. The primary diagnostic used is a set of six neutral pressure gauges, including special-purpose gauges built for in situ tokamak operation. While a low main chamber neutral pressure coincides with high plasma confinement regimes, high divertor pressure is required for heat and particle flux dispersion in future devices such as ITER. Thus we examine conditions that optimize divertor compression, defined here as a divertor-to-midplane pressure ratio. We find both pressures depend primarily on the edge plasma regimes defined by the scrape-off-layer heat transport. While the maximum divertor pressure is achieved at high core plasma densities corresponding to the detached divertor state, the maximum compression is achieved in the high-recycling regime. Variations in the divertor geometry have a weaker effect on the neutral pressures. For otherwise similar plasmas the divertor pressure and compression are maximum when the strike point is at the bottom of the vertical target plate. We introduce a simple flux balance model, which allows us to explain the divertor neutral pressure across a wide range of plasma densities. In particular, high pressure sustained in the detached divertor (despite a considerable drop in the recycling source) can be explained by scattering of neutrals off the cold plasma plugging the divertor throat. Because neutrals are confined in the divertor through scattering and ionization processes (provided the mean-free-paths are much shorter than a typical escape distance) tight mechanical baffling is unnecessary. The analysis suggests that two simple structural modifications may increase the divertor compression in Alcator C-Mod by a factor of about 5. Widening the divertor throat would increase the divertor recycling source, while closing leaks in the divertor structure would eliminate a significant neutral loss mechanism.

  15. Migration of alcator C-Mod computer infrastructure to Linux

    International Nuclear Information System (INIS)

    Fredian, T.W.; Greenwald, M.; Stillerman, J.A.

    2004-01-01

    The Alcator C-Mod fusion experiment at MIT in Cambridge, Massachusetts has been operating for twelve years. The data handling for the experiment during most of this period was based on MDSplus running on a cluster of VAX and Alpha computers using the OpenVMS operating system. While the OpenVMS operating system provided a stable reliable platform, the support of the operating system and the software layered on the system has deteriorated in recent years. With the advent of extremely powerful low cost personal computers and the increasing popularity and robustness of the Linux operating system a decision was made to migrate the data handling systems for C-Mod to a collection of PC's running Linux. This paper will describe the new system configuration, the effort involved in the migration from OpenVMS, the results of the first run campaign under the new configuration and the impact the switch may have on the rest of the MDSplus community

  16. Correlation ECE diagnostic in Alcator C-Mod

    International Nuclear Information System (INIS)

    Sung, C.; Irby, J.; Leccacorvi, R.; Vieira, R.; Oi, C.; Rice, J.; Reinke, M.; Gao, C.; Ennever, P.; Porkolab, M.; Churchill, R.; Theiler, C.; Walk, J.; Hughes, J.; Hubbard, A.; Greenwald, M.

    2015-01-01

    Correlation ECE (CECE) is a diagnostic technique that allows measurement of small amplitude electron temperature, Te, fluctuations through standard cross-correlation analysis methods. In Alcator C-Mod, a new CECE diagnostic has been installed[Sung RSI 2012], and interesting phenomena have been observed in various plasma conditions. We find that local Te fluctuations near the edge (ρ ~ 0:8) decrease across the linearto- saturated ohmic confinement transition, with fluctuations decreasing with increasing plasma density [Sung NF 2013], which occurs simultaneously with rotation reversals [Rice NF 2011]. Te fluctuations are also reduced across core rotation reversals with an increase of plasma density in RF heated L-mode plasmas, which implies that the same physics related to the reduction of Te fluctuations may be applied to both ohmic and RF heated L-mode plasmas. In I-mode plasmas, we observe the reduction of core Te fluctuations, which indicates changes of turbulence occur not only in the pedestal region but also in the core across the L/I transition [White NF 2014]. The present CECE diagnostic system in C-Mod and these experimental results are described in this paper

  17. Superstructure for a super tokamak: Alcator C-MOD

    International Nuclear Information System (INIS)

    Ballinger, R.; Becker, H.; Hwang, I.; Titus, P.; Fisher, K.; Werber, K.

    1989-01-01

    ALCATOR C-MOD is a compact high performance tokamak presently being constructed by the Massachusetts Institute of Technology under contract to the US Department of Energy. The purpose of the program is to study the production, confinement, heating, and control of strongly shaped, fully diverted, high density plasmas. The high toroidal magnetic field produces extremely large forces on the magnet conductors. Those loads are reacted by an external superstructure. The machine will be operated in a pulsed mode, with a design life of 50,000 cycles. That combination places exceptional requirements on the design, materials processing, and fabrication of the superstructure components. The superstructure consists of a large forged AISI 316LN pressure vessel that is assembled with alloy 718 fasteners. The chemistries and thermomechanical processing techniques were selected to provide the necessary mechanical properties at both room temperature and at the 77K operating temperature. This presentation addresses the superstructure design, stress analysis, materials processing, static and fatigue properties, components fabrication, and inspection. 13 refs., 2 tabs

  18. Lower Hybrid Current Drive Experiments in Alcator C-Mod

    Energy Technology Data Exchange (ETDEWEB)

    J.R. Wilson, S. Bernabei, P. Bonoli, A. Hubbard, R. Parker, A. Schmidt, G. Wallace, J. Wright, and the Alcator C-Mod Team

    2007-10-09

    A Lower Hybrid Current Drive (LHCD) system has been installed on the Alcator C-MOD tokamak at MIT. Twelve klystrons at 4.6 GHz feed a 4x22 waveguide array. This system was designed for maximum flexibility in the launched parallel wave-number spectrum. This flexibility allows tailoring of the lower hybrid deposition under a variety of plasma conditions. Power levels up to 900 kW have been injected into the tokomak. The parallel wave number has been varied over a wide range, n|| ~ 1.6–4. Driven currents have been inferred from magnetic measurements by extrapolating to zero loop voltage and by direct comparison to Fisch-Karney theory, yielding an efficiency of n20IR/P ~ 0.3. Modeling using the CQL3D code supports these efficiencies. Sawtooth oscillations vanish, accompanied with peaking of the electron temperature (Te0 rises from 2.8 to 3.8 keV). Central q is inferred to rise above unity from the collapse of the sawtooth inversion radius, indicating off-axis cd as expected. Measurements of non-thermal x-ray and electron cyclotron emission confirm the presence of a significant fast electron population that varies with phase and plasma density. The x-ray emission is observed to be radialy broader than that predicted by simple ray tracing codes. Possible explanations for this broader emission include fast electron diffusion or broader deposition than simple ray tracing predictions (perhaps due to diffractive effects).

  19. Measurement of particle transport coefficients on Alcator C-Mod

    Energy Technology Data Exchange (ETDEWEB)

    Luke, T.C.T.

    1994-10-01

    The goal of this thesis was to study the behavior of the plasma transport during the divertor detachment in order to explain the central electron density rise. The measurement of particle transport coefficients requires sophisticated diagnostic tools. A two color interferometer system was developed and installed on Alcator C-Mod to measure the electron density with high spatial ({approx} 2 cm) and high temporal ({le} 1.0 ms) resolution. The system consists of 10 CO{sub 2} (10.6 {mu}m) and 4 HeNe (.6328 {mu}m) chords that are used to measure the line integrated density to within 0.08 CO{sub 2} degrees or 2.3 {times} 10{sup 16}m{sup {minus}2} theoretically. Using the two color interferometer, a series of gas puffing experiments were conducted. The density was varied above and below the threshold density for detachment at a constant magnetic field and plasma current. Using a gas modulation technique, the particle diffusion, D, and the convective velocity, V, were determined. Profiles were inverted using a SVD inversion and the transport coefficients were extracted with a time regression analysis and a transport simulation analysis. Results from each analysis were in good agreement. Measured profiles of the coefficients increased with the radius and the values were consistent with measurements from other experiments. The values exceeded neoclassical predictions by a factor of 10. The profiles also exhibited an inverse dependence with plasma density. The scaling of both attached and detached plasmas agreed well with this inverse scaling. This result and the lack of change in the energy and impurity transport indicate that there was no change in the underlying transport processes after detachment.

  20. Measurement of particle transport coefficients on Alcator C-Mod

    International Nuclear Information System (INIS)

    Luke, T.C.T.

    1994-10-01

    The goal of this thesis was to study the behavior of the plasma transport during the divertor detachment in order to explain the central electron density rise. The measurement of particle transport coefficients requires sophisticated diagnostic tools. A two color interferometer system was developed and installed on Alcator C-Mod to measure the electron density with high spatial (∼ 2 cm) and high temporal (≤ 1.0 ms) resolution. The system consists of 10 CO 2 (10.6 μm) and 4 HeNe (.6328 μm) chords that are used to measure the line integrated density to within 0.08 CO 2 degrees or 2.3 x 10 16 m -2 theoretically. Using the two color interferometer, a series of gas puffing experiments were conducted. The density was varied above and below the threshold density for detachment at a constant magnetic field and plasma current. Using a gas modulation technique, the particle diffusion, D, and the convective velocity, V, were determined. Profiles were inverted using a SVD inversion and the transport coefficients were extracted with a time regression analysis and a transport simulation analysis. Results from each analysis were in good agreement. Measured profiles of the coefficients increased with the radius and the values were consistent with measurements from other experiments. The values exceeded neoclassical predictions by a factor of 10. The profiles also exhibited an inverse dependence with plasma density. The scaling of both attached and detached plasmas agreed well with this inverse scaling. This result and the lack of change in the energy and impurity transport indicate that there was no change in the underlying transport processes after detachment

  1. Blob sizes and velocities in the Alcator C-Mod scrape-off layer

    DEFF Research Database (Denmark)

    Kube, R.; Garcia, O.E.; LaBombard, B.

    A new blob-tracking algorithm for the GPI diagnostic installed in the outboard-midplane of Alcator C-Mod is developed. I t tracks large-amplitude fluctuations propagating through the scrape-off layer and calculates blob sizes and velocities. We compare the results of this method to a blob velocity...

  2. Disruption Warning Database Development and Exploratory Machine Learning Studies on Alcator C-Mod

    Science.gov (United States)

    Montes, Kevin; Rea, Cristina; Granetz, Robert

    2017-10-01

    A database of about 1800 shots from the 2015 campaign on the Alcator C-Mod tokamak is assembled, including disruptive and non-disruptive discharges. The database consists of 40 relevant plasma parameters with data taken from 160k time slices. In order to investigate the possibility of developing a robust disruption prediction algorithm that is tokamak-independent, we focused machine learning studies on a subset of dimensionless parameters such as βp, n /nG , etc. The Random Forests machine learning algorithm provides insight on the available data set by ranking the relative importance of the input features. Its application on the C-Mod database, however, reveals that virtually no one parameter has more importance than any other, and that its classification algorithm has a low rate of successfully predicted samples, as well as poor false positive and false negative rates. Comparing the analysis of this algorithm on the C-Mod database with its application to a similar database on DIII-D, we conclude that disruption prediction may not be feasible on C-Mod. This conclusion is supported by empirical observations that most C-Mod disruptions are caused by radiative collapse due to molybdenum from the first wall, which happens on just a 1-2ms timescale. Supported by the US Dept. of Energy under DE-FC02-99ER54512 and DE-FC02-04ER54698.

  3. Impurity transport in the divertor of the Alcator C-Mod tokamak

    International Nuclear Information System (INIS)

    McCracken, G.M.; Bombarda, F.; Graf, M.; Goetz, J.A.; Jablonski, D.; Kurz, C.; Labombard, B.; Lipschultz, B.; Rice, J.; Welch, B.

    1995-01-01

    Argon has been injected into the private flux zone of the Alcator C-Mod divertor and its transport into the confined plasma studied. The injected gas pulse lasts for about 200 ms, but the impurity concentration increases to an equilibrium level and remains there for similar 200 ms. It is clear that the argon is acting as a recycling impurity. Nevertheless it has been observed that less than 0.5% of the injected atoms reach the confined plasma and that the percentage decreases with increasing plasma density. The good impurity screening is discussed in terms of the ionisation mean free path in the divertor. ((orig.))

  4. Flux-driven turbulence GDB simulations of the IWL Alcator C-Mod L-mode edge compared with experiment

    Science.gov (United States)

    Francisquez, Manaure; Zhu, Ben; Rogers, Barrett

    2017-10-01

    Prior to predicting confinement regime transitions in tokamaks one may need an accurate description of L-mode profiles and turbulence properties. These features determine the heat-flux width upon which wall integrity depends, a topic of major interest for research aid to ITER. To this end our work uses the GDB model to simulate the Alcator C-Mod edge and contributes support for its use in studying critical edge phenomena in current and future tokamaks. We carried out 3D electromagnetic flux-driven two-fluid turbulence simulations of inner wall limited (IWL) C-Mod shots spanning closed and open flux surfaces. These simulations are compared with gas puff imaging (GPI) and mirror Langmuir probe (MLP) data, examining global features and statistical properties of turbulent dynamics. GDB reproduces important qualitative aspects of the C-Mod edge regarding global density and temperature profiles, within reasonable margins, and though the turbulence statistics of the simulated turbulence follow similar quantitative trends questions remain about the code's difficulty in exactly predicting quantities like the autocorrelation time A proposed breakpoint in the near SOL pressure and the posited separation between drift and ballooning dynamics it represents are examined This work was supported by DOE-SC-0010508. This research used resources of the National Energy Research Scientific Computing Center (NERSC).

  5. ICRF antenna matching system with ferrite tuners for the Alcator C-Mod tokamak

    Science.gov (United States)

    Lin, Y.; Binus, A.; Wukitch, S. J.; Koert, P.; Murray, R.; Pfeiffer, A.

    2015-12-01

    Real-time fast ferrite tuning (FFT) has been successfully implemented on the ICRF antennas on Alcator C-Mod. The former prototypical FFT system on the E-port 2-strap antenna has been upgraded using new ferrite tuners that have been designed specifically for the operational parameters of the Alcator C-Mod ICRF system (˜ 80 MHz). Another similar FFT system, with two ferrite tuners and one fixed-length stub, has been installed on the transmission line of the D-port 2-strap antenna. These two systems share a Linux-server-based real-time controller. These FFT systems are able to achieve and maintain the reflected power to the transmitters to less than 1% in real time during the plasma discharges under almost all plasma conditions, and help ensure reliable high power operation of the antennas. The innovative field-aligned (FA) 4-strap antenna on J-port has been found to have an interesting feature of loading insensitivity vs. plasma conditions. This feature allows us to significantly improve the matching for the FA J-port antenna by installing carefully designed stubs on the two transmission lines. The reduction of the RF voltages in the transmission lines has enabled the FA J-port antenna to deliver 3.7 MW RF power to plasmas out of the 4 MW source power in high performance I-mode plasmas.

  6. Comparison of tungsten nano-tendrils grown in Alcator C-Mod and linear plasma devices

    International Nuclear Information System (INIS)

    Wright, G.M.; Brunner, D.; Baldwin, M.J.; Bystrov, K.; Doerner, R.P.; Labombard, B.; Lipschultz, B.; De Temmerman, G.; Terry, J.L.; Whyte, D.G.; Woller, K.B.

    2013-01-01

    Growth of tungsten nano-tendrils (“fuzz”) has been observed for the first time in the divertor region of a high-power density tokamak experiment. After 14 consecutive helium L-mode discharges in Alcator C-Mod, the tip of a tungsten Langmuir probe at the outer strike point was fully covered with a layer of nano-tendrils. The depth of the W fuzz layer (600 ± 150 nm) is consistent with an empirical growth formula from the PISCES experiment. Re-creating the C-Mod exposures as closely as possible in Pilot-PSI experiment can produce nearly-identical nano-tendril morphology and layer thickness at surface temperatures that agree with uncertainties with the C-Mod W probe temperature data. Helium concentrations in W fuzz layers are measured at 1–4 at.%, which is lower than expected for the observed sub-surface voids to be filled with several GPa of helium pressure. This possibly indicates that the void formation is not pressure driven

  7. Web based electronic logbook and experiment run database viewer for Alcator C-Mod

    International Nuclear Information System (INIS)

    Fredian, T.W.; Stillerman, J.A.

    2006-01-01

    Since 1991, the scientists and engineers at the Alcator C-Mod experiment at MIT have been recording text entries about the experiments being performed in an electronic logbook. In addition, separate documents such as run plans, run summaries and experimental proposals have been created and stored in a variety of formats in computer files. This information has now been organized and made available via any modern web browser. The new web based interface permits the user to browse through all the logbook entries, run information and even view some key data traces of the experiment. Since this information is being catalogued by Internet search engines, these tools can also be used to quickly locate information. The web based logbook and run information interface provides some additional capabilities. Once logged into the web site, users can add, delete or modify logbook entries directly from their browser. The logbook window on their browser also provides dynamic updating when any new logbook entries are made. There is also live C-Mod operation status information with optional audio announcements available. The user can receive the same state change announcements such as 'entering init' or 'entering pulse' as they would if they were sitting in the C-Mod control room. This paper will describe the functionality of the web based logbook and how it was implemented

  8. Comparisons of small ELM H-Mode regimes on the Alcator C-Mod and JFT-2M tokamaks

    International Nuclear Information System (INIS)

    Hubbard, A E; Kamiya, K; Oyama, N; Basse, N; Biewer, T; Edlund, E; Hughes, J W; Lin, L; Porkolab, M; Rowan, W; Snipes, J; Terry, J; Wolfe, S M

    2006-01-01

    Comparisons of H-mode regimes were carried out on the Alcator C-Mod and JFT-2M tokamaks. Shapes were matched apart from aspect ratio, which is lower on C-Mod. The high recycling steady H-mode on JFT-2M and enhanced D-alpha (EDA) regime on C-Mod, both of which feature very small or no ELMs, are found to have similar access conditions in q 95 - ν* space, occurring for pedestal collisionality ν* > 1. Differences in edge fluctuations were found, with lower frequencies but higher mode numbers on C-Mod. In both tokamaks an attractive regime with small ELMs on top of an enhanced D α baseline was obtained at moderate ν* and higher pressure. The JFT-2M shape favoured the appearance of ELMs on C-Mod and also resulted in the appearance of a lower frequency component of the quasicoherent mode during EDA

  9. Density limit and cross-field edge transport scaling in Alcator C-Mod

    International Nuclear Information System (INIS)

    LaBombard, B.; Greenwald, M.; Hughes, J.W.; Lipschultz, B.; Mossessian, D.; Terry, J.L.; Boivin, R.L.; Carreras, B.A.; Pitcher, C.S.; Zweben, S.J.

    2003-01-01

    Recent experiments in Alcator C-Mod have uncovered a direct link between the character and scaling of cross-field particle transport in the edge plasma and the density limit, n G . As n-bar e /n G is increased from low values to values approaching ∼1, an ordered progression in the cross-field edge transport physics occurs: first benign cross-field heat convection, then cross-field heat convection impacting the scrape-off layer (SOL) power loss channels and reducing the separatrix electron temperature, and finally 'bursty' transport (normally associated with the far SOL) invading into closed flux surface regions and carrying a convective power loss that impacts the power balance of the discharge. These observations suggest that SOL transport and its scaling with plasma conditions plays a key role in setting the empirically observed density limit scaling law. (author)

  10. Tungsten nano-tendril growth in the Alcator C-Mod divertor

    International Nuclear Information System (INIS)

    Wright, G.M.; Brunner, D.; Labombard, B.; Lipschultz, B.; Terry, J.L.; Whyte, D.G.; Baldwin, M.J.; Doerner, R.P.

    2012-01-01

    Growth of tungsten nano-tendrils (‘fuzz’) has been observed for the first time in the divertor region of a high-power density tokamak experiment. After 14 consecutive helium L-mode discharges in Alcator C-Mod, the tip of a tungsten Langmuir probe at the outer strike point was fully covered with a layer of nano-tendrils. The thickness of the individual nano-tendrils (50–100 nm) and the depth of the layer (600 ± 150 nm) are consistent with observations from experiments on linear plasma devices. The observation of tungsten fuzz in a tokamak may have important implications for material erosion, dust formation, divertor lifetime and tokamak operations in next-step devices. (letter)

  11. Multispecies density peaking in gyrokinetic turbulence simulations of low collisionality Alcator C-Mod plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Mikkelsen, D. R., E-mail: dmikkelsen@pppl.gov; Bitter, M.; Delgado-Aparicio, L.; Hill, K. W. [Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543 (United States); Greenwald, M.; Howard, N. T.; Hughes, J. W.; Rice, J. E. [MIT Plasma Science and Fusion Center, 175 Albany St., Cambridge, Massachusetts 02139 (United States); Reinke, M. L. [MIT Plasma Science and Fusion Center, 175 Albany St., Cambridge, Massachusetts 02139 (United States); York Plasma Institute, Department of Physics, University of York, Heslington, York YO10 5DD (United Kingdom); Podpaly, Y. [MIT Plasma Science and Fusion Center, 175 Albany St., Cambridge, Massachusetts 02139 (United States); AAAS S and T Fellow placed in the Directorate for Engineering, NSF, 4201 Wilson Blvd., Arlington, Virginia 22230 (United States); Ma, Y. [MIT Plasma Science and Fusion Center, 175 Albany St., Cambridge, Massachusetts 02139 (United States); ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St Paul Lez Durance Cedex (France); Candy, J.; Waltz, R. E. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)

    2015-06-15

    Peaked density profiles in low-collisionality AUG and JET H-mode plasmas are probably caused by a turbulently driven particle pinch, and Alcator C-Mod experiments confirmed that collisionality is a critical parameter. Density peaking in reactors could produce a number of important effects, some beneficial, such as enhanced fusion power and transport of fuel ions from the edge to the core, while others are undesirable, such as lower beta limits, reduced radiation from the plasma edge, and consequently higher divertor heat loads. Fundamental understanding of the pinch will enable planning to optimize these impacts. We show that density peaking is predicted by nonlinear gyrokinetic turbulence simulations based on measured profile data from low collisionality H-mode plasma in Alcator C-Mod. Multiple ion species are included to determine whether hydrogenic density peaking has an isotope dependence or is influenced by typical levels of low-Z impurities, and whether impurity density peaking depends on the species. We find that the deuterium density profile is slightly more peaked than that of hydrogen, and that experimentally relevant levels of boron have no appreciable effect on hydrogenic density peaking. The ratio of density at r/a = 0.44 to that at r/a = 0.74 is 1.2 for the majority D and minority H ions (and for electrons), and increases with impurity Z: 1.1 for helium, 1.15 for boron, 1.3 for neon, 1.4 for argon, and 1.5 for molybdenum. The ion temperature profile is varied to match better the predicted heat flux with the experimental transport analysis, but the resulting factor of two change in heat transport has only a weak effect on the predicted density peaking.

  12. Neutral Transport Simulations of Gas Puff Imaging Experiments on Alcator C-Mod

    International Nuclear Information System (INIS)

    Stotler, D.P.; LaBombard, B.; Terry, J.L.; Zweben, S.J.

    2002-01-01

    Visible imaging of gas puffs has been used on the Alcator C-Mod tokamak to characterize edge plasma turbulence, yielding data that can be compared with plasma turbulence codes. Simulations of these experiments with the DEGAS 2 Monte Carlo neutral transport code have been carried out to explore the relationship between the plasma fluctuations and the observed light emission. By imposing two-dimensional modulations on the measured time-average plasma density and temperature profiles, we demonstrate that the spatial structure of the emission cloud reflects that of the underlying turbulence. However, the photon emission rate depends on the plasma density and temperature in a complicated way, and no simple scheme for inferring the plasma parameters directly from the light emission patterns is apparent. The simulations indicate that excited atoms generated by molecular dissociation are a significant source of photons, further complicating interpretation of the gas puff imaging results.Visibl e imaging of gas puffs has been used on the Alcator C-Mod tokamak to characterize edge plasma turbulence, yielding data that can be compared with plasma turbulence codes. Simulations of these experiments with the DEGAS 2 Monte Carlo neutral transport code have been carried out to explore the relationship between the plasma fluctuations and the observed light emission. By imposing two-dimensional modulations on the measured time-average plasma density and temperature profiles, we demonstrate that the spatial structure of the emission cloud reflects that of the underlying turbulence. However, the photon emission rate depends on the plasma density and temperature in a complicated way, and no simple scheme for inferring the plasma parameters directly from the light emission patterns is apparent. The simulations indicate that excited atoms generated by molecular dissociation are a significant source of photons, further complicating interpretation of the gas puff imaging results

  13. Vertical localization of phase contrast imaging diagnostic in Alcator C-Mod

    Science.gov (United States)

    Lin, L.; Edlund, E. M.; Porkolab, M.; Lin, Y.; Wukitch, S. J.

    2006-10-01

    Phase contrast imaging (PCI) diagnostic has been used to study mode conversion physics of ion cyclotron range of frequency waves [E. Nelson-Melby et al., Phys. Rev. Lett. 90, 155004 (2003)], plasma turbulence [A. Mazurenko et al., Phys. Rev. Lett. 89, 225004 (2002); N. Basse et al., Phys. Plasmas 12, 052512 (2005)], and Alfvén Cascades [M. Porkolab et al., IEEE Trans. Plasma Sci. 34, 229 (2006)] in Alcator C-Mod. The C-Mod PCI system measures line integrated electron density fluctuations along 32 vertical chords with a sampling frequency of 10MHz and wavenumber resolution up to 30cm-1. Although PCI normally lacks localization along the chords, the vertical variation of the magnetic field pitch angle allows for localized measurements for large k⊥ fluctuations. A system consisting of a partially masked phase plate on a rotatable stage has been installed and quasicoherent modes with wave number ˜5cm-1 associated with the enhanced DαH mode at the top and bottom of the plasma have been differentiated. In future experiments, for k ˜30cm-1, a spatial resolution of r /a˜0.3 can be achieved under ideal conditions.

  14. Particle size distribution of dust collected from Alcator C-MOD

    International Nuclear Information System (INIS)

    Gorman, S.V.; Carmack, W.J.; Hembree, P.B.

    1998-01-01

    There are important safety issues associated with tokamak dust, accumulated primarily from sputtering and disruptions. The dust may contain tritium, it may be activated, chemically toxic, and chemically reactive. The purpose of this paper is to present results from analyses of particulate collected from the Alcator C-MOD tokamak located at Massachusetts Institute of Technology (MIT) in Cambridge, Massachusetts. The sample obtained from C-MOD was not originally intended for examination outside of MIT. The sample was collected with the intent of performing only a composition analysis. However, MIT provided the INEEL with this sample for particle analysis. The sample was collected by vacuuming a section of the machine (covering approximately 1/3 of the machine surface) with a coarse fiber filter as the collection surface. The sample was then analyzed using an optical microscope, SEM microscope, Microtrac FRA particle size analyzer. The data fit a log-normal distribution. The count median diameter (CMD) of the samples ranged from 0.3 microm to 1.1 microm with geometric standard deviations (GSD) ranging from 2.8 to 5.2 and a mass median diameter (MMD) ranging from 7.22 to 176 microm

  15. Electron Temperature Fluctuation Measurements and Transport Model Validation at Alcator C-Mod

    Energy Technology Data Exchange (ETDEWEB)

    White, Anne [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2017-06-22

    for studying core turbulence are needed in order to assess the accuracy of gyrokinetic models for turbulent-driven particle, heat and momentum transport. New core turbulence diagnostics at the world-class tokamaks Alcator C-Mod at MIT and ASDEX Upgrade at the Max Planck Institute for Plasma Physics have been designed, developed, and operated over the course of this project. These new instruments are capable of measuring electron temperature fluctuations and the phase angle between density and temperature fluctuations locally and quantitatively. These new data sets from Alcator C-Mod and ASDEX Upgrade are being used to fill key gaps in our understanding of turbulent transport in tokamaks. In particular, this project has results in new results on the topics of the Transport Shortfall, the role of ETG turbulence in tokamak plasmas, profile stiffness, the LOC/SOC transition, and intrinsic rotation reversals. These data are used in a rigorous process of “Transport model validation”, and this group is a world-leader on using turbulence models to design new hardware and new experiments at tokamaks. A correlation electron cyclotron emission (CECE) diagnostic is an instrument used to measure micro-scale fluctuations (mm-scale, compared to the machine size of meters) of electron temperature in magnetically confined fusion plasmas, such as those in tokamaks and stellarators. These micro-scale fluctuations are associated with drift-wave type turbulence, which leads to enhanced cooling and mixing of particles in fusion plasmas and limits achieving the required temperatures and densities for self-sustained fusion reactions. A CECE system can also be coupled with a reflectometer system that measured micro-scale density fluctuations, and from these simultaneous measurements, one can extract the phase between the density (n) and temperature (T) fluctuations, creating an nT phase diagnostic. Measurements of the fluctuations and the phase angle between them are extremely useful for

  16. Electron Profile Stiffness and Critical Gradient Length Studies in the Alcator C-Mod Tokamak

    Science.gov (United States)

    Houshmandyar, Saeid; Hatch, David R.; Liao, Kenneth T.; Zhao, Bingzhe; Phillips, Perry E.; Rowan, William L.; Cao, Norman; Ernst, Darin R.; Rice, John E.

    2017-10-01

    Electron temperature profile stiffness was investigated at Alcator C-Mod L-mode discharges. Electrons were heated by ion cyclotron range of frequencies (ICRF) through minority heating. The intent of the heating mechanism was to vary the heat flux and simultaneously, gradually change the local gradient. The electron temperature gradient scale length (LTe- 1 = | ∇Te |/Te) was accurately measured through a novel technique, using the high-resolution radiometer ECE diagnostic. The TRANSP power balance analysis (Q/QGB) and the measured scale length (a/LTe) result in critical scale length measurements at all major radius locations. These measurements suggest that the profiles are already at the critical values. Furthermore, the dependence of the stiffness on plasma rotation and magnetic shear will be discussed. In order to understand the underlying mechanism of turbulence for these discharges, simulations using the gyrokinetic code, GENE, were carried out. For linear runs at electron scales, it was found that the largest growth rates are very sensitive to a/LTe variation, which suggests the presence of ETG modes, while the sensitivity studies in the ion scales indicate ITG/TEM modes. Supported by USDoE awards DE-FG03-96ER54373 and DE-FC02-99ER54512.

  17. Density limit and cross-field edge transport scaling in Alcator C-Mod

    International Nuclear Information System (INIS)

    LaBombard, B.

    2002-01-01

    Experiments in Alcator C-Mod have uncovered a direct link between the character and scaling of edge transport and the empirical Greenwald density limit (n G ). In low to moderate density discharges, the scrape-off layer (SOL) exhibits a two-layer structure: a near SOL (∼5 mm zone) with steep density and temperature gradients and a far SOL with flatter profiles. In the far SOL, the transport fluxes exhibit large transport events ('bursts' which carry particles to main-chamber structures. In the near SOL, transport fluxes appear to be less 'bursty' particle diffusivities in this region is found to increase strongly with local plasma collisionality. As n/n G (or collisionality) is raised, cross-field heat convection begins to compete with parallel conduction to the divertor. At N/n G ∼0.5, T E at the separatrix is reduced. As n/n G approaches ∼1, regions inside the separatrix exhibit flatter profiles with 'bursty' transport behavior; cross-field heat convection to main-chamber structures becomes comparable to the radiated power. Thus as n/n G is increased, cross-field edge transport physics progressively changes, ultimately impacting the power balance of the discharge near N/n G ∼1. (author)

  18. The high resolution video capture system on the alcator C-Mod tokamak

    Science.gov (United States)

    Allen, A. J.; Terry, J. L.; Garnier, D.; Stillerman, J. A.; Wurden, G. A.

    1997-01-01

    A new system for routine digitization of video images is presently operating on the Alcator C-Mod tokamak. The PC-based system features high resolution video capture, storage, and retrieval. The captured images are stored temporarily on the PC, but are eventually written to CD. Video is captured from one of five filtered RS-170 CCD cameras at 30 frames per second (fps) with 640×480 pixel resolution. In addition, the system can digitize the output from a filtered Kodak Ektapro EM Digital Camera which captures images at 1000 fps with 239×192 resolution. Present views of this set of cameras include a wide angle and a tangential view of the plasma, two high resolution views of gas puff capillaries embedded in the plasma facing components, and a view of ablating, high speed Li pellets. The system is being used to study (1) the structure and location of visible emissions (including MARFEs) from the main plasma and divertor, (2) asymmetries in gas puff plumes due to flows in the scrape-off layer (SOL), and (3) the tilt and cigar-shaped spatial structure of the Li pellet ablation cloud.

  19. Experimental and gyrokinetic investigation of core impurity transport in Alcator C-mod

    Science.gov (United States)

    Howard, N.; Greenwald, M.; Podpaly, Y.; Reinke, M. L.; Rice, J. E.; White, A. E.; Mikkelsen, D. R.; Puetterich, T.

    2010-11-01

    A new multiple pulse laser blow-off system coupled with an upgraded high resolution x-ray spectrometer with spatial resolution allow for the most detailed studies of impurity transport on Alcator C-mod to date. Trace impurity injections created by the laser blow-off technique were introduced into plasmas with a wide range of parameters and time evolving profiles of He-like calcium were measured. The unique measurement of a single charge state profile and line integrated emission measurements from spectroscopic diagnostics were compared with the simulated emission from the impurity transport code STRAHL. A nonlinear least squares fitting routine was coupled with STRAHL, allowing for core impurity transport coefficients with errors to be determined. With this method, experimental data from trace calcium injections were analyzed and radially dependent, core values (< r/a ˜.6) of the diffusive and convective components of the impurity flux were obtained. The STRAHL results are compared with linear and global, nonlinear simulations from the gyrokinetic code GYRO. Results of this comparison and an investigation of the underlying physics associated with turbulent impurity transport will be presented.

  20. Impurity toroidal rotation and transport in Alcator C-Mod ohmic high confinement mode plasmas

    International Nuclear Information System (INIS)

    Rice, J. E.; Goetz, J. A.; Granetz, R. S.; Greenwald, M. J.; Hubbard, A. E.; Hutchinson, I. H.; Marmar, E. S.; Mossessian, D.; Pedersen, T. Sunn; Snipes, J. A.

    2000-01-01

    Central toroidal rotation and impurity transport coefficients have been determined in Alcator C-Mod [I. H. Hutchinson et al., Phys. Plasmas 1, 1511 (1994)] Ohmic high confinement mode (H-mode) plasmas from observations of x-ray emission following impurity injection. Rotation velocities up to 3x10 4 m/sec in the co-current direction have been observed in the center of the best Ohmic H-mode plasmas. Purely ohmic H-mode plasmas display many characteristics similar to ion cyclotron range of frequencies (ICRF) heated H-mode plasmas, including the scaling of the rotation velocity with plasma parameters and the formation of edge pedestals in the electron density and temperature profiles. Very long impurity confinement times (∼1 sec) are seen in edge localized mode-free (ELM-free) Ohmic H-modes and the inward impurity convection velocity profile has been determined to be close to the calculated neoclassical profile. (c) 2000 American Institute of Physics

  1. High-resolution disruption halo current measurements using Langmuir probes in Alcator C-Mod

    Science.gov (United States)

    Tinguely, R. A.; Granetz, R. S.; Berg, A.; Kuang, A. Q.; Brunner, D.; LaBombard, B.

    2018-01-01

    Halo currents generated during disruptions on Alcator C-Mod have been measured with Langmuir ‘rail’ probes. These rail probes are embedded in a lower outboard divertor module in a closely-spaced vertical (poloidal) array. The dense array provides detailed resolution of the spatial dependence (~1 cm spacing) of the halo current distribution in the plasma scrape-off region with high time resolution (400 kHz digitization rate). As the plasma limits on the outboard divertor plate, the contact point is clearly discernible in the halo current data (as an inversion of current) and moves vertically down the divertor plate on many disruptions. These data are consistent with filament reconstructions of the plasma boundary, from which the edge safety factor of the disrupting plasma can be calculated. Additionally, the halo current ‘footprint’ on the divertor plate is obtained and related to the halo flux width. The voltage driving halo current and the effective resistance of the plasma region through which the halo current flows to reach the probes are also investigated. Estimations of the sheath resistance and halo region resistivity and temperature are given. This information could prove useful for modeling halo current dynamics.

  2. Comparison of measured and modeled gas-puff emissions on Alcator C-Mod

    Science.gov (United States)

    Baek, Seung-Gyou; Terry, J. L.; Stotler, D. P.; Labombard, B. L.; Brunner, D. F.

    2017-10-01

    Understanding neutral transport in tokamak boundary plasmas is important because of its possible effects on the pedestal and scrape-off layer (SOL). On Alcator C-Mod, measured neutral line emissions from externally-puffed deuterium and helium gases are compared with the synthetic results of a neutral transport code, DEGAS 2. The injected gas flow rate and the camera response are absolutely calibrated. Time-averaged SOL density and temperature profiles are input to a steady-state simulation. An updated helium atomic model is employed in DEGAS2. Good agreement is found for the D α peak brightness and profile shape. However, the measured helium I line brightness is found to be lower than that in the simulation results by a roughly a factor of three over a wide range of density particularly in the far SOL region. Two possible causes for this discrepancy are reviewed. First, local cooling due to gas puff may suppress the line emission. Second, time-dependent turbulence effect may impact the helium neutral transport. Unlike deuterium atoms that gain energy from charge exchange and dissociation processes, helium neutrals remain cold and have a relatively short mean free path, known to make them prone to turbulence based on the Kubo number criterion. Supported by USDoE awards: DE-FC02-99ER54512, DE-SC0014251, and DE-AC02-09CH11466.

  3. Experimental and computational evaluation of neutrals in the Alcator C-Mod edge pedestal

    Science.gov (United States)

    Hughes, J. W.; Mossessian, D.; Labombard, B.; Terry, J.

    2004-11-01

    Pedestal-forming edge transport barriers (ETBs) in tokamak plasmas and the physics governing them are linked to the enhancement of confinement obtained in H-mode plasmas. Studies on Alcator C-Mod employ experimental measurements and simple 1-D transport models in order to better understand ETB physics. We examine the influences of ionization and charge exchange on the pedestals in electron density and temperature. Routine measurements from edge Thomson scattering (ETS) give pedestal scalings with global plasma parameters, while individual ETS profiles are combined with scanning Langmuir probe data and optical D_α emissivity measurements to give atomic density profiles and the associated radial distribution of the ionization source rate. From H-mode profiles of these quantities a well in effective plasma diffusivity is calculated, and is shown to systematically vary as the confinement regime is varied from ELM-free to EDA. Experimental work is supplemented with modeling and computation of edge neutral transport via KN1D, a kinetic solver for atomic and molecular distribution functions in slab geometry. The level of agreement between experiment and model is encouraging.

  4. The Design and Performance of a Twenty Barrel Hydrogen Pellet Injector for Alcator C-Mod

    Science.gov (United States)

    Urbahn, John A.

    A twenty barrel hydrogen pellet injector has been designed, built and tested both in the laboratory and on the Alcator C-Mod Tokamak at MIT. The injector functions by firing pellets of frozen hydrogen or deuterium deep into the plasma discharge for the purpose of fueling the plasma, modifying the density profile and increasing the global energy confinement time. The design goals of the injector are: (1) Operational flexibility, (2) High reliability, (3) Remote operation with minimal maintenance. These requirements have led to a single stage, pipe gun design with twenty barrels. Pellets are formed by in-situ condensation of the fuel gas, thus avoiding moving parts at cryogenic temperatures. The injector is the first to dispense with the need for cryogenic fluids and instead uses a closed cycle refrigerator to cool the thermal system components. The twenty barrels of the injector produce pellets of four different size groups and allow for a high degree of flexibility in fueling experiments. Operation of the injector is under PLC control allowing for remote operation, interlocked safety features and automated pellet manufacturing. The injector has been extensively tested and shown to produce pellets reliably with velocities up to 1400 m/sec. During the period from September to November of 1993, the injector was successfully used to fire pellets into over fifty plasma discharges. Experimental results include data on the pellet penetration into the plasma using an advanced pellet tracking diagnostic with improved time and spatial response. Data from the tracker indicates pellet penetrations were between 30 and 86 percent of the plasma minor radius. Line averaged density increases of up to 300 percent were recorded with peak densities of just under 1 times 10^ {21} / m^3, the highest achieved on C-Mod to date. A comparison is made between the ablation source function derived from tracker data with that predicted by four different variations of the neutral shield model

  5. Lower hybrid wave edge power loss quantification on the Alcator C-Mod tokamak

    Science.gov (United States)

    Faust, I. C.; Brunner, D.; LaBombard, B.; Parker, R. R.; Terry, J. L.; Whyte, D. G.; Baek, S. G.; Edlund, E.; Hubbard, A. E.; Hughes, J. W.; Kuang, A. Q.; Reinke, M. L.; Shiraiwa, S.; Wallace, G. M.; Walk, J. R.

    2016-05-01

    For the first time, the power deposition of lower hybrid RF waves into the edge plasma of a diverted tokamak has been systematically quantified. Edge deposition represents a parasitic loss of power that can greatly impact the use and efficiency of Lower Hybrid Current Drive (LHCD) at reactor-relevant densities. Through the use of a unique set of fast time resolution edge diagnostics, including innovative fast-thermocouples, an extensive set of Langmuir probes, and a Lyα ionization camera, the toroidal, poloidal, and radial structure of the power deposition has been simultaneously determined. Power modulation was used to directly isolate the RF effects due to the prompt ( t power. LHRF power was found to absorb more strongly in the edge at higher densities. It is found that a majority of this edge-deposited power is promptly conducted to the divertor. This correlates with the loss of current drive efficiency at high density previously observed on Alcator C-Mod, and displaying characteristics that contrast with the local RF edge absorption seen on other tokamaks. Measurements of ionization in the active divertor show dramatic changes due to LHRF power, implying that divertor region can be a key for the LHRF edge power deposition physics. These observations support the existence of a loss mechanism near the edge for LHRF at high density ( n e > 1.0 × 10 20 (m-3)). Results will be shown addressing the distribution of power within the SOL, including the toroidal symmetry and radial distribution. These characteristics are important for deducing the cause of the reduced LHCD efficiency at high density and motivate the tailoring of wave propagation to minimize SOL interaction, for example, through the use of high-field-side launch.

  6. Lithium pellet injection experiments on the Alcator C-Mod tokamak

    International Nuclear Information System (INIS)

    Garnier, D.T.

    1996-06-01

    A pellet enhanced performance mode, showing significantly reduced core transport, is regularly obtained after the injection of deeply penetrating lithium pellets into Alcator C-Mod discharges. These transient modes, which typically persist about two energy confinement times, are characterized by a steep pressure gradient (ell p ≤ a/5) in the inner third of the plasma, indicating the presence of an internal transport barrier. Inside this barrier, particle and energy diffusivities are greatly reduced, with ion thermal diffusivity dropping to near neoclassical values. Meanwhile, the global energy confinement time shows a 30% improvement over ITER89-P L-mode scaling. The addition of ICRF auxiliary heating shortly after the pellet injection leads to high fusion reactivity with neutron rates enhanced by an order of magnitude over L-mode discharges with similar input powers. A diagnostic system for measuring equilibrium current density profiles of tokamak plasmas, employing high speed lithium pellets, is also presented. Because ions are confined to move along field lines, imaging the Li + emission from the toroidally extended pellet ablation cloud gives the direction of the magnetic field. To convert from temporal to radial measurements, the 3-D trajectory of the pellet is determined using a stereoscopic tracking system. These measurements, along with external magnetic measurements, are used to solve the Grad-Shafranov equation for the magnetic equilibrium of the plasma. This diagnostic is used to determine the current density profile of PEP modes by injection of a second pellet during the period of good confinement. This measurement indicates that a region of reversed magnetic shear exists at the plasma core. This current density profile is consistent with TRANSP calculations for the bootstrap current created by the pressure gradient. MHD stability analysis indicates that these plasmas are near the n = ∞ and the n = 1 marginal stability limits

  7. Electron heating via mode converted ion Bernstein waves in the Alcator C-Mod tokamak

    Science.gov (United States)

    Bonoli, P. T.

    1996-11-01

    Highly localized electron heating (FWHM ≈ 0.5) has also been observed in D-(^3He) plasmas at 7.9 T. In this case the ^3He cyclotron resonance is on-axis and the fundamental D resonance and mode conversion layer are on the high field side of the tokamak. The concentration of ^3He in these experiments was in the range n_^3He / ne ~= (0.2 - 0.3) and the location of the mode conversion layer was controlled by changing the ^3He concentration or the toroidal magnetic field. The rf heating profiles were deduced using an rf power modulation technique in which the local electron heating rate was obtained from a ``break in slope'' analysis of the measured electron temperature versus time. Detailed comparisons with 1-D and toroidal full-wave ICRF models (FELICE and FISIC codes) have been carried out. The 1-D predictions for the fractional electron power absorption and damping location are found to be in qualitative agreement with the experiment. However discrepancies have been found between the full-wave toroidal code predictions and experiment. This disagreement is thought to be due to a lack of radial and poloidal resolution in the solution of the mode converted ion Bernstein wave in toroidal geometry and will be discussed. A fast wave current drive package has been modified to study the current generated via the mode converted IBW. Based on these numerical results and the experimental results for power absorption, off-axis current of up to 200 kA is predicted for C-Mod with unidirectional wave spectrum, which should be sufficient for studying reversed shear advanced tokamak plasmas. Work supported by USDOE Contract No. DE-AC02-78ET51013. Ôn behalf of the Alcator Group

  8. The design and performance of a twenty barrel hydrogen pellet injector for Alcator C-Mod

    International Nuclear Information System (INIS)

    Urbahn, J.A.

    1994-05-01

    A twenty barrel hydrogen pellet injector has been designed, built and tested both in the laboratory and on the Alcator C-Mod Tokamak at MIT. The injector functions by firing pellets of frozen hydrogen or deuterium deep into the plasma discharge for the purpose of fueling the plasma, modifying the density profile and increasing the global energy confinement time. The design goals of the injector are: (1) Operational flexibility, (2) High reliability, (3) Remote operation with minimal maintenance. These requirements have lead to a single stage, pipe gun design with twenty barrels. Pellets are formed by in- situ condensation of the fuel gas, thus avoiding moving parts at cryogenic temperatures. The injector is the first to dispense with the need for cryogenic fluids and instead uses a closed cycle refrigerator to cool the thermal system components. The twenty barrels of the injector produce pellets of four different size groups and allow for a high degree of flexibility in fueling experiments. Operation of the injector is under PLC control allowing for remote operation, interlocked safety features and automated pellet manufacturing. The injector has been extrusively tested and shown to produce pellets reliably with velocities up to 1400 m/sec. During the period from September to November of 1993, the injector was successfully used to fire pellets into over fifty plasma discharges. Experimental results include data on the pellet penetration into the plasma using an advanced pellet tracking diagnostic with improved time and spatial response. Data from the tracker indicates pellet penetrations were between 30 and 86 percent of the plasma minor radius

  9. Universality of intermittent fluctuations in the Alcator C-Mod scrape-off layer

    Science.gov (United States)

    Kube, Ralph

    2017-10-01

    A first-principles understanding of scrape-off layer (SOL) transport is needed in order to anticipate plasma-wall interaction conditions in a reactor-scale device. A stochastic model that describes SOL fluctuations and transport as a super-position of uncorrelated pulses is found to accurately reproduce many of the features seen in the experiments. We report on gas puff imaging (GPI) and mirror Langmuir probe (MLP) measurements on Alcator C-Mod compared to a stochastic model that describes electron density, temperature and electric potential fluctuations as arising from a super-position of uncorrelated pulses attributed to blob-like filaments propagating radially outwards. The statistical properties have been unambiguously established by measurement time series of approximately one second duration under stationary plasma conditions. The GPI fluctuation probability density function is found to change from nearly Gaussian at the separatrix to a strongly skewed and flattened Gamma distribution in the far-SOL. Despite this, the frequency power spectrum is identical for all radial positions in the SOL and for a large range of line-averaged densities. This suggests that both the near- and the far-SOL fluctuations are due to uncorrelated exponential pulses but with much more pulse overlap close to the separatrix. These observations run contrary to the ideas that the shape of the power spectrum arises from the interaction of turbulent eddies or self-similar processes. The fluctuation statistics are shown to be the same in both Ohmic plasmas and high confinement modes. Electron density and temperature fluctuations measured by the MLP system are strongly intermittent with large relative fluctuation levels. The fluctuation-induced radial heat flux has significant contributions from both the convective and conductive components. The model parameters are estimated from the data time series and their variation with the line-averaged density is elucidated. In collaboration with

  10. Lithium pellet injection experiments on the Alcator C-Mod tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Garnier, Darren Thomas [Univ. of California, Berkeley, CA (United States)

    1996-06-01

    A pellet enhanced performance mode, showing significantly reduced core transport, is regularly obtained after the injection of deeply penetrating lithium pellets into Alcator C-Mod discharges. These transient modes, which typically persist about two energy confinement times, are characterized by a steep pressure gradient (ℓp ℓ a/5) in the inner third of the plasma, indicating the presence of an internal transport barrier. Inside this barrier, particle and energy diffusivities are greatly reduced, with ion thermal diffusivity dropping to near neoclassical values. Meanwhile, the global energy confinement time shows a 30% improvement over ITER89-P L-mode scaling. The addition of ICRF auxiliary heating shortly after the pellet injection leads to high fusion reactivity with neutron rates enhanced by an order of magnitude over L-mode discharges with similar input powers. A diagnostic system for measuring equilibrium current density profiles of tokamak plasmas, employing high speed lithium pellets, is also presented. Because ions are confined to move along field lines, imaging the Li+ emission from the toroidally extended pellet ablation cloud gives the direction of the magnetic field. To convert from temporal to radial measurements, the 3-D trajectory of the pellet is determined using a stereoscopic tracking system. These measurements, along with external magnetic measurements, are used to solve the Grad-Shafranov equation for the magnetic equilibrium of the plasma. This diagnostic is used to determine the current density profile of PEP modes by injection of a second pellet during the period of good confinement. This measurement indicates that a region of reversed magnetic shear exists at the plasma core. This current density profile is consistent with TRANSP calculations for the bootstrap current created by the pressure gradient. MHD stability analysis indicates that these plasmas are near the n = ∞ and the n = 1 marginal stability limits.

  11. Boundary plasma heat flux width measurements for poloidal magnetic fields above 1 Tesla in the Alcator C-Mod tokamak

    Science.gov (United States)

    Brunner, Dan; Labombard, Brian; Kuang, Adam; Terry, Jim; Alcator C-Mod Team

    2017-10-01

    The boundary heat flux width, along with the total power flowing into the boundary, sets the power exhaust challenge for tokamaks. A multi-machine boundary heat flux width database found that the heat flux width in H-modes scaled inversely with poloidal magnetic field (Bp) and was independent of machine size. The maximum Bp in the database was 0.8 T, whereas the ITER 15 MA, Q =10 scenario will be 1.2 T. New measurements of the boundary heat flux width in Alcator C-Mod extend the international database to plasmas with Bp up to 1.3 T. C-Mod was the only experiment able to operate at ITER-level Bp. These new measurements are from over 300 plasma shots in L-, I-, and EDA H-modes spanning essentially the whole operating space in C-Mod. We find that the inverse-Bp dependence of the heat flux width in H-modes continues to ITER-level Bp, further reinforcing the empirical projection of 500 μm heat flux width for ITER. We find 50% scatter around the inverse-Bp scaling and are searching for the `hidden variables' causing this scatter. Supported by USDoE award DE-FC02-99ER54512.

  12. The measurement of the intrinsic impurities of molybdenum and carbon in the Alcator C-Mod tokamak plasma using low resolution spectroscopy

    Science.gov (United States)

    May, M. J.; Finkenthal, M.; Regan, S. P.; Moos, H. W.; Terry, J. L.; Goetz, J. A.; Graf, M. A.; Rice, J. E.; Marmar, E. S.; Fournier, K. B.; Goldstein, W. H.

    1997-06-01

    The intrinsic impurity content of molybdenum and carbon was measured in the Alcator C-Mod tokamak using low resolution, multilayer mirror (MLM) spectroscopy ( Delta lambda ~1-10 AA). Molybdenum was the dominant high-Z impurity and originated from the molybdenum armour tiles covering all of the plasma facing surfaces (including the inner column, the poloidal divertor plates and the ion cyclotron resonant frequency (ICRF) limiter) at Alcator C-Mod. Despite the all metal first wall, a carbon concentration of 1 to 2% existed in the plasma and was the major low-Z impurity in Alcator C-Mod. Thus, the behaviour of intrinsic molybdenum and carbon penetrating into the main plasma and the effect on the plasma must be measured and characterized during various modes of Alcator C-Mod operation. To this end, soft X-ray extreme ultraviolet (XUV) emission lines of charge states, ranging from hydrogen-like to helium-like lines of carbon (radius/minor radius, r/a~1) at the plasma edge to potassium to chlorine-like (0.4Data Nucl. Data Tables 33 (1985) 149), which were incorporated into the collisional radiative model. The intrinsic i

  13. Experimental Study of Reversed Shear Alfven Eigenmodes During The Current Ramp In The Alcator C-Mod Tokamak

    International Nuclear Information System (INIS)

    Edlund, E.M.; Porkolab, M.; Kramer, G.J.; Lin, L.; Lin, Y.; Tsuji, N.; Wukitch, S.J.

    2010-01-01

    Experiments conducted in the Alcator C-Mod tokamak at MIT have explored the physics of reversed shear Alfven eigenmodes (RSAEs) during the current ramp. The frequency evolution of the RSAEs throughout the current ramp provides a constraint on the evolution of q min , a result which is important in transport modeling and for comparison with other diagnostics which directly measure the magnetic field line structure. Additionally, a scaling of the RSAE minimum frequency with the sound speed is used to derive a measure of the adiabatic index, a measure of the plasma compressibility. This scaling bounds the adiabatic index at 1.40 ± 0.15 used in MHD models and supports the kinetic calculation of separate electron and ion compressibilities with an ion adiabatic index close to 7/4.

  14. X-ray and VUV observations of Mo23+-Mo33+ brightness profiles from Alcator C-Mod plasmas

    International Nuclear Information System (INIS)

    Rice, J.E.; Terry, J.L.; Graf, M.A.; Marmar, E.S.; Hubbard, A.E.; Finkenthal, M.; May, M.J.

    1996-01-01

    Brightness profiles of x-ray and VUV lines from eight molybdenum charge states between Mo 23+ and Mo 33+ have been measured in Alcator C-Mod plasmas. These spatial profiles agree very well with those predicted by a model which includes ionization, recombination, excitation and transport. Comparison with the profiles of many different charge states provides severe constraints upon the rates used in the model. The charge state density profiles are calculated using measured impurity transport coefficients, measured electron density and temperature profiles and newly calculated ionization and recombination rate coefficients. These new rate coefficients include direct collisional ionization, excitation-autoionization, dielectronic and radiative recombination. Excitation-autoionization is shown to be an important process, since the excellent agreement between the measurements and predictions is obtained only with its inclusions. Fits to newly calculated excitation rate coefficients for the transitions are also presented. (author)

  15. Investigation of the critical edge ion heat flux for L-H transitions in Alcator C-Mod and its dependence on B T

    Science.gov (United States)

    Schmidtmayr, M.; Hughes, J. W.; Ryter, F.; Wolfrum, E.; Cao, N.; Creely, A. J.; Howard, N.; Hubbard, A. E.; Lin, Y.; Reinke, M. L.; Rice, J. E.; Tolman, E. A.; Wukitch, S.; Ma, Y.; ASDEX Upgrade Team; Alcator C-Mod Team

    2018-05-01

    This paper presents investigations on the role of the edge ion heat flux for transitions from L-mode to H-mode in Alcator C-Mod. Previous results from the ASDEX Upgrade tokamak indicated that a critical value of edge ion heat flux per particle is needed for the transition. Analysis of C-Mod data confirms this result. The edge ion heat flux is indeed found to increase linearly with density at given magnetic field and plasma current. Furthermore, the Alcator C-Mod data indicate that the edge ion heat flux at the L-H transition also increases with magnetic field. Combining the data from Alcator C-Mod and ASDEX Upgrade yields a general expression for the edge ion heat flux at the L-H transition. These results are discussed from the point of view of the possible physics mechanism of the L-H transition. They are also compared to the L-H power threshold scaling and an extrapolation for ITER is given.

  16. Influence of high magnetic field on access to stationary H-modes and pedestal characteristics in Alcator C-Mod

    Science.gov (United States)

    Tolman, E. A.; Hughes, J. W.; Wolfe, S. M.; Wukitch, S. J.; LaBombard, B.; Hubbard, A. E.; Marmar, E. S.; Snyder, P. B.; Schmidtmayr, M.

    2018-04-01

    Recent Alcator C-Mod experiments have explored access to and characteristics of H-modes at magnetic fields approaching 8 T, the highest field achieved to date in a diverted tokamak. The H-modes originated from L-mode densities ranging from 1.1 × 1020~m-3 to 2.8 × 1020~m-3 , allowing insight into the density dependence of the H-mode power threshold at high magnetic field. This dependence is compared to predictions from the ITPA scaling law ([1]), finding that the law is approximately accurate at 7.8 T. However, the law underpredicted the high density H-mode threshold at lower magnetic field in previous C-Mod experiments ([2]), suggesting that the overall dependence of the threshold on magnetic field is weaker than predicted by the scaling law. The threshold data at 7.8 T also indicates that the onset of a low density branch at this magnetic field on C-Mod occurs below 1.4 × 1020~m-3 , which is lower than predicted by an existing model for low density branch onset. The H-modes achieved steady-state densities ranging from 2.3 × 1020 ~m-3 to 4.4 × 1020 ~m-3 , and higher transient densities, and had values of q 95 from 3.3 to 6.0. This parameter range allowed the achievement of all three types of H-mode routinely observed at lower magnetic field on C-Mod: the stationary, ELM-suppressed Enhanced D α (EDA) regime, seen at high densities and high values of q 95; the nonstationary ELM-free regime, seen at lower densities and values of q 95; and the ELMy regime, seen at low density, moderate q 95, and specialized plasma shape. The parameter space in which these regimes occur at 7.8 T is consistent with lower magnetic field experience. Pressure pedestal height at 7.8 T is compared to EPED [3, 4] predictions, and a scaling law for EDA density pedestal height developed between 4.5 T and 6.0 T is updated to include fields from 2.7 T to 7.8 T. Overall, this analysis increases confidence in the use of low magnetic field experience to predict some elements of high magnetic

  17. Visible Spectrometer at the Compact Toroid Injection Experiment, the Sustained Spheromak Plasma Experiment and the Alcator C-Mod Tokamak for Doppler Width and Shift Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Graf, A; Howard, S; Horton, R; Hwang, D; May, M; Beiersdorfer, P; McLean, H; Terry, J

    2006-05-15

    A novel Doppler spectrometer is currently being used for ion or neutral velocity and temperature measurements on the Alcator C-Mod Tokamak. The spectrometer has an f/No. of {approx}3.1 and is appropriate for visible light (3500-6700 {angstrom}). The full width at half maximum from a line emitting calibration source has been measured to be as small as 0.4 {angstrom}. The ultimate time resolution is line brightness light limited and on the order of ms. A new photon efficient detector is being used for the setup at C-Mod. Time resolution is achieved by moving the camera during a plasma discharge in a perpendicular direction through the dispersion plane of the spectrometer causing a vertical streaking across the camera face. Initial results from C-Mod as well as previous measurements from the Compact Toroid Injection Experiment (CTIX) and the Sustained Spheromak Plasma Experiment (SSPX) are presented.

  18. Changes in core electron temperature fluctuations across the ohmic energy confinement transition in Alcator C-Mod plasmas

    International Nuclear Information System (INIS)

    Sung, C.; White, A.E.; Howard, N.T.; Oi, C.Y.; Rice, J.E.; Gao, C.; Ennever, P.; Porkolab, M.; Parra, F.; Ernst, D.; Walk, J.; Hughes, J.W.; Irby, J.; Kasten, C.; Hubbard, A.E.; Greenwald, M.J.; Mikkelsen, D.

    2013-01-01

    The first measurements of long wavelength (k y ρ s < 0.3) electron temperature fluctuations in Alcator C-Mod made with a new correlation electron cyclotron emission diagnostic support a long-standing hypothesis regarding the confinement transition from linear ohmic confinement (LOC) to saturated ohmic confinement (SOC). Electron temperature fluctuations decrease significantly (∼40%) crossing from LOC to SOC, consistent with a change from trapped electron mode (TEM) turbulence domination to ion temperature gradient (ITG) turbulence as the density is increased. Linear stability analysis performed with the GYRO code (Candy and Waltz 2003 J. Comput. Phys. 186 545) shows that TEMs are dominant for long wavelength turbulence in the LOC regime and ITG modes are dominant in the SOC regime at the radial location (ρ ∼ 0.8) where the changes in electron temperature fluctuations are measured. In contrast, deeper in the core (ρ < 0.8), linear stability analysis indicates that ITG modes remain dominant across the LOC/SOC transition. This radial variation suggests that the robust global changes in confinement of energy and momentum occurring across the LOC/SOC transition are correlated to local changes in the dominant turbulent mode near the edge. (paper)

  19. Upgraded PMI diagnostic capabilities using Accelerator-based In-situ Materials Surveillance (AIMS) on Alcator C-Mod

    Science.gov (United States)

    Kesler, Leigh; Barnard, Harold; Hartwig, Zachary; Sorbom, Brandon; Lanza, Richard; Terry, David; Vieira, Rui; Whyte, Dennis

    2014-10-01

    The AIMS diagnostic was developed to rapidly and non-invasively characterize in-situ plasma material interactions (PMI) in a tokamak. Recent improvements are described which significantly expand this measurement capability on Alcator C-Mod. The detection time at each wall location is reduced from about 10 min to 30 s, via improved hardware and detection geometry. Detectors are in an augmented re-entrant tube to maximize the solid angle between detectors and diagnostic locations. Spatial range is expanded by using beam dynamics simulation to design upgraded B-field power supplies to provide maximal poloidal access, including a ~20° toroidal range in the divertor. Measurement accuracy is improved with angular and energy resolved cross section measurements obtained using a separate 0.9 MeV deuteron ion accelerator. Future improvements include the installation of recessed scintillator tiles as beam targets for calibration of the diagnostic. Additionally, implanted depth marker tiles will enable AIMS to observe the in-situ erosion and deposition of high-Z plasma-facing materials. This work is supported by U.S. DOE Grant No. DE-FG02-94ER54235 and Cooperative Agreement No. DE-FC02-99ER54512.

  20. Discrepancies between soft x-ray emissivity contours and magnetic flux surfaces in Alcator C-Mod

    International Nuclear Information System (INIS)

    Borras, M.C.; Granetz, R.S.

    1996-01-01

    The soft x-ray diagnostic system of Alcator C-Mod, equipped with 152 detectors distributed in four arrays, is used to obtain iso-emissivity surfaces. These surfaces have been characterized by giving their elongation and relative shift from the centre of the tokamak as functions of plasma radius. Flux surfaces, provided by magnetic diagnostics, have also been described with elongation and shift. Results from the comparison of the two sets of geometric parameters obtained from magnetic and x-ray diagnostics are presented. We find that, whereas the shifts obtained from these two diagnostic methods are always in good agreement, the corresponding elongation curves show different patterns. An agreement between elongations better than 2% is only found in a range of about 2 cm in minor radius. On the other hand, the elongations can differ by 10% towards the plasma edge and the plasma centre. Error bars for the x-ray diagnostic are obtained by propagating the effect of ± 1% random errors at the detector signals, and can amount to ± 1-2% of the estimated values near the edge and the centre of the plasma. The estimated uncertainties in the determination of elongation from magnetic flux surfaces are of the order of 4%. A series of tests and simulations performed to verify the accuracy of the X-ray diagnostic system is presented. The discrepancies found could imply the existence of asymmetries in impurity concentration. (Author)

  1. Physics and performance of the I-mode regime over an expanded operating space on Alcator C-Mod

    Science.gov (United States)

    Hubbard, A. E.; Baek, S.-G.; Brunner, D.; Creely, A. J.; Cziegler, I.; Edlund, E.; Hughes, J. W.; LaBombard, B.; Lin, Y.; Liu, Z.; Marmar, E. S.; Reinke, M. L.; Rice, J. E.; Sorbom, B.; Sung, C.; Terry, J.; Theiler, C.; Tolman, E. A.; Walk, J. R.; White, A. E.; Whyte, D.; Wolfe, S. M.; Wukitch, S.; Xu, X. Q.; the Alcator C-Mod Team

    2017-12-01

    New results on the I-mode regime of operation on the Alcator C-Mod tokamak are reported. This ELM-free regime features high energy confinement and a steep temperature pedestal, while particle confinement remains at L-mode levels, giving stationary density and avoiding impurity accumulation. I-mode has now been obtained over nearly all of the magnetic fields and currents possible in this high field tokamak (I p 0.55-1.7 MA, B T 2.8-8 T) using a configuration with B  ×  ∇ B drift away from the X-point. Results at 8 T confirm that the L-I power threshold varies only weakly with B T, and that the power range for I-mode increases with B T; no 8 T discharges transitioned to H-mode. Parameter dependences of energy confinement are investigated. Core transport simulations are giving insight into the observed turbulence reduction, profile stiffness and confinement improvement. Pedestal models explain the observed stability to ELMs, and can simulate the observed weakly coherent mode. Conditions for I-H transitions have complex dependences on density as well as power. I-modes have now been maintained in near-DN configurations, leading to improved divertor power flux sharing. Prospects for I-mode on future fusion devices such as ITER and ARC are encouraging. Further experiments on other tokamaks are needed to improve confidence in extrapolation.

  2. Full-wave and Fokker Planck analysis of ICRF heating experiments in the Alcator C-Mod tokamak

    International Nuclear Information System (INIS)

    Bonoli, P.T.; Golovato, S.; Porkolab, M.; Takase, Y.

    1996-01-01

    The Alcator C-Mod device is a high field, high density, shaped tokamak with parameters a = 0.22 m, R 0 = 0.67 m, B 0 ≤ 9.0 T, κ ≤ 1.8, δ ≤ 0.8, and 1.0 x 10 20 m -3 n e (0) ≤ 1.0 x 10 21 m -3 . Four megawatt of ICRF power is available at 80 MHz. The wide operating range in magnetic field makes several heating schemes possible: (i) Second harmonic heating of hydrogen (f 0 = 2f CH ) at 2.6 T in (D-H); (ii) Fundamental heating of (H) (f 0 = f CH ) at 5.3T in a D-(H) plasma; and (iii) Fundamental heating of ( 3 He) (f 0 = f C 3 He ) at 7.9 T in a D-( 3 He) plasma. The most successful heating regime to date has been (H)-minority heating at 5.3 T. Pellet enhanced performance (PEP) modes have also been achieved in C-Mod in D-(H) at 5.3 T and in D-( 3 He) at 7.9 T, with a combination of intense ICRF heating and Li-pellet injection. A variety of numerical models are used to analyze these heating schemes. A 1-D full-wave code (FELICE) is used to study open-quotes single passclose quotes damping of the ICRF wavefront and damping of mode-converted ion Bernstein waves. A toroidal full-wave code (FISIC) is used to study interference and focussing effects of the ICRF waves as well as damping of the ICRF power upon multiple passes of the ICRF wavefront. A combined bounce averaged Fokker Planck and toroidal full-wave code (FPPRF) is used to study the ion tail formation, orbit losses, and the power partition of the ICRF tail to the background electrons and ions. Full-wave and Fokker Planck analyses confirm the strong single pass absorption of the ICRF power in D-(H) at 5.3 T. Analysis of PEP-mode plasmas in D-( 3 He) indicates improved wave focussing and 3 He-cyclotron absorption of the ICRF waves relative to L-mode. A dramatic increase in the transfer of 3 He tail power to the background deuterium is also found for PEP-mode plasmas

  3. Full-wave and Fokker Planck analysis of ICRF heating experiments in the Alcator C-Mod tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Bonoli, P.T.; Golovato, S.; Porkolab, M.; Takase, Y. [MIT Plasma Fusion Center, Cambridge, MA (United States)

    1996-12-31

    The Alcator C-Mod device is a high field, high density, shaped tokamak with parameters a = 0.22 m, R{sub 0} = 0.67 m, B{sub 0} {le} 9.0 T, {kappa} {le} 1.8, {delta} {le} 0.8, and 1.0 x 10{sup 20} m{sup -3} n{sub e} (0) {le} 1.0 x 10{sup 21} m{sup -3}. Four megawatt of ICRF power is available at 80 MHz. The wide operating range in magnetic field makes several heating schemes possible: (i) Second harmonic heating of hydrogen (f{sub 0} = 2f{sub CH}) at 2.6 T in (D-H); (ii) Fundamental heating of (H) (f{sub 0} = f{sub CH}) at 5.3T in a D-(H) plasma; and (iii) Fundamental heating of ({sup 3}He) (f{sub 0} = f{sub C{sup 3}He}) at 7.9 T in a D-({sup 3}He) plasma. The most successful heating regime to date has been (H)-minority heating at 5.3 T. Pellet enhanced performance (PEP) modes have also been achieved in C-Mod in D-(H) at 5.3 T and in D-({sup 3}He) at 7.9 T, with a combination of intense ICRF heating and Li-pellet injection. A variety of numerical models are used to analyze these heating schemes. A 1-D full-wave code (FELICE) is used to study {open_quotes}single pass{close_quotes} damping of the ICRF wavefront and damping of mode-converted ion Bernstein waves. A toroidal full-wave code (FISIC) is used to study interference and focussing effects of the ICRF waves as well as damping of the ICRF power upon multiple passes of the ICRF wavefront. A combined bounce averaged Fokker Planck and toroidal full-wave code (FPPRF) is used to study the ion tail formation, orbit losses, and the power partition of the ICRF tail to the background electrons and ions. Full-wave and Fokker Planck analyses confirm the strong single pass absorption of the ICRF power in D-(H) at 5.3 T. Analysis of PEP-mode plasmas in D-({sup 3}He) indicates improved wave focussing and {sup 3}He-cyclotron absorption of the ICRF waves relative to L-mode. A dramatic increase in the transfer of {sup 3}He tail power to the background deuterium is also found for PEP-mode plasmas.

  4. Multi-scale gyrokinetic simulations of an Alcator C-Mod, ELM-y H-mode plasma

    Science.gov (United States)

    Howard, N. T.; Holland, C.; White, A. E.; Greenwald, M.; Rodriguez-Fernandez, P.; Candy, J.; Creely, A. J.

    2018-01-01

    High fidelity, multi-scale gyrokinetic simulations capable of capturing both ion ({k}θ {ρ }s∼ { O }(1.0)) and electron-scale ({k}θ {ρ }e∼ { O }(1.0)) turbulence were performed in the core of an Alcator C-Mod ELM-y H-mode discharge which exhibits reactor-relevant characteristics. These simulations, performed with all experimental inputs and realistic ion to electron mass ratio ({({m}i/{m}e)}1/2=60.0) provide insight into the physics fidelity that may be needed for accurate simulation of the core of fusion reactor discharges. Three multi-scale simulations and series of separate ion and electron-scale simulations performed using the GYRO code (Candy and Waltz 2003 J. Comput. Phys. 186 545) are presented. As with earlier multi-scale results in L-mode conditions (Howard et al 2016 Nucl. Fusion 56 014004), both ion and multi-scale simulations results are compared with experimentally inferred ion and electron heat fluxes, as well as the measured values of electron incremental thermal diffusivities—indicative of the experimental electron temperature profile stiffness. Consistent with the L-mode results, cross-scale coupling is found to play an important role in the simulation of these H-mode conditions. Extremely stiff ion-scale transport is observed in these high-performance conditions which is shown to likely play and important role in the reproduction of measurements of perturbative transport. These results provide important insight into the role of multi-scale plasma turbulence in the core of reactor-relevant plasmas and establish important constraints on the the fidelity of models needed for predictive simulations.

  5. Local gas injection as a scrape-off layer diagnostic on the Alcator C-Mod tokamak

    International Nuclear Information System (INIS)

    Jablonski, D.F.

    1996-05-01

    A capillary puffing array has been installed on Alcator C-Mod which allows localized introduction of gaseous species in the scrape-off layer. This system has been utilized in experiments to elucidate both global and local properties of edge transport. Deuterium fueling and recycling impurity screening are observed to be characterized by non-dimensional screening efficiencies which are independent of the location of introduction. In contrast, the behavior of non-recycling impurities is seen to be characterized by a screening time which is dependent on puff location. The work of this thesis has focused on the use of the capillary array with a camera system which can view impurity line emission plumes formed in the region of an injection location. The ionic plumes observed extend along the magnetic field line with a comet-like asymmetry, indicative of background plasma ion flow. The flow is observed to be towards the nearest strike-point, independent of x-point location, magnetic field direction, and other plasma parameters. While the axes of the plumes are generally along the field line, deviations are seen which indicate cross-field ion drifts. A quasi-two dimensional fluid model has been constructed to use the plume shapes of the first charge state impurity ions to extract information about the local background plasma, specifically the temperature, parallel flow velocity, and radial electric field. Through comparisons of model results with those of a three dimensional Monte Carlo code, and comparisons of plume extracted parameters with scanning probe measurements, the efficacy of the model is demonstrated. Plume analysis not only leads to understandings of local edge impurity transport, but also presents a novel diagnostic technique

  6. Local gas injection as a scrape-off layer diagnostic on the Alcator C-Mod tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Jablonski, David F. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    1996-05-01

    A capillary puffing array has been installed on Alcator C-Mod which allows localized introduction of gaseous species in the scrape-off layer. This system has been utilized in experiments to elucidate both global and local properties of edge transport. Deuterium fueling and recycling impurity screening are observed to be characterized by non-dimensional screening efficiencies which are independent of the location of introduction. In contrast, the behavior of non-recycling impurities is seen to be characterized by a screening time which is dependent on puff location. The work of this thesis has focused on the use of the capillary array with a camera system which can view impurity line emission plumes formed in the region of an injection location. The ionic plumes observed extend along the magnetic field line with a comet-like asymmetry, indicative of background plasma ion flow. The flow is observed to be towards the nearest strike-point, independent of x-point location, magnetic field direction, and other plasma parameters. While the axes of the plumes are generally along the field line, deviations are seen which indicate cross-field ion drifts. A quasi-two dimensional fluid model has been constructed to use the plume shapes of the first charge state impurity ions to extract information about the local background plasma, specifically the temperature, parallel flow velocity, and radial electric field. Through comparisons of model results with those of a three dimensional Monte Carlo code, and comparisons of plume extracted parameters with scanning probe measurements, the efficacy of the model is demonstrated. Plume analysis not only leads to understandings of local edge impurity transport, but also presents a novel diagnostic technique.

  7. Linear servomotor probe drive system with real-time self-adaptive position control for the Alcator C-Mod tokamak.

    Science.gov (United States)

    Brunner, D; Kuang, A Q; LaBombard, B; Burke, W

    2017-07-01

    A new servomotor drive system has been developed for the horizontal reciprocating probe on the Alcator C-Mod tokamak. Real-time measurements of plasma temperature and density-through use of a mirror Langmuir probe bias system-combined with a commercial linear servomotor and controller enable self-adaptive position control. Probe surface temperature and its rate of change are computed in real time and used to control probe insertion depth. It is found that a universal trigger threshold can be defined in terms of these two parameters; if the probe is triggered to retract when crossing the trigger threshold, it will reach the same ultimate surface temperature, independent of velocity, acceleration, or scrape-off layer heat flux scale length. In addition to controlling the probe motion, the controller is used to monitor and control all aspects of the integrated probe drive system.

  8. Numerical investigation of edge plasma phenomena in an enhanced D-alpha discharge at Alcator C-Mod: Parallel heat flux and quasi-coherent edge oscillations

    International Nuclear Information System (INIS)

    Russell, D. A.; D’Ippolito, D. A.; Myra, J. R.; LaBombard, B.; Terry, J. L.; Zweben, S. J.

    2012-01-01

    Reduced-model scrape-off layer turbulence (SOLT) simulations of an enhanced D-alpha (EDA) H-mode shot observed in the Alcator C-Mod tokamak were conducted to compare with observed variations in the scrape-off-layer (SOL) width of the parallel heat flux profile. In particular, the role of the competition between sheath- and conduction-limited parallel heat fluxes in determining that width was studied for the turbulent SOL plasma that emerged from the simulations. The SOL width decreases with increasing input power and with increasing separatrix temperature in both the experiment and the simulation, consistent with the strong temperature dependence of the parallel heat flux in balance with the perpendicular transport by turbulence and blobs. The particularly strong temperature dependence observed in the case analyzed is attributed to the fact that these simulations produce SOL plasmas which are in the conduction-limited regime for the parallel heat flux. A persistent quasi-coherent (QC) mode dominates the SOLT simulations and bears considerable resemblance to the QC mode observed in C-Mod EDA operation. The SOLT QC mode consists of nonlinearly saturated wave-fronts located just inside the separatrix that are convected poloidally by the mean flow, continuously transporting particles and energy and intermittently emitting blobs into the SOL.

  9. An assessment of ion temperature measurements in the boundary of the Alcator C-Mod tokamak and implications for ion fluid heat flux limiters

    International Nuclear Information System (INIS)

    Brunner, D; LaBombard, B; Churchill, R M; Hughes, J; Lipschultz, B; Ochoukov, R; Theiler, C; Walk, J; Rognlien, T D; Umansky, M V; Whyte, D

    2013-01-01

    The ion temperature is not frequently measured in the boundary of magnetic fusion devices. Comparisons among different ion temperature techniques and simulations are even rarer. Here we present a comparison of ion temperature measurements in the boundary of the Alcator C-Mod tokamak from three different diagnostics: charge exchange recombination spectroscopy (CXRS), an ion sensitive probe (ISP), and a retarding field analyzer (RFA). Comparison between CXRS and the ISP along with close examination of the ISP measurements reveals that the ISP is space charge limited. It is thus unable to measure ion temperature in the high density (>10 19 m −3 ) boundary plasma of C-Mod with its present geometry. Comparison of ion temperatures measured by CXRS and the RFA shows fair agreement. Ion and electron parallel heat flow is analyzed with a simple 1D fluid code. The code takes divertor measurements as input and results are compared to the measured ratios of upstream ion to electron temperature, as inferred respectively by CXRS and a Langmuir probe. The analysis reveals the limits of the fluid model at high Knudsen number. The upstream temperature ratio is under predicted by a factor of 2. Heat flux limiters (kinetic corrections) to the fluid model are necessary to match experimental data. The values required are found to be close to those reported in kinetic simulations. The 1D code is benchmarked against the 2D plasma fluid code UEDGE with good agreement. (paper)

  10. An assessment of ion temperature measurements in the boundary of the Alcator C-Mod tokamak and implications for ion fluid heat flux limiters

    Science.gov (United States)

    Brunner, D.; LaBombard, B.; Churchill, R. M.; Hughes, J.; Lipschultz, B.; Ochoukov, R.; Rognlien, T. D.; Theiler, C.; Walk, J.; Umansky, M. V.; Whyte, D.

    2013-09-01

    The ion temperature is not frequently measured in the boundary of magnetic fusion devices. Comparisons among different ion temperature techniques and simulations are even rarer. Here we present a comparison of ion temperature measurements in the boundary of the Alcator C-Mod tokamak from three different diagnostics: charge exchange recombination spectroscopy (CXRS), an ion sensitive probe (ISP), and a retarding field analyzer (RFA). Comparison between CXRS and the ISP along with close examination of the ISP measurements reveals that the ISP is space charge limited. It is thus unable to measure ion temperature in the high density (>1019 m-3) boundary plasma of C-Mod with its present geometry. Comparison of ion temperatures measured by CXRS and the RFA shows fair agreement. Ion and electron parallel heat flow is analyzed with a simple 1D fluid code. The code takes divertor measurements as input and results are compared to the measured ratios of upstream ion to electron temperature, as inferred respectively by CXRS and a Langmuir probe. The analysis reveals the limits of the fluid model at high Knudsen number. The upstream temperature ratio is under predicted by a factor of 2. Heat flux limiters (kinetic corrections) to the fluid model are necessary to match experimental data. The values required are found to be close to those reported in kinetic simulations. The 1D code is benchmarked against the 2D plasma fluid code UEDGE with good agreement.

  11. Application of a deconvolution method for identifying burst amplitudes and arrival times in Alcator C-Mod far SOL plasma fluctuations

    Science.gov (United States)

    Theodorsen, Audun; Garcia, Odd Erik; Kube, Ralph; Labombard, Brian; Terry, Jim

    2017-10-01

    In the far scrape-off layer (SOL), radial motion of filamentary structures leads to excess transport of particles and heat. Amplitudes and arrival times of these filaments have previously been studied by conditional averaging in single-point measurements from Langmuir Probes and Gas Puff Imaging (GPI). Conditional averaging can be problematic: the cutoff for large amplitudes is mostly chosen by convention; the conditional windows used may influence the arrival time distribution; and the amplitudes cannot be separated from a background. Previous work has shown that SOL fluctuations are well described by a stochastic model consisting of a super-position of pulses with fixed shape and randomly distributed amplitudes and arrival times. The model can be formulated as a pulse shape convolved with a train of delta pulses. By choosing a pulse shape consistent with the power spectrum of the fluctuation time series, Richardson-Lucy deconvolution can be used to recover the underlying amplitudes and arrival times of the delta pulses. We apply this technique to both L and H-mode GPI data from the Alcator C-Mod tokamak. The pulse arrival times are shown to be uncorrelated and uniformly distributed, consistent with a Poisson process, and the amplitude distribution has an exponential tail.

  12. Mean flows and blob velocities in scrape-off layer (SOLT) simulations of an L-mode discharge on Alcator C-Mod

    International Nuclear Information System (INIS)

    Russell, D. A.; Myra, J. R.; D'Ippolito, D. A.; LaBombard, B.; Hughes, J. W.

    2016-01-01

    Two-dimensional scrape-off layer turbulence (SOLT) code simulations are compared with an L-mode discharge on the Alcator C-Mod tokamak [M. Greenwald, et al., Phys. Plasmas 21, 110501 (2014)]. Density and temperature profiles for the simulations were obtained by smoothly fitting Thomson scattering and mirror Langmuir probe (MLP) data from the shot. Simulations differing in turbulence intensity were obtained by varying a dissipation parameter. Mean flow profiles and density fluctuation amplitudes are consistent with those measured by MLP in the experiment and with a Fourier space diagnostic designed to measure poloidal phase velocity. Blob velocities in the simulations were determined from the correlation function for density fluctuations, as in the analysis of gas-puff-imaging (GPI) blobs in the experiment. In the simulations, it was found that larger blobs moved poloidally with the ExB flow velocity, v E , in the near-SOL, while smaller fluctuations moved with the group velocity of the dominant linear (interchange) mode, v E + 1/2 v di , where v di is the ion diamagnetic drift velocity. Comparisons are made with the measured GPI correlation velocity for the discharge. The saturation mechanisms operative in the simulation of the discharge are also discussed. In conclusion, it is found that neither sheared flow nor pressure gradient modification can be excluded as saturation mechanisms

  13. New insights on boundary plasma turbulence and the quasi-coherent mode in Alcator C-Mod using a Mirror Langmuir Probe

    International Nuclear Information System (INIS)

    LaBombard, B.; Golfinopoulos, T.; Terry, J. L.; Brunner, D.; Davis, E.; Greenwald, M.; Hughes, J. W.

    2014-01-01

    A new “Mirror Langmuir Probe” diagnostic, combined with a double-coil scanning magnetic probe, is used to interrogate Alcator C-Mod's quasi-coherent mode (QCM) with unprecedented detail. In ohmic EDA H-modes, the QCM is found to reside in a region of positive radial electric field, with a radial width (∼3 mm) that spans open and closed field line regions. Large amplitude, in-phase sinusoidal bursts (∼100 kHz) in density, electron temperature, and plasma potential are observed, with potential lagging density by ∼16°, producing an outward radial transport velocity of ∼10 m/s. Mode propagation corresponds to the sum of local E × B and electron diamagnetic drift velocities. Poloidal magnetic field fluctuations project to current filaments carrying peak current densities of ∼25 A/cm 2 . An evaluation of parallel electron force balance (Ohm's law) over a fluctuation cycle indicates a significant electromotive component. Interchange drive is also a contributor in the current continuity (vorticity) equation. Thus, the QCM is primarily a separatrix-spanning electron drift-wave with interchange and electromagnetic contributions

  14. External excitation of a short-wavelength fluctuation in the Alcator C-Mod edge plasma and its relationship to the quasi-coherent mode

    International Nuclear Information System (INIS)

    Golfinopoulos, T.; LaBombard, B.; Parker, R. R.; Burke, W.; Davis, E.; Granetz, R.; Greenwald, M.; Irby, J.; Leccacorvi, R.; Marmar, E.; Parkin, W.; Porkolab, M.; Terry, J.; Vieira, R.; Wolfe, S.

    2014-01-01

    A novel “Shoelace” antenna has been used to inductively excite a short-wavelength edge fluctuation in a tokamak boundary layer for the first time. The principal design parameters, k ⊥ =1.5±0.1 cm −1 and 45 ⊥ ∼1.5 cm −1 , f∼50−150 kHz) in Alcator C-Mod, responsible for exhausting impurities in the steady-state, ELM-free Enhanced D α H-mode. In H-mode, whether or not there is a QCM, the antenna drives coherent, field-aligned perturbations in density, n ~ e , and field, B ~ θ , which are guided by field lines, propagate in the electron diamagnetic drift direction, and exhibit a weakly damped (γ/ω 0 ∼5%−10%) resonance near the natural QCM frequency. This result is significant, offering the possibility that externally driven modes may be used to enhance particle transport. In L-mode, the antenna drives only a non-resonant B ~ θ response. The facts that the driven mode has the same wave number and propagation direction as the QCM, and is resonant at the QCM frequency, suggest the antenna may couple to this mode, which we have shown elsewhere to be predominantly drift-mode-like [B. LaBombard et al., Phys. Plasmas 21, 056108 (2014)

  15. Design and operation of a high-heat flux, flush-mounted ‘rail’ Langmuir probe array on Alcator C-Mod

    Directory of Open Access Journals (Sweden)

    A.Q. Kuang

    2017-08-01

    Full Text Available A poloidal array of toroidally-extended, flush-mounted ‘rail’ Langmuir probes was recently installed on Alcator C-Mod's vertical target plate divertor. The aim was to investigate if a Langmuir probe array could be designed to survive reactor-level heat fluxes and have the ability to make measurements that could be reliably interpreted under reactor-level plasma densities, neutral densities and magnetic fields. Langmuir probes are typically built to have incident field-line angles >10° to avoid interpretation issues associated with sheath expansion. However, at the high parallel heat fluxes experienced in reactor-relevant conditions such a probe would quickly overheat and melt. To mitigate both the issues of extreme heat flux and sheath expansion, each probe was designed to be flush with the divertor surface, toroidally-extended and field-aligned, giving it a ‘rail’ geometry. The flush mounted probes have proven to be exceptionally robust surviving the 2015–2016 campaign – a first for a C-Mod probe system. Examination of the probe current-voltage (I-V characteristics reveals that they are immune to sheath expansion at incident field angles down to ∼0.5°. Comparison of the flush probes to traditional proud probes shows that both measure the same electron pressure across the divertor plate. However, there are significant and systematic differences in the density, temperature and floating potential. This suggests that there is important physics, perhaps unique to conditions in a vertical-target plate divertor with small field-line attack angles, that affects the I-V characteristics and is not currently included in probe data analyses. Finally, the probe response is examined in the ‘death-ray’ regime, just near detachment. Previous work using proud probes has suggested that the ‘death-ray’ is an artefact of the probe bias. However, on flush mounted probes the ‘death-ray’ manifests itself under different conditions, which

  16. Studies of turbulence and transport in Alcator C-Mod H-mode plasmas with phase contrast imaging and comparisons with GYRO

    International Nuclear Information System (INIS)

    Lin, L.; Porkolab, M.; Edlund, E. M.; Rost, J. C.; Fiore, C. L.; Greenwald, M.; Lin, Y.; Tsujii, N.; Wukitch, S. J.; Mikkelsen, D. R.

    2009-01-01

    Recent advances in gyrokinetic simulation of core turbulence and associated transport requires an intensified experimental effort to validate these codes using state of the art synthetic diagnostics to compare simulations with experimental data. A phase contrast imaging (PCI) diagnostic [M. Porkolab, J. C. Rost, N. Basse et al., IEEE Trans. Plasma Sci. 34, 229 (2006)] is used to study H-mode plasmas in Alcator C-Mod [M. Greenwald, D. Andelin, N. Basse et al., Nucl. Fusion 45, S109 (2005)]. The PCI system is capable of measuring density fluctuations with high temporal (2 kHz-5 MHz) and wavenumber (0.5-55 cm -1 ) resolution. Recent upgrades have enabled PCI to localize the short wavelength turbulence in the electron temperature gradient range and resolve the direction of propagation (i.e., electron versus ion diamagnetic direction) of the longer wavelength turbulence in the ion temperature gradient (ITG) and trapped electron mode range. The studies focus on plasmas before and during internal transport barrier formation in an enhanced D α H-mode plasma assisted with ion cyclotron resonance frequency heating. Nonlinear GYRO simulations have also been performed [J. Candy and R. E. Waltz, Phys. Rev. Lett. 91, 045001 (2003)] and the predicted fluctuation is compared against experimental measurements through a synthetic PCI diagnostic method. The simulated fluctuations from GYRO agree with experimental measurements in the ITG regime. GYRO also shows good agreement in transport predictions with experimental measurements after reducing the ion temperature gradient (∼15%) and adding ExB shear suppression, all within the experimental uncertainty.

  17. Studies of turbulence and transport in Alcator C-Mod H-mode plasmas with phase contrast imaging and comparisons with GYRO

    Science.gov (United States)

    Lin, L.; Porkolab, M.; Edlund, E. M.; Rost, J. C.; Fiore, C. L.; Greenwald, M.; Lin, Y.; Mikkelsen, D. R.; Tsujii, N.; Wukitch, S. J.

    2009-01-01

    Recent advances in gyrokinetic simulation of core turbulence and associated transport requires an intensified experimental effort to validate these codes using state of the art synthetic diagnostics to compare simulations with experimental data. A phase contrast imaging (PCI) diagnostic [M. Porkolab, J. C. Rost, N. Basse et al., IEEE Trans. Plasma Sci. 34, 229 (2006)] is used to study H-mode plasmas in Alcator C-Mod [M. Greenwald, D. Andelin, N. Basse et al., Nucl. Fusion 45, S109 (2005)]. The PCI system is capable of measuring density fluctuations with high temporal (2kHz-5MHz) and wavenumber (0.5-55cm-1) resolution. Recent upgrades have enabled PCI to localize the short wavelength turbulence in the electron temperature gradient range and resolve the direction of propagation (i.e., electron versus ion diamagnetic direction) of the longer wavelength turbulence in the ion temperature gradient (ITG) and trapped electron mode range. The studies focus on plasmas before and during internal transport barrier formation in an enhanced Dα H-mode plasma assisted with ion cyclotron resonance frequency heating. Nonlinear GYRO simulations have also been performed [J. Candy and R. E. Waltz, Phys. Rev. Lett. 91, 045001 (2003)] and the predicted fluctuation is compared against experimental measurements through a synthetic PCI diagnostic method. The simulated fluctuations from GYRO agree with experimental measurements in the ITG regime. GYRO also shows good agreement in transport predictions with experimental measurements after reducing the ion temperature gradient (˜15%) and adding E ×B shear suppression, all within the experimental uncertainty.

  18. An experimental assessment of methods used to compute secondary electron emission yield for tungsten and molybdenum electrodes based on exposure to Alcator C-Mod scrape-off layer plasmas

    Science.gov (United States)

    McCarthy, W.; LaBombard, B.; Brunner, D.; Kuang, A. Q.

    2018-03-01

    Plasma potentials computed from Langmuir probe data rely on a method to account for secondary electron emission (SEE) from the electrodes. However, significant variations exist among published models for SEE and the reported experimental parameters used to evaluate them. As a means to critically assess SEE computation methods, two of four tungsten electrodes on a Langmuir-Mach probe head were replaced with molybdenum and exposed to Alcator C-Mod boundary plasmas where electron temperatures exceed 50 eV and SEE becomes significant. In this situation, plasma potentials computed for either material should be identical—the SEE evaluation method should properly account for the differences in SEE yields. Of the six methods used to compute SEE, two are found to produce consistent results (Sternglass model with Bronstein experimental parameters and Young-Dekker model with Bronstein experimental parameters). In contrast, the method previously used for C-Mod data analysis (Sternglass model with Kollath parameters) was found to be inconsistent. We have since adopted Young-Dekker-Bronstein as the preferred method.

  19. Edge turbulence and divertor heat flux width simulations of Alcator C-Mod discharges using an electromagnetic two-fluid model

    Science.gov (United States)

    Chen, B.; Xu, X. Q.; Xia, T. Y.; Porkolab, M.; Edlund, E.; LaBombard, B.; Terry, J.; Hughes, J. W.; Mao, S. F.; Ye, M. Y.; Wan, Y. X.

    2017-11-01

    The BOUT++ code has been exploited in order to improve the understanding of the role of turbulent modes in controlling edge transport and resulting scaling of the scrape-off layer (SOL) heat flux width. For the C-Mod enhanced D_α (EDA) H-mode discharges, BOUT++ six-field two-fluid nonlinear simulations show a reasonable agreement of upstream turbulence and divertor target heat flux behavior: (a) the simulated quasi-coherent modes show consistent characteristics of the frequency versus poloidal wave number spectra of the electromagnetic fluctuations when compared with experimental measurements: frequencies are around 60-120 kHz (experiment: about 70-110 kHz), k_θ are around 2.0 cm-1 which is similar to the phase contrast imaging data; (b) linear spectrum analysis is consistent with the nonlinear phase relationship calculation which indicates the dominance of resistive-ballooning modes and drift-Alfven wave instabilities; (c) the SOL heat flux width λq versus current I p scaling is reproduced by turbulent transport: the simulations yield similar λq to experimental measurements within a factor of 2. However the magnitudes of divertor heat fluxes can be varied, depending on the physics models, sources and sinks, sheath boundary conditions, or flux limiting coefficient; (d) Simple estimate by the ‘2-point model’ for λq is consistent with simulation. Moreover, blobby turbulent spreading is confirmed for these relatively high B p shots.

  20. Analysis of C-MOD molybdenum divertor erosion and code/data comparison

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, J.N., E-mail: brooksjn@purdue.edu [Purdue University, West Lafayette, IN (United States); Allain, J.P. [Purdue University, West Lafayette, IN (United States); Whyte, D.G.; Ochoukov, R.; Lipschultz, B. [Massachusetts Institute of Technology, Cambridge, MA (United States)

    2011-08-01

    We analyze an important 15 year old Alcator C-MOD study of campaign-integrated molybdenum divertor erosion in which the measured net erosion was significantly higher ({approx}X3) than originally predicted by a simple model . We perform full process sputtering erosion/redeposition computational analysis including the effect of a possible RF induced sheath. The simulations show that most sputtered Mo atoms are ionized close to the surface and strongly redeposited, via Lorentz force motion and collisional friction with the high density incoming plasma. The predicted gross erosion profile is a reasonable match to MoI influx data, however, the critically important net erosion comparison with post-exposure Mo tile analysis is poor, with {approx}X10 higher peak erosion measured than computed. An RF sheath increases predicted erosion by {approx}45%, thus being significant but not fundamental. We plan future analysis.

  1. Radiofrequency-heated enhanced confinement modes in the Alcator C-Mod tokamak

    International Nuclear Information System (INIS)

    Takase, Y.; Boivin, R.L.; Bombarda, F.; Bonoli, P.T.; Christensen, C.; Fiore, C.; Garnier, D.; Goetz, J.A.; Golovato, S.N.; Granetz, R.; Greenwald, M.; Horne, S.F.; Hubbard, A.; Hutchinson, I.H.; Irby, J.; LaBombard, B.; Lipschultz, B.; Marmar, E.; May, M.; Mazurenko, A.; McCracken, G.; OShea, P.; Porkolab, M.; Reardon, J.; Rice, J.; Rost, C.; Schachter, J.; Snipes, J.A.; Stek, P.; Terry, J.; Watterson, R.; Welch, B.; Wolfe, S.

    1997-01-01

    Enhanced confinement modes up to a toroidal field of B T =8T have been studied with up to 3.5 MW of radiofrequency (rf) heating power in the ion cyclotron range of frequencies (ICRF) at 80 MHz. H-mode is observed when the edge temperature exceeds a threshold value. The high confinement mode (H-mode) with higher confinement enhancement factors (H) and longer duration became possible after boronization by reducing the radiated power from the main plasma. A quasi-steady state with high confinement (H=2.0), high normalized beta (β N =1.5), low radiated power fraction (P rad main /P loss =0.3), and low effective charge (Z eff =1.5) has been obtained in Enhanced D α H-mode. This type of H-mode has enhanced levels of continuous D α emission and very little or no edge localized mode (ELM) activity, and reduced core particle confinement time relative to ELM-free H-mode. The pellet enhanced performance (PEP) mode is obtained by combining core fueling with pellet injection and core heating. A highly peaked pressure profile with a central value of 8 atmospheres was observed. The steep pressure gradient drives off-axis bootstrap current, resulting in a shear reversed safety factor (q) profile. Suppression of sawteeth appears to be important in maintaining the highly peaked pressure profile. Lithium pellets were found to be more effective than deuterium pellets in raising q 0 . copyright 1997 American Institute of Physics

  2. Divertor IR thermography on Alcator C-Moda)

    Science.gov (United States)

    Terry, J. L.; LaBombard, B.; Brunner, D.; Payne, J.; Wurden, G. A.

    2010-10-01

    Alcator C-Mod is a particularly challenging environment for thermography. It presents issues that will similarly face ITER, including low-emissivity metal targets, low-Z surface films, and closed divertor geometry. In order to make measurements of the incident divertor heat flux using IR thermography, the C-Mod divertor has been modified and instrumented. A 6° toroidal sector has been given a 2° toroidal ramp in order to eliminate magnetic field-line shadowing by imperfectly aligned divertor tiles. This sector is viewed from above by a toroidally displaced IR camera and is instrumented with thermocouples and calorimeters. The camera provides time histories of surface temperatures that are used to compute incident heat-flux profiles. The camera sensitivity is calibrated in situ using the embedded thermocouples, thus correcting for changes and nonuniformities in surface emissivity due to surface coatings.

  3. Direct detection of lower hybrid wave using a reflectometer on Alcator C-Moda)

    Science.gov (United States)

    Shiraiwa, S.; Baek, S.; Dominguez, A.; Marmar, E.; Parker, R.; Kramer, G. J.

    2010-10-01

    The possibility of directly detecting a density perturbation produced by lower hybrid (LH) waves using a reflectometer is presented. We investigate the microwave scattering of reflectometer probe beams by a model density fluctuation produced by short wavelength LH waves in an Alcator C-Mod experimental condition. In the O-mode case, the maximum response of phase measurement is found to occur when the density perturbation is approximately centimeters in front of the antenna, where Bragg scattering condition is satisfied. In the X-mode case, the phase measurement is predicted to be more sensitive to the density fluctuation close to the cut-off layer. A feasibility test was carried out using a 50 GHz O-mode reflectometer on the Alcator C-Mod tokamak, and positive results including the detection of 4.6 GHz pump wave and parametric decay instabilities were obtained.

  4. Nonaxisymmetric field effects on Alcator C-Moda)

    Science.gov (United States)

    Wolfe, S. M.; Hutchinson, I. H.; Granetz, R. S.; Rice, J.; Hubbard, A.; Lynn, A.; Phillips, P.; Hender, T. C.; Howell, D. F.; La Haye, R. J.; Scoville, J. T.

    2005-05-01

    A set of external coils (A-coils) capable of producing nonaxisymmetric, predominantly n =1, fields with different toroidal phase and a range of poloidal mode m spectra has been used to determine the threshold amplitude for mode locking over a range of plasma parameters in Alcator C-Mod [I. H. Hutchinson, R. Boivin, F. Bombarda, P. Bonoli, S. Fairfax, C. Fiore, J. Goetz, S. Golovato, R. Granetz, M. Greenwald et al., Phys. Plasmas 1, 1511 (1994)]. The threshold perturbations and parametric scalings, expressed in terms of (B21/BT), are similar to those observed on larger, lower field devices. The threshold is roughly linear in density, with typical magnitudes of order 10-4. This result implies that locked modes should not be significantly more problematic for the International Thermonuclear Experimental Reactor [I. P. B. Editors, Nucl. Fusion 39, 2286 (1999)] than for existing devices. Coordinated nondimensional identity experiments on the Joint European Torus [Fusion Technol. 11, 13 (1987)], DIII-D [Fusion Technol. 8, 441 (1985)], and C-Mod, with matching applied mode spectra, have been carried out to determine more definitively the field and size scalings. Locked modes on C-Mod are observed to result in braking of core toroidal rotation, modification of sawtooth activity, and significant reduction in energy and particle confinement, frequently leading to disruptions. Intrinsic error fields inferred from the threshold studies are found to be consistent in amplitude and phase with a comprehensive model of the sources of field errors based on "as-built" coil and bus-work details and coil imperfections inferred from measurements using in situ magnetic diagnostics on dedicated test pulses. Use of the A-coils to largely cancel the 2/1 component of the intrinsic nonaxisymmetric field has led to expansion of the accessible operating space in C-Mod, including operation up to 2 MA plasma current at 8 T.

  5. Quantitative comparison of electron temperature fluctuations to nonlinear gyrokinetic simulations in C-Mod Ohmic L-mode discharges

    Energy Technology Data Exchange (ETDEWEB)

    Sung, C., E-mail: csung@physics.ucla.edu [University of California, Los Angeles, Los Angeles, California 90095 (United States); White, A. E.; Greenwald, M.; Howard, N. T. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Mikkelsen, D. R.; Churchill, R. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Holland, C. [University of California, San Diego, La Jolla, California 92093 (United States); Theiler, C. [Ecole Polytechnique Fédérale de Lausanne, SPC, Lausanne 1015 (Switzerland)

    2016-04-15

    Long wavelength turbulent electron temperature fluctuations (k{sub y}ρ{sub s} < 0.3) are measured in the outer core region (r/a > 0.8) of Ohmic L-mode plasmas at Alcator C-Mod [E. S. Marmar et al., Nucl. Fusion 49, 104014 (2009)] with a correlation electron cyclotron emission diagnostic. The relative amplitude and frequency spectrum of the fluctuations are compared quantitatively with nonlinear gyrokinetic simulations using the GYRO code [J. Candy and R. E. Waltz, J. Comput. Phys. 186, 545 (2003)] in two different confinement regimes: linear Ohmic confinement (LOC) regime and saturated Ohmic confinement (SOC) regime. When comparing experiment with nonlinear simulations, it is found that local, electrostatic ion-scale simulations (k{sub y}ρ{sub s} ≲ 1.7) performed at r/a ∼ 0.85 reproduce the experimental ion heat flux levels, electron temperature fluctuation levels, and frequency spectra within experimental error bars. In contrast, the electron heat flux is robustly under-predicted and cannot be recovered by using scans of the simulation inputs within error bars or by using global simulations. If both the ion heat flux and the measured temperature fluctuations are attributed predominantly to long-wavelength turbulence, then under-prediction of electron heat flux strongly suggests that electron scale turbulence is important for transport in C-Mod Ohmic L-mode discharges. In addition, no evidence is found from linear or nonlinear simulations for a clear transition from trapped electron mode to ion temperature gradient turbulence across the LOC/SOC transition, and also there is no evidence in these Ohmic L-mode plasmas of the “Transport Shortfall” [C. Holland et al., Phys. Plasmas 16, 052301 (2009)].

  6. Experimental studies of edge turbulence and confinement in Alcator C-Moda)

    Science.gov (United States)

    Cziegler, I.; Terry, J. L.; Hughes, J. W.; LaBombard, B.

    2010-05-01

    The steep gradient edge region and scrape-off-layer (SOL) on the low-field-side of Alcator C-Mod [I. H. Hutchinson, R. Boivin, F. Bombarda et al., Phys. Plasmas 1, 1511 (1994)] tokamak plasmas are studied using gas-puff-imaging diagnostics. In L-mode plasmas, the region extending ˜2 cm inside the magnetic separatrix has fluctuations showing a broad, turbulent spectrum, propagating in the electron diamagnetic drift direction, whereas features in the open field line region propagate in the ion diamagnetic drift direction. This structure is robust against toroidal field strength, poloidal null-point geometry, plasma current, and plasma density. Global parameter dependence of spectral and spatial structure of the turbulence inside the separatrix is explored and characterized, and both the intensity and spectral distributions are found to depend strongly on the plasma density normalized to the tokamak density limit. In H-mode discharges the fluctuations at and inside the magnetic separatrix show fundamentally different trends compared to L-mode, with the electron diamagnetic direction propagating turbulence greatly reduced in ELM-free [F. Wagner et al., Proceedings of the Thirteenth Conference on Plasma Physics and Controlled Nuclear Fusion Research (IAEA, Vienna, 1982), Vol. I, p. 277], and completely dominated by the modelike structure of the quasicoherent mode in enhanced D-alpha regimes [A. E. Hubbard, R. L. Boivin, R. S. Granetz et al., Phys. Plasmas 8, 2033 (2001)], while the normalized SOL turbulence is largely unaffected.

  7. Two dimensional radiated power diagnostics on Alcator C-Moda)

    Science.gov (United States)

    Reinke, M. L.; Hutchinson, I. H.

    2008-10-01

    The radiated power diagnostics for the Alcator C-Mod tokamak have been upgraded to measure two dimensional structure of the photon emissivity profile in order to investigate poloidal asymmetries in the core radiation. Commonly utilized unbiased absolute extreme ultraviolet (AXUV) diode arrays view the plasma along five different horizontal planes. The layout of the diagnostic set is shown and the results from calibrations and recent experiments are discussed. Data showing a significant, 30%-40%, inboard/outboard emissivity asymmetry during ELM-free H-mode are presented. The ability to use AXUV diode arrays to measure absolute radiated power is explored by comparing diode and resistive bolometer-based emissivity profiles for highly radiative L-mode plasmas seeded with argon. Emissivity profiles match in the core but disagree radially outward resulting in an underprediction of Prad of nearly 50% by the diodes compared to Prad determined using resistive bolometers.

  8. Simulated plasma facing component measurements for an in situ surface diagnostic on Alcator C-Moda)

    Science.gov (United States)

    Hartwig, Z. S.; Whyte, D. G.

    2010-10-01

    The ideal in situ plasma facing component (PFC) diagnostic for magnetic fusion devices would perform surface element and isotope composition measurements on a shot-to-shot (˜10 min) time scale with ˜1 μm depth and ˜1 cm spatial resolution over large areas of PFCs. To this end, the experimental adaptation of the customary laboratory surface diagnostic—nuclear scattering of MeV ions—to the Alcator C-Mod tokamak is being guided by ACRONYM, a Geant4 synthetic diagnostic. The diagnostic technique and ACRONYM are described, and synthetic measurements of film thickness for boron-coated PFCs are presented.

  9. Novel energy resolving x-ray pinhole camera on Alcator C-Moda)

    Science.gov (United States)

    Pablant, N. A.; Delgado-Aparicio, L.; Bitter, M.; Brandstetter, S.; Eikenberry, E.; Ellis, R.; Hill, K. W.; Hofer, P.; Schneebeli, M.

    2012-10-01

    A new energy resolving x-ray pinhole camera has been recently installed on Alcator C-Mod. This diagnostic is capable of 1D or 2D imaging with a spatial resolution of ≈1 cm, an energy resolution of ≈1 keV in the range of 3.5-15 keV and a maximum time resolution of 5 ms. A novel use of a Pilatus 2 hybrid-pixel x-ray detector [P. Kraft et al., J. Synchrotron Rad. 16, 368 (2009), 10.1107/S0909049509009911] is employed in which the lower energy threshold of individual pixels is adjusted, allowing regions of a single detector to be sensitive to different x-ray energy ranges. Development of this new detector calibration technique was done as a collaboration between PPPL and Dectris Ltd. The calibration procedure is described, and the energy resolution of the detector is characterized. Initial data from this installation on Alcator C-Mod is presented. This diagnostic provides line-integrated measurements of impurity emission which can be used to determine impurity concentrations as well as the electron energy distribution.

  10. Production of internal transport barriers via self-generated mean flows in Alcator C-Moda)

    Science.gov (United States)

    Fiore, C. L.; Ernst, D. R.; Podpaly, Y. A.; Mikkelsen, D.; Howard, N. T.; Lee, Jungpyo; Reinke, M. L.; Rice, J. E.; Hughes, J. W.; Ma, Y.; Rowan, W. L.; Bespamyatnov, I.

    2012-05-01

    New results suggest that changes observed in the intrinsic toroidal rotation influence the internal transport barrier (ITB) formation in the Alcator C-Mod tokamak [E. S. Marmar and Alcator C-Mod group, Fusion Sci. Technol. 51, 261 (2007)]. These arise when the resonance for ion cyclotron range of frequencies (ICRF) minority heating is positioned off-axis at or outside of the plasma half-radius. These ITBs form in a reactor relevant regime, without particle or momentum injection, with Ti ≈ Te, and with monotonic q profiles (qmin 1.5 × 105 rad/s) in the region where the ITB foot is observed. Gyrokinetic analyses indicate that this spontaneous shearing rate is comparable to the linear ion temperature gradient (ITG) growth rate at the ITB location and is sufficient to reduce the turbulent particle and energy transport. New and detailed measurement of the ion temperature demonstrates that the radial profile flattens as the ICRF resonance position moves off axis, decreasing the drive for the ITG the instability as well. These results are the first evidence that intrinsic rotation can affect confinement in ITB plasmas.

  11. The Fusion Science Research Plan for the Major U.S. Tokamaks. Advisory report

    International Nuclear Information System (INIS)

    1996-01-01

    In summary, the community has developed a research plan for the major tokamak facilities that will produce impressive scientific benefits over the next two years. The plan is well aligned with the new mission and goals of the restructured fusion energy sciences program recommended by FEAC. Budget increases for all three facilities will allow their programs to move forward in FY 1997, increasing their rate of scientific progress. With a shutdown deadline now established, the TFTR will forego all but a few critical upgrades and maximize operation to achieve a set of high-priority scientific objectives with deuterium-tritium plasmas. The DIII-D and Alcator C-Mod facilities will still fall well short of full utilization. Increasing the run time in vii DIII-D is recommended to increase the scientific output using its existing capabilities, even if scheduled upgrades must be further delayed. An increase in the Alcator C-Mod budget is recommended, at the expense of equal and modest reductions (~1%) in the other two facilities if necessary, to develop its capabilities for the long-term and increase its near-term scientific output.

  12. X-ray observations of {{\\rm{K}}}_{\\beta } emission from medium Z He-like ions in C-Mod tokamak plasmas

    Science.gov (United States)

    Rice, J. E.; Rosmej, F. B.; Cao, N.; Chilenski, M.; Howard, N. T.; Hubbard, A. E.; Hughes, J. W.; Irby, J. H.; Lin, Y.; Rodriguez-Fernandez, P.; Wolfe, S. M.; Wukitch, S. J.; Bitter, M.; Delgado-Aparicio, L.; Hill, K.; Reinke, M. L.

    2018-02-01

    X-ray spectra of n = 3–1 transitions in He-like ions (and satellites) from calcium, argon and chlorine have been measured in the core of Alcator C-Mod tokamak plasmas using high wavelength resolution x-ray spectrometer systems. The intensity ratio of the intercombination line y 3 (1s3p 3P1–1s2 1S0) to the resonance line w 3 (1s3p 1P1–1s2 1S0) is found to be much larger than what is expected if collisional excitation out of the ground state is considered as the only population mechanism for the upper levels. This suggests that recombination and cascades from higher levels with n ≥slant 4 are important. Modeling with the MARIA code is in good agreement with the observations, demonstrating the importance of recombination population of the upper level for y 3. The intensity ratio y 3/w 3 has been studied over a large range of core electron temperature and density, and radial position in the plasma. The observed ratio decreases with increasing T e , increases with increasing Z and is independent of n e , in agreement with modeling.

  13. Scrape-off layer reflectometer for Alcator C-Moda)

    Science.gov (United States)

    Lau, Cornwall; Hanson, Greg; Wilgen, John; Lin, Yijun; Wukitch, Steve

    2010-10-01

    A swept-frequency X-mode reflectometer is being built for Alcator C-Mod to measure the scrape-off layer density profiles at the top, middle, and bottom locations in front of both the new lower hybrid launcher and the new ion cyclotron range of frequencies antenna. The system is planned to operate between 100 and 146 GHz at sweep rates from 10 μs to 1 ms, and will cover a density range of approximately 1016-1020 m-3 at B0=5-5.4 T. To minimize the effects of density fluctuations, both differential phase and full phase reflectometry will be employed. Design, test data, and calibration results of this electronics system will be discussed. To reduce attenuation losses, tallguide (TE01) will be used for most of the transmission line system. Simulations of high mode conversion in tallguide components, such as e-plane hyperbolic secant radius of curvature bends, tapers, and horn antennas will be shown. Experimental measurements of the total attenuation losses of these components in the lower hybrid waveguide run will also be presented.

  14. Design of a correlation electron cyclotron emission diagnostic for Alcator C-Moda)

    Science.gov (United States)

    Sung, C.; White, A. E.; Irby, J. H.; Leccacorvi, R.; Vieira, R.; Oi, C. Y.; Peebles, W. A.; Nguyen, X.

    2012-10-01

    A correlation electron cyclotron emission (CECE) diagnostic has been installed in Alcator C-Mod. In order to measure electron temperature fluctuations, this diagnostic uses a spectral decorrelation technique. Constraints obtained with nonlinear gyrokinetic simulations guided the design of the optical system and receiver. The CECE diagnostic is designed to measure temperature fluctuations which have kθ ≤ 4.8 cm-1 (kθρs < 0.5) using a well-focused beam pattern. Because the CECE diagnostic is a dedicated turbulence diagnostic, the optical system is also flexible, which allows for various collimating lenses and antenna to be used. The system overview and the demonstration of its operability as designed are presented in this paper.

  15. First results of the SOL reflectometer on Alcator C-Moda)

    Science.gov (United States)

    Lau, C.; Hanson, G.; Lin, Y.; Wilgen, J.; Wukitch, S.; Labombard, B.; Wallace, G.

    2012-10-01

    A swept-frequency X-mode reflectometer has been built on Alcator C-Mod to measure the scrape-off layer (SOL) density profiles adjacent to the lower hybrid launcher. The reflectometer system operates between 100 and 146 GHz at sweep rates from 10 μs to 1 ms and covers a density range of ˜1016-1020 m-3 at B0 = 5-5.4 T. This paper discusses the analysis of reflectometer density profiles and presents first experimental results of SOL density profile modifications due to the application of lower hybrid range-of-frequencies power to L-mode discharges. Comparison between density profiles measured by the X-mode reflectometer and scanning Langmuir probes is also shown.

  16. A new interferometry-based electron density fluctuation diagnostic on Alcator C-Moda)

    Science.gov (United States)

    Kasten, C. P.; Irby, J. H.; Murray, R.; White, A. E.; Pace, D. C.

    2012-10-01

    The two-color interferometry diagnostic on the Alcator C-Mod tokamak has been upgraded to measure fluctuations in the electron density and density gradient for turbulence and transport studies. Diagnostic features and capabilities are described. In differential mode, fast phase demodulation electronics detect the relative phase change between ten adjacent, radially-separated (ΔR = 1.2 cm, adjustable), vertical-viewing chords, which allows for measurement of the line-integrated electron density gradient. The system can be configured to detect the absolute phase shift of each chord by comparison to a local oscillator, measuring the line-integrated density. Each chord is sensitive to density fluctuations with kR < 20.3 cm-1 and is digitized at up to 10 MS/s, resolving aspects of ion temperature gradient-driven modes and other long-wavelength turbulence. Data from C-Mod discharges is presented, including observations of the quasi-coherent mode in enhanced D-alpha H-mode plasmas and the weakly coherent mode in I-mode.

  17. Soft x-ray imaging on Alcator

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-05-01

    The development of an advanced uv/x-ray plasma imaging system for the study and control of plasma in the Alcator A tokamak at MIT is discussed. The importance of tomographic imaging systems for reconstructing two-dimensional plasma images is considered. The feasibility of using tomographic techniques for mapping the internal structures of plasmas is considered for Alcator C and TMX. The design, execution and analysis of an x-ray experiment on the MIT magnetic mirror machine are discussed. A series of plasma studies on Alcator A are presented.

  18. Modification of ordinary-mode reflectometry system to detect lower-hybrid waves in Alcator C-Moda)

    Science.gov (United States)

    Baek, S. G.; Shiraiwa, S.; Parker, R. R.; Dominguez, A.; Kramer, G. J.; Marmar, E. S.

    2012-10-01

    Backscattering experiments to detect lower-hybrid (LH) waves have been performed in Alcator C-Mod, using the two modified channels (60 GHz and 75 GHz) of an ordinary-mode reflectometry system with newly developed spectral recorders that can continuously monitor spectral power at a target frequency. The change in the baseline of the spectral recorder during the LH wave injection is highly correlated to the strength of the X-mode non-thermal electron cyclotron emission. In high density plasmas where an anomalous drop in the lower hybrid current drive efficiency is observed, the observed backscattered signals are expected to be generated near the last closed flux surface, demonstrating the presence of LH waves within the plasma. This experimental technique can be useful in identifying spatially localized LH electric fields in the periphery of high-density plasmas.

  19. Phase contrast imaging measurements of reversed shear Alfvén eigenmodes during sawteeth in Alcator C-Moda)

    Science.gov (United States)

    Edlund, E. M.; Porkolab, M.; Kramer, G. J.; Lin, L.; Lin, Y.; Wukitch, S. J.

    2009-05-01

    Reversed shear Alfvén eigenmodes (RSAEs) have been observed with the phase contrast imaging diagnostic and Mirnov coils during the sawtooth cycle in Alcator C-mod [M. Greenwald et al., Nucl. Fusion 45, S109 (2005)] plasmas with minority ion-cyclotron resonance heating. Both down-chirping RSAEs and up-chirping RSAEs have been observed during the sawtooth cycle. Experimental measurements of the spatial structure of the RSAEs are compared to theoretical models based on the code NOVA [C. Z. Cheng and M. S. Chance, J. Comput. Phys. 71, 124 (1987)] and used to derive constraints on the q profile. It is shown that the observed RSAEs can be understood by assuming a reversed shear q profile (up chirping) or a q profile with a local maximum (down chirping) with q ≈1.

  20. Structure and motion of edge turbulence in the National Spherical Torus Experiment and Alcator C-Moda)

    Science.gov (United States)

    Zweben, S. J.; Maqueda, R. J.; Terry, J. L.; Munsat, T.; Myra, J. R.; D'Ippolito, D.; Russell, D. A.; Krommes, J. A.; LeBlanc, B.; Stoltzfus-Dueck, T.; Stotler, D. P.; Williams, K. M.; Bush, C. E.; Maingi, R.; Grulke, O.; Sabbagh, S. A.; White, A. E.

    2006-05-01

    In this paper we compare the structure and motion of edge turbulence observed in L-mode vs. H-mode plasmas in the National Spherical Torus Experiment (NSTX) [M. Ono, M. G. Bell, R. E. Bell et al., Plasma Phys. Controlled Fusion 45, A335 (2003)]. The radial and poloidal correlation lengths are not significantly different between the L-mode and the H-mode in the cases examined. The poloidal velocity fluctuations are lower and the radial profiles of the poloidal turbulence velocity are somewhat flatter in the H-mode compared with the L-mode plasmas. These results are compared with similar measurements Alcator C-Mod [E. Marmar, B. Bai, R. L. Boivin et al., Nucl. Fusion 43, 1610 (2003)], and with theoretical models.

  1. Fluctuating zonal flows in the I-mode regime in Alcator C-Moda)

    Science.gov (United States)

    Cziegler, I.; Diamond, P. H.; Fedorczak, N.; Manz, P.; Tynan, G. R.; Xu, M.; Churchill, R. M.; Hubbard, A. E.; Lipschultz, B.; Sierchio, J. M.; Terry, J. L.; Theiler, C.

    2013-05-01

    Velocity fields and density fluctuations of edge turbulence are studied in I-mode [F. Ryter et al., Plasma Phys. Controlled Fusion 40, 725 (1998)] plasmas of the Alcator C-Mod [I. H. Hutchinson et al., Phys. Plasmas 1, 1511 (1994)] tokamak, which are characterized by a strong thermal transport barrier in the edge while providing little or no barrier to the transport of both bulk and impurity particles. Although previous work showed no clear geodesic-acoustic modes (GAM) on C-Mod, using a newly implemented, gas-puff-imaging based time-delay-estimate velocity inference algorithm, GAM are now shown to be ubiquitous in all I-mode discharges examined to date, with the time histories of the GAM and the I-mode specific [D. Whyte et al., Nucl. Fusion 50, 105005 (2010)] Weakly Coherent Mode (WCM, f = 100-300 kHz, Δf/f≈0.5, and kθ≈1.3 cm-1) closely following each other through the entire duration of the regime. Thus, the I-mode presents an example of a plasma state in which zero frequency zonal flows and GAM continuously coexist. Using two-field (density-velocity and radial-poloidal velocity) bispectral methods, the GAM are shown to be coupled to the WCM and to be responsible for its broad frequency structure. The effective nonlinear growth rate of the GAM is estimated, and its comparison to the collisional damping rate seems to suggest a new view on I-mode threshold physics.

  2. Measured MHD equilibrium in Alcator C

    International Nuclear Information System (INIS)

    Pribyl, P.A.

    1986-03-01

    A method of processing data from a set of partial Rogowski loops is developed to study the MHD equilibrium in Alcator C. Time dependent poloidal fields in the vicinity of the plasma are calculated from measured currents, with field penetration effects being accounted for. Fields from eddy currents induced by the plasma in the tokamak structure are estimated as well. Each of the set of twelve B/sub θ/ measurements can then be separated into a component from the plasma current and a component from currents external to the pickup loops. Harmonic solutions to Maxwell's equations in toroidal coordinates are fit to these measurements in order to infer the fields everywhere in the vacuum region surrounding the plasma. Using this diagnostic, plasma current, position, shape, and the Shafranov term Λ = β/sub p/ + l/sub i//2 - 1 may be computed, and systematic studies of these plasma parameters are undertaken for Alcator C plasmas

  3. Validation of TGLF in C-Mod and DIII-D using machine learning and integrated modeling tools

    Science.gov (United States)

    Rodriguez-Fernandez, P.; White, Ae; Cao, Nm; Creely, Aj; Greenwald, Mj; Grierson, Ba; Howard, Nt; Meneghini, O.; Petty, Cc; Rice, Je; Sciortino, F.; Yuan, X.

    2017-10-01

    Predictive models for steady-state and perturbative transport are necessary to support burning plasma operations. A combination of machine learning algorithms and integrated modeling tools is used to validate TGLF in C-Mod and DIII-D. First, a new code suite, VITALS, is used to compare SAT1 and SAT0 models in C-Mod. VITALS exploits machine learning and optimization algorithms for the validation of transport codes. Unlike SAT0, the SAT1 saturation rule contains a model to capture cross-scale turbulence coupling. Results show that SAT1 agrees better with experiments, further confirming that multi-scale effects are needed to model heat transport in C-Mod L-modes. VITALS will next be used to analyze past data from DIII-D: L-mode ``Shortfall'' plasma and ECH swing experiments. A second code suite, PRIMA, allows for integrated modeling of the plasma response to Laser Blow-Off cold pulses. Preliminary results show that SAT1 qualitatively reproduces the propagation of cold pulses after LBO injections and SAT0 does not, indicating that cross-scale coupling effects play a role in the plasma response. PRIMA will be used to ``predict-first'' cold pulse experiments using the new LBO system at DIII-D, and analyze existing ECH heat pulse data. Work supported by DE-FC02-99ER54512, DE-FC02-04ER54698.

  4. Pumped-limiter study for Alcator DCT

    International Nuclear Information System (INIS)

    Brooks, J.N.; Mattas, R.F.; Cha, Y.S.; Hassanein, A.M.; Majumdar, S.

    1983-06-01

    A study was performed for a pumped-limiter design for the proposed Alcator DCT device. The study focused on reactor-relevant issues. The main issues examined were configuration, surface erosion, thermal hydraulics, and the choice of structural and surface materials. A bottom, flat limiter, with a copper-alloy substrate, seems to be a reasonable design and should provide an opportunity to test high power and particle loadings. Carbon is recommended as a surface material if acceptable redeposition properties can be demonstrated

  5. Pumped-limiter study for Alcator DCT

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, J.N.; Mattas, R.F.; Cha, Y.S.; Hassanein, A.M.; Majumdar, S.

    1983-06-01

    A study was performed for a pumped-limiter design for the proposed Alcator DCT device. The study focused on reactor-relevant issues. The main issues examined were configuration, surface erosion, thermal hydraulics, and the choice of structural and surface materials. A bottom, flat limiter, with a copper-alloy substrate, seems to be a reasonable design and should provide an opportunity to test high power and particle loadings. Carbon is recommended as a surface material if acceptable redeposition properties can be demonstrated.

  6. Investigation of lower hybrid physics through power modulation experiments on Alcator C-Moda)

    Science.gov (United States)

    Schmidt, A.; Bonoli, P. T.; Meneghini, O.; Parker, R. R.; Porkolab, M.; Shiraiwa, S.; Wallace, G.; Wright, J. C.; Harvey, R. W.; Wilson, J. R.

    2011-05-01

    Lower hybrid current drive (LHCD) is an attractive tool for off-axis current profile control in magnetically confined tokamak plasmas and burning plasmas (ITER), because of its high current drive efficiency. The LHCD system on Alcator C-Mod operates at 4.6 GHz, with ~ 1 MW of coupled power, and can produce a wide range of launched parallel refractive index (n||) spectra. A 32 chord, perpendicularly viewing hard x-ray camera has been used to measure the spatial and energy distribution of fast electrons generated by lower hybrid (LH) waves. Square-wave modulation of LH power on a time scale much faster than the current relaxation time does not significantly alter the poloidal magnetic field inside the plasma and thus allows for realistic modeling and consistent plasma conditions for different n|| spectra. Inverted hard x-ray profiles show clear changes in LH-driven fast electron location with differing n||. Boxcar binning of hard x-rays during LH power modulation allows for ~ 1 ms time resolution which is sufficient to resolve the build-up, steady-state, and slowing-down phases of fast electrons. Ray-tracing/Fokker-Planck modeling in combination with a synthetic hard x-ray diagnostic shows quantitative agreement with the x-ray data for high n|| cases. The time histories of hollow x-ray profiles have been used to measure off-axis fast electron transport in the outer half of the plasma, which is found to be small on a slowing down time scale.

  7. H-mode pedestal and threshold studies over an expanded operating space on Alcator C-Moda)

    Science.gov (United States)

    Hubbard, A. E.; Hughes, J. W.; Bespamyatnov, I. O.; Biewer, T.; Cziegler, I.; LaBombard, B.; Lin, Y.; McDermott, R.; Rice, J. E.; Rowan, W. L.; Snipes, J. A.; Terry, J. L.; Wolfe, S. M.; Wukitch, S.

    2007-05-01

    This paper reports on studies of the edge transport barrier and transition threshold of the high confinement (H) mode of operation on the Alcator C-Mod tokamak [I. H. Hutchinson et al., Phys. Plasmas 1, 1511 (1994)], over a wide range of toroidal field (2.6-7.86T) and plasma current (0.4-1.7MA). The H-mode power threshold and edge temperature at the transition increase with field. Barrier widths, pressure limits, and confinement are nearly independent of field at constant current, but the operational space at high B shifts toward higher temperature and lower density and collisionality. Experiments with reversed field and current show that scrape-off-layer flows in the high-field side depend primarily on configuration. In configurations with the B ×∇B drift away from the active X-point, these flows lead to more countercurrent core rotation, which apparently contributes to higher H-mode thresholds. In the unfavorable case, edge temperature thresholds are higher, and slow evolution of profiles indicates a reduction in thermal transport prior to the transition in particle confinement. Pedestal temperatures in this case are also higher than in the favorable configuration. Both high-field and reversed-field results suggest that parameters at the L-H transition are influencing the evolution and parameters of the H-mode pedestal.

  8. Eddy currents in the Alcator Tokamak

    International Nuclear Information System (INIS)

    Schram, D.C.; Rem, J.

    1975-03-01

    A one-dimensional model of an aircore transformer has been developed through which it is possible to analyze the effect of eddy currents in the primary windings and of similar currents in the field coils for the toroidal magnetic field, on the time dependence of the current in a Tokamak experiment. The model is applied to the 'Alcator' Tokamak at MIT and its accuracy is tested by comparing analytical results for the harmonic behaviour of the transformer, with experimental data. The time-dependent behaviour of the plasma current for a constant plasma resistance shows that eddy currents in the primary windings will lead to a reduction of 8% of the current maximum. The eddy currents in the 'Bitter' coils are found to affect predominantly the initial current rise; they lead to a steepening of the current rise. Finally, the influence of the time dependence of the plasma resistance is investigated

  9. Development of a High Resolution X-Ray Imaging Crystal Spectrometer for Measurement of Ion-Temperature and Rotation-Velocity Profiles in Fusion Energy Research Plasmas

    International Nuclear Information System (INIS)

    Hill, K.W.; Bitter, M.L.; Broennimann, Ch.; Eikenberry, E.F.; Ince-Cushman, A.; Lee, S.G.; Rice, J.E.; Scott, S.; Barnsley, R.

    2008-01-01

    A new imaging high resolution x-ray crystal spectrometer (XCS) has been developed to measure continuous profiles of ion temperature and rotation velocity in fusion plasmas. Following proof-of-principle tests on the Alcator C-Mod tokamak and the NSTX spherical tokamak, and successful testing of a new silicon, pixilated detector with 1MHz count rate capability per pixel, an imaging XCS is being designed to measure full profiles of T i and ν φ on C-Mod. The imaging XCS design has also been adopted for ITER. Ion-temperature uncertainty and minimum measurable rotation velocity are calculated for the C-Mod spectrometer. The affects of x-ray and nuclear-radiation background on the measurement uncertainties are calculated to predict performance on ITER

  10. Experiences with remote collaborations in fusion research

    International Nuclear Information System (INIS)

    Wurden, G.A.; Davis, S.; Barnes, D.

    1998-03-01

    The magnetic fusion research community has considerable experience in placing remote collaboration tools in the hands of real user. The ability to remotely view operations and to control selected instrumentation and analysis tasks has been demonstrated. University of Wisconsin scientists making turbulence measurements on TFTR: (1) were provided with a remote control room from which they could operate their diagnostic, while keeping in close contact with their colleagues in Princeton. LLNL has assembled a remote control room in Livermore in support of a large, long term collaboration on the DIII-D tokamak in San Diego. (2) From the same control room, a joint team of MIT and LLNL scientists has conducted full functional operation of the Alcator C-Mod tokamak located 3,000 miles away in Cambridge Massachusetts. (3) These early efforts have been highly successful, but are only the first steps needed to demonstrate the technical feasibility of a complete facilities on line environment. These efforts have provided a proof of principle for the collaboratory concept and they have also pointed out shortcomings in current generation tools and approaches. Current experiences and future directions will be discussed

  11. Surface heat flux feedback controlled impurity seeding experiments with Alcator C-Mod’s high-Z vertical target plate divertor: performance, limitations and implications for fusion power reactors

    Science.gov (United States)

    Brunner, D.; Wolfe, S. M.; LaBombard, B.; Kuang, A. Q.; Lipschultz, B.; Reinke, M. L.; Hubbard, A.; Hughes, J.; Mumgaard, R. T.; Terry, J. L.; Umansky, M. V.; The Alcator C-Mod Team

    2017-08-01

    The Alcator C-Mod team has recently developed a feedback system to measure and control surface heat flux in real-time. The system uses real-time measurements of surface heat flux from surface thermocouples and a pulse-width modulated piezo valve to inject low-Z impurities (typically N2) into the private flux region. It has been used in C-Mod to mitigate peak surface heat fluxes  >40 MW m-2 down to    1. While the system works quite well under relatively steady conditions, use of it during transients has revealed important limitations on feedback control of impurity seeding in conventional vertical target plate divertors. In some cases, the system is unable to avoid plasma reattachment to the divertor plate or the formation of a confinement-damaging x-point MARFE. This is due to the small operational window for mitigated heat flux in the parameters of incident plasma heat flux, plasma density, and impurity density as well as the relatively slow response of the impurity gas injection system compared to plasma transients. Given the severe consequences for failure of such a system to operate reliably in a reactor, there is substantial risk that the conventional vertical target plate divertor will not provide an adequately controllable system in reactor-class devices. These considerations motivate the need to develop passively stable, highly compliant divertor configurations and experimental facilities that can test such possible solutions.

  12. FY-2013 FES (Fusion Energy Sciences) Joint Research Target Report

    Energy Technology Data Exchange (ETDEWEB)

    Fenstermacher, M. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Garofalo, A. M. [General Atomics, San Diego, CA (United States); Gerhardt, S. P. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Hubbard, A. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Maingi, R. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Whyte, D. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2013-09-30

    investigated. The research will strengthen the basis for extrapolation of stationary regimes which combine high energy confinement with good particle and impurity control, to ITER and other future fusion facilities for which avoidance of large ELMs is a critical issue. Data from the Alcator C-Mod tokamak (MIT), DIII-D tokamak (General Atomics), and NSTX spherical tokamak (PPPL) contribute to this report. Experiments specifically motivated by this research target were conducted on DIII-D, with a national team of researchers from GA, LLNL, PPPL, MIT and ORNL contributing. Both the Alcator C-Mod and NSTX-U teams contributed analysis of previously collected data, as those two facilities did not operate in FY2013. Within each of the three research groups, members from both the host institutions and collaborating institutions made critical contributions. Highlights from these research activities are provided, with additional details.

  13. Observation of ion cyclotron range of frequencies mode conversion plasma flow drive on Alcator C-Moda)

    Science.gov (United States)

    Lin, Y.; Rice, J. E.; Wukitch, S. J.; Greenwald, M. J.; Hubbard, A. E.; Ince-Cushman, A.; Lin, L.; Marmar, E. S.; Porkolab, M.; Reinke, M. L.; Tsujii, N.; Wright, J. C.; Alcator C-Mod Team

    2009-05-01

    At modest H3e levels (n3He/ne˜8%-12%), in relatively low density D(H3e) plasmas, n¯e≤1.3×1020 m-3, heated with 50 MHz rf power at Bt0˜5.1 T, strong (up to 90 km/s) toroidal rotation (Vϕ) in the cocurrent direction has been observed by high-resolution x-ray spectroscopy on Alcator C-Mod. The change in central Vϕ scales with the applied rf power (≤30 km s-1 MW-1), and is generally at least a factor of 2 higher than the empirically determined intrinsic plasma rotation scaling. The rotation in the inner plasma (r /a≤0.3) responds to the rf power more quickly than that of the outer region (r /a≥0.7), and the rotation profile is broadly peaked for r /a≤0.5. Localized poloidal rotation (0.3≤r/a≤0.6) in the ion diamagnetic drift direction (˜2 km/s at 3 MW) is also observed, and similarly increases with rf power. Changing the toroidal phase of the antenna does not affect the rotation direction, and it only weakly affects the rotation magnitude. The mode converted ion cyclotron wave (MC ICW) has been detected by a phase contrast imaging system and the MC process is confirmed by two-dimensional full wave TORIC simulations. The simulations also show that the MC ICW is strongly damped on H3e ions in the vicinity of the MC layer, approximately on the same flux surfaces where the rf driven flow is observed. The flow shear in our experiment is marginally sufficient for plasma confinement enhancement based on the comparison of the E ×B shearing rate and gyrokinetic linear stability analysis.

  14. Edge energy transport barrier and turbulence in the I-mode regime on Alcator C-Moda)

    Science.gov (United States)

    Hubbard, A. E.; Whyte, D. G.; Churchill, R. M.; Cziegler, I.; Dominguez, A.; Golfinopoulos, T.; Hughes, J. W.; Rice, J. E.; Bespamyatnov, I.; Greenwald, M. J.; Howard, N.; Lipschultz, B.; Marmar, E. S.; Reinke, M. L.; Rowan, W. L.; Terry, J. L.

    2011-05-01

    We report extended studies of the I-mode regime [Whyte et al., Nucl. Fusion 50, 105005 (2010)] obtained in the Alcator C-Mod tokamak [Marmar et al., Fusion Sci. Technol. 51(3), 3261 (2007)]. This regime, usually accessed with unfavorable ion B × ∇B drift, features an edge thermal transport barrier without a strong particle transport barrier. Steady I-modes have now been obtained with favorable B × ∇B drift, by using specific plasma shapes, as well as with unfavorable drift over a wider range of shapes and plasma parameters. With favorable drift, power thresholds are close to the standard scaling for L-H transitions, while with unfavorable drift they are ˜ 1.5-3 times higher, increasing with Ip. Global energy confinement in both drift configurations is comparable to H-mode scalings, while density profiles and impurity confinement are close to those in L-mode. Transport analysis of the edge region shows a decrease in edge χeff, by typically a factor of 3, between L- and I-mode. The decrease correlates with a drop in mid-frequency fluctuations (f ˜ 50-150 kHz) observed on both density and magnetics diagnostics. Edge fluctuations at higher frequencies often increase above L-mode levels, peaking at f ˜ 250 kHz. This weakly coherent mode is clearest and has narrowest width (Δf/f ˜ 0.45) at low q95 and high Tped, up to 1 keV. The Er well in I-mode is intermediate between L- and H-mode and is dominated by the diamagnetic contribution in the impurity radial force balance, without the Vpol shear typical of H-modes.

  15. Transport-driven scrape-off layer flows and the x-point dependence of the L-H power threshold in Alcator C-Moda)

    Science.gov (United States)

    LaBombard, B.; Rice, J. E.; Hubbard, A. E.; Hughes, J. W.; Greenwald, M.; Granetz, R. S.; Irby, J. H.; Lin, Y.; Lipschultz, B.; Marmar, E. S.; Marr, K.; Mossessian, D.; Parker, R.; Rowan, W.; Smick, N.; Snipes, J. A.; Terry, J. L.; Wolfe, S. M.; Wukitch, S. J.

    2005-05-01

    Factor of ˜2 higher power thresholds for low- to high-confinement mode transitions (L-H) with unfavorable x-point topologies in Alcator C-Mod [Phys. Plasmas 1, 1511 (1994)] are linked to flow boundary conditions imposed by the scrape-off layer (SOL). Ballooning-like transport drives flow along magnetic field lines from low- to high-field regions with toroidal direction dependent on upper/lower x-point balance; the toroidal rotation of the confined plasma responds, exhibiting a strong counter-current rotation when B ×∇B points away from the x point. Increased auxiliary heating power (rf, no momentum input) leads to an L-H transition at approximately twice the edge electron pressure gradient when B ×∇B points away. As gradients rise prior to the transition, toroidal rotation ramps toward the co-current direction; the H mode is seen when the counter-current rotation imposed by the SOL flow becomes compensated. Remarkably, L-H thresholds in lower-limited discharges are identical to lower x-point discharges; SOL flows are also found similar, suggesting a connection.

  16. X-ray imaging crystal spectroscopy for use in plasma transport research

    Science.gov (United States)

    Reinke, M. L.; Podpaly, Y. A.; Bitter, M.; Hutchinson, I. H.; Rice, J. E.; Delgado-Aparicio, L.; Gao, C.; Greenwald, M.; Hill, K.; Howard, N. T.; Hubbard, A.; Hughes, J. W.; Pablant, N.; White, A. E.; Wolfe, S. M.

    2012-11-01

    This research describes advancements in the spectral analysis and error propagation techniques associated with x-ray imaging crystal spectroscopy (XICS) that have enabled this diagnostic to be used to accurately constrain particle, momentum, and heat transport studies in a tokamak for the first time. Doppler tomography techniques have been extended to include propagation of statistical uncertainty due to photon noise, the effect of non-uniform instrumental broadening as well as flux surface variations in impurity density. These methods have been deployed as a suite of modeling and analysis tools, written in interactive data language (IDL) and designed for general use on tokamaks. Its application to the Alcator C-Mod XICS is discussed, along with novel spectral and spatial calibration techniques. Example ion temperature and radial electric field profiles from recent I-mode plasmas are shown, and the impact of poloidally asymmetric impurity density and natural line broadening is discussed in the context of the planned ITER x-ray crystal spectrometer.

  17. Grazing incidence EUV study of the Alcator tokamaks

    International Nuclear Information System (INIS)

    Castracane, J.

    1982-01-01

    The use of impurity radiation to examine plasma conditions is a well known technique. To gain access, however, to the hot, central portion of the plasma created in the present confinement machines it is necessary to be able to observe radiation from medium and heavy elements such as molybdenum and iron. These impurities radiate primarily in the extreme ultra violet region of the spectrum and can play a role in the power balance of the tokamak. Radiation from highly ionized molybdenum was examined on the Alcator A and C tokamaks using a photometrically calibrated one meter grazing incidence monochromator. On Alcator A, a pseudo-continuum of Mo emissions in the 60 to 100 A ranges were seen to comprise 17% of the radiative losses from the plasma. This value closely matched measurements by a broad band bolometer array. Following these preliminary measurements, the monochromator was transferred to Alcator C for a more thorough examination of EUV emissions. Deviations from predicted scaling laws for energy confinement time vs density were observed on this machine

  18. Comparison of Alcator C data with the Rebut-Lallia-Watkins critical gradient scaling

    International Nuclear Information System (INIS)

    Hutchinson, I.H.

    1992-12-01

    The critical temperature gradient model of Rebut, Lallia and Watkins is compared with data from Alcator C. The predicted central electron temperature is derived from the model, and a simple analytic formula is given. It is found to be in quite good agreement with the observed temperatures on Alcator C under ohmic heating conditions. However, the thermal diffusivity postulated in the model for gradients that exceed the critical is not consistent with the observed electron heating by Lower Hybrid waves

  19. D-D fusion neutron-spectra measurements and ion-temperature determination at Alcator C

    International Nuclear Information System (INIS)

    Fisher, W.A.

    1983-02-01

    A neutron spectrometer system has been designed, assembled, and used to measure the D-D neutron spectrum at Alcator C. The design of the shielding and collimation was critical to the successful measurement of the spectrum and involved an integral approach in which the neutronics of the Alcator C was exploited to obtain a successful system. The system consists of a 3 He ionization chamber mounted in a multi-component shield system. Essentially the outermost part of the shield and collimator has been designed to moderate the MeV-range neutrons to thermal energies. The inner part of the shield is designed to capture the thermalized neutrons with a minimum of gamma production. As a result, measurements during plasma discharges indicate that the ratio of the number of counts in the 2.45-MeV peak to the total number of neutron counts in the ion chamber is 1.67

  20. An alcator-like confinement time scaling law derived from buckingham's PI theorem

    International Nuclear Information System (INIS)

    Roth, J.R.

    1983-01-01

    The unsatisfactory state of understanding of particle transport and confinement in tokamaks is well known. The best available theory, neoclassical transport, predicts a confinement time which scales as the square of the magnetic field, and inversely as the number density. Until recently, the best available phenomenological scaling law was the Alcator scaling law. This scaling law has recently been supplanted by the neoAlcator scaling law. Both of these expressions are unsatisfactory, because they not only are unsupported by any physical theory, but also their numerical constants are dimensional, suggesting that additional physical parameters need to be accounted for. A more firmly based scaling law can be derived from Buckingham's pi theorem. We adopt the particle confinement time as the dependent variable (derived dimension), and as independent variables (fundamental dimensions) we use the plasma volume, the average ion charge density, the ion current on the limiter, and the magnetic induction. From Buckingham's pi theorem, we obtain an equation which correctly predicts the absence of magnetic induction dependence, and the direct dependence on the ion density. The dependence on the product of the major radius and the plasma radius is intermediate between the original and neoAlcator scaling laws, and may be consistent with the data if the ion kinetic temperature and limiter area were accounted for

  1. Plasma physics and controlled nuclear fusion research 1994. V. 1. Proceedings of the fifteenth international conference

    International Nuclear Information System (INIS)

    1995-01-01

    This volume contains (i) the traditional Artsimovich Memorial Lecture; (ii) nine presentations giving an overview of toroidal confinement systems (TFTR, JT-60U, JET, DIII-D, TORE SUPRA, Alcator C-Mod, JFT-2M and T-10 tokamaks and the Wendelstein 7-AS stellarator), (iii) twenty-three presentations on core plasma physics (mostly on charged-particle transport and improved confinement regimes), (iv) eight presentations on plasma heating and current drive, (v) twelve presentations on divertors and edge physics, (vi) thirteen on concept optimization (shaping of magnetic field configuration, control of plasma profiles and of disruptions, a.o.), and (vii) six on helical systems (stellarators, including torsatron/heliotron). Refs, figs and tabs

  2. Massachusetts Institute of Technology, Plasma Fusion Center FY97--FY98 work proposal

    International Nuclear Information System (INIS)

    1996-03-01

    Alcator C-Mod is the high-field, high-density divertor tokamak in the world fusion program. It is one of five divertor experiments capable of plasma currents exceeding one megamp. Because of its compact dimensions, Alcator C-Mod investigates an essential area in parameter space, which complements the world's larger experiments, in establishing the tokamak physics database. Three key areas of investigation have been called out in which Alcator C-Mod has a vital role to play: (1) divertor research on C-Mod takes advantage of the advanced divertor shaping, the very high scrap-off-layer power density, unique abilities in impurity diagnosis, and the High-Z metal wall, to advance the physics understanding of this critical topic; (2) in transport studies, C-Mod is making critical tests of both empirical scalings and theoretically based interpretations of tokamak transport, at dimensional parameters that are unique but dimensionless parameters often comparable to those in much larger experiments; (3) in the area of Advanced Tokamak research, so important to concept optimization, the high-field design of the device also provides long pulse length, compared to resistive skin time, which provides an outstanding opportunity to investigate the extent to which enhanced confinement and stability can be sustained in steady-state, using active profile control. In addition to these main programmatic emphasis, important enabling research is being performed in MHD stability and control, which has great significance for the immediate design of ITER, and in the physics and engineering of ICRF, which is the main auxiliary heating method on C-Mod

  3. Massachusetts Institute of Technology, Plasma Fusion Center FY97--FY98 work proposal

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Alcator C-Mod is the high-field, high-density divertor tokamak in the world fusion program. It is one of five divertor experiments capable of plasma currents exceeding one megamp. Because of its compact dimensions, Alcator C-Mod investigates an essential area in parameter space, which complements the world`s larger experiments, in establishing the tokamak physics database. Three key areas of investigation have been called out in which Alcator C-Mod has a vital role to play: (1) divertor research on C-Mod takes advantage of the advanced divertor shaping, the very high scrap-off-layer power density, unique abilities in impurity diagnosis, and the High-Z metal wall, to advance the physics understanding of this critical topic; (2) in transport studies, C-Mod is making critical tests of both empirical scalings and theoretically based interpretations of tokamak transport, at dimensional parameters that are unique but dimensionless parameters often comparable to those in much larger experiments; (3) in the area of Advanced Tokamak research, so important to concept optimization, the high-field design of the device also provides long pulse length, compared to resistive skin time, which provides an outstanding opportunity to investigate the extent to which enhanced confinement and stability can be sustained in steady-state, using active profile control. In addition to these main programmatic emphasis, important enabling research is being performed in MHD stability and control, which has great significance for the immediate design of ITER, and in the physics and engineering of ICRF, which is the main auxiliary heating method on C-Mod.

  4. Ion and electron parameters in the alcator C tokamak scrape-off region

    International Nuclear Information System (INIS)

    Wan, A.S.H.

    1986-05-01

    Janus is a bi-directional, multi-functional edge probe used to diagnose the ion and electron parameters in the Alcator C tokamak scrape-off region. Two mirror image sets of diagnostics are aligned to face the electron and ion sides along magnetic field lines. Each set of diagnostics consists of a retarding-field energy analyzer (RFEA), a Langmuir probe, and a calorimeter. The RFEA can alternatively sample both the ion and electron parallel energy distribution functions during a tokamak discharge. From the Langmuir probe, one can infer electron temperature, density, and the plasma floating potential. Simple Langmuir probe theory is found to yield the best agreement between the measured Langmuir probe characteristics and the RFEA-inferred T/sub e/. The calorimeter independently detects the total parallel heat flux incident to an electrically floating plate. The measured sheath transmission coefficient, however, is typically lower than the theoretically predicted value by a factor of approx.3. Together these diagnostics enable detailed, localized edge plasma characterization on Alcator C

  5. Poloidal asymmetries in the limiter shadow plasma of the Alcator C tokamak. Volume 1

    International Nuclear Information System (INIS)

    LaBombard, B.

    1986-05-01

    This thesis investigates conditions which exist in the limiter shadow plasma of the Alcator C tokamak. The understanding of this edge plasma region is approached from both experimental and theoretical points of view. First, a general overview of edge plasma physical processes is presented. Simple edge plasma models and conditions which can theoretically result in a poloidally asymmetric edge plasma are discussed. A review of data obtained from previous diagnostics in the Alcator C edge plasma is then used to motivate the development of a new edge plasma diagnostic system (DENSEPACK) to experimentally investigate poloidal asymmetries in this region. The bulk of this thesis focuses on the marked poloidal asymmetries detected by this poloidal probe array and possible mechanisms which might support such asymmetries on a magnetic flux surface. In processing the probe data, some important considerations on fitting Langmuir probe characteristics are identified. The remainder of this thesis catalogues edge versus central plasma parameter dependences. Regression analysis techniques are applied to characterize edge density for various central plasma parameters. Edge plasma conditions during lower hybrid radio frequency heating and pellet injection are also discussed

  6. High-energy-ion depletion in the charge exchange spectrum of Alcator C

    International Nuclear Information System (INIS)

    Schissel, D.P.

    1982-01-01

    A three-dimensional, guiding center, Monte Carlo code is developed to study ion orbits in Alcator C. The highly peaked ripple of the magnetic field of Alcator is represented by an analytical expression for the vector potential. The analytical ripple field is compared to the resulting magnetic field generated by a current model of the toroidal plates; agreement is excellent. Ion-Ion scattering is simulated by a pitch angle and an energy scattering operator. The equations of motion are integrated with a variable time step, extrapolating integrator. The code produces collisionless banana and ripple trapped loss cones which agree well with present theory. Global energy distributions have been calculated and show a slight depletion above 8.5 keV. Particles which are ripple trapped and lost are at energies below where depletion is observed. It is found that ions pitch angle scatter less as energy is increased. The result is that, when viewed in velocity space, ions form probability lobes the shape of mouse ears which are fat near the thermal energy. Therefore, particles enter the loss cone at low energies near the bottom of the core. Recommendations for future work include improving the analytic model of the ripple field, testing the effect of del . B not equal to 0 on ion orbits, and improving the efficiency of the code by either using a spline fit for the magnetic fields or by creating a vectorized Monte Carlo code

  7. Numerical investigation of ICRF antenna designs and heating schemes for Alcator C

    International Nuclear Information System (INIS)

    Blackfield, D.T.; Blackwell, B.D.

    1983-02-01

    Initially, approximately 500 kW of rf power will be launched through one port of Alcator C at a frequency of 180 to 220 MHz. We use a hot-plasma slab model to examine antenna coupling and power deposition for second harmonic (H, B 0 = 6.7 T) heating regime. The plasma medium is assumed uniform in y and z and is stratified in x. Three-dimensional, four-mode field solutions are obtained by solution of the boundary condition equations in the x direction, and by Fourier transform methods in y and z. We study the dependence of radiation resistance upon coupling parameters such as antenna width and radial position. This is interpreted in terms of the spectral (k/sub y/, k/sub z/) distribution of power, the effect of the evanescent region at the edge, and the attenuation length of the waves

  8. Visible continuum measurements on the Alcator C Tokamak: Changes in particle transport during pellet fuelled discharges

    International Nuclear Information System (INIS)

    Foord, M.E.

    1986-12-01

    A spatially resolving visible light detector system is used to measure continuum radiation near 5360A on the Alcator C Tokamak. For the typically hot plasmas studied, the continuum emission is found to be dominated by bremsstrahlung radiation near this wavelength region. Accurate determinations of Z/sub eff/ are obtained from continuum measurements using independently determined temperature and density measurements. Density profiles during high density, clean pellet fueled discharges, are also determined and are used to study the changes in particle transport after injection. For discharges with sufficiently large pellet density increases, density profiles are found to become more peaked following the injection. In these cases, the profiles are found to remain peaked for the remainder of the discharge, or until a ''giant'' sawtooth or minor disruption abruptly returns the profiles to a flatter pre-pellet condition. Analysis of density profiles after pellet injection yields information about the radial diffusion and convection velocity of the plasma particles. The peakedness in the density profiles, observed after pellet injection, is attributable mostly to increases in inward convection. It is concluded that neoclassical fluxes are too small to account for these changes. 70 refs., 55 figs

  9. Diagnosis of mildly relativistic electron velocity distributions by electron cyclotron emission in the Alcator C tokamak

    International Nuclear Information System (INIS)

    Kato, K.

    1986-09-01

    Mildly relativistic electron velocity distributions are diagnosed from measurements of the first few electron cyclotron emission harmonics in the Alcator C tokamak. The approach employs a vertical viewing chord through the center of the tokamak plasma terminating at a compact, high-performance viewing dump. The cyclotron emission spectra obtained in this way are dominated by frequency downshifts due to the relativistic mass increase, which discriminates the electrons by their total energy. In this way a one-to-one correspondence between the energy and the emission frequency is accomplished in the absence of harmonic superpositions. The distribution, described by f/sub p/, the line-averaged phase space density, and Λ, the anisotropy factor, is determined from the ratio of the optically thin harmonics or polarizations. Diagnosis of spectra in the second and the third harmonic range of frequencies obtained during lower hybrid heating, current drive, and low density ohmic discharges are carried out, using different methods depending on the degree of harmonic superposition present in the spectrum and the availability of more than one ratio measurement. Discussions of transient phenomena, the radiation temperature measurement from the optically thick first harmonic, and the measurements compared to the angular hard x-ray diagnostic results illuminate the capabilities of the vertically viewing electron cyclotron emission diagnostic

  10. The effect of ICRF on the Alcator C Scrape-Off Layer plasma

    International Nuclear Information System (INIS)

    Wan, A.S.; Lipschultz, B.; McDermott, F.S.; Terry, J.L.

    1988-05-01

    This paper presents a characterization of the Alcator C Scrape-Off Layer (SOL) plasma during ICRF hydrogen-minority fast wave heating experiments. The SOL plasma parameters were measured using a multifunctional probe, JANUS, which is capable of simultaneously measuring the ion and electron parameters both parallel and antiparallel with respect to the toroidal magnetic field. The probe data indicate, at low value of injected rf power, there is direct edge heating and density increases at radii greater than that of the antenna Faraday shield. Increasing the injected rf power spreads both the temperature and density increases throughout the edge region, flattening the radial profiles. Varying the position of the resonance layer in the main plasma does not significantly change the effect of ICRF on the SOL parameters. Given this single spatial point characterization of the SOL, a crude estimate of power flow into and through the edge plasma indicate that /approximately/20% of the ICRF power launched from the antenna is absorbed /und directly/ in the SOL plasma. Additional observation of the impurity source rates confirms the conclusions of an earlier paper, which attributed increasing central densities of high-Z impurities to the increase in physical sputtering rate at both the ICRF antenna's Faraday shield and the limiter surface

  11. Lower hybrid heating and current drive, and ion cyclotron heating experiments on the Alcator C and the Versator II tokamaks

    International Nuclear Information System (INIS)

    Porkolab, M.; Blackwell, B.; Bonoli, P.

    1984-08-01

    Lower hybrid electron Landau heting experiments have been carried out on the Alcator C tokamak at densities 0.8 x 10 14 less than or equal to anti n(cm -3 ) less than or equal to 1.7 x 10 14 , and at B = 7 T - 11 T. Using SiC coated graphite limiters, upon injection of 850 kW of power at a density of anti n/sub e/ approx. = 1.3 x 10 14 cm -3 in deuterium typical temperature increases of ΔTi approx. = 0.7 keV, ΔT/sub e/ approx. = 1.0 keV were observed. Current drive and ramping experiments have also been carried out at densities 10 13 less than or equal to anti n/sub e/(cm -3 ) less than or equal to 10 14 . The maximum current drive efficiency, defined as eta = anti n(10 14 cm -3 )I(MA)R(m)/P(MW), was eta approx. = 0.12 at B = 10 T and eta approx. = 0.08 at B = 8 T. Current ramping experiments have resulted in ramping rates of ΔI/Δt approx. = 400 kA/sec with P/sub rf/ approx. = 860 kW at a density of anti n/sub e/ approx. = 3.0 x 10 13 cm -3 . Initial results from the Alcator C 180 MHz ICRF heating program are reported. Significant heating results were obtained in the hydrogen minority regime: upon injection of 400 kW of rf power the ion temperature rose by as much as 600 eV at a density of anti n/sub e/ less than or equal to 1.9 x 10 14 cm -3 . In Versator II, during lower hybrid current drive experiments the global particle confinement increased by approximately a factor of two above the ohmic discharge value when the Parail-Pogutse electron tail instability was stabilized

  12. Study of electron temperature evolution during sawtoothing and pellet injection using thermal electron cyclotron emission in the Alcator C tokamak

    International Nuclear Information System (INIS)

    Gomez, C.C.

    1986-05-01

    A study of the electron temperature evolution has been performed using thermal electron cyclotron emission. A six channel far infrared polychromator was used to monitor the radiation eminating from six radial locations. The time resolution was <3 μs. Three events were studied, the sawtooth disruption, propagation of the sawtooth generated heatpulse and the electron temperature response to pellet injection. The sawtooth disruption in Alcator takes place in 20 to 50 μs, the energy mixing radius is approx. 8 cm or a/2. It is shown that this is inconsistent with single resonant surface Kadomtsev reconnection. Various forms of scalings for the sawtooth period and amplitude were compared. The electron heatpulse propagation has been used to estimate chi e(the electron thermal diffusivity). The fast temperature relaxation observed during pellet injection has also been studied. Electron temperature profile reconstructions have shown that the profile shape can recover to its pre-injection form in a time scale of 200 μs to 3 ms depending on pellet size

  13. 2012 Joint Research Target (JRT) Final Report

    International Nuclear Information System (INIS)

    2012-01-01

    The report summarizes: 1. Diagnostic upgrades and analysis improvements that support the JRT; 2. Descriptions of new experiments and a brief summary of findings; 3. New analysis of previous experiments; 4. Plans for further data analysis and recommendations for further work; 5. Scientific publications that are derived from or contributed directly to the JRT. The report is organized as follows: Section 1: Describes inter-machine comparisons that were facilitated by the JRT focus. Similarities and differences found on the different facilities are outlined, and plans for additional analysis of data and supporting simulations are described.Section 2: Reviews diagnostic development, experiments and results from C-Mod. C-Mod dedicated 13.1 run days to the JRT divided among 10 experimental proposals. These were organized into three general thrust areas that represent distinct experimental approaches to realizing the regimes called for in the JRT description. Initial comparisons with linear and nonlinear simulation have been carried out for these experiments, and plans for an extensive campaign of analysis have been outlined. Section 3: Reviews results from DIII-D including new experiments, detailed comparisons of simulations to previously collected data and connections between the new work and past research. Four experimental days were dedicated to the JRT in 2012. These included studies of L-modes, H-modes and QH-modes. Section 4: Summarizes new analysis of data collected before the NSTX shutdown. The work focuses on the roles of low and high-k turbulence; collisionality scans and impurity particle transport.

  14. 2012 Joint Research Target (JRT) Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Team, JRT

    2012-09-30

    The report summarizes: [1] Diagnostic upgrades and analysis improvements that support the JRT; [2] Descriptions of new experiments and a brief summary of findings; [3] New analysis of previous experiments; [4] Plans for further data analysis and recommendations for further work; [5] Scientific publications that are derived from or contributed directly to the JRT. The report is organized as follows: Section 1: Describes inter-machine comparisons that were facilitated by the JRT focus. Similarities and differences found on the different facilities are outlined, and plans for additional analysis of data and supporting simulations are described.Section 2: Reviews diagnostic development, experiments and results from C-Mod. C-Mod dedicated 13.1 run days to the JRT divided among 10 experimental proposals. These were organized into three general thrust areas that represent distinct experimental approaches to realizing the regimes called for in the JRT description. Initial comparisons with linear and nonlinear simulation have been carried out for these experiments, and plans for an extensive campaign of analysis have been outlined. Section 3: Reviews results from DIII-D including new experiments, detailed comparisons of simulations to previously collected data and connections between the new work and past research. Four experimental days were dedicated to the JRT in 2012. These included studies of L-modes, H-modes and QH-modes. Section 4: Summarizes new analysis of data collected before the NSTX shutdown. The work focuses on the roles of low and high-k turbulence; collisionality scans and impurity particle transport.

  15. Research

    African Journals Online (AJOL)

    abp

    2015-09-09

    Sep 9, 2015 ... Orthopaedics and Traumatology, Faculty of Medicine, Adiyaman University, 02040 Adiyaman, Turkey,3Department of Orthopedics and. Traumatology, Umraniye Research and Education Hospital, 34899 Istanbul, Turkey, 4Department of Orthopedics and Traumatology, Umraniye. Research and Education ...

  16. Research

    African Journals Online (AJOL)

    The research methodology module was reviewed as part of the overall revision of the undergraduate physiotherapy curriculum of ... Structuring the research methodology module using an EBP teaching framework prepares students to formulate a research question, effectively ... manage, and organise bibliographic citations.

  17. Research

    African Journals Online (AJOL)

    ebutamanya

    2015-05-13

    May 13, 2015 ... Systems (SEEDS)-INDEPTH Network Accra, Ghana, 3KEMRI/Wellcome Trust Research Programme, The Centre of Geographical Medicine Research-. Coast, Kilifi, Kenya, 4Population Health Sciences/Research Support Unit, Faculty of Health Sciences, Aga Khan University- East Africa, Nairobi,. Kenya ...

  18. Research

    African Journals Online (AJOL)

    research process, as part of which students must find and appraise evidence from research.[5] This highlights that teaching research methodology is inclined towards equipping students ... Students believed that evidence-based practice was vital, yet their understanding of the concept was restricted when compared with the.

  19. Research

    African Journals Online (AJOL)

    ebutamanya

    2015-03-02

    Mar 2, 2015 ... this program provided short-term and long-term research training to. US infectious disease fellows who would work on collaborative research projects with Kenyan trainees. Since the program began in. 1988, there have been 56 US trainees, and 13 of these continue to collaborate with Kenyan researchers.

  20. ALCATOR DCT MAGNETIC SYSTEMS DESIGN

    OpenAIRE

    Montgomery, D.; Schultz, O.; Thome, R.

    1984-01-01

    A 2 meter major radius tokamak with 24 (150 x 200 cm) 10 telsa peak field superconducting coils and an all superconductor PF system is described. All coil systems utilize internally-cooled conductor concepts.

  1. Research

    African Journals Online (AJOL)

    abp

    2015-01-19

    Jan 19, 2015 ... in Cameroon. This study aimed at examining the sexual risk behaviours of high school female learners in Mbonge subdivision of rural Cameroon. ... Despite a wealth of research on youth, little research has been done on the sexual ..... Behavior, and Mental Health: a study of University Students in. Uganda.

  2. researchers

    African Journals Online (AJOL)

    African Sociological Review, 7, (2), 2003, pp.149-161. RESEARCH REPORTS. Revisiting “insiders' and 'outsiders' as social researchers. Marlize Rabe .... use of knowledgeable fieldworkers is then examined by focussing on the work ... A study by Russell (1995:p.95–97) on the long-term effects of incestuous abuse.

  3. Research

    African Journals Online (AJOL)

    2014-05-06

    May 6, 2014 ... facilitate and support articulation between the ECT mid-level worker qualification and the professional B EMC degree. Methods. The researchers used an exploratory, sequential mixed-method design, which is characterised by a qualitative phase of research followed by a quantitative phase. This design is ...

  4. Research

    African Journals Online (AJOL)

    In-depth telephonic interviews were voice recorded and transcribed. Through an inductive ... Two research assistants conducted the research to ..... Assistant Nutritionist. 1.25. M. 30.5. Single. BSc Food Science and Technology. Dietitian. 6. M. 25.6. Single. BSc Human Nutrition and Dietetics. Dietitian. 1. M. 29.6. Single.

  5. Research

    African Journals Online (AJOL)

    abp

    Research Team in Maternal and Child Health and Nutrition, Mohammed V. University, Rabat, Morocco. Key words: Breast cancer, risk factor, case-control study. Received: 04/01/2016 - Accepted: 17/03/2016 - Published: 06/05/2016. Abstract.

  6. Research

    Science.gov (United States)

    Mathematics Teaching, 1973

    1973-01-01

    Implications for teachers from Piagetian-oriented piagetian-oriented research on problem solving reported in an article by Eleanor Duckworth are presented. Edward de Bono's Children Solve Problems,'' a collection of examples, is also discussed. (MS)

  7. Research

    African Journals Online (AJOL)

    their academic performance, capabilities and functionings. At a tertiary educational level ... Research indicates that academic stressors, living circumstances, working conditions and where students undertake leisure activities affect academic performance .... Insufficient sleep, mild exhaustion, poor eating habits and little ...

  8. Research

    International Nuclear Information System (INIS)

    1999-01-01

    Subjects covered in this section are: (1) PCAST panel promotes energy research cooperation; (2) Letter issued by ANS urges funding balance in FFTF restart consideration and (3) FESAC panel releases report on priorities and balance

  9. Research

    African Journals Online (AJOL)

    ebutamanya

    2016-03-24

    Mar 24, 2016 ... national non-governmental organization (NGO) ”Arc en Ciel„. This. NGO, which is familiar with research activities, identified the MSM community leaders in the .... whom there is an emotional attachment) in both homosexual and heterosexual populations [14, 19]. Like other reports from. Cameroon [19] and ...

  10. Research

    African Journals Online (AJOL)

    raoul

    2012-01-11

    Jan 11, 2012 ... 1MPH Programme, Department of Community Medicine, University of Zimbabwe, Zimbabwe, 2Department of Epidemiology and Disease Control,. Ministry ... Pan African Medical Journal. 2012; 11: ..... Mufuta Tshimanga: Had oversight of all the stages of the research and critically reviewed the final draft for.

  11. Research

    African Journals Online (AJOL)

    raoul

    2011-08-25

    Aug 25, 2011 ... euthanasia were also queried. Data was analyzed using Epidata, SPSS 16.0 and Microsoft Excel. Results: Thirty-eight (97.4%) of thirty-nine institutions reported using animals for education and/or research. Thirty (76.9%) institutions reported using analgesics or anesthetics on a regular basis. Thirteen ...

  12. Research

    African Journals Online (AJOL)

    abp

    2016-02-01

    Feb 1, 2016 ... University Hospital, DK-5000 Odense, Denmark, 3Center for Global Health, Institute of Clinical Research, University of Southern Denmark, DK-5000. Odense .... BHP is a Danish-Guinean Demographic Surveillance Site with a study-area .... variables such as age groups, previous military duty, history of.

  13. Research

    African Journals Online (AJOL)

    Research. May 2016, Vol. 8, No. 1 AJHPE 37. Students who enrol in occupational therapy (OT) at the. University of Kwa Zulu-Natal (UKZN), Durban, South Africa ... The latter may include becoming familiar with the disintegrating social systems in primary .... They also lacked the skills needed to adapt sessions and failed to ...

  14. Research

    African Journals Online (AJOL)

    raoul

    2011-12-14

    Dec 14, 2011 ... skills through hands-on application of epidemiology to real public health issues. For the most part, residents carry out research projects in priority areas of the districts they are attached, often under direct supervision of the local or provincial health leaders [2]. In Africa, these programs formed a networking ...

  15. Research

    African Journals Online (AJOL)

    abp

    2014-03-21

    Mar 21, 2014 ... Published in partnership with the African Field Epidemiology Network (AFENET). (www.afenet.net). Research ... were intervention strategies for primary health care delivery at the district and community levels ..... to be a gap between policy formation and implementation as only immunization services are.

  16. Research

    African Journals Online (AJOL)

    abp

    2013-03-05

    Mar 5, 2013 ... food market) [10]. There are few studies that provide data on NCDs from Africa and these are mainly from South Africa [11]. In the same vein, research efforts in The .... males, in view of the relationships between obesity, physical inactivity and .... pronged intervention strategies-epidemiological surveillance,.

  17. Research

    African Journals Online (AJOL)

    ebutamanya

    2015-11-23

    Nov 23, 2015 ... 1Amref Health Africa, P.O Box 2773 Dar es Salaam, Tanzania, 2Kilimanjaro Reproductive Health Program, Moshi, Tanzania, 3Population Services. International, Nairobi .... testing, HIV testing history and HIV test results. ..... due to differences in the research designs, nature of population and sample size ...

  18. Research

    African Journals Online (AJOL)

    ebutamanya

    2015-06-22

    Jun 22, 2015 ... collaboration with Makerere University, School of Public Health. We acknowledge The Family Health Research and Development Centre. (FHRDC) Uganda. Supported by Bill & Melinda Gates Institute for. Population & Reproductive Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, ...

  19. Research

    African Journals Online (AJOL)

    abp

    2016-04-14

    Apr 14, 2016 ... Methods. Study design: A mixed method cross-sectional design using both quantitative and qualitative research methods as described by. Hanson et al [33] was employed. Settings: The study was based on data from the midterm evaluation that was conducted between August-December 2012 involving ...

  20. Research

    African Journals Online (AJOL)

    The study followed a qualitative research design using semi-structured interviews with full-time SA- or foreign-qualified specialists at. Kimberley Hospital ... average number of weekly hours spent on undergraduate student training ... The best place to learn is at the bedside; a student should see the patient, read up and ...

  1. Research

    African Journals Online (AJOL)

    the importance of the learning setting (curriculum context), a capability approach to learning (the process), and the production of expert generalists. (the outcome) .... including communication, learning transfer, teamwork, self-confidence, and reciprocal and effective practice.[6-8] Research also shows that PAL provides a.

  2. Research

    African Journals Online (AJOL)

    raoul

    2011-11-14

    Nov 14, 2011 ... Data were collected between February and March 2010 using a questionnaire, designed by the researcher. It comprised two sections; the ..... Bazant ES, Koenig MA, Fotso J-C, Mills S. Women's Use of Private and Government Health Facilities for Childbirth in Nairobi's Informal. Settlements. Stud Fam Plann ...

  3. Research

    African Journals Online (AJOL)

    Research. This article provides a detailed description of the development of an evaluation matrix that represents the organising structure for evaluating the impact of the interdisciplinary health-promotion course on multiple stakeholders. The evaluation was designed to answer the questions relating to the perceptions and ...

  4. Research

    African Journals Online (AJOL)

    2017-03-18

    Mar 18, 2017 ... promote CPD by working in partnership with employers, academic institutions ... SORK, employers and institutions of higher education all have a responsibility towards the culture of lifelong learning. As the ... further approved by the Higher Degrees and Research Ethics Committees of the University of ...

  5. Research

    African Journals Online (AJOL)

    abp

    2014-08-29

    Aug 29, 2014 ... Page number not for citation purposes ... Pan African Medical Journal – ISSN: 1937- 8688 (www.panafrican-med-journal.com). Published in partnership with the African Field Epidemiology Network (AFENET). (www.afenet.net). Research .... and education, hence a higher risk of morbidity and mortality and a.

  6. Research

    African Journals Online (AJOL)

    tions as their reality.[14]. Research context. At Stellenbosch University (SU), Cape Town,. SA, final-year physiotherapy students each spend. 6 weeks at a community site learning to integrate and apply the principles of PHC and community- based rehabilitation. Approximately 5 - 10 clients are seen in their homes per week.

  7. Research

    African Journals Online (AJOL)

    the classroom.[9] Cognitive learning is achieved when students can make connections among and interpret different aspects of a subject to apply what they have learned in other fields of ... the effect of the field trips on the students' perceptions. ... researcher in higher education teaching and learning facilitated the data-.

  8. Research

    African Journals Online (AJOL)

    ebutamanya

    2015-12-02

    Dec 2, 2015 ... It is an important aspect of quality of life which is often neglected by people in this age group, attending physicians and the society as a whole. The study was aimed at determining ... or a trained research assistant for those who could neither read nor write. Consenting individuals above this age who have ...

  9. Research

    African Journals Online (AJOL)

    abp

    2014-01-31

    Jan 31, 2014 ... by Hazarika in a population-based study in India. The researcher noted that patients' preference to the private health facilities was due mainly to their dissatisfaction with the services in the public health facilities [11]. Furthermore, the quality of the services in the private health facilities could also be a major ...

  10. Research

    African Journals Online (AJOL)

    abp

    2017-11-30

    Nov 30, 2017 ... Authors' contributions. All the authors have read and agreed to the final manuscript. Acknowledgments. The author was supported by a postdoctoral fellowship awarded by the South African National Research Foundation (NRF). The content of this manuscript does not necessarily represent the official views.

  11. Research

    African Journals Online (AJOL)

    abp

    2017-12-05

    Dec 5, 2017 ... work is properly cited. Pan African Medical Journal – ISSN: 1937- 8688 ... an unfinished business as dozens of studies reveal millions of children worldwide have not yet benefited from the .... regions included in the research site [24]. Results. In the final analysis, three working themes were generated.

  12. Research

    African Journals Online (AJOL)

    Workshop on {topic}; research project; clinical practical experience. Outputs. Tangible products/by-products of activities (but not whether students learned anything). Certificates of completion; records of actions by participants (i.e. log books); number of students at clinical site. Intermediate outcomes Learning connected to ...

  13. Research

    African Journals Online (AJOL)

    abp

    2017-05-18

    May 18, 2017 ... available to populations of developing countries [2-5]. In 2013, in. Western and Central Europe and ..... initiation among the infected persons in the community. Addressing stigma and educating ... Lifespan/Tufts/Brown Center for AIDS Research (P30AI042853). Tables. Table 1: Baseline characteristics of ...

  14. Research

    African Journals Online (AJOL)

    2014-05-18

    May 18, 2014 ... Research. Practice within the clinical arena is recognised as the best means of socialising students into the physiotherapy profession[1-5] and is known to ..... A ect. Intervention. Overall preparedness. Fig. 1. Means and 95% CIs of the mean scores of each component (n=58; 9 missing). There is a significant ...

  15. Research

    African Journals Online (AJOL)

    YouTube, TED and other podcast websites. Other researchers have also documented their procedures. Corl et al.[5] describe the basic process of producing a podcast, and Jham et al.[6] list a number of universities actively doing podcasts. Besides the lecture podcasts, we have also captured numerous clinical.

  16. Improved Controls for Fusion RF Systems. Final technical report

    International Nuclear Information System (INIS)

    Casey, Jeffrey A.

    2011-01-01

    We have addressed the specific requirements for the integrated systems controlling an array of klystrons used for Lower Hybrid Current Drive (LHCD). The immediate goal for our design was to modernize the transmitter protection system (TPS) for LHCD on the Alcator C-Mod tokamak at the MIT Plasma Science and Fusion Center (MIT-PSFC). Working with the Alcator C-Mod team, we have upgraded the design of these controls to retrofit for improvements in performance and safety, as well as to facilitate the upcoming expansion from 12 to 16 klystrons. The longer range goals to generalize the designs in such a way that they will be of benefit to other programs within the international fusion effort was met by designing a system which was flexible enough to address all the MIT system requirements, and modular enough to adapt to a large variety of other requirements with minimal reconfiguration

  17. Use of reconstructed 3D equilibria to determine onset conditions of helical cores in tokamaks for extrapolation to ITER

    Science.gov (United States)

    Wingen, A.; Wilcox, R. S.; Seal, S. K.; Unterberg, E. A.; Cianciosa, M. R.; Delgado-Aparicio, L. F.; Hirshman, S. P.; Lao, L. L.

    2018-03-01

    Large, spontaneous m/n  =  1/1 helical cores are shown to be expected in tokamaks such as ITER with extended regions of low- or reversed- magnetic shear profiles and q near 1 in the core. The threshold for this spontaneous symmetry breaking is determined using VMEC scans, beginning with reconstructed 3D equilibria from DIII-D and Alcator C-Mod based on observed internal 3D deformations. The helical core is a saturated internal kink mode (Wesson 1986 Plasma Phys. Control. Fusion 28 243); its onset threshold is shown to be proportional to (dp/dρ)/B_t2 around q  =  1. Below the threshold, applied 3D fields can drive a helical core to finite size, as in DIII-D. The helical core size thereby depends on the magnitude of the applied perturbation. Above it, a small, random 3D kick causes a bifurcation from axisymmetry and excites a spontaneous helical core, which is independent of the kick size. Systematic scans of the q-profile show that the onset threshold is very sensitive to the q-shear in the core. Helical cores occur frequently in Alcator C-Mod during ramp-up when slow current penetration results in a reversed shear q-profile, which is favorable for helical core formation. Finally, a comparison of the helical core onset threshold for discharges from DIII-D, Alcator C-Mod and ITER confirms that while DIII-D is marginally stable, Alcator C-Mod and especially ITER are highly susceptible to helical core formation without being driven by an externally applied 3D magnetic field.

  18. Research Research

    African Journals Online (AJOL)

    Research. May 2014, Vol. 6, No. 1 AJHPE 33. Research. Currently, radiography students are faced with the challenge of having to learn factual information, while ... A descriptive exploratory research design was used to collect both ..... Creswell J. Research Design: Quantitative, Qualitative and Mixed Methods Approaches.

  19. Researching research

    DEFF Research Database (Denmark)

    Pais, Alexandre; Valero, Paola

    2012-01-01

    We discuss contemporary theories in mathematics education in order to do research on research. Our strategy consists of analysing discursively and ideologically recent key publications addressing the role of theory in mathematics education research. We examine how the field fabricates its object...... of research by deploying Foucault’s notion of bio-politics - mainly to address the object “learning” - and Žižek’s ideology critique - to address the object “mathematics”. These theories, which have already been used in the field to research teaching and learning, have a great potential to contribute...... to a reflexivity of research on its discourses and effects. Furthermore, they enable us to present a clear distinction between what has been called the sociopolitical turn in mathematics education research and what we call a positioning of mathematics education (research) practices in the Political....

  20. Laudation Laudation

    Science.gov (United States)

    Bychkov, A.

    2015-01-01

    During the opening session of the 2014 IAEA Fusion Energy Conference in St Petersburg, Russian Federation, I was pleased to present the 2013 and 2014 Nuclear Fusion journal prizes. The IAEA's monthly journal, Nuclear Fusion, has been publishing preeminent research in controlled thermonuclear fusion for over 50 years. In 2006, we inaugurated an annual journal prize to recognise outstanding contributions. This prize is presented to the lead author of the paper judged by the journal's Board of Editors to have made the greatest scientific contribution in the two years following its publication. The 2013 prize was awarded to Dennis Whyte, Massachusetts Institute of Technology, for the 2010 paper: 'I-mode: an H-mode energy confinement regime with L-mode particle transport in Alcator C-Mod' [1] This ground breaking paper, presenting results from Alcator C-Mod, enhances our understanding of the formation of energy transport barriers and temperature pedestals, without particle barriers, through the I-mode regime. The discovery of a stationary ELM-free improved confinement regime with no impurity accumulation in a metallic high field tokamak, like ITER, has implications that will stimulate much future research. The 2014 prize was awarded to Philip Snyder, General Atomics, USA, for the 2011 paper: 'A first-principles predictive model of the pedestal height and width: development, testing and ITER optimization with the EPED model' [2]. Pedestal height will have a dramatic impact on overall fusion performance in next-step devices. This exceptional paper presents a compelling model for the edge pedestal width and height based on coupling peeling-ballooning theory for stability and kinetic ballooning transport theory. Comparison is made to experimental observations across a range of devices and convincing agreement is demonstrated. This model, therefore, has the potential to significantly focus the predictions of performance in future devices. I congratulate the prize winners and

  1. Axisymmetric control in tokamaks

    International Nuclear Information System (INIS)

    Humphreys, D.A.

    1991-02-01

    Vertically elongated tokamak plasmas are intrinsically susceptible to vertical axisymmetric instabilities as a result of the quadrupole field which must be applied to produce the elongation. The present work analyzes the axisymmetric control necessary to stabilize elongated equilibria, with special application to the Alcator C-MOD tokamak. A rigid current-conserving filamentary plasma model is applied to Alcator C-MOD stability analysis, and limitations of the model are addressed. A more physically accurate nonrigid plasma model is developed using a perturbed equilibrium approach to estimate linearized plasma response to conductor current variations. This model includes novel flux conservation and vacuum vessel stabilization effects. It is found that the nonrigid model predicts significantly higher growth rates than predicted by the rigid model applied to the same equilibria. The nonrigid model is then applied to active control system design. Multivariable pole placement techniques are used to determine performance optimized control laws. Formalisms are developed for implementing and improving nominal feedback laws using the C-MOD digital-analog hybrid control system architecture. A proportional-derivative output observer which does not require solution of the nonlinear Ricatti equation is developed to help accomplish this implementation. The nonrigid flux conserving perturbed equilibrium plasma model indicates that equilibria with separatrix elongation of at least κ sep = 1.85 can be stabilized robustly with the present control architecture and conductor/sensor configuration

  2. Rehabilitation of the Goal of Ignition, Sober Assessments of the Large Machine Approach to Fusion and the Ignitor Program

    Science.gov (United States)

    Spillantini, P.; Coppi, B.; Ignitor Collaboration

    2017-10-01

    Although the value of investigating the physics of plasmas close to or at ignition condition has never been questioned. The ``relevance'' of efforts with this goal has been too frequently passed under silence by supporters of large scale programs that cannot claim this objective. By now studies of the characteristics of ignited plasmas and of the requirements of power producing reactors have led to conclude that operating at ignition is necessary for a practically useful fusion reactor. The confinement scaling laws, that were identified originally when the line of high field compact experiments began to be proposed in order in order to investigate igniting plasmas, have been rediscovered and confirmed. Both ``Damnatio Memoriae'' and ``Renovatio Memoriae'' episodes have occurred in this context as well as in that of the first introduction of high field superconducting magnet technology in fusion research. The record confinement parameters, beginning to approach the ideal ignition conditions, obtained recently by the Alcator C Mod machine have validated the perspectives of success of the Ignitor experiment.

  3. Development of a Spatially Resolving X-Ray Crystal Spectrometer (XCS) for Measurement of Ion-Temperature (Ti) and Rotation-Velocity (v) Profiles in ITER

    Energy Technology Data Exchange (ETDEWEB)

    Hill, K W; Delgado-Aprico, L; Johnson, D; Feder, R; Beiersdorfer,; Dunn, J; Morris, K; Wang, E; Reinke, M; Podpaly, Y; Rice, J E; Barnsley, R; O' Mullane, M; Lee, S G

    2010-05-21

    Imaging XCS arrays are being developed as a US-ITER activity for Doppler measurement of Ti and v profiles of impurities (W, Kr, Fe) with ~7 cm (a/30) and 10-100 ms resolution in ITER. The imaging XCS, modeled after a PPPL-MIT instrument on Alcator C-Mod, uses a spherically bent crystal and 2d x-ray detectors to achieve high spectral resolving power (E/dE>6000) horizontally and spatial imaging vertically. Two arrays will measure Ti and both poloidal and toroidal rotation velocity profiles. Measurement of many spatial chords permits tomographic inversion for inference of local parameters. The instrument design, predictions of performance, and results from C-Mod will be presented.

  4. An in situ accelerator-based diagnostic for plasma-material interactions science on magnetic fusion devices.

    Science.gov (United States)

    Hartwig, Zachary S; Barnard, Harold S; Lanza, Richard C; Sorbom, Brandon N; Stahle, Peter W; Whyte, Dennis G

    2013-12-01

    This paper presents a novel particle accelerator-based diagnostic that nondestructively measures the evolution of material surface compositions inside magnetic fusion devices. The diagnostic's purpose is to contribute to an integrated understanding of plasma-material interactions in magnetic fusion, which is severely hindered by a dearth of in situ material surface diagnosis. The diagnostic aims to remotely generate isotopic concentration maps on a plasma shot-to-shot timescale that cover a large fraction of the plasma-facing surface inside of a magnetic fusion device without the need for vacuum breaks or physical access to the material surfaces. Our instrument uses a compact (~1 m), high-current (~1 milliamp) radio-frequency quadrupole accelerator to inject 0.9 MeV deuterons into the Alcator C-Mod tokamak at MIT. We control the tokamak magnetic fields--in between plasma shots--to steer the deuterons to material surfaces where the deuterons cause high-Q nuclear reactions with low-Z isotopes ~5 μm into the material. The induced neutrons and gamma rays are measured with scintillation detectors; energy spectra analysis provides quantitative reconstruction of surface compositions. An overview of the diagnostic technique, known as accelerator-based in situ materials surveillance (AIMS), and the first AIMS diagnostic on the Alcator C-Mod tokamak is given. Experimental validation is shown to demonstrate that an optimized deuteron beam is injected into the tokamak, that low-Z isotopes such as deuterium and boron can be quantified on the material surfaces, and that magnetic steering provides access to different measurement locations. The first AIMS analysis, which measures the relative change in deuterium at a single surface location at the end of the Alcator C-Mod FY2012 plasma campaign, is also presented.

  5. CSPM (Center for the Study of Plasma Microturbulence)

    Energy Technology Data Exchange (ETDEWEB)

    Candy, Jeff [General Atomics, San Diego, CA (United States)

    2017-11-13

    This final report for CSPM documents the contributions from General Atomics over the period of the award (15 Feb. 2011 to 14 Feb. 2017). This project focused on the development of gyrokinetic simulation capabilities relevant for the description of particle and energy transport in tokamak plasmas. This included significant comparisons with results on the DIII-D and Alcator C-Mod tokamaks. In addition, advances in a number of theoretical areas (collision operators, discretization methods, transport model recalibration, etc) were also documented and are described herein.

  6. Researcher / Researched: Repositioning Research Paradigms

    Science.gov (United States)

    Meerwald, Agnes May Lin

    2013-01-01

    "Researcher / Researched" calls for a complementary research methodology by proposing autoethnography as both a method and text that crosses the boundaries of conventional and alternative methodologies in higher education. Autoethnography rearticulates the researcher / researched positions by blurring the boundary between them. This…

  7. Investigation of fluctuations in the HDH and H* regime of Wendelstein 7-AS

    International Nuclear Information System (INIS)

    Baeumel, S.; Werner, A.; McCormick, K.

    2003-01-01

    The High Density H-Mode Regime was discovered in Island Divertor operation of the Wendelstein 7-AS (W7-AS)stellerator. This regime is characterized by low impurity, high-energy confinement times - up to twice the value of the International Stellarator Scaling ISS95 - and edge radiated power fractions of up to 90% in detached state. Regarding the enhanced impurity transport at good energy confinement there are similarities to the enhanced D α H-mode found on the Alcator C-Mod tokamak. In W7-AS studies were performed in order to compare the HDH regime with the classical ELM-free discharges (H * ). Although both regimes are similar in collisionality and have almost the same n e (r)- and T e (r)-profile shapes, the H * regime suffers a radiation collapse due to impurity accumulation. The short impurity confinement times in HDH discharges requires enhanced transport at the plasma edge. The cause is not clear and this contribution looks for similarities to the enhanced D α H-mode of Alcator C-Mod, that is, whether quasicoherent modes exist in W7-AS causing enhanced edge transport. Discharges with a variation of magnetic configurations, densities (up to 4.10 20 m -3 ) and powers (up to 3.2 MW absorbed) will be discussed with respect to the different behaviour of fluctuations. (orig.)

  8. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    The research design used in this study is analytical research design. Moreover, the research approach used in the study was a quantitative approach supplemented or complemented by a qualitative research approach. Subjects of the Study and Sampling Techniques. The study was designed to explore the effect of.

  9. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    rts Research Journal. 2015, 4(4): 58-64. ://www.starjournal.org/ ts of Some Species stern Ghats. 577 451, vempu University,. Article Information. Article History: ..... Journal of. Medicinal Plants Research 4(3): 267-270. Johns, T., Duquette, M. (1991). Deficiency of phosphorus in man. The American Journal of Clinical Nutrition ...

  10. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    ere analyzed by descriptive statistics, Pearson Product nd factor analysis. Findings showed that 64.3percent of in Ise Ekiti. The mean score of the respondent's age was re married with ... n, storage of watermelon, market price of watermelon and elon disease .... research objectives and research works related to the issues.

  11. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    Faculty of Education and Behavioral Science,. Abstract. The main purpose of this research was to examine th styles, academic self concept, academic motivation and s sample for this research consisted of 136 from stratified random sampling of which 82 males and 54 students consisting grade 9th and 10th. Data analysis w.

  12. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    . This study focused on assessing the perceptions, prac instruction by primary school teachers. The research type with embedded mixed approach. Data were ga primary school teachers via questionnaire, semi discussion. The reliability ...

  13. Artistic research, context research

    Directory of Open Access Journals (Sweden)

    Ricardo Benjamín Toledo Castellanos

    2012-06-01

    Full Text Available Some concepts in contemporary art works, dealing with some life aspects and passed through the sensitive and expressive test, are formulated in this paper and shed light on the foundation of researches about singular phenomenons of the existence. For this, it is argued that there are researches belonging to arts, fundamental researches that compromise the certainty of the assumptions where the sense system of a context has its bases (epoch, culture, nation, region. These researches come ahead of the researches of the rational-discursive enunciation fields, given that the last ones haven’t passed any protocol accepted yet by any community. To bring into play the certainty is done by a cognitive movement named by Martin Heidegger unconcealment [Unverborgenheit], and it consist on the interruption of the habituality of the beings who form the (trustworthy family setting to put into perspective the fundamental structures that allow to produce its sense. The unconcealment, typical in art and in creative actions, sets up an event that stops the solidity of the established (social, ethical, technical, scientific, philosophical order, and unleashes conditions for changing the lifestyles hold until then.

  14. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    Science, T. Sci. Technol. Study on Silkworm Bed Cleaning. Abiy Tilahun*, Kedir Shifa, Ah. Ethiopian Institute of Agricultural Research, M. Abstract. Bed cleaning is an important ... DOI: http://dx.doi.org/10.4314/star.v4. ISSN: 2226-7522(Print) and .... to them and invariably a part of the feed is left behind on the rearing bed.

  15. Original Research Original Research

    African Journals Online (AJOL)

    User

    2013-03-28

    Mar 28, 2013 ... food production in sub-Saharan Africa coun. (Sanchez, 2010). Soil is the most precious vital natural resource and it must be mana. Original Research .... Exchangeable K and Na were measured by fl photometer. Exchangeable acidity determined by saturating the samples with. KCl solution and titrated with ...

  16. Original Research Original Research

    African Journals Online (AJOL)

    User

    questionnaires and analyzed using cross tab revealed the transfer of ... informal enterprises with the rural economy. Original Research. 95 ... ise from the formal sectors ew (1994) accepts these is study of the dynamics of lared the informal tailoring inputs from intermediary of and this is economic of inputs. According to.

  17. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    rRNA was amplified in MJ Research PTC-225 Peltier. Thermal Cycler. The 27F primer with the sequence. (AGAGTTTGATCMTGGCTCAG) having 20 bases and primer. 1492R with the sequence. (TACGGYTACCTTGTTACGACTT) having 22 bases was used.1ng of template DNA was added to 20 ng of PCR reaction solution.

  18. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    ISSN: 2226-7522(Print) and 2305-. Science, Technology and Arts Research Journ. Sci. Technol. Arts Res. .... did a study on early grade reading and writing. Accordingly, although students in grades 1-3 have been ..... on reading comprehension, vocabulary and grammar sections were developed from chapters covered. In.

  19. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    When the quantitative method was a dominant approach to address the research problem, the qualitative one was used to substantiate the quantitative data. In this study which was conducted at Bahir Dar. University, subjects of the study included 445 the summer modality secondary education prospective teachers of 10.

  20. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    Thirty Grade 4 experimental pre- and post-test research design to ing strategies and fluency as a result of teacher cy tests, two structured classroom observation sed as data collecting instruments. The quantitative and percentages whereas the qualitative ones were ative and qualitative data indicated improvements in use.

  1. Original Research Original Research

    African Journals Online (AJOL)

    User

    2013-05-22

    May 22, 2013 ... and low levels of irrigation, soil degradation, soil erosion, inadequate agricultural research and extension, and constraints in market development. (Alemayehu ..... farm's primary asset. Printed in Australia by BPA Print. Group. Pp. 191. Hazelton Pam and Brian Murphy. (2007). Interpreting Soil. Test Results.

  2. Original Research Original Research

    African Journals Online (AJOL)

    User

    2013-06-20

    Jun 20, 2013 ... great value in Ethiopian socio-economic growt requires small capital, promote inter linkages as it is a base for medium and large enterprises, increased domestic saving investment. Also they help for bal development provision of goods and services. Original Research. 123. 3327 (Online) esearch Journal.

  3. Original Research Original Research

    African Journals Online (AJOL)

    User

    , fatty makeup of compost and raised the tempera of composting dairy manure and bedding by average of 3.4°C during an 8-wk developm period. BD compost preparation are used to. Original Research. 32. 3327 (Online) esearch Journal.

  4. Original Research Original Research

    African Journals Online (AJOL)

    User

    2013-06-25

    Jun 25, 2013 ... the feeding practices (Kassahun, 2000). This involves the use of fodder bank, f trees, agro-industrial by-products such as, seed cake and urea to overcome CP shor. (ILCA, 1990). Supplementation of poor q roughage feed with suitable energy and p. Original Research. 38. 3327 (Online) esearch Journal.

  5. Original Research Original Research

    African Journals Online (AJOL)

    User

    2013-03-30

    Mar 30, 2013 ... cience, Technology and Arts Research. Jan-Mar 2013, .... manner. The 1958/9 curriculum marks the second development in English language education. The third English curriculum appeared in 1963-4. The 1967-8 curriculum is the last ... The students continued using it as a. Medium of Instruction from ...

  6. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    antioxidant activity of the stem bark extract was studied assay. Extract was shown to display a dose dependent f ... play an essential role in the primary health care of 80% the world's underdeveloped and developing countri ... Science, Technology and Arts Research Journ. Sci. Technol. Arts Res. J., April-June 2015, 4.

  7. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    Abstract. This study examined the effects of teacher scaff comprehension in Dona Berber Primary School, Ethiopi were selected using purposive sampling. A quasi research design was employed to examine chang strategies and reading comprehension as a pre-and post-reading comprehension tests checklists, and Focus ...

  8. Original Research Original Research

    African Journals Online (AJOL)

    RAGHAVENDRA

    Ethiopian Institute of Agricultural Research, Kulu. Abstract. There is high wheat yield variation among smallholders in mainly due to socio-economic, farm inputs utiliza characteristics of the farmers. This study identifies the probability of wheat yield tends to be relatively low, med influencing factors. Cross-sectional data ...

  9. Cancer Research

    Science.gov (United States)

    NCI is the nation's leader in cancer research. Learn more about NCI's cancer research areas, key initiatives, progress made in cancer research, and resources for researchers like research tools, specimens and data.

  10. Massachusetts Institute of Technology Plasma Fusion Center, 1988--1989 report to the President

    International Nuclear Information System (INIS)

    1989-07-01

    This report discusses the following topics on fusion energy: cold fusion; alcator confinement experiments; applied plasma physics research; fusion systems; coherent electromagnetic wave generation; and fusion technology and engineering

  11. Research about Research

    OpenAIRE

    2016-01-01

    Conté els articles següents: PhD Selection: Factors to take into account / Natalia Delgado, Tessy Troes, Meghana Sudhindra, and Helena Cuesta -- Portrait of a science disseminator / Beatriz Cabrero Daniel, Alberto Martínez-Rodríguez, Mari Celi Morales Muñoz and Carla Ten Ventura -- Social impact of Artificial Intelligence: Robotics / Kushagra Sharma, Manaswi Mishra, Siddharth Bhardwaj -- Is Interdisciplinary research the way to go? / Adrian Arroyo Perez, Giorgos Neokleous, Pantelis Stylianid...

  12. 2013 Nuclear Fusion Prize Acceptance Speech 2013 Nuclear Fusion Prize Acceptance Speech

    Science.gov (United States)

    Whyte, D.

    2015-01-01

    I would like to express gratitude to the IAEA, the journal Nuclear Fusion and its board for this acknowledgement of work carried out at the MIT Alcator C-Mod tokamak. I must begin by making it clear that this is in no way an award to an individual. The experiments, data analysis and paper were a true collaborative effort from the C-Mod team. It is a honor to work with them and to accept the award on their behalf. I would also like to thank the US Department of Energy for their support in funding this research. The paper describes the exploration of the 'improved' confinement regime dubbed 'I-mode'. The distinguishing feature of this operational mode is a robust boundary pedestal in temperature with the somewhat surprising lack of any form of density pedestal. Thus the regime exhibits an enhanced energy confinement similar to H-mode, roughly double of L-mode at fixed input power, yet has global fuel and impurity particle transport of L-mode. These features are intriguing from a scientific and practical point of view. On the science side it is extremely useful to obtain such a clear demarcation between the energy and particle transport. For example, soon after its discovery, the I-mode was used to extract the observation that the edge T pedestal is the strongest determinant for intrinsic rotation in work by John Rice, Pat Diamond and colleagues. Recent results regarding core transport by Anne White, Nate Howard and colleagues show that I-mode has intriguing properties with respect to core response of fluctuations and profile stiffness. Mike Churchill's recent Ph. D study on C-Mod shows that I-mode exhibits no strong poloidal impurity asymmetry, unlike H-mode. The I-mode posed an interesting test for the peeling-ballooning-KBM model of the pedestal, the subject of the 2014 Nuclear Fusion award of Phil Snyder, and was examined by John Walk and Jerry Hughes showing that in fact the lack of the density pedestal pushed the I-mode far away from the P-B limit, and thus the

  13. ALCBEAM - Neutral beam formation and propagation code for beam-based plasma diagnostics

    Science.gov (United States)

    Bespamyatnov, I. O.; Rowan, W. L.; Liao, K. T.

    2012-03-01

    ALCBEAM is a new three-dimensional neutral beam formation and propagation code. It was developed to support the beam-based diagnostics installed on the Alcator C-Mod tokamak. The purpose of the code is to provide reliable estimates of the local beam equilibrium parameters: such as beam energy fractions, density profiles and excitation populations. The code effectively unifies the ion beam formation, extraction and neutralization processes with beam attenuation and excitation in plasma and neutral gas and beam stopping by the beam apertures. This paper describes the physical processes interpreted and utilized by the code, along with exploited computational methods. The description is concluded by an example simulation of beam penetration into plasma of Alcator C-Mod. The code is successfully being used in Alcator C-Mod tokamak and expected to be valuable in the support of beam-based diagnostics in most other tokamak environments. Program summaryProgram title: ALCBEAM Catalogue identifier: AEKU_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKU_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 66 459 No. of bytes in distributed program, including test data, etc.: 7 841 051 Distribution format: tar.gz Programming language: IDL Computer: Workstation, PC Operating system: Linux RAM: 1 GB Classification: 19.2 Nature of problem: Neutral beams are commonly used to heat and/or diagnose high-temperature magnetically-confined laboratory plasmas. An accurate neutral beam characterization is required for beam-based measurements of plasma properties. Beam parameters such as density distribution, energy composition, and atomic excited populations of the beam atoms need to be known. Solution method: A neutral beam is initially formed as an ion beam which is extracted from

  14. Research organizations

    DEFF Research Database (Denmark)

    Larsen, Bøje; Aagaard, Peter

    in Copenhagen - we argue that a post-rational form of research activity is emerging which revert these features. We term this new type of research "enchanted research", "sciencetainment" and "Mode2-b research". The factors that facilitate this development include the boring style of conventional research...

  15. Research vessels

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, P.S.

    The role of the research vessels as a tool for marine research and exploration is very important. Technical requirements of a suitable vessel and the laboratories needed on board are discussed. The history and the research work carried out...

  16. Research organizations

    DEFF Research Database (Denmark)

    Larsen, Bøje; Aagaard, Peter

    in Copenhagen - we argue that a post-rational form of research activity is emerging which revert these features. We term this new type of research "enchanted research", "sciencetainment" and "Mode2-b research". The factors that facilitate this development include the boring style of conventional research......, growing competition for research funds, more project funding compared to institutional funding and a demand for accountability. Countervailing forces also exist, however....

  17. Explaining Cold-Pulse Dynamics in Tokamak Plasmas Using Local Turbulent Transport Models

    Science.gov (United States)

    Rodriguez-Fernandez, P.; White, A. E.; Howard, N. T.; Grierson, B. A.; Staebler, G. M.; Rice, J. E.; Yuan, X.; Cao, N. M.; Creely, A. J.; Greenwald, M. J.; Hubbard, A. E.; Hughes, J. W.; Irby, J. H.; Sciortino, F.

    2018-02-01

    A long-standing enigma in plasma transport has been resolved by modeling of cold-pulse experiments conducted on the Alcator C-Mod tokamak. Controlled edge cooling of fusion plasmas triggers core electron heating on time scales faster than an energy confinement time, which has long been interpreted as strong evidence of nonlocal transport. This Letter shows that the steady-state profiles, the cold-pulse rise time, and disappearance at higher density as measured in these experiments are successfully captured by a recent local quasilinear turbulent transport model, demonstrating that the existence of nonlocal transport phenomena is not necessary for explaining the behavior and time scales of cold-pulse experiments in tokamak plasmas.

  18. Plasma blob transport in scrape-off layer

    International Nuclear Information System (INIS)

    Ohno, Noriyasu

    2006-01-01

    Scrape off layer (SOL) is an open magnetic field between wall and high temperature core plasma field with magnetic surface. The recent theories, simulation and experimental results of plasma blob transport are described. Characteristic properties and physical mechanism of plasma blob, magnetic structure of divertor, plasma density of SOL in Alcator C-Mod tokamak, analytical model of plasma blob transport, simulation of stability of second-dimension flow of plasma blob, change of the second-dimension structure, the probability density function (PDF), change of plasma parameters in the SOL field of DIII-D, change of ion saturation current observed in confining magnetic field and NAGDIS-II are shown. (S.Y.)

  19. Papers presented at the eleventh topical conference on high-temperature plasma diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    This report contains the following eleven papers presented at the conference: Neutral Beam Diagnostics for Alcator C-Mod; A Study for the Installation of the TEXT HIBP on DIII-D; Time-domain Triple-probe Measurement of Edge Plasma Turbulence on TEXT-U; A Langmuir/Mach Probe Array for Edge Plasma Turbulence and Flow; Determination of Field Line Location and Safety Factor in TEXT-U; Hybrid ECE Imaging Array System for TEXT-U; First Results from the Phase Contrast Imaging System on TEXT-U; A Fast Tokamak Plasma Flux and Electron Density Reconstruction Technique; Time-series Analysis of Nonstationary Plasma Fluctuations Using Wavelet Transforms; Quantitative Modeling of 3-D Camera Views for Tokamak Divertors; and Variable-frequency Complex Demodulation Technique for Extracting Amplitude and Phase Information. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  20. Intra-shot MSE Calibration Technique For LHCD Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Jinseok; Scott, Steve; Shiraiwa, Syun' ichi; Greenwald, Martin; Parker, Ronald; Wallace, Gregory

    2009-11-23

    The spurious drift in pitch angle of order several degrees measured by the Motional Stark Effect (MSE) diagnostic in the Alcator C-Mod tokamak1 over the course of an experimental run day has precluded direct utilization of independent absolute calibrations. Recently, the underlying cause of the drift has been identified as thermal stress-induced birefringence in a set of in-vessel lenses. The shot-to-shot drift can be avoided by using MSE to measure only the change in pitch angle between a reference phase and a phase of physical interest within a single plasma discharge. This intra-shot calibration technique has been applied to the Lower Hybrid Current Drive (LHCD) experiments and the measured current profiles qualitatively demonstrate several predictions of LHCD theory such as an inverse dependence of current drive efficiency on the parallel refractive index and the presence of off-axis current drive.

  1. Papers presented at the eleventh topical conference on high-temperature plasma diagnostics

    International Nuclear Information System (INIS)

    1996-01-01

    This report contains the following eleven papers presented at the conference: Neutral Beam Diagnostics for Alcator C-Mod; A Study for the Installation of the TEXT HIBP on DIII-D; Time-domain Triple-probe Measurement of Edge Plasma Turbulence on TEXT-U; A Langmuir/Mach Probe Array for Edge Plasma Turbulence and Flow; Determination of Field Line Location and Safety Factor in TEXT-U; Hybrid ECE Imaging Array System for TEXT-U; First Results from the Phase Contrast Imaging System on TEXT-U; A Fast Tokamak Plasma Flux and Electron Density Reconstruction Technique; Time-series Analysis of Nonstationary Plasma Fluctuations Using Wavelet Transforms; Quantitative Modeling of 3-D Camera Views for Tokamak Divertors; and Variable-frequency Complex Demodulation Technique for Extracting Amplitude and Phase Information. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database

  2. Observation of Self-Generated Flows in Tokamak Plasmas with Lower-Hybrid-Driven Current

    International Nuclear Information System (INIS)

    Ince-Cushman, A.; Rice, J. E.; Reinke, M.; Greenwald, M.; Wallace, G.; Parker, R.; Fiore, C.; Hughes, J. W.; Bonoli, P.; Shiraiwa, S.; Hubbard, A.; Wolfe, S.; Hutchinson, I. H.; Marmar, E.; Bitter, M.; Wilson, J.; Hill, K.

    2009-01-01

    In Alcator C-Mod discharges lower hybrid waves have been shown to induce a countercurrent change in toroidal rotation of up to 60 km/s in the central region of the plasma (r/a∼<0.4). This modification of the toroidal rotation profile develops on a time scale comparable to the current redistribution time (∼100 ms) but longer than the energy and momentum confinement times (∼20 ms). A comparison of the co- and countercurrent injected waves indicates that current drive (as opposed to heating) is responsible for the rotation profile modifications. Furthermore, the changes in central rotation velocity induced by lower hybrid current drive (LHCD) are well correlated with changes in normalized internal inductance. The application of LHCD has been shown to generate sheared rotation profiles and a negative increment in the radial electric field profile consistent with a fast electron pinch

  3. Low cycle fatigue of alloy 718 in cryogenic environment

    International Nuclear Information System (INIS)

    Vergara Aimone, J.

    1989-01-01

    A specially processed Ni-Fe base superalloy 718 has been selected as a structural material for a critical component in ALCATOR C-MOD, the new fusion experimental facility at the Massachusetts Institute of Technology. Draw bars made out of this material will be subjected to large alternating loads while operating at 77 0 K. Monotonic and cyclic mechanical properties were determined in order to evaluate the reactor's maintenance schedule with special emphasis in developing a Low Cycle Fatigue database for this special alloy. Improved monotonic properties over conventionally heat treated alloy 718 were observed. Partial hardening was observed at 77 0 K at 1% of the fatigue life, while softening was observed at room temperature, both relative to their respective monotonic stress strain curves. The fatigue curves were corrected for non-zero mean stress allowing satisfactory safety margin for the expected alternating stress. (author)

  4. Imaging with Spherically Bent Crystals or Reflectors

    Energy Technology Data Exchange (ETDEWEB)

    Bitter, M; Hill, K W; Scott, S; Ince-Cushman, A; Reinke, M; Podpaly, Y; Rice, J E; Beiersdorfer, P

    2010-06-01

    This paper consists of two parts: Part I describes the working principle of a recently developed x-ray imaging crystal spectrometer, where the astigmatism of spherically bent crystals is being used with advantage to record spatially resolved spectra of highly charged ions for Doppler measurements of the ion-temperature and toroidal plasmarotation- velocity profiles in tokamak plasmas. This type of spectrometer was thoroughly tested on NSTX and Alcator C-Mod, and its concept was recently adopted for the design of the ITER crystal spectrometers. Part II describes imaging schemes, where the astigmatism has been eliminated by the use of matched pairs of spherically bent crystals or reflectors. These imaging schemes are applicable over a wide range of the electromagnetic radiation, which includes microwaves, visible light, EUV radiation, and x-rays. Potential applications with EUV radiation and x-rays are the diagnosis of laserproduced plasmas, imaging of biological samples with synchrotron radiation, and lithography.

  5. Fusion Development Facility Machine Design Aspects

    Science.gov (United States)

    Smith, J. P.; Chan, V. S.; Garofalo, A. M.; Stambaugh, R. D.; Wong, C. P. C.

    2008-11-01

    To fill the gap prior to building a fusion demonstration power plant (DEMO), a Fusion Development Facility (FDF) is proposed. As currently configured, FDF is a copper, water-cooled coil machine capable of running continuously for several weeks with the goal to test several blanket configurations in its lifetime. To accommodate multiple changes in blankets, a machine configuration must be chosen that allows for the efficient remote exchange. The TF coil configuration drives the primary maintenance approach decision. A TF coil with joints similar to DIII-D and Alcator C-Mod, allows for one maintenance approach while a continuously wound TF coil drives a different approach. The base machine design parameters are described. The different machine configuration options are presented which consider the design aspects for the machine including alignment of the first wall and divertor, coolant access, and exchange of the blanket.

  6. Additive Manufacture (3D Printing) of Plasma Diagnostic Components and Assemblies for Fusion Experiments

    Science.gov (United States)

    Quinley, Morgan; Chun, Katherine; Melnik, Paul; Sieck, Paul; Smith, Trevor; Stuber, James; Woodruff, Simon; Romero-Talamas, Carlos; Rivera, William; Card, Alexander

    2016-10-01

    We are investigating the potential impact of additive manufacturing (3D printing) on the cost and complexity of plasma diagnostics. We present a survey of the current state-of-the-art in additive manufacture of metals, as well as the design of diagnostic components that have been optimized for and take advantage of these processes. Included among these is a set of retarding field analyzer probe heads that have been printed in tungsten with internal heat sinks and cooling channels. Finite element analysis of these probe heads shows the potential for a 750K reduction in peak temperature, allowing the probe to take data twice as often without melting. Results of the evaluation of these probe heads for mechanical strength and outgassing, as well as their use on Alcator C-Mod will be presented. Supported by DOE SBIR Grant DE-SC0011858.

  7. Action Research and Interactive Research

    DEFF Research Database (Denmark)

    Svensson, lennart; Nielsen, Kurt Aagaard

    2006-01-01

    The authors present trends in Nordic action research. They ask critical questions in the development towards mode 2 and points out alternative roads for a scientific consolidation of action research and interactive research.......The authors present trends in Nordic action research. They ask critical questions in the development towards mode 2 and points out alternative roads for a scientific consolidation of action research and interactive research....

  8. Researcher Positioning

    DEFF Research Database (Denmark)

    Khawaja, Iram; Mørck, Line Lerche

    2009-01-01

    involvement by the researcher, which challenges traditional perspectives onresearch and researcher positioning. A key point in this regard is the importance ofconstant awareness of and reflection on the multiple ways in which one's positioningas a researcher influences the research process. Studying the other...

  9. Expanding the role of impurity spectroscopy for investigating the physics of high-Z dissipative divertors

    Directory of Open Access Journals (Sweden)

    M.L. Reinke

    2017-08-01

    Full Text Available New techniques that attempt to more fully exploit spectroscopic diagnostics in the divertor and pedestal region during highly dissipative scenarios are demonstrated using experimental results from recent low-Z seeding experiments on Alcator C-Mod, JET and ASDEX Upgrade. To exhaust power at high parallel heat flux, q∥ > 1 GW/m2, while minimizing erosion, reactors with solid, high-Z plasma facing components (PFCs are expected to use extrinsic impurity seeding. Due to transport and atomic physics processes which impact impurity ionization balance, so-called ‘non-coronal’ effects, we do not accurately know and have yet to demonstrate the maximum q∥ which can be mitigated in a tokamak. Radiation enhancement for nitrogen is shown to arise primarily from changes in Li- and Be-like charge states on open field lines, but also through transport-driven enhancement of H- and He-like charge states in the pedestal region. Measurements are presented from nitrogen seeded H-mode and L-mode plasmas where emission from N1+ through N6+ are observed. Active charge exchange spectroscopy of partially ionized low-Z impurities in the plasma edge is explored to measure N5+ and N6+ within the confined plasma, while passive UV and visible spectroscopy is used to measure N1+-N4+ in the boundary. Examples from recent JET and Alcator C-Mod experiments which employ nitrogen seeding highlight how improving spectroscopic coverage can be used to gain empirical insight and provide more data to validate boundary simulations.

  10. Research Design

    DEFF Research Database (Denmark)

    2019-01-01

    Gunnar Scott Reinbacher (editor) Antology.  Research Design : Validation in Social Sciences. Gunnar Scott Reinbacher: Introduction. Research design and validity. 15p Ole Riis: Creative Research design. 16 p Lennart Nørreklit: Validity in Research Design. 24p Gitte Sommer Harrits: Praxeological...... Scott Reinbacher: Multidisciplinary Research Designs in Problem Based Research. The case of an european project on chronical diseases, the Tandem project (Training Alternmative Networking Skills in Diabetes Management). 15p Niels Nørgaard Kristensen: A qualitative bottom up approach to post modern...... knowledge: An integrated strategy for combining "explaining" and "understanding". 22p Heidi Houlberg Salomonsen & Viola Burau: Comparative research designs. 40p Rasmus Antoft & Heidi Houlberg Salomonsen: Studying organizations by a Pragmatic Research Design: the case of qualitative case study  designs. 31p...

  11. Research circles

    DEFF Research Database (Denmark)

    Nordentoft, Helle Merete; Thomsen, Rie; Möller, Jonas

    lifelong guidance policies. This paper presents `research circles´ as a way to develop guidance practices through long-term research relationships between practice and research. Research circles support a bottom up approach to policy development just like ELGPN considers to be necessary and required...... in career guidance development. In the paper we draw on the preliminary findings from an ongoing Nordic project: “The future of career guidance and educational counselling”. Specifically, we explore the career guidance practitioners´ response to research circles as means to professional development. We...... argue that this practicebased way of organizing research facilitates learning, and potentially, qualifies practice. The collaboration between researchers and practitioners in the research circle fosters a joint venture and an academic perspective on practice, which stimulates practitioners to step out...

  12. Research Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Martens, Frederick H. [Argonne National Laboratory; Jacobson, Norman H.

    1968-09-01

    This booklet discusses research reactors - reactors designed to provide a source of neutrons and/or gamma radiation for research, or to aid in the investigation of the effects of radiation on any type of material.

  13. [Genealogical Research.

    Science.gov (United States)

    McClure, Patricia Harlan

    Two Institute papers were concerned with genealogical research. "Manuscripts, Private Papers and Genealogical Research," deals with the handling and evaluation of unpublished and private papers in genealogical research. "The Genealogical Society of the Church of Jesus Christ of the Latter-Day Saints," discusses the Mormon…

  14. Editorial -Research! Research! Research! What are Thou?

    Directory of Open Access Journals (Sweden)

    Ashok Shyam

    2013-04-01

    Full Text Available Being in field of Orthopaedic research since last 6 years, I have personally been witness to the rapid change in landscape of Othopaedic Research and also medical research in general. The sheer volumes of publications is overwhelming to the extent of being mostly ineffective in providing significant positive addition to the current literature. “There are too many variables” is one of my favorite phrase when I start to explain something to myself. Looking at as many variables as we can think of, makes us understand concepts within the limitations of given variables. Something similar to Ashby’s law that we spoke about in last Editorial [1]. However when we try to apply this to word ‘Research’ the amount of subjective stereotype that is associated with the word defeats all attempt to decipher and communicate clearly. Originally word Research derived from French ‘Researche’ simply means ‘Pursuit of Knowledge’. We as medical practitioners in search of better treatment for our patients are always in pursuit of knowledge. This knowledge is mostly build individually and is learned from individual experience and learning. This is a subjective body of knowledge and this is what makes one surgeon better than another. But is this ‘Research’? Yes it is Research and it serves the main purpose of medical research that is to improve the treatment given to patients. However this is a limited form of research, limited by individual’s ability and capacity. It also does not subject itself to rigorous ‘scientific methods’ and may not be acceptable to a community of ‘Modern Researchers’. Another form of Research of pursuit of knowledge is again from the clinics and from reading journals and books. A collaboration of clinical experience and written word adds a more thoughtful way of pursuing knowledge. This I think is the way majority of medical practitioners acquire knowledge. This keeps them updated and also helps them provide good

  15. Research misconduct

    International Nuclear Information System (INIS)

    Gilbert, F.J.; Denison, A.R.

    2003-01-01

    Good research practice is important to the scientific community. An awareness of what constitutes poor practice is important. Various types of research misconduct are defined in this article. The extent of research misconduct in the field of radiology has been assessed by contacting five English language radiology journals. Redundant or duplicate publication has been reported infrequently, Radiology (1), American Journal of Roentgenology (3), Clinical Radiology (3), British Journal of Radiology (2) and European Radiology (1). The issue of how the radiology community might tackle research misconduct is discussed with reference to guidance from the Medical Research Council, the Wellcome Trust and the Committee of Publication Ethics

  16. Descriptive Research

    DEFF Research Database (Denmark)

    Wigram, Anthony Lewis

    2003-01-01

    Descriptive research is described by Lathom-Radocy and Radocy (1995) to include Survey research, ex post facto research, case studies and developmental studies. Descriptive research also includes a review of the literature in order to provide both quantitative and qualitative evidence of the effect...... starts will allow effect size calculations to be made in order to evaluate effect over time. Given the difficulties in undertaking controlled experimental studies in the creative arts therapies, descriptive research methods offer a way of quantifying effect through descriptive statistical analysis...

  17. Research ethics for clinical researchers.

    Science.gov (United States)

    Harnett, John D; Neuman, Richard

    2015-01-01

    This chapter describes the history of the development of modern research ethics. The governance of research ethics is discussed and varies according to geographical location. However, the guidelines used for research ethics review are very similar across a wide variety of jurisdictions. The paramount importance of protecting the privacy and confidentiality of research participants is discussed at length. Particular emphasis is placed on the process of informed consent, and step-by-step practical guidelines are described. The issue of research in vulnerable populations is touched upon and guidelines are provided. Practical advice is provided for researchers to guide their interactions with research ethics boards. Issues related to scientific misconduct and research fraud are not dealt with in this paper.

  18. Research Review: Doing Artistic Research

    Science.gov (United States)

    Serig, Dan

    2012-01-01

    In this review, the author focuses on the pragmatic consideration: How do artists do artistic research? Artistic research in the context of this review is about the connections and relationships among three primary domains: (1) the arts; (2) higher education; and (3) arts education. Broadly stated, all artists do research when they do art--whether…

  19. Research Impact and Educational Research

    Science.gov (United States)

    Oancea, Alis

    2013-01-01

    Based on a 2010-11 study involving senior researchers from seven disciplines, this article explores critically some of the diverse interpretations of impact in different disciplines, sub-fields and modes of research, and researchers' views about how these interpretations articulate with top-down impact agendas and with university structures…

  20. Is operations research really research?

    African Journals Online (AJOL)

    Science [23], is concerned with man-made, artificial phenomena. 2.3 Types of research. If one reads almost any book ... may be considered basic research if the practical application is only potential. 3.2 Practice of operations research .... academics to supplement their salaries. For these academics it is of great advantage if.

  1. Global 3D Braginskii simulations of the tokamak edge region of IWL discharges

    Science.gov (United States)

    Francisquez, M.; Zhu, B.; Rogers, B. N.

    2017-11-01

    A study of plasma turbulence and profile evolution in conditions of low (L-mode) and high (H-mode) confinement at the edge of an axisymmetric, nested circular flux-surface approximation to an inner wall limited (IWL) Alcator C-Mod discharge is presented, using numerical simulations with the global drift-ballooning (GDB) code. GDB solves drift-reduced Braginskii two-fluid equations for electromagnetic low-frequency turbulence in a 3D annulus centered on the last closed flux-surface (LCFS). Three simulations that investigate the conditions of a reference L-mode, a high density, and a high temperature (or H-mode-like) shot were performed using realistic parameters. L-mode transport appears to be largely driven by drift resistive ballooning structures. Its pressure profile exhibits a near-SOL breakpoint that Mirror Langmuir Probes (MLP) detect in C-Mod. The high density simulation sees an increase in the size of convective cells and enhanced turbulent transport, while H-mode conditions develop improved confinement, balanced E × B and ion diamagnetic drifts in the closed-flux region, and spontaneous generation of temperature pedestal with a density pedestal remaining absent. A statistical characterization of the turbulence both in the SOL and the closed-flux region is presented.

  2. Research management and research output

    Directory of Open Access Journals (Sweden)

    Anita Bosch

    2011-12-01

    Full Text Available Purpose: A study was conducted at two merged South African higher education institutions to determine which management factors, as identified in a literature study as well as through a factor analysis of survey data, were predictive of the dependent variable 'research output'. Problem investigated: Research output contributes to creating sustainability of knowledge of management sciences and therefore the active management of research is in the interest of progressive universities. Research management related activities are usually associated with measurable targets, detailed plans, rigorous evaluation and decisive action - all of which are observable (perhaps programmable behaviour also referred to as tangible factors. Authors argue that the tangible factors of any successful institution can be copied, technology can be bought, and in theory you should have an instantly thriving research institution. It is, however, clear that although many institutions have exactly the same technology and structure as their successful competitors, they still fail to succeed in increasing research output. Design and Research methodology or approach: A survey was distributed to n=411 and yielded a 49.6% response rate. A confirmatory reliability analysis as well as a factor analysis was conducted. Findings/implications: The empirical model that was derived through a factor analysis strengthens the argument that both tangible and intangible factors exist in a research environment. Tangible and intangible factors play a different role in predicting research output. The tangible factors are predictors of research output for non-research-active academics. The theoretical research output prediction model highlights predictors such as 'professional activities' and 'individual skills and competence' for specific groupings. The theoretical model indicates that the factors that predict research output are largely intrinsic to a researcher but could also be supported by

  3. Investigation of dynamics of ELM crashes and their mitigation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Pankin, Alexei Y. [Tech-X Corporation, Boulder, CO (United States)

    2015-08-14

    The accurate prediction of H-mode pedestal dynamics is critical for planning experiments in existing tokamaks and in the design of future tokamaks such as ITER and DEMO. The main objective of the proposed research is to advance the understanding of the physics of H-mode pedestal. Through advances in coupled kinetic-MHD simulations, a new model for H-mode pedestal and ELM crashes as well as an improved model for the bootstrap current will be developed. ELMmitigation techniques will also be investigated. The proposed research will help design efficient confinement scenarios and reduce transient heat loads on the divertor and plasma facing components. During the last two years, the principal investigator (PI) of this proposal actively participated in physics studies related to the DOE Joint Research Targets. These studies include the modeling of divertor heat load in the DIII-D, Alcator C-Mod, and NSTX tokamaks in 2010, and the modeling of H-mode pedestal structure in the DIII-D tokamak in 2011. It is proposed that this close collaboration with experimentalists from major US tokamaks continue during the next funding period. Verification and validation will be a strong component of the proposed research. During the course of the project, advances will be made in the following areas; Dynamics of the H-mode pedestal buildup and recovery after ELM crashes – The effects of neutral fueling, particle and thermal pinches will be explored; Dynamics of ELM crashes in realistic tokamak geometries – Heat loads associated with ELM crashes will be validated against experimental measurements. An improved model for ELM crashes will be developed; ELM mitigation – The effect of resonant magnetic perturbations on ELMs stability and their evolution will be investigated; Development of a new bootstrap current model – A reduced model for will be developed through careful verification of existing models for bootstrap current against first-principle kinetic neoclassical simulations

  4. Operational Research

    CERN Document Server

    Almeida, João; Oliveira, José; Pinto, Alberto

    2018-01-01

    This proceedings book presents selected contributions from the XVIII Congress of APDIO (the Portuguese Association of Operational Research) held in Valença on June 28–30, 2017. Prepared by leading Portuguese and international researchers in the field of operations research, it covers a wide range of complex real-world applications of operations research methods using recent theoretical techniques, in order to narrow the gap between academic research and practical applications. Of particular interest are the applications of, nonlinear and mixed-integer programming, data envelopment analysis, clustering techniques, hybrid heuristics, supply chain management, and lot sizing and job scheduling problems. In most chapters, the problems, methods and methodologies described are complemented by supporting figures, tables and algorithms.   The XVIII Congress of APDIO marked the 18th installment of the regular biannual meetings of APDIO – the Portuguese Association of Operational Research. The meetings bring toget...

  5. Researcher positioning

    DEFF Research Database (Denmark)

    Mørck, Line Lerche; Khawaja, Iram

    2009-01-01

    abstract  This article focuses on the complex and multi-layered process of researcher positioning, specifically in relation to the politically sensitive study of marginalised and ‘othered' groups such as Muslims living in Denmark. We discuss the impact of different ethnic, religious and racial...... backgrounds, of membership in a minoritised[i] or majoritised group, and the influence of different theoretical and methodological outlooks on our common goal of trying to transcend existing othering and objectifying representations of Muslims in Western societies. This process sometimes entails a direct...... political and personal involvement by the researcher, which challenges traditional perspectives on research and researcher positioning. A key point in this regard is the importance of constant awareness of and reflection on the multiple ways in which one's positioning as a researcher influences the research...

  6. Immunome Research

    Science.gov (United States)

    Petrovsky, Nikolai

    2005-01-01

    Immunology research has been transformed in the post-genomics era, with high throughput molecular biology and information technologies taking an increasingly central role. This has led to the development of a new area of science termed "Immunomics", that encompasses genomic, high throughput and bioinformatic approaches to immunology. In recognition of the increasing importance of this field, Immunome Research is a new Open Access, online journal, that will publish cutting edge research across the field of Immunomics. Immunome Research will publish a wide range of article types including specialty immunology databases, immunology database tools, immunome epitope research, epitope analysis tools, high-throughput technologies (gene sequencing, microarrays, proteomics), white papers, mathematical and theoretical models, and prediction tools. Immunome Research is the official journal of the International Immunomics Society (IIMMS). PMID:16305754

  7. Centering research

    DEFF Research Database (Denmark)

    Katan, Lina Hauge; Baarts, Charlotte

    idea, insofar as the ways students read and write need altering to correspond to the practice of research and prepare students accordingly. In the paper, we discuss therefore the possible challenges of grounding research-based teaching in reading, thinking and writing, as indicated by our empirical......’ exercises tend to dominate the common understandings of research-based learning. Here we address a specific area of inquiry overlooked by previous studies: whether and how reading, thinking and writing indeed share the same learning potentials as the practical foundation for research-based teaching....... In the humanities and social sciences, integrated acts of reading, writing and thinking account for an obvious and substantial overlap in student and researcher practices, creating a clear opportunity for research-based teaching. Moreover, our empirical data point to reading, thinking and writing as quintessential...

  8. Research methodology

    DEFF Research Database (Denmark)

    Kuada, John

    This book deals with how students should use of research methods in their university projects. It aims at helping students in developing comprehensive research strategies for their projects. It also provides introduction to issues of philosophy of science as applied in the social sciences....... That is it provides them with a fair understanding of the root assumptions that guide researchers in their investigations and how these assumptions inform their theoretical thinking and choice of methods....

  9. Research Review

    OpenAIRE

    Anonymous

    1981-01-01

    Research Reviewed: "Global Modeling After Its First Decade"; "Monthly Food Price Forecasts"; "Costs of Marketing Slaughter Cattle: Computerized versus Conventional Auction Systems"; "Survival Strategies for Agricultural Cooperatives"

  10. Plant Research

    Science.gov (United States)

    1990-01-01

    The Land's agricultural research team is testing new ways to sustain life in space as a research participant with Kennedy Space Center's Controlled Ecological Life Support System (CELSS). The Land, sponsored by Kraft General Foods, is an entertainment, research, and education facility at EPCOT Center, part of Walt Disney World. The cooperative effort is simultaneously a research and development program, a technology demonstration that provides the public to see high technology at work and an area of potential spinoff: the CELSS work may generate Earth use technology beneficial to the hydroponic (soilless growing) vegetable production industries of the world.

  11. Animal research

    DEFF Research Database (Denmark)

    Olsson, I.A.S.; Sandøe, Peter

    2012-01-01

    in research is analyzed from the viewpoint of three distinct ethical approaches: contractarianism, utilitarianism, and animal rights view. On a contractarian view, research on animals is only an ethical issue to the extent that other humans as parties to the social contract care about how research animals...... are faring. From the utilitarian perspective, the use of sentient animals in research that may harm them is an ethical issue, but harm done to animals can be balanced by benefit generated for humans and other animals. The animal rights view, when thoroughgoing, is abolitionist as regards the use of animals...

  12. Clinical Research

    DEFF Research Database (Denmark)

    Christensen, Irene

    2016-01-01

    This paper is about the logic of problem solving and the production of scientific knowledge through the utilisation of clinical research perspective. Ramp-up effectiveness, productivity, efficiency and organizational excellence are topics that continue to engage research and will continue doing so...... for years to come. This paper seeks to provide insights into ramp-up management studies through providing an agenda for conducting collaborative clinical research and extend this area by proposing how clinical research could be designed and executed in the Ramp- up management setting....

  13. Letterform research

    DEFF Research Database (Denmark)

    Beier, Sofie

    2016-01-01

    This paper looks into the history of letterform research and discusses why the discipline has yet to make the big break within design research. By highlighting two of the most popular focus areas (letter distinctiveness and the role of serifs) and by discussing various forms of methodological...... shortcomings, the paper suggests that future research into letterforms should (1) draw on results from the field of reading research (2) be based on test material informed by design knowledge and (3) move away from the former tendency of looking for universal answers....

  14. Researching experiences

    DEFF Research Database (Denmark)

    Gjedde, Lisa; Ingemann, Bruno

    , dialogue, moods, values and narratives have been investigated qualitatively with more than sixty informants in a range of projects. The processual methodological insights are put into a theoretical perspective and also presented as pragmatic dilemmas. Researching Experiences is relevant not only...... for students and researchers in media and communication studies but also for practitioners within the fields of media, communication and experience design....... for researching experiences in a variety of settings ranging from the museum, to news photography, and interactive media. The research led to the development of a set of methodological tools and approaches we term the reflexivity lab. The interaction in the experimental situation between the media and body...

  15. Atomic physics for fusion plasma spectroscopy; a soft x-ray study of molybdenum ions

    International Nuclear Information System (INIS)

    Fournier, K.B.

    1996-01-01

    Understanding the radiative patterns of the ions of heavy atoms (Z approx-gt 18) is crucial to fusion experiments. The present thesis applies ab initio, relativistic calculations of atomic data to modeling the emission of molybdenum (Z = 42) ions in magnetically confined fusion plasmas. The models are compared to observations made in the Alcator C-Mod tokamak (Plasma Fusion Center, Massachusetts Institute of Technology), and the Frascati Tokamak Upgrade. Experimental confirmation of these models allows confidence in calculations of the total molybdenum concentration and quantitative estimates of the total power lost from the plasmas due to molybdenum line radiation. Charge states in the plasma core (Mo 33+ to Mo 29+ ) emit strong x-ray and XUV spectra which allow benchmarking of models for the spatial distribution of highly stripped molybdenum ions; the models only achieve agreement with observations when the rates of indirect ionization and recombination processes are included in the calculation of the charge state distribution of the central molybdenum ions. The total concentration of molybdenum in the core of the plasma is found, and the total power radiated from the plasma core is computed. Observations of line emission from more highly charged molybdenum ions (Mo 36+ to Mo 34+ ) are presented. open-quotes Bulkclose quotes molybdenum charge states (Mo 25+ to Mo 23+ ) emit complicated XUV spectra from a position in the plasma near C-Mod's half radius; spatial profiles of these ions' emission are analyzed. Models for the line-emission spectra of adjacent ions (Mo 28+ to Mo 26+ ) are offered, and the accuracy and limits of ab initio energy level calculations are discussed. open-quotes Edgeclose quotes charge states (Mo 22+ to Mo 15 ) extend to the last closed magnetic flux surface of the C-Mod plasma. The strongest features from these charge states are emitted in a narrow band from ∼70 Angstrom

  16. Research Ethics

    Science.gov (United States)

    Dooly, Melinda; Moore, Emilee; Vallejo, Claudia

    2017-01-01

    Qualitative research, especially studies in educational contexts, often brings up questions of ethics because the study design involves human subjects, some of whom are under age (e.g. data collected in primary education classrooms). It is not always easy for young researchers to anticipate where ethical issues might emerge while designing their…

  17. Research Review

    Science.gov (United States)

    Serig, Dan, Ed.

    2010-01-01

    This research review is dedicated to the memory of William Safire (1929-2009). A visionary leader, Safire brought other visionaries, researchers, educators, artists, and policymakers together to explore the confluence of arts education and neuroscience. He fostered the new field of neuroeducation in his work as chair of The Dana Foundation in…

  18. Research Review

    Science.gov (United States)

    Serig, Dan

    2011-01-01

    In this review, the author explores an often-used process in research--the mind map. He uses this method in his own research and artwork. He also uses this extensively with students, particularly master students when they are trying to surround issues in their thesis projects. Mind maps are closely associated with brainstorming, as brainstorming…

  19. Remote Research

    CERN Document Server

    Tulathimutte, Tony

    2011-01-01

    Remote studies allow you to recruit subjects quickly, cheaply, and immediately, and give you the opportunity to observe users as they behave naturally in their own environment. In Remote Research, Nate Bolt and Tony Tulathimutte teach you how to design and conduct remote research studies, top to bottom, with little more than a phone and a laptop.

  20. Research Article

    African Journals Online (AJOL)

    2016-06-18

    Jun 18, 2016 ... Published o. ABSTRACT. Recommender systems for research pape years more than 170 research papers,paten. Scientific papers recommender systemsare user which are consistent with the users' tastes and users behaviors.Since the volu recommender systemshave not the ability papers according to ...

  1. Centering research

    DEFF Research Database (Denmark)

    Katan, Lina Hauge; Baarts, Charlotte

    ’ exercises tend to dominate the common understandings of research-based learning. Here we address a specific area of inquiry overlooked by previous studies: whether and how reading, thinking and writing indeed share the same learning potentials as the practical foundation for research-based teaching...... and collected 24 portfolios in which students reflect auto-ethnographically on their educational practices. Analyzing this qualitative material, we explore how researchers and students respectively read and write to develop and advance their thinking in those learning processes that the two groups fundamentally...... findings We then propose a set of experimentally designed curricular frameworks that have been shown to alter student engagement in reading and writing, encouraging their learning to become more research-like. Finally, we return to the literature on research-based teaching, asking how an emphasis...

  2. Design Research

    DEFF Research Database (Denmark)

    Design Research is a new interdisciplinary research area with a social science orientation at its heart, and this book explores how scientific knowledge can be put into practice in ways that are at once ethical, creative, helpful, and extraordinary in their results. In order to clarify the common...... aspects – in terms of features and approaches – that characterize all strands of research disciplines addressing design, Design Research undertakes an in depth exploration of the social processes involved in doing design, as well as analyses of the contexts for design use. The book further elicits...... ‘synergies from interdisciplinary perspectives’ by discussing and elaborating on differing academic perspectives, theoretical backgrounds, and design concept definitions, and evaluating their unique contribution to a general core of design research. This book is an exciting contribution to this little...

  3. Research report

    International Nuclear Information System (INIS)

    Whitley, J.E.

    1990-07-01

    The SURRC (Scottish Universities Research and Reactor Centre) is a multidisciplinary research centre shared by a consortium of Scottish Universities. Funding is jointly by the University Funding Committee and commercially from Research Councils, government departments and industry. The focus of research lies in earth, environmental and biomedical sciences. The research activities are discussed under the following headings: environmental radioactivity and nuclear geochemistry, neutron activation analysis, inductively coupled plasma-mass spectrometry, body composition studies, stable isotopes in biological sciences, nuclear physics, luminescence dating and dosimetry radiation effects in electrical insulation, gamma-ray irradiation processing, radiogenic isotopes in geology, stable isotope geology, laser microprobe mass spectrometry for geology and NERC Radiocarbon Laboratory work. There are also reports on the reactor itself; reactor operation, production of radioactive isotopes and application of radioactive tracers. The educational aspects of the Centre, safety aspects, staffing, funding and all publications are reported. (UK)

  4. Survey research.

    Science.gov (United States)

    Alderman, Amy K; Salem, Barbara

    2010-10-01

    Survey research is a unique methodology that can provide insight into individuals' perspectives and experiences and can be collected on a large population-based sample. Specifically, in plastic surgery, survey research can provide patients and providers with accurate and reproducible information to assist with medical decision-making. When using survey methods in research, researchers should develop a conceptual model that explains the relationships of the independent and dependent variables. The items of the survey are of primary importance. Collected data are only useful if they accurately measure the concepts of interest. In addition, administration of the survey must follow basic principles to ensure an adequate response rate and representation of the intended target sample. In this article, the authors review some general concepts important for successful survey research and discuss the many advantages this methodology has for obtaining limitless amounts of valuable information.

  5. Research reactors

    International Nuclear Information System (INIS)

    Merchie, Francois

    2015-10-01

    This article proposes an overview of research reactors, i.e. nuclear reactors of less than 100 MW. Generally, these reactors are used as neutron generators for basic research in matter sciences and for technological research as a support to power reactors. The author proposes an overview of the general design of research reactors in terms of core size, of number of fissions, of neutron flow, of neutron space distribution. He outlines that this design is a compromise between a compact enough core, a sufficient experiment volume, and high enough power densities without affecting neutron performance or its experimental use. The author evokes the safety framework (same regulations as for power reactors, more constraining measures after Fukushima, international bodies). He presents the main characteristics and operation of the two families which represent almost all research reactors; firstly, heavy water reactors (photos, drawings and figures illustrate different examples); and secondly light water moderated and cooled reactors with a distinction between open core pool reactors like Melusine and Triton, pool reactors with containment, experimental fast breeder reactors (Rapsodie, the Russian BOR 60, the Chinese CEFR). The author describes the main uses of research reactors: basic research, applied and technological research, safety tests, production of radio-isotopes for medicine and industry, analysis of elements present under the form of traces at very low concentrations, non destructive testing, doping of silicon mono-crystalline ingots. The author then discusses the relationship between research reactors and non proliferation, and finally evokes perspectives (decrease of the number of research reactors in the world, the Jules Horowitz project)

  6. Research reactors

    International Nuclear Information System (INIS)

    Kowarski, L.

    1955-01-01

    It brings together the techniques data which are involved in the discussion about the utility for a research institute to acquire an atomic reactor for research purposes. This type of decision are often taken by non-specialist people who can need a brief presentation of a research reactor and its possibilities in term of research before asking advises to experts. In a first part, it draws up a list of the different research programs which can be studied by getting a research reactor. First of all is the reactor behaviour and kinetics studies (reproducibility factor, exploration of neutron density, effect of reactor structure, effect of material irradiation...). Physical studies includes study of the behaviour of the control system, studies of neutron resonance phenomena and study of the fission process for example. Chemical studies involves the study of manipulation and control of hot material, characterisation of nuclear species produced in the reactor and chemical effects of irradiation on chemical properties and reactions. Biology and medicine research involves studies of irradiation on man and animals, genetics research, food or medical tools sterilization and neutron beams effect on tumour for example. A large number of other subjects can be studied in a reactor research as reactor construction material research, fabrication of radioactive sources for radiographic techniques or applied research as in agriculture or electronic. The second part discussed the technological considerations when choosing the reactor type. The technological factors, which are considered for its choice, are the power of the reactor, the nature of the fuel which is used, the type of moderator (water, heavy water, graphite or BeO) and the reflector, the type of coolants, the protection shield and the control systems. In the third part, it described the characteristics (place of installation, type of combustible and comments) and performance (power, neutron flux ) of already existing

  7. Researching Undergraduate Social Science Research

    Science.gov (United States)

    Rand, Jane

    2016-01-01

    The experience(s) of undergraduate research students in the social sciences is under-represented in the literature in comparison to the natural sciences or science, technology, engineering and maths (STEM). The strength of STEM undergraduate research learning environments is understood to be related to an apprenticeship-mode of learning supported…

  8. Action Research and Interactive Research

    DEFF Research Database (Denmark)

    First part of the book is written by senior researchers on specific issues like validity, gender, new forms of organisations, methodologies and methods, earlier and new trends. - The second part of the book is written by doctoral students reporting experiences doing action research in their PhD-projects....

  9. Original Research

    African Journals Online (AJOL)

    home

    2014-06-02

    3372 (Online). Science, Technology and Arts Research Journal. Sci. ..... The reason behind these are geographical location, the nature of the forest. (whether it is moist or dry), altitudinal variation, age of the forest, degree of ...

  10. Aging research

    International Nuclear Information System (INIS)

    Ross, D.F. Jr.

    1988-01-01

    The USNRC Office of Nuclear Regulatory Research has developed a program for nuclear plant aging research (NPAR) to achieve an understanding of nuclear plant aging, its potential effects on safety, and methods for its detection and mitigation, sufficient for addressing safety and regulatory issues and supporting regulatory decisions on issues. Specifically, the NRC has aggressive research and regulatory programs associated with aging effects on piping, steam generators, containments, structures, and electrical and mechanical systems and components. In addition to safety assessment for the original license period for nuclear power plants, this aging information will be extremely useful in providing technical bases for efficient and effective regulation associated with possible license extension. This paper discusses the major activities of USNRC sponsored aging research program and recommends an approach to manage and handle aging at nuclear power plants

  11. Research Reports

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Centers for Medicare and Medicaid Services (CMS) research efforts span many topics, methods, and interests. Some projects address the Agencys immediate...

  12. Research Review

    OpenAIRE

    Anonymous

    1986-01-01

    Research Reviewed: "Crop Insurance for Agricultural Development: Issues and Experience"; "Linking Macroeconomic and Agricultural Policies for Adjustments with Growth: The Colombian Experience"; "Removal of Price Supports and Supply Controls for U.S. Tobacco: An Economic Analysis of the Impact"

  13. Research needs

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Research needs were identified during working sessions for several potential separation options. These options include sequestering agents, solvent extraction, membranes, solid sorbents, novel approaches, organic separation and destruction methods, and radiation and chemical stability of separation materials

  14. Research Review

    OpenAIRE

    Anonymous

    1986-01-01

    Research Reviewed: "Sources of International Comparative Advantage: Theory and Evidence"; "Made in Washington: Food Policy and the Political Expedient"; "The Handbook of Econometrics"; "Farm Equipment Innovations in Eastern and Central Southern Africa"

  15. Research materials

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    Development of techniques required for the preparation and characterization of ultrahigh-purity and controlled-impurity research specimens of interest to ORNL and other ERDA installations is described

  16. Disaster Research

    DEFF Research Database (Denmark)

    Given the tendency of books on disasters to predominantly focus on strong geophysical or descriptive perspectives and in-depth accounts of particular catastrophes, Disaster Research provides a much-needed multidisciplinary perspective of the area. This book is is structured thematically around key...... approaches to disaster research from a range of different, but often complementary academic disciplines. Each chapter presents distinct approaches to disaster research that is anchored in a particular discipline; ranging from the law of disasters and disaster historiography to disaster politics...... and anthropology of disaster. The methodological and theoretical contributions underlining a specific approach to disasters are discussed and illustrative empirical cases are examined that support and further inform the proposed approach to disaster research. The book thus provides unique insights into fourteen...

  17. Researching Experiences

    DEFF Research Database (Denmark)

    Gjedde, Lisa; Ingemann, Bruno

    , dialogue, moods, values and narratives have been investigated qualitatively with more than sixty informants in a range of projects. The processual methodological insights are put into a theoretical perspective and also presented as pragmatic dilemmas.      Researching Experiences is relevant not only...... for students and researchers in media and communication studies but also for practitioners within the fields of media, communication and experience design....... for researching experiences in a variety of settings ranging from the museum, to news photography, and interactive media. The research led to the development of a set of methodological tools and approaches we term the ReflexivityLab. The interaction in the experimental situation between the media and body...

  18. Air Research

    Science.gov (United States)

    EPA's air research provides the critical science to develop and implement outdoor air regulations under the Clean Air Act and puts new tools and information in the hands of air quality managers and regulators to protect the air we breathe.

  19. Latvian research

    International Nuclear Information System (INIS)

    1992-12-01

    The Latvian Council of Science asked the Danish Research Councils and the Danish Academy for Technical Sciences for help in evaluating Latvian scientific research. The background for this request was the Latvian desire to stimulate an approach towards full integration in the European society. Based on reports, site visits and interviews, 19 panels of experts covering all subject areas prepared evaluation reports. These detailed evaluations of actual research projects are included in the publication in addition to general recommendations. The panels recommend that Latvian authorities take into consideration when planning scientific research, especially with regard to those branches which contribute to the industrial development and social and economic sciences, that a balance should be made between long range basic, and short range applied, science activities. Despite the very serious economic conditions in Latvia, it was also advised that immediate measures should be taken to ensure a stable funding of the research system as the future development of Latvian society is dependent on the stability and high quality of its research activities. Other recommendations are given in detail. (AB)

  20. Researching experiences

    DEFF Research Database (Denmark)

    Gjedde, Lisa; Ingemann, Bruno

    In the beginning was - not the word - but the experience. This phenomenological approach provides the basis for this book, which focuses on how a person-in-situation experiences and constructs meaning from a variety of cultural visual events. This book presents video-based processual methods...... for researching experiences in a variety of settings ranging from the museum, to news photography, and interactive media. The research led to the development of a set of methodological tools and approaches we term the reflexivity lab. The interaction in the experimental situation between the media and body......, dialogue, moods, values and narratives have been investigated qualitatively with more than sixty informants in a range of projects. The processual methodological insights are put into a theoretical perspective and also presented as pragmatic dilemmas. Researching Experiences is relevant not only...

  1. Quantitative research.

    Science.gov (United States)

    Watson, Roger

    2015-04-01

    This article describes the basic tenets of quantitative research. The concepts of dependent and independent variables are addressed and the concept of measurement and its associated issues, such as error, reliability and validity, are explored. Experiments and surveys – the principal research designs in quantitative research – are described and key features explained. The importance of the double-blind randomised controlled trial is emphasised, alongside the importance of longitudinal surveys, as opposed to cross-sectional surveys. Essential features of data storage are covered, with an emphasis on safe, anonymous storage. Finally, the article explores the analysis of quantitative data, considering what may be analysed and the main uses of statistics in analysis.

  2. Management research

    International Nuclear Information System (INIS)

    Berry, M.

    1988-01-01

    The 1988 progress report of the Management Research center (Polytechnic School, France), is presented. The Center research programs include the management of different organizations, such as industry, administrative systems, hospitals and cultural systems. The investigations performed concern the improvement and better knowledge of the new methods of analysis: the role of the speech, the logic conflicts; the crisis development, symptoms and effects; the relationship between the management practices and the prevailing ideas or theories. The approach adopted by the scientists involves the accurate analysis of the essential management activities. The investigations carried out in 1988 are summarized. The published papers, the congress communications and the thesis are listed [fr

  3. Research Results

    Science.gov (United States)

    2011-12-01

    Research on Global Carbon Emission and Sequestration NSFC Funded Project Made Significant Progress in Quantum Dynamics Functional Human Blood Protein Obtained from Rice How Giant Pandas Thrive on a Bamboo Diet New Evidence of Interpersonal Violence from 129,000 Years Ago Found in China Aptamer-Mediated Efficient Capture and Release of T Lymphocytes on Nanostructured Surfaces BGI Study Results on Resequencing 50 Accessions of Rice Cast New Light on Molecular Breeding BGI Reports Study Results on Frequent Mutation of Genes Encoding UMPP Components in Kidney Cancer Research on Habitat Shift Promoting Species Diversification

  4. Tungsten as First Wall Material in Fusion Devices

    International Nuclear Information System (INIS)

    Kaufmann, M.

    2006-01-01

    In the PLT tokamak with a tungsten limiter strong cooling of the central plasma was observed. Since then mostly graphite has been used as limiter or target plate material. Only a few tokamaks (limiter: FTU, TEXTOR; divertor: Alcator C-Mod, ASDEX Upgrade) gained experience with high-Z-materials. With the observed strong co- deposition of tritium together with carbon in JET and as a result of design studies of fusion reactors, it became clear that in the long run tungsten is the favourite for the first-wall material. Tungsten as a plasma facing material requires intensive research in all areas, i.e. in plasma physics, plasma wall-interaction and material development. Tungsten as an impurity in the confined plasma reveals considerable differences to carbon. Strong radiation at high temperatures, in connection with mostly a pronounced inward drift forms a particular challenge. Turbulent transport plays a beneficial role in this regard. The inward drift is an additional problem in the pedestal region of H-mode plasmas in ITER-like configurations. The erosion by low energy hydrogen atoms is in contrast to carbon small. However, erosion by fast particles from heating measures and impurity ions, accelerated in the sheath potential, play an important role in the case of tungsten. Radiation by carbon in the plasma boundary reduces the load to the target plates. Neon or Argon as substitutes will increase the erosion of tungsten. So far experiments have demonstrated that in most scenarios the tungsten content in the central plasma can be kept sufficiently small. The material development is directed to the specific needs of existing or future devices. In ASDEX Upgrade, which will soon be a divertor experiment with a complete tungsten first-wall, graphite tiles are coated with tungsten layers. In ITER, the solid tungsten armour of the target plates has to be castellated because of its difference in thermal expansion compared to the cooling structure. In a reactor the technical

  5. Original Research

    African Journals Online (AJOL)

    home

    2014-12-23

    3372 (Online). Science, Technology and Arts Research Journal. Sci. Technol. Arts Res. J., Oct-Dec 2014, 3(4): 71-78 ..... However, the reason behind the taste chemistry for the pork in the present study was not clear except.

  6. Original Research

    African Journals Online (AJOL)

    home

    2014-12-22

    3372 (Online). Science, Technology and Arts Research Journal. Sci. Technol. Arts Res. J., Oct-Dec 2014, 3(4): 122-134 ...... species of these two families. The reason behind the fact that samma (Urtica simensis) was cited by most.

  7. Original Research

    African Journals Online (AJOL)

    2013-12-17

    .starjournal.org ... Soil pH can vary from 7 to 8.3 when only. Original Research. DOI: http://dx.doi.org/10.4314/star.v2i4.9 ...... to solve fertility management related problems in the area. Thus identification of the reasons behind.

  8. Research Article

    African Journals Online (AJOL)

    2016-06-05

    Jun 5, 2016 ... Palladium (Pd) accumulates in many organs and renders many deleterious effects. Although the Pd toxicity has been documented, the precise mechanism of Pd toxicity still needs to be elucidated. In the current research, a hepatotoxicity mechanism of Pd has been investigated. Our findings clearly indicate ...

  9. Research Paper:

    African Journals Online (AJOL)

    Shanu

    2014-01-08

    Jan 8, 2014 ... Forty years in capsaicin research for sensory pharmacology and physiology. Neuropeptides 38:377-384. Thomas E (2002). Tissue culture studies in Arachis hypogea L. and. Vignaunguiculata (L.) Walp. for micropropagation and cell line selection for amino acid overproduction, Ph.D. Thesis, University of.

  10. Research Article

    African Journals Online (AJOL)

    2018-01-01

    Jan 1, 2018 ... ferrocene derivatives and potentially all analogous organometallic compounds. The results confirm the utility of use of square wave voltammetry techniques for measuring octanol-water partition coefficients of ferrocene derivatives. 5. ACKNOWLEDGEMENT. This research was financed by the laboratory of ...

  11. Research Blog

    NARCIS (Netherlands)

    Jautze, K.J.

    2014-01-01

    Welcome to my personal research blog. I'm a PhD candidate from the Netherlands who has an interest in language and literature. In the project The Riddle of Literary Quality my colleagues and I explore the assumption that formal characteristics play a role in the aesthetic appreciation of novels. In

  12. Research Article

    African Journals Online (AJOL)

    2016-06-11

    Jun 11, 2016 ... This research aimed to study the effects of window position on natural cross ventilation in Vernacular architecture of .... sustainable development and keep construction in accordance with the principles of climate. 2 Qanbari and. Sharif. Qajeh. Pasha, 2013. The use of vernacular architecture in the design of.

  13. Research Article

    African Journals Online (AJOL)

    2016-06-25

    Jun 25, 2016 ... This article aims at evaluating the fun oftware which are employed for approximate solution in optimization been produced least squares by usual methods for linear and non enetic algorithm in this research. t Squares, Genetic Algorithm, Linear Model, Nonlinear Model, S dence, e-mail: c.author@mail.com.

  14. original research

    African Journals Online (AJOL)

    jenny

    Original Research: Computer-based learning for the enhancement of breastfeeding training. 2009;22(3) ... Conclusion: It is recommended that validated computer-based breastfeeding training modules be integrated as part of multi-media methods .... training and consultations at community and individual level. 3. 0.

  15. Research Article

    African Journals Online (AJOL)

    2016-01-01

    Jan 1, 2016 ... ABSTRACT. One of the hottest issues in the recent environmental research worldwide has become the harmful effects of climate change on the ecosystems and environment due to global warming. Bangladesh is one of the most vulnerable countries not only in the South East Asia but also in the world.

  16. Research Article

    African Journals Online (AJOL)

    1 janv. 2017 ... Agronomy Departement, Fac. Lif. 2. Ecology and Biology Department, Fac. 3. National Center for Seed and Plants Contr. Received: 05 September 2016 / Accepted: 1. ABSTRACT. This research was conducted to screen populations of bread wheat (Triticum aesti. The results indicated the presence of suffic.

  17. Research Summaries

    Science.gov (United States)

    Brock, Stephen E., Ed.

    2010-01-01

    This column features summaries of research articles from 3 recent crisis management publications. The first, "School Shootings and Counselor Leadership: Four Lessons from the Field" summarized by Kristi Fenning, was conducted as the result of the increased demand for trained crisis personnel on school campuses. Survey participants were…

  18. Research Article

    African Journals Online (AJOL)

    2016-06-18

    Jun 18, 2016 ... different modes of equations is used in a number of semi-empirical equations. Due to the high pressure, semi-empirical equations can not predict the solubility of solids as well. The cubic equations of state have been used by many researchers because of their simplicity, but these equations face problems ...

  19. Population Research.

    Science.gov (United States)

    National Inst. of Child Health and Human Development (NIH), Bethesda, MD.

    The scope of population research as carried on by the National Institute of Child Health and Human Development (NICHD) is set forth in this booklet. Population problems of the world, United States, and the individual are considered along with international population policies based on voluntary family planning programs. NICHD goals for biological…

  20. Energy research

    International Nuclear Information System (INIS)

    1979-03-01

    Status reports are given for the Danish Trade Ministry's energy research projects on uranium prospecting and extraction, oil and gas recovery, underground storage of district heating, electrochemical energy storage systems, wind mills, coal deposits, coal cambustion, energy consumption in buildings, solar heat, biogas, compost heat. (B.P.)

  1. RESEARCH ARTICLE

    Indian Academy of Sciences (India)

    Navya

    2012; Thomas et al. 2016). As IGF1 plays crucial role in almost all body functions, including, growth, reproduction and metabolism, the current research was designed to investigate the nucleotide sequences ..... Rep. 39, 9801–9807. Koohmaraie M., Shackelford S. D., Wheeler T. L., Lonergan S. M. and Doumit M. E. 1995 A.

  2. Research Article

    African Journals Online (AJOL)

    2016-06-18

    Jun 18, 2016 ... ABSTRACT. Users encounter a huge volume of papers i. IEEE Explore, ACM Digital library, Goo make some difficulties for researcher. Recommender systems contain successful their priorities. These systems present a p special kind of relevant data or thei. Recommendersystem based on personaliza.

  3. Research medicine

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    Highlights of the research effort during 1978 and 1979 include the development and use of a 280-crystal position tomograph; use of 11 C-labeled methionine in studies of heart metabolism and brain metabolism in humans; and studies of the megakaryocytic cell system

  4. Research Article

    African Journals Online (AJOL)

    2016-06-18

    Jun 18, 2016 ... Research Article. Journal of Fundamental and Applied Sciences is licensed under a Creative Commons Attribution-NonCommercial 4.0. International ... and breakthrough for human not only in some location and for some year rather for the ... they are used for the new source for building a new structure.

  5. Original Research

    African Journals Online (AJOL)

    home

    2014-12-21

    Dec 21, 2014 ... ISSN: 2226-7522(Print) and 2305-3372 (Online). Science, Technology and Arts Research Journal. Sci. Technol. Arts Res. J., Oct-Dec 2014, 3(4): 01-09. Journal Homepage: http://www.starjournal.org/. Correlation and Divergence Analysis for Phenotypic Traits in Sesame. (Sesamum indicum L.) Genotypes.

  6. Rainfall Research.

    Science.gov (United States)

    Melber, Leah M.

    2003-01-01

    Presents procedures for weather studies as exciting and relatively simple research projects for students to perform. Expects that students gain an accurate view of the scientific process in addition to real-world experience as they face challenging setbacks and make unexpected discoveries along the way. Includes cross-curricular applications.…

  7. Quantitative research

    DEFF Research Database (Denmark)

    Wigram, Anthony Lewis

    2003-01-01

    possible and desirable. It is not just a type of research done in a laboratory, or by PhD students. Some for of reliable measurement can be applied to many clinical situationsto evaluate the effects of therapy over time, or the difference between clients who receive therapy and those who don't. Evaluating...

  8. Original Research

    African Journals Online (AJOL)

    home

    2014-02-18

    Feb 18, 2014 ... ISSN: 2226-7522(Print) and 2305-3327 (Online). Science, Technology and Arts Research Journal. Sci. Technol. Arts Res. J., Jan-March 2014, 3(1): 08-13. Journal Homepage: http://www.starjournal.org/. In Vitro Anticancer Activity of Ethanolic Extract of Euphorbia hirta (L.) Anitha P1*, Geegi PG2, Yogeswari ...

  9. Original Research

    African Journals Online (AJOL)

    home

    2014-03-17

    Mar 17, 2014 ... ISSN: 2226-7522(Print) and 2305-3327 (Online). Science, Technology and Arts Research Journal. Sci. Technol. Arts Res. J., Jan-March 2014, 3(1): 53-56. Journal Homepage: http://www.starjournal.org/. Measurement of Turbid Body Optical Properties Using Attenuation of Laser. Light Intensity Techniques.

  10. Original Research

    African Journals Online (AJOL)

    home

    2014-03-25

    Mar 25, 2014 ... ISSN: 2226-7522(Print) and 2305-3327 (Online). Science, Technology and Arts Research Journal. Sci. Technol. Arts Res. J., Jan-March 2014, 3(1): 84-89. Journal Homepage: http://www.starjournal.org/. Effect of Variety and Storage on the Tuber Quality of Potatoes Cultivated in the Eastern Highlands of ...

  11. Research Article

    African Journals Online (AJOL)

    2016-06-13

    Jun 13, 2016 ... emerging drug-resistant pathogens in research programme around the world. This article reviews the .... classes are as follows: a) ß-Lactams (Penicillins, Cephalosporins, Monobactams and Carbapenems) .... Vancomycin Resistant Enterococci (VRE), Pseudomonas aeruginosa and Candida albicans, etc.

  12. Research Article

    African Journals Online (AJOL)

    2016-01-01

    Jan 1, 2016 ... One of the hottest issues in the recent environmental research worldwide has become the harmful effects of climate change on the ecosystems and environment due to global warming. Bangladesh is one of the ... atmosphere during the last decades has been extremely important and the ultimate result is.

  13. Research Article

    African Journals Online (AJOL)

    Department of Physics, Science and Research Branch, Islamic Azad University, Iran. Published online: 05 June 2016. ABSTRACT. YBCO specimens along with different amounts of ... should trigger a great technological revolution. To enable the emerging new technologies, the superconducting materials with a superior ...

  14. Research Article

    African Journals Online (AJOL)

    2016-06-11

    Jun 11, 2016 ... Journal of Fundamental and Applied Sciences is licensed under a Creative Commons Attribution-NonCommercial 4.0 ... Hence, a lot of researches have done to improve the braces to achieve the ideal behavior. In connection of Gusset plate, with analysis of cycle tensile and pressure forces can address to ...

  15. RESEARCH ARTICLE

    Indian Academy of Sciences (India)

    Navya

    research model. Therefore, the objectives of the current study were: 1/ to determine the complete cDNA sequences of porcine AhR and ARNT; 2/ to compare the AhR and ARNT. cDNA sequences with ... The study was approved by the Local Ethical Commission for Animal Experiments of the. University of Warmia and ...

  16. Original Research

    African Journals Online (AJOL)

    home

    2014-03-15

    Mar 15, 2014 ... Abstract. Article Information. This research paper deals with the development of supplier selection methodology for an organization. In today's dynamic environment supplier selection decision presents organizations with a complex scenario and the age old tradition of selecting suppliers based on solitary ...

  17. Original Research

    African Journals Online (AJOL)

    2013-09-18

    Sep 18, 2013 ... 1998) and involves the movement of water along evapotranspiration, precipitation, surface runoff, subsurface flow, and groundwater pathways. Evapotranspiration (ET) is usually the largest component of the hydrologic cycle, given that most precipitation that falls on land is returned to the. Original Research ...

  18. Research Article

    African Journals Online (AJOL)

    2017-01-01

    Jan 1, 2017 ... temperature, Gibbs free energy of dissociation of the γ matrix to form γ′, nucleation rate, effective diffusivity and interfacial energy. Nucleation ... Libraries Resource Directory. We are listed under Research ..... Many authors are of a view that a trade off b/w diffusion and undercooling rule the formation of the ...

  19. Original Research

    African Journals Online (AJOL)

    2012-12-15

    Dec 15, 2012 ... Department of Special Needs Education, College of Education and Behavioral Sciences,. Haramaya ... (learning to learn). Similarly, Good and Brophy. (2006) reported that one important variable that contributed to students' achievement is the involvement of .... research in the area of active learning.

  20. RESEARCH REPORTS

    African Journals Online (AJOL)

    concluded that self-managing teams tend to increase group performance. How- ever, some researchers have found that group cohesiveness is only positively related to performance if the group's goals include high performance. The type of health facility or work setting did not have a strong relationship with productivity.

  1. RESEARCH ARTICLE

    Indian Academy of Sciences (India)

    USER

    RESEARCH ARTICLE. Loss of smooth muscle myosin heavy chain results in the bladder and stomach developing lesion during mouse fetal development in mice. Running title. Bladder and stomach lesion without SM-MHC. MEIJUAN LI, SHILI LI, YU RAO, SHENG CUI, KEMIAN GOU*. State Key Laboratory of ...

  2. RESEARCH ARTICLE

    Indian Academy of Sciences (India)

    Navya

    RESEARCH ARTICLE. Expression analysis of Argonaute, Dicer-like and .... provided a foundation for future functional genomics studies of transcriptional silencing-associated gene families in ..... developmental and stress responses, antiviral immune responses and chromatin structure. These genes can affect the growth, ...

  3. Research Article

    African Journals Online (AJOL)

    1 janv. 2016 ... Keywords: thermal energy; solar collector plane; air; simulation; outlet temperature. Author Correspondence, e-mail: ghodbanemokhtar39@yahoo.com doi: http://dx.doi.org/10.4314/jfas.v8i1.3. Journal of Fundamental and Applied Sciences. ISSN 1112-9867. Available online at http://www.jfas.info. Research ...

  4. Research Article

    African Journals Online (AJOL)

    2016-06-18

    Jun 18, 2016 ... IMPROVEMENT OF RECOMMENDER SYSTEMS CONSIDERING BIG DATA OF. USERS' ... In this condition, the large volume of data and its increasing process make users face with the problem of ... This research includes the following hypotheses and after implementation and applying the system, we ...

  5. Research supervision

    African Journals Online (AJOL)

    Bachelor of Nursing: Advanced Practice (BNAP) degree, and 44.6% (n=25) had an Honours degree in nursing. The sociodemographic characteristics of the sample are given in Table 1. Research supervisor skills. One of the areas explored in this study is the students' perception of their supervisors' skills and knowledge of ...

  6. Energy research

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    The Ministry of Trade and Industry in Finland has the main responsibility for energy policy planning. An important and integral part of this activity is energy research and development. In 1988 the ministry consolidated most of the publicly funded energy research under ten five-year programmes. Formally these programmes will be completed by the end of 1992 and will be fully reported on during 1993, both in Finnish and English. A new set of energy technology programmes has been organized. The second generation energy technology programmes will start in 1993 and continue up to 1998. Within general R and D policy, the government of Finland has decided to establish a national innovation strategy, which aims to support our economic and industrial development objectives. Energy R and D will be an integral part of this national innovation strategy. The primary objectives of energy research have served the development of national energy policy. Finland has a long tradition of promoting efficient energy use, renewable energy sources and environmentally benign energy production technology. In efficient energy use Finland has specialized in e.g. district heating and energy conservation in the pulp and paper industry and in buildings. Our national expertise within energy production includes areas such as the combustion and gasification of solid fuels, biomass energy etc. In future, global market development will plan an increasing role when energy research activities are focused. The global marketplace for energy technology products is undergoing rapid expansion and opening up to new countries and manufacturers. Thus the economic integration and globalization of energy technology have become more and more relevant, and international collaboration in these fields will become an ever higher priority in Finland.

  7. Nutrition Research.

    Science.gov (United States)

    1983-10-01

    Athletic Performance 71% Nutrition and Coronary Heart Disease 68% Weight Control 67% Nutrition and Cancer 61% Sugar and Fiber in the Diet 46% Vegetarianism ...interested 4 0 .9% D. Not interested E. Don’t know 20. Diet , Nutrition and Athletic Performance 20 .9%A. Fairly interested 29 .3% B. Moderately interested...identify by block number) The objectives of this research centered in two major areas. A computerized nutritional analysis of the diet offered to USAFA

  8. Dialogue Research

    DEFF Research Database (Denmark)

    Duelund, Peter

    1991-01-01

    Departing from Anthony Giddens´s theory of structuration and the concept double hermeneutics and Jürgen Habermas´s Theory of Communicative Actions the article specifies theories and methods af dialogue as method in the humanities and social sciences. The article concludes by pointing at dialogues...... as a new theoretical, methodological and empirical research concept i an society where the traditional planning instruments have failed....

  9. Research Methods

    Science.gov (United States)

    1992-01-01

    WasI* Ion Headquarters Services. Directorate for Information Operations anc: 1fngton, VA 22202-4302, and to the Office of Management and Budget...Post . associate editors. Jeffrey D. Orossman and Jan Walravsn. 0. ca. -- (Defense research series ; v. 31 "Publisheb in cooperat ion with NATO...In S.S. Williamson, M. Hoke, G. Stroink, & M. Kotani (Eds.), Advances in biomagnetism . New York: Plenum. Lewis, G.W., Trejo, L.J., Nunez, P

  10. RESEARCH COMMUNITIES

    Directory of Open Access Journals (Sweden)

    HUGO ESCOBAR-MELO

    2006-05-01

    Full Text Available This article constitutes an anthology of the research in the Department of Psychology of the UniversidadJaveriana and it takes as point of consultations the book Saber, sujeto y sociedad: Una década de investigación enPsicología published in the year 2006 by the Editorial Pontificia Universidad Javeriana as a collective work;it shows the research itinerary of the groups and authors which have worked in multiple problematicnucleus like the affective bonds in terms of emotional security and care, the psychological welfare as axleof the psychology of the health, the meanings and bonds to build cultures of peace, the public opinionthat mobilizes different senses in the world, the culture of the transport, the subjetivation and the speechthat mean to the work, the experimented body in the woman, the kidnapping and their ghost of thedeath, the family as a person networks linked by the language, person, relationships and psychic operation,quality of life, numeric thought, experimental psychology and cognitive neuropsycology.Without a doubt all these problematic nucleus seemingly diverse but crossed by the significance andsignificant implication, they have conformed a true disciplinary intersection, to the style of the geometric,convergent and strong cobwebs of the spiders. It also includes the present anthology, the basic principlesof a research culture and their most visible production in the Universitas Psychologica magazine.

  11. Researching Experiences

    DEFF Research Database (Denmark)

    Gjedde, Lisa; Ingemann, Bruno

    In the beginning was - not the word - but the experience. This phenomenological approach provides the basis for this book, which focuses on how a person-in-situation experiences and constructs meaning from a variety of cultural visual events. This book presents video-based processual methods for ...... for students and researchers in media and communication studies but also for practitioners within the fields of media, communication and experience design.......In the beginning was - not the word - but the experience. This phenomenological approach provides the basis for this book, which focuses on how a person-in-situation experiences and constructs meaning from a variety of cultural visual events. This book presents video-based processual methods...... for researching experiences in a variety of settings ranging from the museum, to news photography, and interactive media. The research led to the development of a set of methodological tools and approaches we term the ReflexivityLab. The interaction in the experimental situation between the media and body...

  12. Federal research

    International Nuclear Information System (INIS)

    1991-04-01

    This book reviews the status of the Department of Energy's (DOE) Superconducting Super Collider (SSC), which will be located 30 miles south of Dallas, Texas. The SSC will be the world's largest high energy particle accelerator a research tool used by physicists to seek fundamental knowledge about energy and matter. DOE recently estimated that the SSC will cost $8.2 billion (in current-year dollars). This report provides information on the instability in tenure of DOE and SSC Laboratory project management, uncertainties related to the SSC site geology, uncertainties and risks with magnet development and production, and Texas' proposed contribution to the project's costs

  13. Research Brief.

    Science.gov (United States)

    Schoenfelder, Erin; McCabe, Connor; Fife, Aurora; Herzig, Lisa; Ahrens, Kym

    2017-01-01

    Adolescents with ADHD are at risk of functional problems that may be mitigated by consistent ADHD treatment. This study pilots a brief intervention for adolescents with ADHD and their parents to increase treatment knowledge and family motivation to seek treatment. The 3-hr curriculum was developed by a multidisciplinary team and included psychoeducation, goal setting, and motivational interviewing. Fifteen adolescents and 20 caregivers participated in the workshop, completed pre- and post-test assessments, and reported on acceptability. Acceptability and satisfaction with the intervention were high. Perceived knowledge of ADHD increased post intervention; stigma was unchanged. Parents reported more acceptability of stimulant medications and less willingness to use special diets or cognitive games. Family feedback informed modifications to the curriculum. The Teen ADHD Workshop is a feasible and acceptable intervention to increase knowledge of ADHD and evidence-based treatments. Further research will evaluate effects on treatment participation.

  14. Research Note:

    DEFF Research Database (Denmark)

    Behuria, Pritish; Buur, Lars; Gray, Hazel

    2017-01-01

    employed in varied ways in the political settlements literature, which in turn has led to various methodologies to study power. The note discusses a number of these methodologies, including studying political ruptures as a window into analyzing the distribution of power in African countries, and emphasizes......The political settlements approach emerged out of a critique of new institutional economics developed by Mushtaq Khan in the 1990s. Since then, the political settlements approach has proliferated in donor programmingand academic scholarship on African countries. This has led to some confusion about...... its core conceptual and methodological features. This Research Note starts by setting out our understanding of political settlements and provides an overview of existing political settlements literature on African countries. The note then explores how the key concept of ‘holding power’ has been...

  15. Types of Cancer Research

    Science.gov (United States)

    An infographic from the National Cancer Institute (NCI) describing the four broad categories of cancer research: basic research, clinical research, population-based research, and translational research.

  16. Research medicine

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    In Section I of this annual report, a brief summary of work is presented by the Research Medicine Group. The major emphasis has been the study of the blood system in man with a special emphasis on the examination of platelet abnormalities in human disease. New programs of major importance include the study of aging or dementia of the Alzheimer's type. A differential diagnosis technique has been perfected using positron emission tomography. Studies on the biochemical basis of schizophrenia have proceeded using radioisotope studies which image physiological and biochemical processes. In the investigation of atherosclerosis, techniques have been developed to measure blood perfusion of the heart muscle by labelling platelets and lipoproteins. Progress is reported in a new program which uses NMR for both imaging and spectroscopic studies in humans. The group has determined through an epidemiological study that bubble chamber and cyclotron workers who have been exposed to high electromagnetic fields for two decades have no significant increases in the prevalence of 21 diseases as compared with controls

  17. Novel research

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Author Robert Harris and film director Paul Greengrass visited CERN on 26 April, passing by SM18 as well as the CCC and the ATLAS control room.   Film director Paul Greengrass (left) and author Robert Harris (right). Author Robert Harris and film director Paul Greengrass visited CERN on 26 April as part of their preliminary research on an idea that Harris has for a book, which Greengrass might turn into a film. One of the characters would be a theoretical physicist from CERN – but to say more than that might give away the story! There is definite irony in the fact that their visit was delayed for a week by the ash from the Icelandic volcanic eruption. Harris is well known for several historical novels, including ‘Pompeii’, which tells the story of a fictional hydraulic engineer at the time of the eruption of Mount Vesuvius in 79 AD. His latest book, ‘The Ghost’, became a film directed by Roman Polanski, while the latest film from Greengrass is &a...

  18. Message from the Editor

    Science.gov (United States)

    Stambaugh, Ronald D.

    2014-01-01

    , General Atomics, USA A. Hassanein, Purdue University, USA Y.-M. Jeon, National Fusion Research Institute, Spain S. Kajita, Nagoya University, Japan T.P. Kiviniemi, Aalto University, Finland R.M. More, Lawrence Livermore National Laboratory, USA F. Sattin, Associazione Euratom-ENEA-CNR, Italy J.A. Snipes, ITER Organization, France W. Suttrop, Max Planck Institute for Plasma Physics-Garching, Germany F.L. Tabares, Energy Environment and Technology Research Centre, Spain Y. Ueda, Osaka University, Japan V.S. Voitsenya, Kharkov Institute of Physics and Technology, Ukraine G. Xu, Chinese Academy of Sciences-Hefei Institutes of Physical Sciences, People's Republic of China In addition, there is a group of several hundred referees who have helped us in the past year to maintain the high scientific standard of Nuclear Fusion . At the end of this issue we give the full list of all referees for 2013. Our thanks to them! We also wish to express our thanks to Paul Thomas, who served as Guest Editor for the special issue of the overview and summary reports from the 24th Fusion Energy Conference in San Diego, October 2012. This issue is of great value as a summary of the major developments worldwide in fusion research in the last two years. Authors The winner of the 2013 Nuclear Fusion Award is D.G. Whyte for the paper: I-mode: an H-mode energy confinement regime with L-mode particle transport in Alcator C-Mod [1], and we congratulate him and coauthors on this achievement. We also note special topic papers published in 2013: Technical challenges in the construction of the steady-state stellarator Wendestein 7-X by H.S. Bosch et al [2], Power requirements for electron cyclotron current drive and ion cyclotron resonance heating for sawtooth control in ITER by I.T. Chapman et al [3] and IFMIF: overview of the validation activities by J. Knaster et al [4]. The Board of Editors The Board of Editors has had a substantial turnover in members. For their great service to the journal, we wish to

  19. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... in Health NIH Research Matters NIH Record Research & Training Medical Research Initiatives Science Highlights Science Education Research in NIH Labs & Clinics Training Opportunities Library Resources Research Resources Clinical Research Resources ...

  20. Research practices and assessment of research misconduct

    NARCIS (Netherlands)

    Hartgerink, C.H.J.; Wicherts, J.M.

    2016-01-01

    This article discusses the responsible conduct of research, questionable research practices, and research misconduct. Responsible conduct of research is often defined in terms of a set of abstract, normative principles, professional standards, and ethics in doing research. In order to accommodate

  1. Cancer Research UK | IDRC - International Development Research ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Cancer Research UK. Cancer Research UK. https://www.cancerresearchuk.org/. The Economics of Tobacco Control Research Initiative. The Economics of Tobacco Control Research Initiative funds innovative fiscal policy research supporting tobacco control in low and middle-income countries. View more. The Economics ...

  2. Research Productivity and Academics' Conceptions of Research

    Science.gov (United States)

    Brew, Angela; Boud, David; Namgung, Sang Un; Lucas, Lisa; Crawford, Karin

    2016-01-01

    This paper asks the question: do people with different levels of research productivity and identification as a researcher think of research differently? It discusses a study that differentiated levels of research productivity among English and Australian academics working in research-intensive environments in three broad discipline areas: science,…

  3. Current Research Studies

    Science.gov (United States)

    ... Success Home > Explore Research > Current Research Studies Current Research Studies Email Print + Share The Crohn’s & Colitis Foundation ... conducted online. Learn more about IBD Partners. Clinical Research Alliance The Clinical Research Alliance is a network ...

  4. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Record Research & Training Medical Research Initiatives Science Highlights Science Education Research in NIH Labs & Clinics Training Opportunities Library Resources Research Resources Clinical Research Resources Safety, Regulation ...

  5. Changing Research Practices and Research Infrastructure Development

    Science.gov (United States)

    Houghton, John W.

    2005-01-01

    This paper examines changing research practices in the digital environment and draws out implications for the development of research infrastructure. Reviews of the literature, quantitative indicators of research activities and our own field research in Australia suggest that there is a new mode of knowledge production emerging, changing research…

  6. Research tools | IDRC - International Development Research Centre

    International Development Research Centre (IDRC) Digital Library (Canada)

    Through training materials and guides, we aim to build skills and knowledge to enhance the quality of development research. We also offer free access to our database of funded research projects, known as IDRIS+, and our digital library. Our research tools include. Guide to research databases at IDRC: How to access and ...

  7. Mixed methods research.

    Science.gov (United States)

    Halcomb, Elizabeth; Hickman, Louise

    2015-04-08

    Mixed methods research involves the use of qualitative and quantitative data in a single research project. It represents an alternative methodological approach, combining qualitative and quantitative research approaches, which enables nurse researchers to explore complex phenomena in detail. This article provides a practical overview of mixed methods research and its application in nursing, to guide the novice researcher considering a mixed methods research project.

  8. Distributed control system for lower hybrid RF experiments on the Alcator C tokamak

    International Nuclear Information System (INIS)

    Bredin, C.W.

    1982-12-01

    This paper will address systems requirements, make/buy tradeoff issues, design considerations, implementation, system flexibility/expansion, acceptance test results, and performance evaluation for the control system

  9. Scaling of the power exhaust channel in Alcator C-Moda)

    Science.gov (United States)

    LaBombard, B.; Terry, J. L.; Hughes, J. W.; Brunner, D.; Payne, J.; Reinke, M. L.; Cziegler, I.; Granetz, R.; Greenwald, M.; Hutchinson, I. H.; Irby, J.; Lin, Y.; Lipschultz, B.; Ma, Y.; Marmar, E. S.; Rowan, W. L.; Tsujii, N.; Wallace, G.; Whyte, D. G.; Wolfe, S.; Wukitch, S.; Wurden, G.; Team, Alcator C-Mod

    2011-05-01

    Parametric dependences of the heat flux footprint on the outer divertor target plate are explored in EDA H-mode and ohmic L-mode plasmas over a wide range of parameters with attached plasma conditions. Heat flux profile shapes are found to be independent of toroidal field strength, independent of power flow along magnetic field lines and insensitive to x-point topology (single-null versus double-null). The magnitudes and widths closely follow that of the "upstream" pressure profile, which are correlated to plasma thermal energy content and plasma current. Heat flux decay lengths near the strike-point in H- and L-mode plasmas scale approximately with the inverse of plasma current, with a diminished dependence at high collisionality in L-mode. Consistent with previous studies, pressure gradients in the boundary scale with plasma current squared, holding the magnetohydrodynamic ballooning parameter approximately invariant at fixed collisionality—strong evidence that critical-gradient transport physics plays a key role in setting the power exhaust channel.

  10. Wide-view charge exchange recombination spectroscopy diagnostic for Alcator C-Moda)

    Science.gov (United States)

    Rowan, W. L.; Bespamyatnov, I. O.; Granetz, R. S.

    2008-10-01

    This diagnostic measures temperature, density, and rotation for the fully stripped boron ion between the pedestal top and the plasma core with resolution consistent with the profile gradients. The diagnostic neutral beam used for the measurements generates a 50 keV, 6 A hydrogen beam. The optical systems provide views in both poloidal and toroidal directions. The imaging spectrometer is optimized to simultaneously accept 45 views as input with minimum cross-talk. In situ calibration techniques are applied for spatial location, spectral intensity, and wavelength. In the analysis, measured spectra are fitted to a model constructed from a detailed description of the emission physics. Methods for removal of interfering spectra are included. Applications include impurity and thermal transport.

  11. Active and fast particle driven Alfvén eigenmodes in Alcator C-Moda)

    Science.gov (United States)

    Snipes, J. A.; Basse, N.; Boswell, C.; Edlund, E.; Fasoli, A.; Gorelenkov, N. N.; Granetz, R. S.; Lin, L.; Lin, Y.; Parker, R.; Porkolab, M.; Sears, J.; Sharapov, S.; Tang, V.; Wukitch, S.

    2005-05-01

    Alfvén eigenmodes (AEs) are studied to assess their stability in high density reactor relevant regimes where Ti≈Te and as a diagnostic tool. Stable AEs are excited with active magnetohydrodynamics antennas in the range of the expected AE frequency. Toroidal Alfvén eigenmode (TAE) damping rates between 0.5%<γ/ω<4.5% have been observed in diverted and limited Ohmic plasmas. Unstable AEs are excited with a fast ion tail driven by H minority ion cyclotron radio frequency (ICRF) heating with electron densities in the range of n¯e=0.5-2×1020m-3. Energetic particle modes or TAEs have been observed to decrease in frequency and mode number with time up to a large sawtooth collapse, indicating the role fast particles play in stabilizing sawteeth. In the current rise phase, unstable modes with frequencies that increase rapidly with time are observed with magnetic pick-up coils at the wall and phase contrast imaging density fluctuation measurements in the core. Modeling of these modes constrains the calculated safety factor profile to be very flat or with slightly reversed shear. AEs are found to be more stable for an inboard than for central or outboard ICRF resonances in qualitative agreement with modeling.

  12. Critical gradients and plasma flows in the edge plasma of Alcator C-Moda)

    Science.gov (United States)

    Labombard, B.; Hughes, J. W.; Smick, N.; Graf, A.; Marr, K.; McDermott, R.; Reinke, M.; Greenwald, M.; Lipschultz, B.; Terry, J. L.; Whyte, D. G.; Zweben, S. J.; Alcator C-Mod Team

    2008-05-01

    Recent experiments have led to a fundamental shift in our view of edge transport physics; transport near the last-closed flux surface may be more appropriately described in terms of a critical gradient phenomenon rather than a diffusive and/or convective paradigm. Edge pressure gradients, normalized by the square of the poloidal magnetic field strength, appear invariant in plasmas with the same normalized collisionality, despite vastly different currents and magnetic fields—a behavior that connects with first-principles electromagnetic plasma turbulence simulations. Near-sonic scrape-off layer (SOL) flows impose a cocurrent rotation boundary condition on the confined plasma when B ×∇B points toward the active x-point, suggesting a link to the concomitant reduction in input power needed to attain high-confinement modes. Indeed, low-confinement mode plasmas are found to attain higher edge pressure gradients in this configuration, independent of the direction of B, evidence that SOL flows may affect transport and "critical gradient" values in the edge plasma.

  13. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Trials and You Talking to Your Doctor Science Education Resources Community Resources Clear Health A–Z Publications ... in Health NIH Research Matters NIH Record Research & Training Medical Research Initiatives Science Highlights Science Education Research ...

  14. Architectural project and research

    DEFF Research Database (Denmark)

    Lotz, Katrine

    2005-01-01

    Discussion of criterias for research including the researchers or designers own project as theme.......Discussion of criterias for research including the researchers or designers own project as theme....

  15. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Health NIH Research Matters NIH Record Research & Training Medical Research Initiatives Science Highlights Science Education Research in ... can. The genetic methods for all sorts of medical genetic disorders have been refined over the past ...

  16. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Lines Health Services Locator HealthCare.gov NIH Clinical Research Trials and You Talking to Your Doctor Science ... More » Quick Links NIH News in Health NIH Research Matters NIH Record Research & Training Medical Research Initiatives ...

  17. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Research Trials and You Talking to Your Doctor Science Education Resources Community Resources Clear Health A–Z Publications ... Record Research & Training Medical Research Initiatives Science Highlights Science Education Research in NIH Labs & Clinics Training Opportunities Library ...

  18. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Research Trials and You Talking to Your Doctor Science Education Resources Community Resources Clear Health A–Z ... Matters NIH Record Research & Training Medical Research Initiatives Science Highlights Science Education Research in NIH Labs & Clinics ...

  19. From Action Research to Practice Research

    Directory of Open Access Journals (Sweden)

    Goran Goldkuhl

    2012-04-01

    Full Text Available Action research (AR has gained more acceptance as an approach to qualitative research in information systems (IS. The complexities of organisational and technical change makes this approach a suitable one in IS research. There are, however, still some controversies and confusions about the relation between “action” and “research”. The many types of AR and similar approaches (not labelled as AR that have emerged demands further conceptual clarification of AR. A conceptual inquiry of AR, presented in the paper, has led to the identification of several unresolved issues concerning intervention research like AR. An alternative research approach is presented: practice research. This research approach is well founded in pragmatism and it builds on the two premises: 1 to contribute to general practice through abstract and useful knowledge and 2 to study the empirical field as interconnected practices. Several important concepts of practice research are described as: local practice contribution vs. general practice contribution; theorizing vs. situational inquiry. Practice research is seen as a broader notion encompassing AR and other research approaches as e.g. design research and evaluation research. Two case examples of practice research are briefly presented and compared: one AR-based study in the social welfare sector and one evaluation study of a taxation e-service.

  20. The modern research environment

    DEFF Research Database (Denmark)

    Topsøe, Flemming

    1993-01-01

    Information Technology, research environment, structured documents, networked information retrieval......Information Technology, research environment, structured documents, networked information retrieval...

  1. The School Research Lead

    Science.gov (United States)

    Bennett, Tom

    2015-01-01

    The researchED movement has generated a new debate about the role of research in schools. Of course there have always been teachers interested in undertaking research and applying the research findings of others. However, involvement in research has tended to be the personal enthusiasm of the individual teacher rather than a coordinated whole…

  2. ARTICLE Nutritional Intervention Research Unit, Medical Research ...

    African Journals Online (AJOL)

    ARTICLE. Nutritional Intervention Research Unit, Medical Research Council of South Africa, Tygerberg,. W Cape ... determined by questionnaire; anunquantified food frequency questionnaire was used to determine usual food intake. Biochemical ..... complementary foods, incorrect preparation of formula feeds, and frequent ...

  3. π Scope: python based scientific workbench with visualization tool for MDSplus data

    Science.gov (United States)

    Shiraiwa, S.

    2014-10-01

    π Scope is a python based scientific data analysis and visualization tool constructed on wxPython and Matplotlib. Although it is designed to be a generic tool, the primary motivation for developing the new software is 1) to provide an updated tool to browse MDSplus data, with functionalities beyond dwscope and jScope, and 2) to provide a universal foundation to construct interface tools to perform computer simulation and modeling for Alcator C-Mod. It provides many features to visualize MDSplus data during tokamak experiments including overplotting different signals and discharges, various plot types (line, contour, image, etc.), in-panel data analysis using python scripts, and publication quality graphics generation. Additionally, the logic to produce multi-panel plots is designed to be backward compatible with dwscope, enabling smooth migration for dwscope users. πScope uses multi-threading to reduce data transfer latency, and its object-oriented design makes it easy to modify and expand while the open source nature allows portability. A built-in tree data browser allows a user to approach the data structure both from a GUI and a script, enabling relatively complex data analysis workflow to be built quickly. As an example, an IDL-based interface to perform GENRAY/CQL3D simulations was ported on πScope, thus allowing LHCD simulation to be run between-shot using C-Mod experimental profiles. This workflow is being used to generate a large database to develop a LHCD actuator model for the plasma control system. Supported by USDoE Award DE-FC02-99ER54512.

  4. Measurements of the parallel wavenumber of lower hybrid waves in the scrape-off layer of a high-density tokamak

    International Nuclear Information System (INIS)

    Baek, S. G.; Wallace, G. M.; Parker, R. R.; Shiraiwa, S.; Bonoli, P. T.; Brunner, D.; Faust, I.; LaBombard, B. L.; Wukitch, S.; Shinya, T.; Takase, Y.

    2016-01-01

    In lower hybrid current drive (LHCD) experiments on tokamaks, the parallel wavenumber of lower hybrid waves is an important physics parameter that governs the wave propagation and absorption physics. However, this parameter has not been experimentally well-characterized in the present-day high density tokamaks, despite the advances in the wave physics modeling. In this paper, we present the first measurement of the dominant parallel wavenumber of lower hybrid waves in the scrape-off layer (SOL) of the Alcator C-Mod tokamak with an array of magnetic loop probes. The electric field strength measured with the probe in typical C-Mod plasmas is about one-fifth of that of the electric field at the mouth of the grill antenna. The amplitude and phase responses of the measured signals on the applied power spectrum are consistent with the expected wave energy propagation. At higher density, the observed k || increases for the fixed launched k || , and the wave amplitude decreases rapidly. This decrease is correlated with the loss of LHCD efficiency at high density, suggesting the presence of loss mechanisms. Evidence of the spectral broadening mechanisms is observed in the frequency spectra. However, no clear modifications in the dominant k || are observed in the spectrally broadened wave components, as compared to the measured k || at the applied frequency. It could be due to (1) the probe being in the SOL and (2) the limited k || resolution of the diagnostic. Future experiments are planned to investigate the roles of the observed spectral broadening mechanisms on the LH density limit problem in the strong single pass damping regime.

  5. Research Methodology in Global Strategy Research

    DEFF Research Database (Denmark)

    Cuervo-Cazurra, Alvaro; Mudambi, Ram; Pedersen, Torben

    2017-01-01

    We review advances in research methodology used in global strategy research and provide suggestions on how researchers can improve their analyses and arguments. Methodological advances in the extraction of information, such as computer-aided text analysis, and in the analysis of datasets......-explained logics and mechanisms so that researchers can provide better and more relevant recommendations to managers designing the global strategies of their organizations....

  6. Case Study Research Methodology in Nursing Research.

    Science.gov (United States)

    Cope, Diane G

    2015-11-01

    Through data collection methods using a holistic approach that focuses on variables in a natural setting, qualitative research methods seek to understand participants' perceptions and interpretations. Common qualitative research methods include ethnography, phenomenology, grounded theory, and historic research. Another type of methodology that has a similar qualitative approach is case study research, which seeks to understand a phenomenon or case from multiple perspectives within a given real-world context.

  7. Design Research between Design and Research

    DEFF Research Database (Denmark)

    Steinø, Nicolai; Markussen, Thomas

    2011-01-01

    The discourse on architecture and design research in Denmark in the past thirty years has been stuck in a unproductive dichotomy between research through design on the one hand and a phantom image of academic and theoretical, word-based research on the other. Advocates of the research through des......, the main difference between design and research is in the object; design creates artefacts (physical or abstract) and research creates knowledge.......The discourse on architecture and design research in Denmark in the past thirty years has been stuck in a unproductive dichotomy between research through design on the one hand and a phantom image of academic and theoretical, word-based research on the other. Advocates of the research through...... design strand have argued, that architecture and design research must follow an architecture and design methodology – designing – and be communicated by means of architecture and design media – images and artefacts. Essentially, this view sees no difference between architecture and design research...

  8. Research reactors and alternative devices for research

    International Nuclear Information System (INIS)

    1985-01-01

    This report includes papers on research reactors and alternatives to the research reactors - radioisotopic neutron sources, cyclotrons, D-T neutron generators and small accelerators, used for radioisotope production, neutron activation analysis, material science, applied and basic research using neutron beams. A separate abstract was prepared for each of the 7 papers

  9. Research Through Design & Research Through Education

    NARCIS (Netherlands)

    Eggink, Wouter; Mulder-Nijkamp, Maaike; Bohemia, Erik; Kovacevic, Ahmed; Buck, Lyndon; Tollestrup, Christian; Eriksen, Kaare; Ovesen, Nis

    2016-01-01

    The very definition of a university is a place where research and education are intertwined. When there is no research, a university will look like a place for vocational training, and when there are no students to teach, the university is no more than a research institution. This convention of

  10. Research award: Collaborative Adaptation Research Initiative in ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2017-09-06

    Sep 6, 2017 ... We offer a number of research awards providing a unique opportunity to enhance research skills and gain a fresh perspective on crucial development issues. These one‐year, paid, in‐house programs of training and mentorship allow award holders to pursue their research goals and work in one of IDRC's ...

  11. Research Award: Global Health Research Iniave

    International Development Research Centre (IDRC) Digital Library (Canada)

    Corey Piccioni

    2013-08-07

    Aug 7, 2013 ... IDRC is one of the world's leaders in generang new knowledge to meet global challenges. We offer a number of research awards providing a unique opportunity to enhance ... Strong research and analycal skills;. • Knowledge of research for development;. • Field experience in an LMIC would be an asset;.

  12. Research Award: Advisory Committee on Research Ethics

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    Canada. Candidates should possess: • Demonstrated interest in research ethics in international development or global health. • Knowledge of research for development. • Strong research and analytical skills. • Proficiency in English; French language skills an asset. • Strong verbal and written communication skills.

  13. Research Supervision: The Research Management Matrix

    Science.gov (United States)

    Maxwell, T. W.; Smyth, Robyn

    2010-01-01

    We briefly make a case for re-conceptualising research project supervision/advising as the consideration of three inter-related areas: the learning and teaching process; developing the student; and producing the research project/outcome as a social practice. We use this as our theoretical base for an heuristic tool, "the research management…

  14. Mixed methods research in music therapy research.

    Science.gov (United States)

    Bradt, Joke; Burns, Debra S; Creswell, John W

    2013-01-01

    Music therapists have an ethical and professional responsibility to provide the highest quality care possible to their patients. Much of the time, high quality care is guided by evidence-based practice standards that integrate the most current, available research in making decisions. Accordingly, music therapists need research that integrates multiple ways of knowing and forms of evidence. Mixed methods research holds great promise for facilitating such integration. At this time, there have not been any methodological articles published on mixed methods research in music therapy. The purpose of this article is to introduce mixed methods research as an approach to address research questions relevant to music therapy practice. This article describes the core characteristics of mixed methods research, considers paradigmatic issues related to this research approach, articulates major challenges in conducting mixed methods research, illustrates four basic designs, and provides criteria for evaluating the quality of mixed methods articles using examples of mixed methods research from the music therapy literature. Mixed methods research offers unique opportunities for strengthening the evidence base in music therapy. Recommendations are provided to ensure rigorous implementation of this research approach.

  15. Questionable research practices among italian research psychologists

    Science.gov (United States)

    Wicherts, Jelte M.; Veldkamp, Coosje L. S.; Albiero, Paolo; Cubelli, Roberto

    2017-01-01

    A survey in the United States revealed that an alarmingly large percentage of university psychologists admitted having used questionable research practices that can contaminate the research literature with false positive and biased findings. We conducted a replication of this study among Italian research psychologists to investigate whether these findings generalize to other countries. All the original materials were translated into Italian, and members of the Italian Association of Psychology were invited to participate via an online survey. The percentages of Italian psychologists who admitted to having used ten questionable research practices were similar to the results obtained in the United States although there were small but significant differences in self-admission rates for some QRPs. Nearly all researchers (88%) admitted using at least one of the practices, and researchers generally considered a practice possibly defensible if they admitted using it, but Italian researchers were much less likely than US researchers to consider a practice defensible. Participants’ estimates of the percentage of researchers who have used these practices were greater than the self-admission rates, and participants estimated that researchers would be unlikely to admit it. In written responses, participants argued that some of these practices are not questionable and they have used some practices because reviewers and journals demand it. The similarity of results obtained in the United States, this study, and a related study conducted in Germany suggest that adoption of these practices is an international phenomenon and is likely due to systemic features of the international research and publication processes. PMID:28296929

  16. Publication ethics for researchers

    OpenAIRE

    Banerjee, Probir K.

    2013-01-01

    The community of researchers unanimously agrees that a code of ethics must be followed when engaging in research and consenting to publication of research findings in academic journals. However, unethical research practice continues to cause concern. In an effort to address the concern, several researchers have prescribed remedial action. Publishers and members of the research community have also tried to raise awareness of this malady plaguing the research community. For example, Ethics in R...

  17. Researcher-researched relationship in qualitative research: Shifts in positions and researcher vulnerability.

    Science.gov (United States)

    Råheim, Målfrid; Magnussen, Liv Heide; Sekse, Ragnhild Johanne Tveit; Lunde, Åshild; Jacobsen, Torild; Blystad, Astrid

    2016-01-01

    The researcher role is highly debated in qualitative research. This article concerns the researcher-researched relationship. A group of health science researchers anchored in various qualitative research traditions gathered in reflective group discussions over a period of two years. Efforts to establish an anti-authoritarian relationship between researcher and researched, negotiation of who actually "rules" the research agenda, and experiences of shifts in "inferior" and "superior" knowledge positions emerged as central and intertwined themes throughout the discussions. The dual role as both insider and outsider, characteristic of qualitative approaches, seemed to lead to power relations and researcher vulnerability which manifested in tangible ways. Shifting positions and vulnerability surfaced in various ways in the projects. They nonetheless indicated a number of similar experiences which can shed light on the researcher-researched relationship. These issues could benefit from further discussion in the qualitative health research literature.

  18. Nuclear energy related research

    International Nuclear Information System (INIS)

    Rintamaa, R.

    1992-05-01

    The annual Research Programme Plan describes publicly funded nuclear energy related research to be carried out mainly at the Technical Research Centre of Finland (VTT) in 1992. The research is financed primarily by the Ministry of Trade and Industry (KTM), the Finnish Centre for Radiation and Nuclear Safety (STUK) and VTT itself. Other research institutes, utilities and industry also contribute to many projects

  19. Nuclear research reactors

    International Nuclear Information System (INIS)

    1985-01-01

    It's presented data about nuclear research reactors in the world, retrieved from the Sien (Nuclear and Energetic Information System) data bank. The information are organized in table forms as follows: research reactors by countries; research reactors by type; research reactors by fuel and research reactors by purpose. (E.G.) [pt

  20. Mixed methods research for the novice researcher.

    Science.gov (United States)

    Giddings, Lynne S; Grant, Barbara M

    2006-10-01

    Mixed methods research is becoming increasingly popular in the health and social science disciplines. The aim of this article is to give an overview of the varieties of mixed methods designs. We begin by situating mixed methods research in the context of a paradigmatic framework which assists a researcher in making decisions concerning the design of their study. Although the most commonly used mixed methods designs are underpinned by positivist/postpositivist assumptions, the combination of qualitative and quantitative methods can be used within any research paradigm.

  1. Research Associate | Center for Cancer Research

    Science.gov (United States)

    PROGRAM DESCRIPTION The Cancer Research Technology Program (CRTP) develops and implements emerging technology, cancer biology expertise and research capabilities to accomplish NCI research objectives.  The CRTP is an outward-facing, multi-disciplinary hub purposed to enable the external cancer research community and provides dedicated support to NCI’s intramural Center for Cancer Research (CCR).  The dedicated units provide electron microscopy, protein characterization, protein expression, optical microscopy and nextGen sequencing. These research efforts are an integral part of CCR at the Frederick National Laboratory for Cancer Research.  CRTP scientists also work collaboratively with intramural NCI investigators to provide research technologies and expertise. KEY ROLES/RESPONSIBILITIES We are seeking a highly motivated Research Associate II to join the newly established Single Cell Analysis Facility (SCAF) of the CCR at NCI.  The SCAF will house state of the art single cell sequencing technologies including 10xGenomics Chromium, BD Genomics Rhapsody, DEPPArray, and other emerging single cell technologies. This person will work under the guidance of SCAF senior staff to carry out single cell sequencing experiments.

  2. From Research Assistant to Professional Research Assistance: Research Consulting as a Form of Research Practice

    Directory of Open Access Journals (Sweden)

    Dawn E. Pollon

    2013-01-01

    Full Text Available Research assistantships have long been viewed as an extension of the formal education process, a form of apprenticeship, and a pathway into the professional practice of research in institutional settings. However, there are other contexts in which researchers practice research. This self-study documents the formative role research assistantships played in the authors’ development as professional research consultants. Four professional research consultants who held research assistant positions during their master’s and doctoral studies describe the contributions of their research assistantship experiences to the advancement of their knowledge, skills, and passion for research and subsequently to their career decisions. Professional research consulting is identified as a natural extension of research assistant roles and a potential career path. The article enhances current understandings about the ways research assistantships contribute to the development of researchers, and specifically to the development of professional research consultants. The analysis will be of interest to students contemplating entering into research assistantships, current research assistants, current research assistant supervisors, academic staff looking to improve their research productivity, and department chairs.

  3. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... NIH…Turning Discovery Into Health ® Impact of NIH Research Science, Health, and Public Trust You are here Home » Health Information » NIH Clinical Research Trials and You NIH Clinical Research Trials and ...

  4. Children's Environmental Health Research

    Science.gov (United States)

    Conducted in-house, with our federal partners like NIH’s National Institute of Environmental Health Services (NIEHS), and by external researchers through a research grants program administered through the agency’s Office of Research & Development.

  5. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Toolkits Grants & Funding Grants Home Page Funding Forms Library Due Dates How to Apply About Grants Policy & ... Education Research in NIH Labs & Clinics Training Opportunities Library Resources Research Resources Clinical Research Resources Safety, Regulation ...

  6. Research on Catalysis.

    Science.gov (United States)

    Bartholomew, Calvin H.; Hecker, William C.

    1984-01-01

    The objectives and philosophy of the Catalysis Laboratory at Brigham Young University are discussed. Also discusses recent and current research activities at the laboratory as well as educational opportunities, research facilities, and sources of research support. (JN)

  7. Researcher Story: Stuttering

    Science.gov (United States)

    ... Have a Question In the News Researcher Story: Stuttering In a 2010 movie, The King’s Speech, many ... effects of the disorder. How Do Researchers Study Stuttering? Video of How Do Researchers Study Stuttering? A ...

  8. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Have a Question In the News Researcher Story: Stuttering In a 2010 movie, The King’s Speech, many ... effects of the disorder. How Do Researchers Study Stuttering? Video of How Do Researchers Study Stuttering? A ...

  9. National Privacy Research Strategy

    Data.gov (United States)

    Networking and Information Technology Research and Development, Executive Office of the President — On July 1, NITRD released the National Privacy Research Strategy. Research agencies across government participated in the development of the strategy, reviewing...

  10. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Trials and You Talking to Your Doctor Science Education Resources Community Resources Clear Health A–Z Publications ... Research & Training Medical Research Initiatives Science Highlights Science Education Research in NIH Labs & Clinics Training Opportunities Library ...

  11. Research Areas: Liver Disease

    Science.gov (United States)

    ... to their families, health professionals, and the public. Research Updates and News NIH study sheds light on ... findings to health professionals and the public. Support Research NIDDK invests in basic, clinical and translational research ...

  12. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Info Lines Health Services Locator HealthCare.gov NIH Clinical Research Trials and You Talking to Your Doctor ... Labs & Clinics Training Opportunities Library Resources Research Resources Clinical Research Resources Safety, Regulation and Guidance More » Quick ...

  13. Research on Tourism

    OpenAIRE

    Špačková, Martina

    2009-01-01

    The thesis acquaints with issues and problems of research on tourism, summarizes existing knowledge and development of this theme. It also addresses the issue of institutional, legislative and financial security of research in the Czech Republic (research in general and specifically research on tourism) and the current problems with which the research on tourism meets in the Czech Republic. The thesis also maps out the research activities of some foreign institutions and organizations. Part o...

  14. High Combustion Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — At NETL's High-Pressure Combustion Research Facility in Morgantown, WV, researchers can investigate new high-pressure, high-temperature hydrogen turbine combustion...

  15. Research essentials. How to critique quantitative research.

    Science.gov (United States)

    Clarke, Sharon; Collier, Sue

    2015-11-01

    QUANTITATIVE RESEARCH is a systematic approach to investigating numerical data and involves measuring or counting attributes, that is quantities. Through a process of transforming information that is collected or observed, the researcher can often describes a situation or event, answering the 'what' and 'how many' questions about a situation ( Parahoo 2014 ).

  16. Research Associate | Center for Cancer Research

    Science.gov (United States)

    PROGRAM DESCRIPTION The Basic Science Program (BSP) pursues independent, multidisciplinary research in basic and applied molecular biology, immunology, retrovirology, cancer biology, and human genetics. Research efforts and support are an integral part of the Center for Cancer Research (CCR) at the Frederick National Laboratory for Cancer Research (FNLCR). KEY ROLES/RESPONSIBILITIES - Research Associate III Dr. Zbigniew Dauter is the head investigator of the Synchrotron Radiation Research Section (SRRS) of CCR’s Macromolecular Crystallography Laboratory. The Synchrotron Radiation Research Section is located at Argonne National Laboratory, Argonne, Illinois; this is the site of the largest U.S. synchrotron facility. The SRRS uses X-ray diffraction technique to solve crystal structures of various proteins and nucleic acids of biological and medical relevance. The section is also specializing in analyzing crystal structures at extremely high resolution and accuracy and in developing methods of effective diffraction data collection and in using weak anomalous dispersion effects to solve structures of macromolecules. The areas of expertise are: Structural and molecular biology Macromolecular crystallography Diffraction data collection Dr. Dauter requires research support in these areas, and the individual will engage in the purification and preparation of samples, crystallize proteins using various techniques, and derivatize them with heavy atoms/anomalous scatterers, and establish conditions for cryogenic freezing. Individual will also participate in diffraction data collection at the Advanced Photon Source. In addition, the candidate will perform spectroscopic and chromatographic analyses of protein and nucleic acid samples in the context of their purity, oligomeric state and photophysical properties.

  17. Research Summary Multipollutant Control Research Facility (MPCRF)

    Science.gov (United States)

    The U.S. Environmental Protection Agency’s (EPA) Multipollutant Control Research Facility (MPCRF) is located at their Research Triangle Park, North Carolina, campus. The MPCRF combustor is a pulverized coal-, natural gas-, and biomass-fired furnace with a maximum firing rat...

  18. Storytelling as Research/Research as Storytelling

    Science.gov (United States)

    Lewis, Patrick J.

    2011-01-01

    If story is central to human meaning why, in the research world, is there not more storytelling? Walter Benjamin (1973) noted that, "a story is different. It does not expend itself. It preserves and concentrates its strength and is capable of releasing it even after a long time" (p. 90). How might research not expend itself, but preserve and…

  19. Teaching Qualitative Research to Practitioner-Researchers

    Science.gov (United States)

    Cox, Rebecca D.

    2012-01-01

    Practitioner-researchers are well-positioned to apply qualitative methods to the study of significant problems of educational practice. However, while learning the skills of qualitative inquiry, practitioners may be compelled by forces outside of qualitative research classrooms to think quantitatively. In this article, the author considers two…

  20. Researching as an Enactivist Mathematics Education Researcher

    Science.gov (United States)

    Brown, Laurinda

    2015-01-01

    This paper focusses on how researching is done through reflections about, or at a meta-level to, the practice over time of an enactivist mathematics education researcher. How are the key concepts of enactivist theory ("ZDM Mathematics Education," doi: 10.1007/s11858-014-0634-7, 2015) applied? This paper begins by giving an…

  1. From nuclear research to multidisciplinary research

    International Nuclear Information System (INIS)

    Theenhaus, R.; Baurmann, K.W.

    1996-01-01

    Forty years ago, the North Rhine-Westphalian State Government founded the then Juelich Nuclear Research Center. After a growth period of the reactor engineering program until 1980, claiming a share of 42% of R and D resources, that share declined continuously to a present level of 8%. This development is an expression of the activities successfully completed in the past, of progress achieved in industrial reactor development, but also of the fact that the high temperature reactor, which had been run successfully for twenty years, failed as a technical scale THTR-300 version. The Center has reorientated its line of research in a process of structural reshuffle beginning some fifteen years ago and still going on. Information technology, materials research, life sciences, environmental research, and energy technology have become main activities of equal weight. Activities specific to nuclear reactors have been incorporated in this new line of work as nuclear safety research and work on safe repository storage. (orig.) [de

  2. Catalog of Research Reports

    Science.gov (United States)

    College Board, 2011

    2011-01-01

    This catalog lists research reports, research notes, and other publications available from the College Board's website. The catalog briefly describes research publications available free of charge. Introduced in 1981, the Research Report series includes studies and reviews in areas such as college admission, special populations, subgroup…

  3. Nuclear energy related research

    International Nuclear Information System (INIS)

    Salminen, P.; Mattila, L.

    1990-08-01

    The annual Research Programme Plan describes the publicly funded nuclear energy related research to be carried out at the Technical Research Centre of Finland (VTT) in 1990. The research is financed primarily by the Ministry of Trade and Industry (KTM), the Finnish Centre for Radiation and Nuclear Safety (STUK) and VTT itself. Utilities and industry also contribute to some projects

  4. Research in Mathematics Education

    Science.gov (United States)

    Schoenfeld, Alan H.

    2016-01-01

    As one of the three Rs, "'rithmetic" has always been central to education and education research. By virtue of that centrality, research in mathematics education has often reflected and at times led trends in education research. This chapter provides some deep background on epistemological and other issues that shape current research,…

  5. Researching entrepreneurship with autoethnography

    DEFF Research Database (Denmark)

    Gottlieb, Frederik

    2015-01-01

    In this paper, the author presents a discussion of the implications and opportunities of researching with autoethnography, in an entrepreneurial context. The research is based on 2 narratives written on the account of the researchers deep involvement in a small startup company. The researcher rel...

  6. Nuclear energy related research

    International Nuclear Information System (INIS)

    Salminen, P.

    1988-02-01

    This annual Research Programme Plan covers the publicly funded nuclear energy related research planned to be carried out at the Technical Research Centre of Finland (VTT) in 1988. The research will be financed by the Ministry of Trade and Industry, the Finnish Centre for Radiation and Nuclear Safety, the Nordic Council of Ministers and VTT itself

  7. Policy Research and Politics.

    Science.gov (United States)

    Gaskell, Jane

    1988-01-01

    Explores what it means to do research intended to be relevant for public policy. Argues against perception of policy research as politically neutral technical exercise. Discusses political implications of methodology. Discusses research examples to illustrate point. Discusses implications for how research might be used in political process.…

  8. Nuclear energy related research

    International Nuclear Information System (INIS)

    Salminen, Pertti

    1989-03-01

    This annual Research Programme Plan covers the publicly funded nuclear energy related research planned to be carried out at the Technical Research Centre of Finland (VTT) in 1989. The research will be financed by the Ministry of Trade and Industry, the Finnish Centre for Radiation and Nuclear Safety, the Nordic Council of Ministers and VTT itself

  9. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Resources Media Contacts Images and B-roll Events Social Media More » Quick Links NIH News in Health NIH Research Matters NIH Record Research & Training Medical Research Initiatives Science Highlights Science Education Research in NIH Labs & Clinics ...

  10. NFSMI Research Summary

    Science.gov (United States)

    Nettles, Mary Frances

    2014-01-01

    The NFSMI Research Summary is a continuing series of summaries reporting recently completed research and research-based resources funded by the National Food Service Management Institute. The following research studies are summarized in this article: (1) Succession Planning for Management Level Staff in School Nutrition Programs; (2)…

  11. Research Methods Tutorial

    Science.gov (United States)

    Aguilera, Frank J.

    2015-01-01

    A guiding principle for conducting research in technology, science, and engineering, leading to innovation is based on our use of research methodology (both qualitative and qualitative). A brief review of research methodology will be presented with an overview of NASA process in developing aeronautics technologies and other things to consider in research including what is innovation.

  12. Research Data Management - Handouts

    OpenAIRE

    Collins, Anna

    2012-01-01

    This is a series of handouts that can be used to assist researchers with data management. They are all available under a CC-BY-NC-SA license. The forms include: Defining Digital Research Data, Drafting a Data Management Plan in Reverse, File Formats - text files, Research Projects: File Structure & Naming and Data Management Plan for Research Projects

  13. Consumer Behavior Research Methods

    DEFF Research Database (Denmark)

    Chrysochou, Polymeros

    2017-01-01

    This chapter starts by distinguishing consumer behavior research methods based on the type of data used, being either secondary or primary. Most consumer behavior research studies phenomena that require researchers to enter the field and collect data on their own, and therefore the chapter...... of the methods and how to improve quality in consumer behavior research methods....

  14. Teaching to Enhance Research

    Science.gov (United States)

    Harland, Tony

    2016-01-01

    In this paper, I present a conceptual argument for "teaching-led research" in which university lecturers construct courses that directly and positively influence their research, while at the same time, safeguard and enhance the student experience. A research-pedagogy for higher education considers the link between teaching and research,…

  15. Case study research.

    Science.gov (United States)

    Taylor, Ruth; Thomas-Gregory, Annette

    2015-06-10

    This article describes case study research for nursing and healthcare practice. Case study research offers the researcher an approach by which a phenomenon can be investigated from multiple perspectives within a bounded context, allowing the researcher to provide a 'thick' description of the phenomenon. Although case study research is a flexible approach for the investigation of complex nursing and healthcare issues, it has methodological challenges, often associated with the multiple methods used in individual studies. These are explored through examples of case study research carried out in practice and education settings. An overview of what constitutes 'good' case study research is proposed.

  16. Final Technical Report -- Bridging the PSI Knowledge Gap: A Multiscale Approach

    Energy Technology Data Exchange (ETDEWEB)

    Whyte, Dennis [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2014-12-12

    The Plasma Surface Interactions (PSI) Science Center formed by the grant undertook a multidisciplinary set of studies on the complex interface between the plasma and solid states of matter. The strategy of the center was to combine and integrate the experimental, diagnostic and modeling toolkits from multiple institutions towards specific PSI problems. In this way the Center could tackle integrated science issues which were not addressable by single institutions, as well as evolve the underlying science of the PSI in a more general way than just for fusion applications. The overall strategy proved very successful. The research result and highlights of the MIT portion of the Center are primarily described. A particular highlight is the study of tungsten nano-tendril growth in the presence of helium plasmas. The Center research provided valuable new insights to the mechanisms controlling the nano-tendrils by developing coupled modeling and in situ diagnostic methods which could be directly compared. For example, the role of helium accumulation in tungsten distortion in the surface was followed with unique in situ helium concentration diagnostics developed. These depth-profiled, time-resolved helium concentration measurements continue to challenge the numerical models of nano-tendrils. The Center team also combined its expertise on tungsten nano-tendrils to demonstrate for the first time the growth of the tendrils in a fusion environment on the Alcator C-Mod fusion experiment, thus having significant impact on the broader fusion research effort. A new form of isolated nano-tendril “columns” were identified which are now being used to understand the underlying mechanisms controlling the tendril growth. The Center also advanced PSI science on a broader front with a particular emphasis on developing a wide range of in situ PSI diagnostic tools at the DIONISOS facility at MIT. For example the strong suppression of sputtering by the certain combination of light

  17. Fundamentals of surgical research course: research presentations.

    Science.gov (United States)

    Mayer, Kathrin

    2005-10-01

    The effective communication of research outcomes is a skill that can be learned. To make the greatest impact, it is imperative to know your audience. Oral communication is a highly effective means for dissemination of new information. The preparation of a research presentation requires significant time. The researcher must determine the key messages to be delivered and plan the presentation accordingly. High quality visual aids can impress your audience and, in combination with a succinct oral presentation, can increase retention of the material. In addition to the communication of the raw scientific data and results, the importance of stance, appearance, voice, and eye contact necessary to engage your audience should not be overlooked.

  18. Improving University Research Value

    Directory of Open Access Journals (Sweden)

    Kelley O’Reilly

    2012-07-01

    Full Text Available This article investigates the current data management practices of university researchers at an Intermountain West land-grant research university in the United States. Key findings suggest that researchers are primarily focused on the collection and housing of research data. However, additional research value exists within the other life cycle stages for research data—specifically in the stages of delivery and maintenance. These stages are where most new demands and requirements exist for data management plans and policies that are conditional for external grant funding; therefore, these findings expose a “gap” in current research practice. These findings should be of interest to academics and practitioners alike as findings highlight key management gaps in the life cycle of research data. This study also suggests a course of action for academic institutions to coalesce campus-wide assets to assist researchers in improving research value.

  19. Rigour in quantitative research.

    Science.gov (United States)

    Claydon, Leica Sarah

    2015-07-22

    This article which forms part of the research series addresses scientific rigour in quantitative research. It explores the basis and use of quantitative research and the nature of scientific rigour. It examines how the reader may determine whether quantitative research results are accurate, the questions that should be asked to determine accuracy and the checklists that may be used in this process. Quantitative research has advantages in nursing, since it can provide numerical data to help answer questions encountered in everyday practice.

  20. Fusion Energy Science Joint Facilities and Theory Research Target 2011: Final Report for the Period October 1, 2010 through September 30, 2011

    Energy Technology Data Exchange (ETDEWEB)

    Groebner, R. J. [General Atomics, La Jolla, CA (United States); Chang, C. S. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Diamond, P. H. [Univ. of California, San Diego, CA (United States); Hughes, J. W. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Maingi, R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Snyder, P. B. [General Atomics, La Jolla, CA (United States); Xu, X. Q. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2011-10-01

    Briefly stated, the goal of this combined experiment/theory milestone was to improve our knowledge of the physics processes that control the H-mode pedestal by applying models of these mechanisms to experimental data. A concerted and coordinated effort of experimental, theory and modeling activities has examined several physics mechanisms of interest, and has met the goals of the milestone. A few noteworthy results will be noted here. The activity has applied peeling-ballooning theory to all three machines, and increased confidence that the theory predicts the ultimate limits to pedestal height in an ELMing plasma. The activity has expanded the range of conditions for testing of the EPED model, and increased confidence in the ability of the model to compute the pedestal pressure height in medium aspect ratio tokamaks. Kinetic neoclassical models have been used to verify that an important analytic model for the pedestal bootstrap current has good accuracy in many regimes of interest but needs correction at high collisionality. A benchmarking effort between electromagnetic gyrokinetic codes has provided increased understanding of how to use these codes in the pedestal, and has laid the groundwork for using these codes to study linear stability of gyrokinetic modes in and on top of the pedestal. Comparisons of data and models have led to successful simulations of a quasi-coherent mode in C-Mod and to the tentative identification of a high frequency mode in DIII-D. A kinetic neoclassical model qualitatively agrees with some features of pedestal density profiles. A paleoclassical transport model quantitatively predicts some features of the electron temperature profiles in NSTX and DIII-D. The milestone activity also laid the groundwork for future advancements in understanding and predicting the pedestal. All three machines obtained a wealth of pedestal data under a wide variety of operating conditions. Some of these data have been analyzed already, and the analysis and

  1. Water Environment Research Foundation research program

    Science.gov (United States)

    Noss, Charles I.

    2002-02-01

    The Water Environment Research Foundation (WERF) is a not- for-profit organization established in 1989 to advance the science and technology of a broad spectrum of environmental and human health concerns to the wastewater industry and the public. It is a unique public/private partnership between utilities, academia, government, and industry, committed to funding research by leveraging resources and expertise to develop and disseminate sound scientific and technological information. Funded by subscribers, grants and contributions, WERF manages a broad array of research projects aimed at protecting human health and the environment. While WERF funds and manages projects, the actual research is carried out by individual organizations or teams composed of utilities, consultants, universities, and industrial or commercial firms. Examples of WERF's current research program include the investigation of on- line monitoring techniques for microbial and chemical contaminants in water and wastewater, optimization of processes for pathogen removal and inactivation, improved treatment of toxic compounds, and assessing the potential risks to public health from exposure to these microbial and chemical contaminants. This paper will provide an overview of the program, research funded to date, and technology needs for the future.

  2. Special issue: overview and summary reports from the 24th Fusion Energy Conference (San Diego, CA, 8-13 October 2012)

    Science.gov (United States)

    Thomas, Paul

    2013-10-01

    The group of 27 papers published in this special issue of Nuclear Fusion aims to monitor the worldwide progress made in the period 2010-2012 in the field of thermonuclear fusion. Of these papers, 24 are based on overview reports presented at the 24th Fusion Energy Conference (FEC 2012) and three are summary reports. The conference was hosted by the Government of the United States of America and organized by the IAEA in cooperation with the United States Department of Energy and General Atomics. It took place in San Diego on 8-13 October 2012. The overviews presented at the conference have been rewritten and extended for the purpose of this special issue and submitted to the standard double-referee peer-review of Nuclear Fusion . The articles are placed in the following sequence: Overview articles, presented in programme order, are as follows: • Tokamaks DIII-D research towards resolving key issues for ITER and steady-state tokamaks; Overview of the JET results with the ITER-like wall; Overview of ASDEX Upgrade results; Overview of experimental results and code validation activities at Alcator C-Mod; An overview of KSTAR results; Progress of long pulse and H-mode experiments in EAST; Overview of physics results from the National Spherical Torus Experiment; Overview of physics results from MAST towards ITER/DEMO and the MAST Upgrade; An overview of recent HL-2A experiments; Progress of the JT-60SA project; Overview of recent and current research on the TCV tokamak; An overview of FTU results; New developments, plasma physics regimes and issues for the Ignitor experiment; Recent research work on the J-TEXT tokamak. • Other MCF Extension of operation regimes and investigation of three-dimensional current-less plasmas in the Large Helical Device; Dynamics of flows and confinement in the TJ-II stellarator; Overview of results from the MST reversed field pinch experiment; Overview of the RFX Fusion Science Program; An overview of intrinsic torque and momentum

  3. Ageing of research reactors

    International Nuclear Information System (INIS)

    Ciocanescu, M.

    2001-01-01

    Historically, many of the research institutions were centred on a research reactor facility as main technological asset and major source of neutrons for research. Important achievements were made in time in these research institutions for development of nuclear materials technology and nuclear safety for nuclear energy. At present, ageing of nuclear research facilities among these research reactors and ageing of staff are considerable factors of reduction of competence in research centres. The safe way of mitigation of this trend deals with ageing management by so called, for power reactors, Plant Life Management and new investments in staff as investments in research, or in future resources of competence. A programmatic approach of ageing of research reactors in correlation with their actual and future utilisation, will be used as a basis for safety evaluation and future spending. (author)

  4. Responsible conduct of research

    CERN Document Server

    Shamoo, Adil E

    2015-01-01

    Since the early 2000s, the field of Responsible Conduct of Research has become widely recognized as essential to scientific education, investigation, and training. At present, research institutions with public funding are expected to have some minimal training and education in RCR for their graduate students, fellows and trainees. These institutions also are expected to have a system in place for investigating and reporting misconduct in research or violations of regulations in research with human subjects, or in their applications to federal agencies for funding. Public scrutiny of the conduct of scientific researchers remains high. Media reports of misconduct scandals, biased research, violations of human research ethics rules, and moral controversies in research occur on a weekly basis. Since the 2009 publication of the 2nd edition of Shamoo and Resnik's Responsible Conduct of Research, there has been a vast expansion in the information, knowledge, methods, and diagnosis of problems related to RCR and the ...

  5. Translational Educational Research

    Science.gov (United States)

    Issenberg, S. Barry; Cohen, Elaine R.; Barsuk, Jeffrey H.; Wayne, Diane B.

    2012-01-01

    Medical education research contributes to translational science (TS) when its outcomes not only impact educational settings, but also downstream results, including better patient-care practices and improved patient outcomes. Simulation-based medical education (SBME) has demonstrated its role in achieving such distal results. Effective TS also encompasses implementation science, the science of health-care delivery. Educational, clinical, quality, and safety goals can only be achieved by thematic, sustained, and cumulative research programs, not isolated studies. Components of an SBME TS research program include motivated learners, curriculum grounded in evidence-based learning theory, educational resources, evaluation of downstream results, a productive research team, rigorous research methods, research resources, and health-care system acceptance and implementation. National research priorities are served from translational educational research. National funding priorities should endorse the contribution and value of translational education research. PMID:23138127

  6. Fuel safety research 2001

    Energy Technology Data Exchange (ETDEWEB)

    Uetsuka, Hiroshi (ed.) [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2002-11-01

    The Fuel Safety Research Laboratory is in charge of research activity which covers almost research items related to fuel safety of water reactor in JAERI. Various types of experimental and analytical researches are being conducted by using some unique facilities such as the Nuclear Safety Research Reactor (NSRR), the Japan Material Testing Reactor (JMTR), the Japan Research Reactor 3 (JRR-3) and the Reactor Fuel Examination Facility (RFEF) of JAERI. The research to confirm the safety of high burn-up fuel and MOX fuel under accident conditions is the most important item among them. The laboratory consists of following five research groups corresponding to each research fields; Research group of fuel behavior under the reactivity initiated accident conditions (RIA group). Research group of fuel behavior under the loss-of-coolant accident conditions (LOCA group). Research group of fuel behavior under the normal operation conditions (JMTR/BOCA group). Research group of fuel behavior analysis (FEMAXI group). Research group of radionuclides release and transport behavior from irradiated fuel under severe accident conditions (VEGA group). The research conducted in the year 2001 produced many important data and information. They are, for example, the fuel behavior data under BWR power oscillation conditions in the NSRR, the data on failure-bearing capability of hydrided cladding under LOCA conditions and the FP release data at very high temperature in steam which simulate the reactor core condition during severe accidents. This report summarizes the outline of research activities and major outcomes of the research executed in 2001 in the Fuel Safety Research Laboratory. (author)

  7. Executable research compendia in geoscience research infrastructures

    Science.gov (United States)

    Nüst, Daniel

    2017-04-01

    From generation through analysis and collaboration to communication, scientific research requires the right tools. Scientists create their own software using third party libraries and platforms. Cloud computing, Open Science, public data infrastructures, and Open Source enable scientists with unprecedented opportunites, nowadays often in a field "Computational X" (e.g. computational seismology) or X-informatics (e.g. geoinformatics) [0]. This increases complexity and generates more innovation, e.g. Environmental Research Infrastructures (environmental RIs [1]). Researchers in Computational X write their software relying on both source code (e.g. from https://github.com) and binary libraries (e.g. from package managers such as APT, https://wiki.debian.org/Apt, or CRAN, https://cran.r-project.org/). They download data from domain specific (cf. https://re3data.org) or generic (e.g. https://zenodo.org) data repositories, and deploy computations remotely (e.g. European Open Science Cloud). The results themselves are archived, given persistent identifiers, connected to other works (e.g. using https://orcid.org/), and listed in metadata catalogues. A single researcher, intentionally or not, interacts with all sub-systems of RIs: data acquisition, data access, data processing, data curation, and community support [3]. To preserve computational research [3] proposes the Executable Research Compendium (ERC), a container format closing the gap of dependency preservation by encapsulating the runtime environment. ERCs and RIs can be integrated for different uses: (i) Coherence: ERC services validate completeness, integrity and results (ii) Metadata: ERCs connect the different parts of a piece of research and faciliate discovery (iii) Exchange and Preservation: ERC as usable building blocks are the shared and archived entity (iv) Self-consistency: ERCs remove dependence on ephemeral sources (v) Execution: ERC services create and execute a packaged analysis but integrate with

  8. Research in business ethics

    Directory of Open Access Journals (Sweden)

    G.J. Rossouw

    2001-08-01

    Full Text Available Research in business ethics is vital for the expansion and credibility of this fairly recent academic field. This article argues that there are three factors that are crucially important for research in business ethics. They are (a the ontological assumptions that research in this field is premised upon, (b the choice of research strategies and methodologies and (c the role of theory in research practice. Each of these three factors is explored and pitfalls relating to each of them are identified. The article also suggests guidelines for dealing with each of these factors in business ethics research.

  9. Fostering Integrity in Research

    Science.gov (United States)

    McNutt, M. K.

    2017-12-01

    The responsible conduct of research requires that all involved in the research enterprise - researchers, sponsors, reviewers, publishers, and communicators - adhere to a set of integrity principles to protect the public's investment. Given the increasing complexity and globalization of the research enterprise, the National Academies recently re-examined and updated its integrity recommendations for researchers in the report Fostering Integrity in Research, with sponsorship from the National Science Foundation. Major departures from the previous recommendations 25-years earlier are the recognition that practices that were previously classified as merely questionable are indeed detrimental to the responsible conduct of research. Furthermore, the report concludes that there has been insufficient effort to respond to the threats that lapses in research integrity pose to the quality of research products and the reputation of researchers as deserving of the public trust. It recommends the creation of an independent, non-profit entity dedicated to promoting research integrity by serving as a resource and clearing house for expertise, advice, materials, and best practices on fostering research integrity and responding to allegations of research misconduct.

  10. Economics of fusion research

    International Nuclear Information System (INIS)

    1977-01-01

    This report provides the results of a study of methods of economic analysis applied to the evaluation of fusion research. The study recognizes that a hierarchy of economic analyses of research programs exists: standard benefit-cost analysis, expected value of R and D information, and expected utility analysis. It is shown that standard benefit-cost analysis, as commonly applied to research programs, is inadequate for the evaluation of a high technology research effort such as fusion research. A methodology for performing an expected value analysis is developed and demonstrated and an overview of an approach to perform an expected utility analysis of fusion research is presented. In addition, a potential benefit of fusion research, not previously identified, is discussed and rough estimates of its magnitude are presented. This benefit deals with the effect of a fusion research program on optimal fossil fuel consumption patterns. The results of this study indicate that it is both appropriate and possible to perform an expected value analysis of fusion research in order to assess the economics of a fusion research program. The results indicate further that the major area of benefits of fusion research is likely due to the impact of a fusion research program on optimal fossil fuel consumption patterns and it is recommended that this benefit be included in future assessments of fusion research economics

  11. Economics of fusion research

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    1977-10-15

    This report provides the results of a study of methods of economic analysis applied to the evaluation of fusion research. The study recognizes that a hierarchy of economic analyses of research programs exists: standard benefit-cost analysis, expected value of R and D information, and expected utility analysis. It is shown that standard benefit-cost analysis, as commonly applied to research programs, is inadequate for the evaluation of a high technology research effort such as fusion research. A methodology for performing an expected value analysis is developed and demonstrated and an overview of an approach to perform an expected utility analysis of fusion research is presented. In addition, a potential benefit of fusion research, not previously identified, is discussed and rough estimates of its magnitude are presented. This benefit deals with the effect of a fusion research program on optimal fossil fuel consumption patterns. The results of this study indicate that it is both appropriate and possible to perform an expected value analysis of fusion research in order to assess the economics of a fusion research program. The results indicate further that the major area of benefits of fusion research is likely due to the impact of a fusion research program on optimal fossil fuel consumption patterns and it is recommended that this benefit be included in future assessments of fusion research economics.

  12. Research by design - a research strategy

    DEFF Research Database (Denmark)

    Hauberg, Jørgen

    2011-01-01

    Abstract The idea of an expressive component in research is important to the architectural industry. The expressive element - the possibility of expressing the qualitative aspects of the world and adding something new to the existing through experiments and proposals - is characteristic for the f......Abstract The idea of an expressive component in research is important to the architectural industry. The expressive element - the possibility of expressing the qualitative aspects of the world and adding something new to the existing through experiments and proposals - is characteristic...... for the field. All research environments, in the science tradition and in the humanities, have their characteristics. On the one hand, they live up to certain common scientific and methodological criteria - originality and transparency - on the other hand they have different practices, using different methods....... Research is ‘coloured’ by traditions and professions, and research in architecture should be coloured too, taking in consideration that the practise of architects stretch from natural science and sociology to art, and because the most important way in which the architect achieves new cognition is through...

  13. Research by Design - a research strategy

    DEFF Research Database (Denmark)

    Hauberg, Jørgen

    2011-01-01

    Abstract The idea of an expressive component in research is important to the architectural industry. The expressive element - the possibility of expressing the qualitative aspects of the world and adding something new to the existing through experiments and proposals - is characteristic for the f......Abstract The idea of an expressive component in research is important to the architectural industry. The expressive element - the possibility of expressing the qualitative aspects of the world and adding something new to the existing through experiments and proposals - is characteristic...... for the field. All research environments, in the science tradition and in the humanities, have their characteristics. On the one hand, they live up to certain common scientific and methodological criteria - originality and transparency – and on the other hand, they have different practices, using different...... methods. Research is ‘coloured’ by traditions and professions, and research in architecture should be coloured too, taking into consideration that the practice of architects stretches from natural science and sociology to art and that the most important way in which the architect achieves new cognition...

  14. Research Programs & Initiatives

    Science.gov (United States)

    CGH develops international initiatives and collaborates with other NCI divisions, NCI-designated Cancer Centers, and other countries to support cancer control planning, encourage capacity building, and support cancer research and research networks.

  15. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Highlights Science Education Research in NIH Labs & Clinics Training Opportunities Library Resources Research ... Who We Are What We Do Jobs at NIH Visitor Information Frequently Asked Questions Contact ...

  16. Research reactor instrumentation

    International Nuclear Information System (INIS)

    Boeck, H.; Villa, M.

    2001-02-01

    This is a textbook on research reactor instrumentation for training purposes, it gives a survey on research reactor instrumentation requirements and eight exercises covering the major aspects of this topic are presented. (author)

  17. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... at the NIH, is studying stuttering with the participation of research volunteers. If you stutter or have ... to participate in Dr. Drayna’s clinical research trial. Participation involves providing a small blood sample and a ...

  18. Cereal Crops Research Unit

    Data.gov (United States)

    Federal Laboratory Consortium — The mission of the Cereal Crops Research Unit is to 1) conduct basic research to identify and understand the biological processes affecting the growth, development...

  19. Researcher Interview: Tom Hudson

    Science.gov (United States)

    Tom Hudson, M.D., President and Scientific Director of the Ontario Institute for Cancer Research, describes the International Cancer Genome Consortium (ICGC), which brings together cancer genomic data and research from across the world.

  20. Newport Research Station

    Data.gov (United States)

    Federal Laboratory Consortium — The Newport Research Station is the Center's only ocean-port research facility. This station is located at Oregon State University's Hatfield Marine Science Center,...

  1. Understanding Medical Research

    Science.gov (United States)

    ... hear about the results of a new medical research study. Sometimes the results of one study seem ... a randomized controlled clinical trial? Where was the research done? If a new treatment was being tested, ...

  2. Ice Engineering Research Area

    Data.gov (United States)

    Federal Laboratory Consortium — Refrigerated Physical Modeling of Waterways in a Controlled EnvironmentThe Research Area in the Ice Engineering Facility at the Cold Regions Research and Engineering...

  3. Basic Research Firing Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Basic Research Firing Facility is an indoor ballistic test facility that has recently transitioned from a customer-based facility to a dedicated basic research...

  4. Researching Identity and Interculturality

    DEFF Research Database (Denmark)

    Lønsmann, Dorte

    2016-01-01

    Review of: Researching Identity and Interculturality / by F. Dervin and K. Risager (eds.). Routledge 2015, 245 pp.......Review of: Researching Identity and Interculturality / by F. Dervin and K. Risager (eds.). Routledge 2015, 245 pp....

  5. Scoliosis Research Society

    Science.gov (United States)

    Scoliosis Research Society Close Menu Member Login Become a Member Home Find a Specialist | Calendar Contact | Donate ... a Member Find a Specialist Calendar Contact Donate Scoliosis Research Society Dedicated to the optimal care of ...

  6. The Singapore research story

    CERN Document Server

    Teck Seng, Low; Thampuran, Raj

    2016-01-01

    Ever since Singapore became independent in 1965, its leaders have invested tremendous efforts and resources to develop its economy in order to create jobs for its people and to support national development. This book describes the challenging journey of Singapore in developing a knowledge-based economy driven by research and innovation and the roles played by research institutes, universities, research manpower and appropriate collaboration between research institutes and industry. The book traces the foundations of Singapore's research story from the time of its independence in 1965 to the present day. Through interviews with the key players and research into the records, the establishment of the key institutes and the roles of a global cast of researchers, scientists and engineers in setting up the R&D infrastructure are outlined. The impact that the concerted efforts of the last 25 years to build up a credible and world-class research capability in Singapore is discussed, as are the tremendous challeng...

  7. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... the effects of the disorder. How Do Researchers Study Stuttering? Video of How Do Researchers Study Stuttering? ... March 23, 2016 Connect with Us Contact Us Twitter Facebook Instagram YouTube Flickr More Social Media from ...

  8. Mukilteo Research Station

    Data.gov (United States)

    Federal Laboratory Consortium — Research at the Mukilteo Research Station focuses on understanding the life cycle of marine species and the impacts of ecosystem stressors on anadromous and marine...

  9. Headache: Hope through Research

    Science.gov (United States)

    ... Home » Disorders » Patient & Caregiver Education » Hope Through Research Headache: Hope Through Research Download publication Introduction Why Headaches ... of cancer or HIV/AIDS. top Diagnosing Your Headache How and under what circumstances a person experiences ...

  10. Research peer exchange, 2014.

    Science.gov (United States)

    2017-08-01

    The WSDOT Research Peer Exchange was held in Olympia, Washington on May 13 and 14, 2014 and addressed Research Program and Project Management as described in the following paragraphs: Program Management There are numerous funding programs, standing c...

  11. Framing Artistic Research

    DEFF Research Database (Denmark)

    Oxvig, Henrik; Peder Pedersen, Claus

    2016-01-01

    A mail correspondence between heads of research at respectively The Royal Danish Academy of Fine Arts Schools of Architecture, Design and Conservation and the Aarhus School of Architecture. The correspondence discuss how to implement artistic research....

  12. DCB - Tumor Metastasis Research

    Science.gov (United States)

    Tumor metastasis research examines the mechanisms that allow cancer cells to leave the primary tumor and spread to another part of the body. Learn about recent tumor metastasis research studies supported by the Division of Cancer Biology.

  13. Research Reports: Marijuana

    Science.gov (United States)

    ... Publications » Research Reports » Marijuana » Letter From the Director Marijuana Email Facebook Twitter Letter From the Director Photo ... May 2, 2018. press ctrl+c to copy Marijuana and Cannabinoids: A Neuroscience Research Summit March 22- ...

  14. Aquatic Research Laboratory (ARL)

    Data.gov (United States)

    Federal Laboratory Consortium — Columbia River and groundwater well water sources are delivered to the Aquatic Research Laboratory (ARL), where these resources are used to conduct research on fish...

  15. Environmental Toxicology Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Fully-equipped facilities for environmental toxicology researchThe Environmental Toxicology Research Facility (ETRF) located in Vicksburg, MS provides over 8,200 ft...

  16. Nordic research in ophthalmology

    DEFF Research Database (Denmark)

    Stefánsson, Einar; Zetterström, Charlotta; Ehlers, Niels

    2003-01-01

    Ophthalmology, eye research, cornea, catarcat, paediatric ophthalmology, glaucoma, diabetic eye disease, age-related macular degeneration, ophthalmic oncology......Ophthalmology, eye research, cornea, catarcat, paediatric ophthalmology, glaucoma, diabetic eye disease, age-related macular degeneration, ophthalmic oncology...

  17. Lymphatic Education & Research Network

    Science.gov (United States)

    Lymphatic Education & Research Network Donate Now Become a Supporting Member X Living with LYMPHEDEMA AND Lymphatic Disease FAQs About ... December 8, 2017 11.08.2017 The Lymphatic Education & Research Network… Read More > ASRM LE&RN Combined ...

  18. Epidemiology & Genomics Research Program

    Science.gov (United States)

    The Epidemiology and Genomics Research Program, in the National Cancer Institute's Division of Cancer Control and Population Sciences, funds research in human populations to understand the determinants of cancer occurrence and outcomes.

  19. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Educational Resources Glossary of Common Terms If You Have a Question In the News Researcher Story: Stuttering ... participation of research volunteers. If you stutter or have a family member who stutters, you could be ...

  20. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... research volunteers. If you stutter or have a family member who stutters, you could be eligible to ... Researchers Study Stuttering? A large portion of the family clustering of stuttering is explained by genes and ...

  1. Mesothelioma Applied Research Foundation

    Science.gov (United States)

    Mesothelioma Foundation Experts Can Answer Your Questions! The Mesothelioma Applied Research Foundation's team of experts is available ... up for our e-newsletter . Our Impact Against Mesothelioma 9.8 Million in research funded 600 People ...

  2. Fanconi Anemia Research Fund

    Science.gov (United States)

    ... Support Publications Fundraising News What is the Fanconi Anemia Research Fund? Fanconi anemia is an inherited disease that can lead to ... population. Lynn and Dave Frohnmayer started the Fanconi Anemia Research Fund, in 1989 to find effective treatments ...

  3. Framing Artistic Research

    DEFF Research Database (Denmark)

    Oxvig, Henrik; Peder Pedersen, Claus

    2016-01-01

    A mail correspondence between heads of research at respectively The Royal Danish Academy of Fine Arts Schools of Architecture, Design and Conservation and the Aarhus School of Architecture. The correspondence discuss how to implement artistic research.......A mail correspondence between heads of research at respectively The Royal Danish Academy of Fine Arts Schools of Architecture, Design and Conservation and the Aarhus School of Architecture. The correspondence discuss how to implement artistic research....

  4. Marketing research with SPSS

    OpenAIRE

    JANSSENS, Wim; WIJNEN, Katrien; DE PELSMACKER, Patrick; VAN KENHOVE, Patrick

    2008-01-01

    In the past, there have been Marketing Research books and there have been SPSS guide books. This book combines the two, providing a step-by-step treatment of the major choices facing marketing researchers when using SPSS. The authors offer a concise approach to analysing quantitative marketing research data in practice. Whether at undergraduate or graduate level, students are often required to analyse data, in methodology and marketing research courses, in a thesis, or in project work. Althou...

  5. The qualitative research proposal

    OpenAIRE

    Klopper, Hester

    2008-01-01

    Qualitative research in the health sciences has had to overcome many prejudices and a number of misunderstandings, but today qualitative research is as acceptable as quantitative research designs and is widely funded and published. Writing the proposal of a qualitative study, however, can be a challenging feat, due to the emergent nature of the qualitative research design and the description of the methodology as a process. Even today, many sub-standard proposals at post-graduate evaluation c...

  6. Research in cardiovascular care

    DEFF Research Database (Denmark)

    Jaarsma, Tiny; Deaton, Christi; Fitzsimmons, Donna

    2014-01-01

    with the increasing opportunities and challenges in multidisciplinary research, the Science Committee of the Council on Cardiovascular Nursing and Allied Professionals (CCNAP) recognised the need for a position statement to guide researchers, policymakers and funding bodies to contribute to the advancement...... of the body of knowledge that is needed to further improve cardiovascular care. In this paper, knowledge gaps in current research related to cardiovascular patient care are identified, upcoming challenges are explored and recommendations for future research are given....

  7. What Is Qualitative Research?

    Science.gov (United States)

    Otani, Takashi

    2017-01-01

    The article is an in-depth explanation of qualitative research, an approach increasingly prevalent among today's research communities. After discussing its present spread within the health sciences, the author addresses: 1. Its definition. 2. Its characteristics, as well as its theoretical and procedural background. 3. Its procedures. 4. Differences between qualitative and quantitative approaches. 5. Mixed methods incorporating quantitative research. And in conclusion: 6. The importance of establishing an epistemological perspective in qualitative research.

  8. Ecological Research Division, Marine Research Program

    International Nuclear Information System (INIS)

    1980-05-01

    This report presents program summaries of the various projects sponsored during 1979 by the Marine Research Program of the Ecological Research Division. Program areas include the effects of petroleum hydrocarbons on the marine environment; a study of the baseline ecology of a proposed OTEC site near Puerto Rico; the environmental impact of offshore geothermal energy development; the movement of radionuclides through the marine environment; the environmental aspects of power plant cooling systems; and studies of the physical and biological oceangraphy of the continental shelves bordering the United States

  9. Ecological Research Division, Marine Research Program

    Energy Technology Data Exchange (ETDEWEB)

    1980-05-01

    This report presents program summaries of the various projects sponsored during 1979 by the Marine Research Program of the Ecological Research Division. Program areas include the effects of petroleum hydrocarbons on the marine environment; a study of the baseline ecology of a proposed OTEC site near Puerto Rico; the environmental impact of offshore geothermal energy development; the movement of radionuclides through the marine environment; the environmental aspects of power plant cooling systems; and studies of the physical and biological oceangraphy of the continental shelves bordering the United States.

  10. Research of vs research for education policy

    DEFF Research Database (Denmark)

    of implications for education policy-making processes and not least it has had an impact on who conducts policy studies and how. This book brings together a variety of contributions which explore recent political economic changes affecting education policy-making processes including the ascension of neo......-liberalism and the transnationalization of education policy-making, as well as the tension between research of policy and research for policy. Working from different perspectives, the authors help to provide a better understanding of these two important sets of issues which the field of education must contend with today....

  11. School Climate Research

    Science.gov (United States)

    Thapa, Amrit

    2013-01-01

    School climate research is clearly evolving. The field demands rigorous and empirically sound research that focuses on relating specific aspects and activities of interventions to changes in specific components of school climate. We also need empirical evidence based on sound research techniques on how both interventions and climate affect…

  12. Interviewing like a researcher

    DEFF Research Database (Denmark)

    Evald, Majbritt Rostgaard; Freytag, Per Vagn; Nielsen, Suna Løwe

    2018-01-01

    the transformation that neutral research methods go through, we consider an often-used method in business research, which researchers often become familiar with or have opinions about, which is the personal interview. The illustration of how the personal interview can be influenced by three different paradigms lays...

  13. Developing the research idea.

    Science.gov (United States)

    Toledo-Pereyra, Luis H

    2011-01-01

    After the interest in surgical research, developing the research idea is of fundamental importance because without it we can not have research. Where do the research ideas come from then? Is there any better way to improve our ability to generate research ideas? Where do they come from? What are the factors that stimulate the research idea? Anything we do in and out of medicine or surgery should be the force that will maintain our mind occupied on our future research ideas. From events in the clinical arena to discussions in formal rounds or informal meetings should be the origin of our thinking in research. So, the generation of research ideas come from any place and we should be aware of it. We could be successful in research if we could produce and accumulate the ideas as they frequently present to us in our professional or daily life. The research environment could help us in securing the presence and evolution of the idea. Be aware of changes and future developments and be ready to admit and grow the research idea that could be presented to you during the practice of medicine.

  14. Designing requirements engineering research

    NARCIS (Netherlands)

    Wieringa, Roelf J.; Heerkens, Johannes M.G.

    2007-01-01

    Engineering sciences study different topics than natural sciences, and utility is an essential factor in choosing engineering research problems. But despite these differences, research methods for the engineering sciences are no different than research methods for any other kind of science. At most

  15. Nuclear energy related research

    International Nuclear Information System (INIS)

    Salminen, Pertti

    1987-02-01

    This annual Research Programme Plan covers the nuclear related research planned to be carried out at the Technical Research Centre of Finland (VTT) in 1987 and funded by the Ministry of Trade and Industry in Finland, the Nordic Council of Ministers and VTT itself

  16. Physical Research Laboratory

    Indian Academy of Sciences (India)

    The Physical Research Laboratory (PRL) is a leading research institution of the country engaged in basic research in several areas of experimental and theoretical physics, space and earth sciences. The Laboratory conducts summer training programme for students every year for about 2 months (during May 15 - July 15) ...

  17. Advanced research technology transfer

    International Nuclear Information System (INIS)

    Naraghi, Masud

    1977-01-01

    The importance of advanced research in the less developed countries of the world is described. Advanced research is a way of building from the top; it helps industrial development; it provides ''know-how'' economically; it enhances international understanding; it prevents the brain drain to developed countries and is of mutual benefit. The problems concerned with this type of research are pointed out

  18. Action and Interactiv research

    DEFF Research Database (Denmark)

    Nielsen, Kurt Aagaard; Svensson, Lennart

    The text is written as a first version of editors introduction to a book about action research/interactive research in Nordic countries. You can read abouttrends and contradictions in the history of action research.The authors question the trends and demands a more explicit critical approach...

  19. Isotopic research in Antarctica

    International Nuclear Information System (INIS)

    Schuetze, H.

    1983-01-01

    Since 1978 scientists of the Central Institute of Isotope- and Radiation Research of the Academy of Sciences of the GDR have participated in antarctic research. Substantial results have been achieved in research on isotope ratios, on the dynamics of water resources, on concentration of deuterium in lichens, and on age determination of a mummified seal and a penguin colony

  20. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Info Lines Health Services Locator HealthCare.gov NIH Clinical Research Trials and You Talking to Your Doctor Science ... Labs & Clinics Training Opportunities Library Resources Research Resources Clinical Research Resources Safety, Regulation and Guidance More » Quick Links ...

  1. Nuclear energy related research

    International Nuclear Information System (INIS)

    Toerroenen, K.; Kilpi, K.

    1985-01-01

    This research programme plan for 1985 covers the nuclear energy related research planned to be carried out at the Technical Research Centre of Finland (VTT) and funded by the Ministry of Trade and Industry in Finland, the Nordic Council of Ministers and VTT

  2. Research Utilization in Rehabilitation.

    Science.gov (United States)

    Rogers, Everett M.

    In terms of its attention to research utilization, vocational rehabilitation today may be where agriculture was in 1913. One reason for this is an inadequate understanding of the process of research utilization. Scattered studies of research utilization have occurred, but suffer from a lack of integration. Among propositions that may be postulated…

  3. Researcher Story: Stuttering

    Medline Plus

    Full Text Available ... Health Services Locator HealthCare.gov NIH Clinical Research Trials and You Talking to Your Doctor Science Education ... are here Home » Health Information » NIH Clinical Research Trials and You NIH Clinical Research Trials and You ...

  4. Research at WNRE

    International Nuclear Information System (INIS)

    Johnson, H.M.

    1986-01-01

    A broad overview of the structure and research of Whiteshell Nuclear Research Establishment (WNRE) is presented. The research programs are divided amongst four divisions and a new business project: Waste Management Division, Applied Science Division, Chemistry and Materials Science Division, Mini-Reactor Business, and the Health and Safety Division. All divisions are briefly described. Emphasis is placed upon the Health and Safety division

  5. FAQs for Research Awards

    International Development Research Centre (IDRC) Digital Library (Canada)

    Jean-Claude Dumais

    Visit the Grants page for details on the positions offered by IDRC's programs. 9) How do you select Research Awardees? You can find out more about the Research Awards evaluation process in the Call for Application and Checklist documents under the Grants Web page. 10) Can someone at IDRC review my research ...

  6. Multimedia Teacher Research

    Science.gov (United States)

    Leaman, Heather; DiLucchio, Connie

    2015-01-01

    In this qualitative study, two teacher educators and course instructors in a Masters of Education (M.Ed.) program explored beginning teacher researchers' use of multimedia to support action research. Fifty-eight teachers (36 in spring 2010 and 22 in spring 2011) completed teacher research as the capstone in their M.Ed. program. Teachers utilized…

  7. Research in International Education

    Science.gov (United States)

    Dolby, Nadine; Rahman, Aliya

    2008-01-01

    Until recently, international education has existed at the margins of educational research. However, in the current context of globalization, international education has moved closer to the center of educational research throughout the world. In this article, the authors identify, describe, and analyze six distinct research approaches to…

  8. Music Researchers' Musical Engagement

    Science.gov (United States)

    Wollner, Clemens; Ginsborg, Jane; Williamon, Aaron

    2011-01-01

    There is an increasing awareness of the importance of reflexivity across various disciplines, which encourages researchers to scrutinize their research perspectives. In order to contextualize and reflect upon research in music, this study explores the musical background, current level of musical engagement and the listening habits of music…

  9. Educational design research

    NARCIS (Netherlands)

    McKenney, Susan; Reeves, Thomas C.; Spector, J. Michael; Merrill, M. David; Elen, Jan; Bishop, M.J.

    2014-01-01

    Educational design research is a genre of research in which the iterative development of solutions to practical and complex educational problems provides the setting for scientific inquiry. The solutions can be educational products, processes, programs, or policies. Educational design research not

  10. Research Messages 2014

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2015

    2015-01-01

    "Research Messages 2014" is a collection of summaries of research published by the National Centre for Vocational Education Research (NCVER) in 2014 in the context of changing economic, industrial, social and education conditions, organised under the following broad categories: (1) Productivity: to sustain and build Australia's human…

  11. 7. Framework Research Program

    International Nuclear Information System (INIS)

    Donghi, C.; Pieri, Alberto; Manzini, G.

    2006-01-01

    The UE it means to face the problem of the deficiency if investments in the RS field. In particular politics of research are turned to pursue three main goals: the strengthening of the scientific excellence in Europe; the increase of total investments for research; the realization of European space of research [it

  12. Research Methods in Education

    Science.gov (United States)

    Check, Joseph; Schutt, Russell K.

    2011-01-01

    "Research Methods in Education" introduces research methods as an integrated set of techniques for investigating questions about the educational world. This lively, innovative text helps students connect technique and substance, appreciate the value of both qualitative and quantitative methodologies, and make ethical research decisions.…

  13. Isotope research materials

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    Preparation of research isotope materials is described. Topics covered include: separation of tritium from aqueous effluents by bipolar electrolysis; stable isotope targets and research materials; radioisotope targets and research materials; preparation of an 241 Am metallurgical specimen; reactor dosimeters; ceramic and cermet development; fission-fragment-generating targets of 235 UO 2 ; and wire dosimeters for Westinghouse--Bettis

  14. Highland Medical Research Journal

    African Journals Online (AJOL)

    The aim of the Highland Medical Research Journal is to publish scientific research in various fields of medical science and to communicate such research findings to the larger world community. It aims to promote cooperation and understanding amoungst workers in various fields of medical science.

  15. Stimulating translational research

    DEFF Research Database (Denmark)

    Bentires-Alj, Mohamed; Rajan, Abinaya; van Harten, Wim

    2015-01-01

    Translational research leaves no-one indifferent and everyone expects a particular benefit. We as EU-LIFE (www.eu-life.eu), an alliance of 13 research institutes in European life sciences, would like to share our experience in an attempt to identify measures to promote translational research...

  16. Action research: Scandinavian Experiences

    DEFF Research Database (Denmark)

    Rasmussen, Lauge Baungaard

    2004-01-01

    The article focus on paradigms, methods and ethics of action research in the Scandinavian countries. The special features of the action research paradigm is identified. A historical overview follows of some main action research projects in Norway, Sweden and Denmark. The tendency towards upsclae...

  17. Research Messages 2017

    Science.gov (United States)

    National Centre for Vocational Education Research (NCVER), 2018

    2018-01-01

    This report brings together research publicly released by the National Centre for Vocational Education Research (NCVER) over the year. The 2017 compilation reflects an extensive collection of NCVER research activities undertaken during 2017, comprising reports, summaries, infographics, occasional papers, presentations and webinars. NCVER has…

  18. Translation of research outcome

    African Journals Online (AJOL)

    unhcc

    2017-01-03

    Jan 3, 2017 ... century, advances in science and technology have immensely contributed to global development in general ... Addressing such challenges requires investment in research and innovation. Relevant research is always a .... Do we need "more research" or better implementation through knowledge brokering.

  19. Translation of research outcome

    African Journals Online (AJOL)

    unhcc

    2017-01-03

    Jan 3, 2017 ... introducing implementation research, implementation science, knowledge translation to improve the role of research in development programs including health policies and programs. In Ethiopia, health sector felt the gap between health research and health policy, strategy and. 2 CNN TV host's statement.

  20. Rich Design Research Space

    Directory of Open Access Journals (Sweden)

    Birger Sevaldson

    2008-10-01

    Full Text Available This paper introduces and discusses a Rich Research Space as an inclusive methodological framework and scaffold for research-by-design. The Rich Research Space especially addresses the issue of richness in design processes and design-led research. There is a general trend towards increased complexity in design processes, caused on one hand by the increasing depth and width in the use of design media and methods, and on the other hand by the increasing complexity and interdependency of society due to globalisation. These issues confront the designer-researcher with new challenges. This paper formulates a research strategy for research-by-design in fields that have a high degree of richness in the use of media, the amount of information, and the methods involved. The Rich Research Space concept proposed takes into account the physical, social, and cultural spaces, and the virtual and visual media spaces in which the research-by-design takes place. The concept takes the form of a specific integral approach to design, and a holistic theoretical mindset. It embraces many types of investigation, from analytical to intuitive. The Rich Research Space provides a flexible framework within which the complexity of research-by-design can be interrelated, discussed, and reflected upon. Potentially, it can create a more involved role for the designer-researcher, a role that allows contributions towards the resolution of ever more pressing issues in our society. This approach is currently one of a limited number of possible frameworks that the design professions can utilize in order to make a difference in a world of at times overwhelming complexity. The concept of the Rich Research Space is discussed with reference to an art installation called Barely.Keywords: Research by design, collaborative design, complexity, creativity, research methods.