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1

Strike Point Control for the National Spherical Torus Experiment (NSTX)  

SciTech Connect (OSTI)

This paper presents the first control algorithm for the inner and outer strike point position for a Spherical Torus (ST) fusion experiment and the performance analysis of the controller. A liquid lithium divertor (LLD) will be installed on NSTX which is believed to provide better pumping than lithium coatings on carbon PFCs. The shape of the plasma dictates the pumping rate of the lithium by channeling the plasma to LLD, where strike point location is the most important shape parameter. Simulations show that the density reduction depends on the proximity of strike point to LLD. Experiments were performed to study the dynamics of the strike point, design a new controller to change the location of the strike point to desired location and stabilize it. The most effective PF coils in changing inner and outer strike points were identified using equilibrium code. The PF coil inputs were changed in a step fashion between various set points and the step response of the strike point position was obtained. From the analysis of the step responses, PID controllers for the strike points were obtained and the controller was tuned experimentally for better performance. The strike controller was extended to include the outer-strike point on the inner plate to accommodate the desired low outer-strike points for the experiment with the aim of achieving "snowflake" divertor configuration in NSTX.

E. Kolemen, D. A. Gates, C.W. Rowley, N. J. Kasdin, J. Kallman,S. Gerhardt, V. Soukhanovskii, D. Mueller

2010-07-09T23:59:59.000Z

2

Overview of Results from the National Spherical Torus Experiment (NSTX)  

SciTech Connect (OSTI)

The mission of NSTX is the demonstration of the physics basis required to extrapolate to the next steps for the spherical torus (ST), such as a plasma facing component test facility (NHTX) or an ST based component test facility (ST-CTF), and to support ITER. Key issues for the ST are transport, and steady state high {beta} operation. To better understand electron transport, a new high-k scattering diagnostic was used extensively to investigate electron gyro-scale fluctuations with varying electron temperature gradient scale-length. Results from n = 3 braking studies confirm the flow shear dependence of ion transport. New results from electron Bernstein wave emission measurements from plasmas with lithium wall coating applied indicate transmission efficiencies near 70% in H-mode as a result of reduced collisionality. Improved coupling of High Harmonic Fast-Waves has been achieved by reducing the edge density relative to the critical density for surface wave coupling. In order to achieve high bootstrap fraction, future ST designs envision running at very high elongation. Plasmas have been maintained on NSTX at very low internal inductance l{sub i} {approx} 0.4 with strong shaping ({kappa} {approx} 2.7, {delta} {approx} 0.8) with {beta}{sub N} approaching the with-wall beta limit for several energy confinement times. By operating at lower collisionality in this regime, NSTX has achieved record non-inductive current drive fraction f{sub NI} {approx} 71%. Instabilities driven by super-Alfvenic ions are an important issue for all burning plasmas, including ITER. Fast ions from NBI on NSTX are super-Alfvenic. Linear TAE thresholds and appreciable fast-ion loss during multi-mode bursts are measured and these results are compared to theory. RWM/RFA feedback combined with n = 3 error field control was used on NSTX to maintain plasma rotation with {beta} above the no-wall limit. The impact of n > 1 error fields on stability is a important result for ITER. Other highlights are: results of lithium coating experiments, momentum confinement studies, scrape-off layer width scaling, demonstration of divertor heat load mitigation in strongly shaped plasmas, and coupling of CHI plasmas to OH ramp-up. These results advance the ST towards next step fusion energy devices such as NHTX and ST-CTF.

Gates, D; Ahn, J; Allain, J; Andre, R; Bastasz, R; Bell, M; Bell, R; Belova, E; Berkery, J; Betti, R; Bialek, J; Biewer, T; Bigelow, T; Bitter, M; Boedo, J; Bonoli, P; Bozzer, A; Brennan, D; Breslau, J; Brower, D; Bush, C; Canik, J; Caravelli, G; Carter, M; Caughman, J; Chang, C; Choe, W; Crocker, N; Darrow, D; Delgado-Aparicio, L; Diem, S; D'Ippolito, D; Domier, C; Dorland, W; Efthimion, P; Ejiri, A; Ershov, N; Evans, T; Feibush, E; Fenstermacher, M; Ferron, J; Finkenthal, M; Foley, J; Frazin, R; Fredrickson, E; Fu, G; Funaba, H; Gerhardt, S; Glasser, A; Gorelenkov, N; Grisham, L; Hahm, T; Harvey, R; Hassanein, A; Heidbrink, W; Hill, K; Hillesheim, J; Hillis, D; Hirooka, Y; Hosea, J; Hu, B; Humphreys, D; Idehara, T; Indireshkumar, K; Ishida, A; Jaeger, F; Jarboe, T; Jardin, S; Jaworski, M; Ji, H; Jung, H; Kaita, R; Kallman, J; Katsuro-Hopkins, O; Kawahata, K; Kawamori, E; Kaye, S; Kessel, C; Kim, J; Kimura, H; Kolemen, E; Krasheninnikov, S; Krstic, P; Ku, S; Kubota, S; Kugel, H; La Haye, R; Lao, L; LeBlanc, B; Lee, W; Lee, K; Leuer, J; Levinton, F; Liang, Y; Liu, D; Luhmann, N; Maingi, R; Majeski, R; Manickam, J; Mansfield, D; Maqueda, R; Mazzucato, E; McCune, D; McGeehan, B; McKee, G; Medley, S; Menard, J; Menon, M; Meyer, H; Mikkelsen, D; Miloshevsky, G; Mitarai, O; Mueller, D; Mueller, S; Munsat, T; Myra, J; Nagayama, Y; Nelson, B; Nguyen, X; Nishino, N; Nishiura, M; Nygren, R; Ono, M; Osborne, T; Pacella, D; Park, H; Park, J; Paul, S; Peebles, W; Penaflor, B; Peng, M; Phillips, C; Pigarov, A; Podesta, M; Preinhaelter, J; Ram, A; Raman, R; Rasmussen, D; Redd, A; Reimerdes, H; Rewoldt, G; Ross, P; Rowley, C; Ruskov, E; Russell, D; Ruzic, D; Ryan, P; Sabbagh, S; Schaffer, M; Schuster, E; Scott, S; Shaing, K; Sharpe, P; Shevchenko, V; Shinohara, K; Sizyuk, V; Skinner, C; Smirnov, A; Smith, D; Smith, S; Snyder, P; Soloman, W; Sontag, A; Soukhanovskii, V; Stoltzfus-Dueck, T; Stotler, D; Strait, T; Stratton, B; Stutman, D; Takahashi, R; Takase, Y; Tamura, N; Tang, X; Taylor, G; Taylor, C; Ticos, C; Tritz, K; Tsarouhas, D; Turrnbull, A; Tynan, G; Ulrickson, M; Umansky, M; Urban, J; Utergberg, E; Walker, M; Wampler, W; Wang, J; Wang, W; Weland, A

2009-01-05T23:59:59.000Z

3

Plasma Shape Control on the National Spherical Torus Experiment (NSTX) using Real-time Equilibrium Reconstruction  

SciTech Connect (OSTI)

Plasma shape control using real-time equilibrium reconstruction has been implemented on the National Spherical Torus Experiment (NSTX). The rtEFIT code originally developed for use on DIII-D was adapted for use on NSTX. The real-time equilibria provide calculations of the flux at points on the plasma boundary, which is used as input to a shape control algorithm known as isoflux control. The flux at the desired boundary location is compared to a reference flux value, and this flux error is used as the basic feedback quantity for the poloidal-field coils on NSTX. The hardware that comprises the control system is described, as well as the software infrastructure. Examples of precise boundary control are also presented.

D.A. Gates; J.R. Ferron; M. Bell; T. Gibney; R. Johnson; R.J. Marsala; D. Mastrovito; J.E. Menard; D. Mueller; B. Penaflor; S.A. Sabbagh; T. Stevenson

2005-04-15T23:59:59.000Z

4

Status of the control system on the National Spherical Torus Experiment (NSTX)  

Science Journals Connector (OSTI)

In 2003, the National Spherical Torus Experiment (NSTX) plasma control system was used for plasma shape control using real-time equilibrium reconstruction (using the rtEFIT code). rtEFIT is now in routine use for plasma boundary control. More recently, the system has been upgraded to support feedback control of the resistive wall mode (RWM). This paper describes the hardware and software improvements that were made in support of these physics requirements. The control computer is an eight processor embedded system. The real-time data acquisition system now acquires 352 channels of data at 5 kHz for each NSTX plasma discharge. The latency for the data acquisition, which uses the Front Panel Data Port (FPDP) protocol, is measured to be ?8 ?s. A Stand-Alone Digitizer (SAD), designed at PPPL, along with an FPDP Input Multiplexing Module (FIMM) allows for simple modular upgrades. An interface module was built to interface between the FPDP output of the NSTX control system and the legacy Power Conversion Link (PCLink) used for communicating with the PPPL power supplies (first used for TFTR). Additionally a module has been built for communicating with the switching power amplifiers (SPA) recently installed on NSTX. In addition to the hardware developments, the control software on the NSTX control system has been upgraded. The device driver software for the hardware described above will be discussed, as well as the new control algorithms that have been developed to control the switching power supplies for RWM control. A reliable mode detection algorithm for RWM feedback is currently under development.

D.A. Gates; J.R. Ferron; M. Bell; T. Gibney; R. Johnson; R.J. Marsala; D. Mastrovito; J.E. Menard; D. Mueller; C. Neumeyer; B. Penaflor; T. Stevenson

2006-01-01T23:59:59.000Z

5

Detection of Disruptions in the High-? Spherical Torus NSTX  

SciTech Connect (OSTI)

This paper describes the prediction of disruptions based on diagnostic data in the high-? spherical torus NSTX [M. Ono, et al., Nuclear Fusion 40 , 557 (2000)]. The disruptive threshold values on many signals are examined. In some cases, raw diagnostic data can be used as a signal for disruption prediction. In others, the deviations of the plasma data from simple models provides the signal used to determine the proximity to disruption. However, no single signal and threshold value can form the basis for disruption prediction in NSTX; thresholds that produce an acceptable false positive rate have too large a missed or late warning rate, while combinations that produce an acceptable rate of missed or late warnings have an unacceptable false positive rate. To solve this problem, a novel means of combining multiple threshold tests has been developed. After being properly tuned, this algorithm can produce a false positive rate of 2.8%, with a late warning rate of 3.7% when applied to a database of ~2000 disruptions collected from three run campaigns. Furthermore, many of these false positives are triggered by near-disruptive MHD events that might indeed be disruptive in larger plasmas with more stored energy. However, the algorithm is less efficient at detecting the MHD event that prompts the disruption process.

Gerhardt, S P; Bell, R E; LeBlanc, B P; Menard, J E; Mueller, D; Roquemore, A L; Sabbagh, S A

2013-01-16T23:59:59.000Z

6

FACT SHEET NSTX-U  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

is virtually inexhaustible. The largest project at PPPL today is an advanced nuclear fusion reactor-or toka- mak-called the National Spherical Torus Experiment (NSTX)....

7

Ohmic Flux Consumption During Initial Operation of the NSTX Spherical Torus  

E-Print Network [OSTI]

Ohmic Flux Consumption During Initial Operation of the NSTX Spherical Torus J. Menard 1 , B. Le­2.2, triangularity #=0.4, internal inductance l i =0.6, and Ejima coe#cient CE=0.35. Flux consumption e of the equations used for parameterizing flux consumption, Section 3. describes the experimental results including

8

Disruptions, Disruptivity, and Safer Operating Windows in the High-? Spherical Torus NSTX  

SciTech Connect (OSTI)

This paper discusses disruption rates, disruption causes, and disruptivity statistics in the high- ?N National Spherical Torus Experiment (NSTX) [M. Ono, et al. Nuclear Fusion 40, 557 (2000)]. While the overall disruption rate is rather high, configurations with high ?N , moderate q*, strong boundary shaping, sufficient rotation, and broad pressure and current profiles are found to have the lowest disruptivity; active n=1 control further reduces the disruptivity. The disruptivity increases rapidly for q*<2.7, which is substantially above the ideal MHD current limit. In quiescent conditions, qmin >1.25 is generally acceptable for avoiding the onset of core rotating n=1 kink/tearing modes; when EPM and ELM disturbances are present, the required qmin for avoiding those modes is raised to ~1.5. The current ramp and early flat-top phase of the discharges are prone to n=1 core rotating modes locking to the wall, leading to a disruption. Small changes to the discharge fueling during this phase can often mitigate the rotation damping associated with these modes and eliminate the disruption. The largest stored energy disruptions are those that occur at high current when a plasma current rampdown is initiated incorrectly.

Gerhardt, S P; Diallo, A; Gates, D; LeBlanc, B P; Menard, J E; Mueller, D; Sabbagh, S A; Soukhanovskii, V; Tritz, K

2012-09-27T23:59:59.000Z

9

National Spherical Torus Experiment (NSTX) | Princeton Plasma...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

the physics principles of spherically shaped plasmas -- hot ionized gases in which nuclear fusion will occur under the appropriate conditions of temperature, density, and...

10

National Spherical Torus Experiment NSTX UPGRADE PROJECT  

E-Print Network [OSTI]

test plans, and operating procedures relevant to the safe conduct of operations. It will also include not be applicable. PPPL uses ESHD 5008 (PPPL Environment, Safety & Health Manual) Section 11 ("Operations Hazard) Guiding Principle for Operations Authorization of experimental projects. The PPPL approval process

Princeton Plasma Physics Laboratory

11

Divertor Heat Flux Mitigation in the National Spherical Torus Experiment  

SciTech Connect (OSTI)

Steady-state handling of divertor heat flux is a critical issue for both ITER and spherical torus-based devices with compact high power density divertors. Significant reduction of heat flux to the divertor plate has been achieved simultaneously with favorable core and pedestal confinement and stability properties in a highly-shaped lower single null configuration in the National Spherical Torus Experiment (NSTX) [M. Ono et al., Nucl. Fusion 40, 557 2000] using high magnetic flux expansion at the divertor strike point and the radiative divertor technique. A partial detachment of the outer strike point was achieved with divertor deuterium injection leading to peak flux reduction from 4-6 MW m{sup -2} to 0.5-2 MW m{sup -2} in small-ELM 0.8-1.0 MA, 4-6 MW neutral beam injection-heated H-mode discharges. A self-consistent picture of outer strike point partial detachment was evident from divertor heat flux profiles and recombination, particle flux and neutral pressure measurements. Analytic scrape-off layer parallel transport models were used for interpretation of NSTX detachment experiments. The modeling showed that the observed peak heat flux reduction and detachment are possible with high radiated power and momentum loss fractions, achievable with divertor gas injection, and nearly impossible to achieve with main electron density, divertor neutral density or recombination increases alone.

Soukhanovskii, V A; Maingi, R; Gates, D A; Menard, J E; Paul, S F; Raman, R; Roquemore, A L; Bell, M G; Bell, R E; Boedo, J A; Bush, C E; Kaita, R; Kugel, H W; LeBlanc, B P; Mueller, D

2008-08-04T23:59:59.000Z

12

Operational limits in the National Spherical Torus Experiment  

SciTech Connect (OSTI)

The National Spherical Torus Experiment (NSTX) is a proof-of-principle scale device whose mission is to establish the physics basis of low aspect configurations most notably in the areas of plasma stability, transport and non-inductive current drive. The first series of physics experiments was conducted during the period from Sept. 1999 through Jan. 2000. Among the first experiments was a study to map out and characterize the operational density and q-limits. Density limits have typically been associated with enhanced radiated power due to overfuelling or impurity influx, although ion neoclassical transport may impose a density limit at very high densities in ohmic, gas-fueled plasmas. q-limits have typically been manifestations of destabilization of m=2/n=1 kink or tearing modes that lead to a sudden discharge termination.

S.M. Kaye; M. G. Bell; R. E. Bell; D. Gates; R. Maingi; E. Mazzucato; J. Menard; D. Mueller; W. Park; S. Paul; S. Sabbagh; D. Stutman

2000-06-12T23:59:59.000Z

13

Final Technical Report on DOE Grant for Modeling of Plasma Rotation in the National Spherical Torus Experiment  

SciTech Connect (OSTI)

This is the final technical report on the Modeling of Plasma Rotation in National Spherical Torus Experiment (NSTX) DOE Grant No. DE-FG02-02ER54679. The research subjects, technical abstracts, and publications where details of the research results can be found are reported here.

Shaing, K. C.

2009-07-09T23:59:59.000Z

14

Final Design Review (FDR) Committee Report National Spherical Torus Experiment  

E-Print Network [OSTI]

) Upgrade Project Princeton Plasma Physics Laboratory Princeton, NJ June 22-24, 2011 #12;Table of Contents 1.........................................................................................................................15 #12;2 1. Introduction A Final Design Review (FDR) was held at the Princeton Plasma Physics of a second neutral beam for plasma heating: The NSTX is the world's highest performance Spherical Torus (ST

Princeton Plasma Physics Laboratory

15

A Megawatt-level 28z GHz Heating System For The National Spherical Torus Experiment Upgrade  

SciTech Connect (OSTI)

The National Spherical Torus Experiment Upgrade (NSTX-U) will operate at axial toroidal fields of < 1 T and plasma currents, Ip < 2 MA. The development of non-inductive (NI) plasmas is a major long-term research goal for NSTX-U. Time dependent numerical simulations of 28 GHz electron cyclotron (EC) heating of low density NI start-up plasmas generated by Coaxial Helicity Injection (CHI) in NSTX-U predict a significant and rapid increase of the central electron temperature (Te(0)) before the plasma becomes overdense. The increased Te(0) will significantly reduce the Ip decay rate of CHI plasmas, allowing the coupling of fast wave heating and neutral beam injection. A megawatt-level, 28 GHz electron heating system is planned for heating NI start-up plasmas in NSTX-U. In addition to EC heating of CHI start-up discharges, this system will be used for electron Bernstein wave (EBW) plasma start-up, and eventually for EBW heating and current drive during the Ip flattop.

Taylor, Gary [PPPL

2014-04-01T23:59:59.000Z

16

Physics Design of a 28 GHz Electron Heating System for the National Spherical Torus Experiment Upgrade  

SciTech Connect (OSTI)

A megawatt-level, 28 GHz electron heating system is being designed to support non-inductive (NI) plasma current (I{sub p}) start-up and local heating and current drive (CD) in H-mode discharges in the National Spherical Torus Experiment Upgrade (NSTX-U). The development of fully NI I{sub p} start-up and ramp-up is an important goal of the NSTX-U research program. 28 GHz electron cyclotron (EC) heating is predicted to rapidly increase the central electron temperature (T{sub e}(0)) of low density NI plasmas generated by Coaxial Helicity Injection (CHI). The increased T{sub e}(0) will significantly reduce the Ip decay rate of CHI plasmas, allowing the coupling of fast wave heating and neutral beam injection. Also 28 GHz electron Bernstein wave (EBW) heating and CD can be used during the I{sub p} flat top in NSTX-U discharges when the plasma is overdense. Ray tracing and Fokker-Planck numerical simulation codes have been used to model EC and EBW heating and CD in NSTX-U. This paper presents a pre-conceptual design for the 28 GHz heating system and some of the results from the numerical simulations.

none,

2013-07-09T23:59:59.000Z

17

Conceptual design for the NSTX central instrumentation and control system  

Science Journals Connector (OSTI)

The design and construction phase for the national spherical torus experiment (NSTX) is under way at the Princeton Plasma Physics Laboratory (PPPL). Operation is scheduled to begin on April 30, 1999. This paper describes the conceptual design for the NSTX central instrumentation and control (I&C) system. Major elements of the central I&C system include the process control system, plasma control system, network system, data acquisition system, and synchronization system to support the NSTX experimental device.

D Bashore; G Oliaro; P Roney; P Sichta; K Tindall

1999-01-01T23:59:59.000Z

18

Imaging x-ray crystal spectrometers for the National Spherical Torus Experiment  

SciTech Connect (OSTI)

A new type of high-resolution x-ray imaging crystal spectrometers is described for implementation on the National Spherical Torus Experiment (NSTX) to provide spatially and temporally resolved data on the ion temperature, toroidal and poloidal plasma rotation, electron temperature, impurity ion-charge state distributions, and impurity transport. These data are derived from observations of the satellite spectra of heliumlike argon, ArthinspXVII, which is the dominant charge state for electron temperatures in the range from 0.4 to 3.0 keV and which is accessible to NSTX. Experiments at the Torus Experiment for Technology Oriented Research (TEXTOR) demonstrate that a throughput of 2{times}10{sup 5}thinspphotons/s (corresponding to the count-rate limit of the present detectors) can easily be obtained with small, nonperturbing argon gas puffs of less than 1{times}10{sup {minus}3}thinspTorrthinspscr(l)/s, so that it is possible to record spectra with a small statistical error and a good time resolution (typically 50 and 1 ms in some cases). Employing a novel design, which is based on the imaging properties of spherically bent crystals, the spectrometers will provide spectrally and spatially resolved images of the plasma for all experimental conditions, which include ohmically heated discharges as well as plasmas with rf and neutral-beam heating. The conceptual design, experimental results on the focusing properties, and relevant spectral data from TEXTOR are presented. {copyright} {ital 1999 American Institute of Physics.}

Bitter, M.; Hill, K.W.; Roquemore, A.L. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Beiersdorfer, P. [Department of Physics, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)] [Department of Physics, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Kahn, S.M. [Department of Physics, Columbia University, New York, New York 10027 (United States)] [Department of Physics, Columbia University, New York, New York 10027 (United States); Elliott, S.R. [Department of Physics, University of Washington, Seattle, Washington 98195 (United States)] [Department of Physics, University of Washington, Seattle, Washington 98195 (United States); Fraenkel, B. [Racah Institute of Physics, Hebrew University, Jerusalem (Israel)] [Racah Institute of Physics, Hebrew University, Jerusalem (Israel)

1999-01-01T23:59:59.000Z

19

Physics design of a 28 GHz electron heating system for the National Spherical Torus experiment upgrade  

SciTech Connect (OSTI)

A megawatt-level, 28 GHz electron heating system is being designed to support non-inductive (NI) plasma current (I{sub p}) start-up and local heating and current drive (CD) in H-mode discharges in the National Spherical Torus Experiment Upgrade (NSTX-U). The development of fully NI I{sub p} start-up and ramp-up is an important goal of the NSTXU research program. 28 GHz electron cyclotron (EC) heating is predicted to rapidly increase the central electron temperature (T{sub e}(0)) of low density NI plasmas generated by Coaxial Helicity Injection (CHI). The increased T{sub e}(0) will significantly reduce the I{sub p} decay rate of CHI plasmas, allowing the coupling of fast wave heating and neutral beam injection. Also 28 GHz electron Bernstein wave (EBW) heating and CD can be used during the I{sub p} flat top in NSTX-U discharges when the plasma is overdense. Ray tracing and Fokker-Planck numerical simulation codes have been used to model EC and EBW heating and CD in NSTX-U. This paper presents a pre-conceptual design for the 28 GHz heating system and some of the results from the numerical simulations.

Taylor, G.; Bertelli, N.; Ellis, R. A.; Gerhardt, S. P.; Hosea, J. C.; Poli, F. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Harvey, R. W. [CompX, Del Mar, California 92014 (United States); Raman, R. [University of Washington, Seattle, Washington 98195 (United States); Smirnov, A. P. [M.V. Lomonosov Moscow State University, Moscow (Russian Federation)

2014-02-12T23:59:59.000Z

20

The impact of lithium wall coatings on NSTX discharges and the engineering of the Lithium Tokamak eXperiment (LTX)  

SciTech Connect (OSTI)

Recent experiments on the National Spherical Torus eXperiment (NSTX) have shown the benefits of solid lithium coatings on carbon PFC's to diverted plasma performance, in both L- and H-mode confinement regimes. Better particle control, with decreased inductive flux consumption, and increased electron temperature, ion temperature, energy confinement time, and DD neutron rate were observed. Successive increases in lithium coverage resulted in the complete suppression of ELM activity in H-mode discharges. A liquid lithium divertor (LLD), which will employ the porous molybdenum surface developed for the LTX shell, is being installed on NSTX for the 2010 run period, and will provide comparisons between liquid walls in the Lithium Tokamak eXperiment (LTX) and liquid divertor targets in NSTX. LTX, which recently began operations at the Princeton Plasma Physics Laboratory, is the world's first confinement experiment with full liquid metal plasma-facing components (PFCs). All materials and construction techniques in LTX are compatible with liquid lithium. LTX employs an inner, heated, stainless steel-faced liner or shell, which will be lithium-coated. In order to ensure that lithium adheres to the shell, it is designed to operate at up to 500-600 degrees C to promote wetting of the stainless by the lithium, providing the first hot wall in a tokamak to Operate at reactor-relevant temperatures. The engineering of LTX will be discussed. (c) 2010 Elsevier B.V. All rights reserved.

Majeski, R. [Princeton Plasma Physics Laboratory (PPPL); Kugel, H. [Princeton Plasma Physics Laboratory (PPPL); Kaita, R. [Princeton Plasma Physics Laboratory (PPPL); Avasarala, S. [Princeton Plasma Physics Laboratory (PPPL); Bell, M. G. [Princeton Plasma Physics Laboratory (PPPL); Bell, R. E. [Princeton Plasma Physics Laboratory (PPPL); Berzak, L. [Princeton Plasma Physics Laboratory (PPPL); Beiersdorfer, P. [Lawrence Livermore National Laboratory (LLNL); Gerhardt, S. P. [Princeton Plasma Physics Laboratory (PPPL); Gransted, E. [Princeton Plasma Physics Laboratory (PPPL); Gray, T. [Princeton Plasma Physics Laboratory (PPPL); Jacobson, C. [Princeton Plasma Physics Laboratory (PPPL); Kallman, J. [Princeton Plasma Physics Laboratory (PPPL); Kaye, S. [Princeton Plasma Physics Laboratory (PPPL); Kozub, T. [Princeton Plasma Physics Laboratory (PPPL); LeBlanc, B. P. [Princeton Plasma Physics Laboratory (PPPL); Lepson, J. [Lawrence Livermore National Laboratory (LLNL); Lundberg, D. P. [Princeton Plasma Physics Laboratory (PPPL); Maingi, Rajesh [ORNL; Mansfield, D. [Princeton Plasma Physics Laboratory (PPPL); Paul, S. F. [Princeton Plasma Physics Laboratory (PPPL); Pereverzev, G. V. [Max-Planck-Institut fur Plasmaphysik, EURATOM Association, Garching, Germany; Schneider, H. [Princeton Plasma Physics Laboratory (PPPL); Soukhanovskii, V. [Lawrence Livermore National Laboratory (LLNL); Strickler, T. [Princeton Plasma Physics Laboratory (PPPL); Stotler, D. [Princeton Plasma Physics Laboratory (PPPL); Timberlake, J. [Princeton Plasma Physics Laboratory (PPPL); Zakharov, L. E. [Princeton Plasma Physics Laboratory (PPPL)

2010-01-01T23:59:59.000Z

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21

Modeling of Spherical Torus Plasmas for Liquid Lithium Wall Experiments  

SciTech Connect (OSTI)

Liquid metal walls have the potential to solve first-wall problems for fusion reactors, such as heat load and erosion of dry walls, neutron damage and activation, and tritium inventory and breeding. In the near term, such walls can serve as the basis for schemes to stabilize magnetohydrodynamic (MHD) modes. Furthermore, the low recycling characteristics of lithium walls can be used for particle control. Liquid lithium experiments have already begun in the Current Drive eXperiment-Upgrade (CDX-U). Plasmas limited with a toroidally localized limiter have been investigated, and experiments with a fully toroidal lithium limiter are in progress. A liquid surface module (LSM) has been proposed for the National Spherical Torus Experiment (NSTX). In this larger ST, plasma currents are in excess of 1 MA and a typical discharge radius is about 68 cm. The primary motivation for the LSM is particle control, and options for mounting it on the horizontal midplane or in the divertor region are under consideration. A key consideration is the magnitude of the eddy currents at the location of a liquid lithium surface. During plasma start up and disruptions, the force due to such currents and the magnetic field can force a conducting liquid off of the surface behind it. The Tokamak Simulation Code (TSC) has been used to estimate the magnitude of this effect. This program is a two dimensional, time dependent, free boundary simulation code that solves the MHD equations for an axisymmetric toroidal plasma. From calculations that match actual ST equilibria, the eddy current densities can be determined at the locations of the liquid lithium. Initial results have shown that the effects could be significant, and ways of explicitly treating toroidally local structures are under investigation.

R. Kaita; S. Jardin; B. Jones; C. Kessel; R. Majeski; J. Spaleta; R. Woolley; L. Zakharo; B. Nelson; M. Ulrickson

2002-01-29T23:59:59.000Z

22

National Spherical Torus Experiment (NSTX) Construction, Commissioning, and Initial Operations  

E-Print Network [OSTI]

Poloidal Field (PF) coils, thermal insulation, and a center stack casing which forms the inner wall vacuum insulator assemblies which permit the use of Coaxial Helicity Injection (CHI) as one of the means, 5 sec Coaxial Helicity Injection (CHI) 50kA injection @ 1kV Neutral Beam Injection Upgrade (NBI) 5

23

National Spherical Torus Experiment (NSTX) Construction, Commissioning, and Initial Operations  

E-Print Network [OSTI]

cylinder, a pair of inner Poloidal Field (PF) coils, thermal insulation, and a center stack casing which of the machine via ceramic insulator assemblies which permit the use of Coaxial Helicity Injection (CHI) as one, 5 sec Coaxial Helicity Injection (CHI) 50kA injection @ 1kV Neutral Beam Injection Upgrade (NBI) 5

24

National Spherical Torus Experiment NSTX CENTER STACK UPGRADE  

E-Print Network [OSTI]

Analysis (FMEA) 14 2.6.3 Structural Design Criteria 15 2.7 Material Selection 15 2.8 General Electrical

Princeton Plasma Physics Laboratory

25

NSTX Electrical Power Systems  

SciTech Connect (OSTI)

The National Spherical Torus Experiment (NSTX) has been designed and installed in the existing facilities at Princeton Plasma Physic Laboratory (PPPL). Most of the hardware, plant facilities, auxiliary sub-systems, and power systems originally used for the Tokamak Fusion Test Reactor (TFTR) have been used with suitable modifications to reflect NSTX needs. The design of the NSTX electrical power system was tailored to suit the available infrastructure and electrical equipment on site. Components were analyzed to verify their suitability for use in NSTX. The total number of circuits and the location of the NSTX device drove the major changes in the Power system hardware. The NSTX has eleven (11) circuits to be fed as compared to the basic three power loops for TFTR. This required changes in cabling to insure that each cable tray system has the positive and negative leg of cables in the same tray. Also additional power cabling had to be installed to the new location. The hardware had to b e modified to address the need for eleven power loops. Power converters had to be reconnected and controlled in anti-parallel mode for the Ohmic heating and two of the Poloidal Field circuits. The circuit for the Coaxial Helicity Injection (CHI) System had to be carefully developed to meet this special application. Additional Protection devices were designed and installed for the magnet coils and the CHI. The thrust was to making the changes in the most cost-effective manner without compromising technical requirements. This paper describes the changes and addition to the Electrical Power System components for the NSTX magnet systems.

A. Ilic; E. Baker; R. Hatcher; S. Ramakrishnan; et al

1999-12-16T23:59:59.000Z

26

Design, Installation and Performance of the New insulator for NSTX CHI Experiments  

SciTech Connect (OSTI)

Coaxial Helicity Injection (CHI), a non-inductive method to initiate plasma and generate toroidal plasma current, is being investigated in the National Spherical Torus Experiment (NSTX). The center stack and outer vacuum vessel are separated by insulating gaps at the top and bottom of the slim central column so that a high voltage (up to 2 kV) can be applied between them from a pulsed power supply or a capacitor bank to initiate an arc discharge. In the presence of a suitable poloidal magnetic field, the discharge is initiated at the lower gap (the injector gap) and because of the strong toroidal field develops a helical structure resulting in substantial toroidal plasma current being driven. In NSTX, up to 390 kA of toroidal current has been generated for an injected current of 25 kA. The early investigations of CHI however frequently developed arcs across the insulator at the top of the machine (the absorber gap), which terminated the desired discharge. This arcing greatly restricted the operational space available for CHI studies. During 2002, the absorber region was modified to suppress these arcs. The new design includes a new ceramic insulator on the high field side of the absorber region with a much longer tracking distance between conducting elements at the different potentials. Furthermore, two new coils were installed near the absorber to provide the ability to minimize the poloidal field connecting the center stack and outer vacuum vessel. During the subsequent experimental campaign, CHI operation was less prone to arcing in the absorber and those arcs that did occur did not terminate the main discharge.)

Mueller, D; Chrzanowski, J; Gates, D; Menard, J; Raman, R; Jarboe, T R; Nelson, B A; Maqueda, R J

2008-03-05T23:59:59.000Z

27

Fast-ion Energy Loss During TAE Avalanches in the National Spherical Torus Experiment  

SciTech Connect (OSTI)

Strong TAE avalanches on NSTX, the National Spherical Torus Experiment [M. Ono, et al., Nucl. Fusion 40 (2000) 557] are typically correlated with drops in the neutron rate in the range of 5% - 15%. In previous studies of avalanches in L-mode plasmas, these neutron drops were found to be consistent with modeled losses of fast ions. Here we expand the study to TAE avalanches in NSTX H-mode plasmas with improved analysis techniques. At the measured TAE mode amplitudes, simulations with the ORBIT code predict that fast ion losses are negligible. However, the simulations predict that the TAE scatter the fast ions in energy, resulting in a small (? 6%) drop in fast ion ?. The net decrease in energy of the fast ions is sufficient to account for the bulk of the drop in neutron rate, even in the absence of fast ion losses. This loss of energy from the fast ion population is comparable to the estimated energy lost by damping from the Alfven wave during the burst. The previously studied TAE avalanches in L-mode are re-evaluated using an improved calculation of the potential fluctuations in the ORBIT code.

Fredrickson, E D; Darrow, D S; Gorelenkov, N N; Kramer, G J; Kubota, S; Podesta, M; White, R B; Bortolon, A; Gerhardt, S P; Bell, R E; Diallo, A; LeBlanc, B; Levinton, F M

2012-07-11T23:59:59.000Z

28

Intermittent Divertor Filaments in the National Spherical Torus Experiment and Their Relation to Midplane Blobs  

SciTech Connect (OSTI)

While intermittent filamentary structures, also known as blobs, are routinely seen in the low-field-side scrape-off layer of the National Spherical Torus Experiment (NSTX) (Ono et al 2000 Nucl. Fusion 40 557), fine structured filaments are also seen on the lower divertor target plates of NSTX. These filaments, not associated with edge localized modes, correspond to the interaction of the turbulent blobs seen near the midplane with the divertor plasma facing components. The fluctuation level of the neutral lithium light observed at the divertor, and the skewness and kurtosis of its probability distribution function, is similar to that of midplane blobs seen in D?; e.g. increasing with increasing radii outside the outer strike point (OSP) (separatrix). In addition, their toroidal and radial movement agrees with the typical movement of midplane blobs. Furthermore, with the appropriate magnetic topology, i.e. mapping between the portion of the target plates being observed into the field of view of the midplane gas puff imaging diagnostic, very good correlation is observed between the blobs and the divertor filaments. The correlation between divertor plate filaments and midplane blobs is lost close to the OSP. This latter observation is consistent with the existence of ‘magnetic shear disconnection’ due to the lower X-point, as proposed by Cohen and Ryutov (1997 Nucl. Fusion 37 621).

R.J. Maqueda, D.P. Stotler and the NSTX Team.

2010-05-19T23:59:59.000Z

29

Full wave simulations of fast wave heating losses in the scrape-off layer of NSTX and NSTX-U  

SciTech Connect (OSTI)

Full wave simulations of fusion plasmas show a direct correlation between the location of the fast-wave cut-off, radiofrequency (RF) field amplitude in the scrape-off layer (SOL) and the RF power losses in the SOL observed in the National Spherical Torus eXperiment (NSTX). In particular, the RF power losses in the SOL increase significantly when the launched waves transition from evanescent to propagating in that region. Subsequently, a large amplitude electric field occurs in the SOL, driving RF power losses when a proxy collisional loss term is added. A 3D reconstruction of absorbed power in the SOL is presented showing agreement with the RF experiments in NSTX. Loss predictions for the future experiment NSTX-Upgrade (NSTX-U) are also obtained and discussed.

Bertelli, Nicola [Princeton Plasma Physics Laboratory (PPPL); Jaeger, E. F. [XCEL; Hosea, J. [Princeton Plasma Physics Laboratory (PPPL); Phillips, C. K. [Princeton Plasma Physics Laboratory (PPPL); Berry, Lee Alan [XCEL Engineering Inc., Oak Ridge; Gerhardt, S. [Princeton Plasma Physics Laboratory (PPPL); Green, David L [ORNL; LeBlanc, B [Princeton Plasma Physics Laboratory (PPPL); Perkins, R. J. [Princeton Plasma Physics Laboratory (PPPL); Ryan, Philip Michael [ORNL; Taylor, G. [Princeton Plasma Physics Laboratory (PPPL); Valeo, E. J. [Princeton Plasma Physics Laboratory (PPPL); Wilson, J. R. [Princeton Plasma Physics Laboratory (PPPL)

2014-01-01T23:59:59.000Z

30

High-harmonic Fast Wave Heating and Current Drive Results for Deuterium H-mode Plasmas in the National Spherical Torus Experiment  

SciTech Connect (OSTI)

A critical research goal for the spherical torus (ST) program is to initiate, ramp-up, and sustain a discharge without using the central solenoid. Simulations of non-solenoidal plasma scenarios in the National Spherical Torus Experiment (NSTX) [1] predict that high-harmonic fast wave (HHFW) heating and current drive (CD) [2] can play an important roll in enabling fully non-inductive (fNI {approx} 1) ST operation. The NSTX fNI {approx} 1 strategy requires 5-6 MW of HHFW power (PRF) to be coupled into a non-inductively generated discharge [3] with a plasma current, Ip {approx} 250-350 kA, driving the plasma into an HHFW H-mode with Ip {approx} 500 kA, a level where 90 keV deuterium neutral beam injection (NBI) can heat the plasma and provide additional CD. The initial approach on NSTX has been to heat Ip {approx} 300 kA, inductively heated, deuterium plasmas with CD phased HHFW power [2], in order to drive the plasma into an H-mode with fNI {approx} 1.

G. Taylor, P.T. Bonoli, R.W. Harvey, J.C. hosea, E.F. Jaeger, B.P. LeBlanc, C.K. Phillisp, P.M. Ryan, E.J. Valeo, J.R. Wilson, J.C. Wright, and the NSTX Team

2012-07-25T23:59:59.000Z

31

Dynamical Evolution of Pedestal Parameters in ELMy H-mode in the National Spherical Torus Experiment  

SciTech Connect (OSTI)

Characterizations of the pedestal parameter dynamics throughout the edge localized modes(ELM) cycles are performed on the National Spherical Torus Experiment (NSTX, [M. Ono et al., Nucl. Fusion 40, 557 (2000)]). A clear buildup of the pedestal height is observed between ELMs for three di erent plasma currents, which tends to saturate prior to the onset of ELM at low and medium plasma current. Similarly, the pedestal width increases with no clear evidence of saturation during an ELM cycle. The maximum pedestal gradient increases as a function of plasma current, reaches a nominal value after the ELM crash, and remains constant until the end of the ELM cycle. The pedestal height just prior to the onset of ELM is shown to increase quadratically with plasma current. The pedestal width ? is proportional to the square-root of the poloidal ? at the top of the pedestal. Coherent density uctuations strongly increasing at the plasma edge are observed to be maximum after the ELM crash and to decay during the rest of the ELM cycle. Finally, the pedestal parameters evolution during the ELM cycle as well as the scaling with Ip of the pedestal pressure prior to the onset ELM are found to be qualitatively consistent with the peeling ballooning theory.

Diallo, A; Kubota, S; Sontag, A; Osborne, T; Podesta, M; Bell, R E; LeBlanc, B P; Menard, J

2011-07-27T23:59:59.000Z

32

Direct X-B mode conversion for high-? national spherical torus experiment in nonlinear regime  

SciTech Connect (OSTI)

Electron Bernstein wave (EBW) can be effective for heating and driving currents in spherical tokamak plasmas. Power can be coupled to EBW via mode conversion of the extraordinary (X) mode wave. The most common and successful approach to study the conditions for optimized mode conversion to EBW was evaluated analytically and numerically using a cold plasma model and an approximate kinetic model. The major drawback in using radio frequency waves was the lack of continuous wave sources at very high frequencies (above the electron plasma frequency), which has been addressed. A future milestone is to approach high power regime, where the nonlinear effects become significant, exceeding the limits of validity for present linear theory. Therefore, one appropriate tool would be particle in cell (PIC) simulation. The PIC method retains most of the nonlinear physics without approximations. In this work, we study the direct X-B mode conversion process stages using PIC method for incident wave frequency f{sub 0}?=?15?GHz, and maximum amplitude E{sub 0}?=?10{sup 5?}V/m in the national spherical torus experiment (NSTX). The modelling shows a considerable reduction in X-B mode conversion efficiency, C{sub modelling}?=?0.43, due to the presence of nonlinearities. Comparison of system properties to the linear state reveals predominant nonlinear effects; EBW wavelength and group velocity in comparison with linear regime exhibit an increment around ?36% and 17%, respectively.

Ali Asgarian, M., E-mail: maliasgarian@ph.iut.ac.ir, E-mail: maa@msu.edu [Physics Department, Isfahan University of Technology, Isfahan 84156 (Iran, Islamic Republic of); Department of Electrical and Computer Engineering, Michigan State University, Michigan 48824-1226 (United States); Parvazian, A.; Abbasi, M. [Physics Department, Isfahan University of Technology, Isfahan 84156 (Iran, Islamic Republic of); Verboncoeur, J. P. [Department of Electrical and Computer Engineering, Michigan State University, Michigan 48824-1226 (United States)

2014-09-15T23:59:59.000Z

33

Non-linear Dynamics Of Toroidicity-induced Alfven Eigenmodes On The National Spherical Torus Experiment  

SciTech Connect (OSTI)

The National Spherical Torus Experiment (NSTX, [M. Ono et al., Nucl. Fusion 40, 557 (2000)]) routinely operates with neutral beam injection as the primary system for heating and current drive. The resulting fast ion population is super-Alfv#19;enic, with velocities 1 < vfast=vAlfven < 5. This provides a strong drive for toroidicity-induced Alfv#19;en eigenmodes (TAEs). As the discharge evolves, the fast ion population builds up and TAEs exhibit increasing bursts in amplitude and down-chirps in frequency, which eventually lead to a so-called TAE avalanche. Avalanches cause large (? 30%) fast ion losses over ~ 1 ms, as inferred from the neutron rate. The increased fast ion losses correlate with a stronger activity in the TAE band. In addition, it is shown that a n = 1 mode with frequency well below the TAE gap appears in the Fourier spectrum of magnetic fluctuations as a result of non-linear mode coupling between TAEs during avalanche events. The non-linear coupling between modes, which leads to enhanced fast ion transport during avalanches, is investigated.

Podesta, M; Crocker, N A; Fredrickson, E D; Gorelenkov, N N; Heidbrink, W W; Kubota, S; LeBlanc, B P

2011-04-26T23:59:59.000Z

34

ECRH/EBWH SYSTEM FOR NSTX-  

SciTech Connect (OSTI)

The National Spherical Torus Experiment Upgrade (NSTX-U) will operate at an axial toroidal field of up to 1 T, about twice the field available on NSTX. A 28 GHz electron cylotron resonance heating (ECRH) system is currently being planned for NSTX-U. A 1 MW 28 GHz gyrotron will be employed. Intially the system will use short, 10-50 ms, 1 MW pulses for ECRH-assisted discharge start-up. Later the pulse length will be extended to 1-5 s to study electron Bernstein wave heating (EBWH) during the plasma current flat top. A mirror launcher will be used to couple microwave power to the plasma via O-mode to the slow X-mode to EBW (O-X-B) double mode conversion. This paper presents a pre-conceptual design for the ECRH/EBWH system proposed for NSTX-U and includes ray tracing and Fokker-Planck modeling results for 28 GHz ECRH during plasma start-up and EBW heating and current drive during the plasma current flattop of a NSTX-U advanced H-mode plasma scenario.

G. Taylor, R.A. Ellis, R.W. Harvey, J.C. Hosea and A.P. Smirnov

2012-06-15T23:59:59.000Z

35

Implementation of BN Control in the National Spherical Torus Experiment  

SciTech Connect (OSTI)

We have designed and constructed a system for control of the normalized B in the National Spherical Torus Experiment [M. Ono, et al., Nuclear Fusion 40, 557 (2000)]. A PID operator is applied to the difference between the present value of B N (from realtime equilibrium reconstruction) and a time-dependent request, in order to calculate the required injected power. This injected power request is then turned into modulations of the neutral beams. The details of this algorithm are described, including the techniques used to develop the appropriate control gains. Example uses of the system are shown

Gerhardt, S; Bell, M G; Cropper, M; Gates, D A; Koleman, E; Lawson, J; Marsala, B; Menard, J E; Mueller, D

2012-09-15T23:59:59.000Z

36

Mission Need for NSTX CenterMission Need for NSTX Center--Stack (CS)Stack (CS) and Neutral Beam Injector (NBI) Upgradesand Neutral Beam Injector (NBI) Upgrades  

E-Print Network [OSTI]

Fusion Energy Sciences research center in U.S. NSTX Test Cell NSTX Power Supplies NSTX Cooling Towers Spherical Torus (ST) in the world and is the core of the PPPL experimental research program · NSTX , compactness of ST to achieve high neutron flux and fluence at reduced size and cost, reduced T consumption

Princeton Plasma Physics Laboratory

37

Fast ion absorption of the high harmonic fast wave in the National Spherical Torus Experiment a...  

E-Print Network [OSTI]

Fast ion absorption of the high harmonic fast wave in the National Spherical Torus Experiment a; published online 23 April 2004# Ion absorption of the high harmonic fast wave in a spherical torus #Y.­K. M, likely due to a larger # profile, which promotes greater off­axis absorption where the fast ion

Egedal, Jan

38

Power Supply Changes for NSTX Resistive Wall Mode Coils  

SciTech Connect (OSTI)

The National Spherical Torus Experiment (NSTX) has been designed and installed in the existing facilities at Princeton Plasma Physics Laboratory (PPPL). Most of the hardware, plant facilities, auxiliary sub-systems, and power systems originally used for the Tokamak Fusion Test Reactor (TFTR) have been used with suitable modifications to reflect NSTX needs. Prior to 2004, the NSTX power system was feeding twelve (12) circuits in the machine. In 2004 the Resistive Wall Mode (RWM) Coils were installed on the machine to correct error fields. There are six of these coils installed around the machine in the mid-plane. Since these coils need fast and accurate controls, a Switching Power Amplifier (SPA) with three sub-units was procured, installed and commissioned along with other power loop components. Two RWM Coils were connected in series and fed from one SPA sub-unit. After the initial RWM campaign, operational requirements evolved such that each of the RWM coils now requires separate power and control. Hence a second SPA with three sub-units has been procured and installed. The second unit is of improved design and has the controls and power components completely isolated. The existing thyristor rectifier is used as DC Link to both of the Switching Power Amplifiers. The controls for the RWM are integrated into the overall computer control of the DC Power systems for NSTX. This paper describes the design changes in the RWM Power system for NSTX.

Ramakrishnan, S S.

2013-06-28T23:59:59.000Z

39

Divertor Heat Flux Mitigation in High-Performance H-mode Plasmas in the National Spherical Torus Experiment.  

SciTech Connect (OSTI)

Experiments conducted in high-performance 1.0-1.2 MA 6 MW NBI-heated H-mode plasmas with a high flux expansion radiative divertor in NSTX demonstrate that significant divertor peak heat flux reduction and access to detachment may be facilitated naturally in a highly-shaped spherical torus (ST) configuration. Improved plasma performance with high {beta}{sub p} = 15-25%, a high bootstrap current fraction f{sub BS} = 45-50%, longer plasma pulses, and an H-mode regime with smaller ELMs has been achieved in the lower single null configuration with higher-end elongation 2.2-2.4 and triangularity 0.6-0.8. Divertor peak heat fluxes were reduced from 6-12 MW/m{sup 2} to 0.5-2 MW/m{sup 2} in ELMy H-mode discharges using high magnetic flux expansion and partial detachment of the outer strike point at several D{sub 2} injection rates, while good core confinement and pedestal characteristics were maintained. The partially detached divertor regime was characterized by a 30-60% increase in divertor plasma radiation, a peak heat flux reduction by up to 70%, measured in a 10 cm radial zone, a five-fold increase in divertor neutral pressure, and a significant volume recombination rate increase.

Soukhanovskii, V A; Maingi, R; Gates, D; Menard, J; Paul, S F; Raman, R; Roquemore, A L; Bell, R E; Bush, C; Kaita, R

2008-09-22T23:59:59.000Z

40

The Effect of Progressively Increasing Lithium Coatings on Plasma Discharge Characteristics, Transport, Edge Profiles, and ELM Stability in the National Spherical Torus Experiment  

SciTech Connect (OSTI)

Lithium wall coatings have been shown to reduce recycling, suppress edge localized modes (ELMs), and improve energy confinement in the National Spherical Torus Experiment (NSTX). Here we document the effect of gradually increasing lithium wall coatings on the discharge characteristics, with the reference ELMy discharges obtained in boronized, i.e. non-lithiated, conditions. We observed a continuous but not quite monotonic reduction in recycling and improvement in energy confinement, a gradual alteration of edge plasma profiles, and slowly increasing periods of ELM quiescence. The measured edge plasma profiles during the lithium coating scan were simulated with the SOLPS code, which quantified the reduction in divertor recycling coefficient from ~98% to ~90%. The reduction in recycling and core fueling, coupled with a drop in the edge particle transport rate, reduced the average edge density profile gradient, and shifted it radially inward from the separatrix location. In contrast, the edge electron temperature (Te) profile was unaffected in the H-mode pedestal steep gradient region within the last 5% of normalized poloidal flux, N; however, the region of steep Te gradients extended radially inward from the top of the H-mode pedestal for 0.8< N <0.94 with lithium coatings. The peak pressure gradients were comparable during ELMy and ELM-free phases, but were shifted away from the separatrix in the ELM-free discharges, which is stabilizing to the current driven instabilities thought to be responsible for ELMs in NSTX.

Maingi, Rajesh [ORNL; Boyle, D. P. [Princeton University; Canik, John [ORNL; Kaye, S. M. [Princeton Plasma Physics Laboratory (PPPL); Skinner, C. H. [Princeton Plasma Physics Laboratory (PPPL); Allain, J. P. [Purdue University; Bell, M. G. [Princeton Plasma Physics Laboratory (PPPL); Bell, R. E. [Princeton Plasma Physics Laboratory (PPPL); Gray, Travis K [ORNL; Jaworski, M. A. [Princeton Plasma Physics Laboratory (PPPL); Kaita, R. [Princeton Plasma Physics Laboratory (PPPL); Kugel, H. [Princeton Plasma Physics Laboratory (PPPL); LeBlanc, B. P. [Princeton Plasma Physics Laboratory (PPPL); Mansfield, D.K. [Princeton Plasma Physics Laboratory (PPPL); Osborne, T. H. [General Atomics; Raman, R. [University of Washington, Seattle; Sabbagh, S. A. [Columbia University; Soukhanovskii, V. A. [Lawrence Livermore National Laboratory (LLNL)

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "torus experiment nstx" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

The effect of progressively increasing lithium coatings on plasma discharge characteristics, transport, edge profiles and ELM stability in the National Spherical Torus Experiment  

SciTech Connect (OSTI)

Lithium wall coatings have been shown to reduce recycling, suppress edge-localized modes (ELMs), and improve energy confinement in the National Spherical Torus Experiment (NSTX). Here we document the effect of gradually increasing lithium wall coatings on the discharge characteristics, with the reference ELMy discharges obtained in boronized, i.e. non-lithiated conditions. We observed a continuous but not quite monotonic reduction in recycling and improvement in energy confinement, a gradual alteration of edge plasma profiles, and slowly increasing periods of ELM quiescence. The measured edge plasma profiles during the lithium-coating scan were simulated with the SOLPS code, which quantified the reduction in divertor recycling coefficient from similar to 98% to similar to 90%. The reduction in recycling and fuelling, coupled with a drop in the edge particle transport rate, reduced the average edge density profile gradient, and shifted it radially inwards from the separatrix location. In contrast, the edge electron temperature (T-e) profile was unaffected in the H-mode pedestal steep gradient region within the last 5% of normalized poloidal flux, psi(N); however, the T-e gradient became steeper at the top of the H-mode pedestal for 0.8 < psi(N) < 0.94 with lithium coatings. The peak pressure gradients were comparable during ELMy and ELM-free phases, but were shifted away from the separatrix in the ELM-free discharges, which is stabilizing to the current-driven instabilities thought to be responsible for ELMs in NSTX.

Maingi, Rajesh [ORNL; Boyle, D. P. [Princeton University; Canik, John [ORNL; Kaye, S. [Princeton Plasma Physics Laboratory (PPPL); Skinner, C. H. [Princeton Plasma Physics Laboratory (PPPL); Allain, J. P. [Purdue University; Bell, R. E. [Princeton Plasma Physics Laboratory (PPPL); Bell, M. G. [Princeton Plasma Physics Laboratory (PPPL); Gerhardt, S. P. [Princeton Plasma Physics Laboratory (PPPL); Gray, Travis K [ORNL; Jaworski, M. A. [Princeton Plasma Physics Laboratory (PPPL); Kaita, R. [Princeton Plasma Physics Laboratory (PPPL); Kugel, H. W. [Princeton Plasma Physics Laboratory (PPPL); Le Blanc, B. P. [Princeton Plasma Physics Laboratory (PPPL); Manickam, J. [Princeton Plasma Physics Laboratory (PPPL); Mansfield, D.K. [Princeton Plasma Physics Laboratory (PPPL); Menard, J. E. [Princeton Plasma Physics Laboratory (PPPL); Osborne, T. H. [General Atomics; Raman, R. [University of Washington, Seattle; Roquemore, A. L. [Princeton Plasma Physics Laboratory (PPPL); Sabbagh, S. A. [Columbia University; Snyder, P. B. [General Atomics; Soukhanovskii, V. A. [Lawrence Livermore National Laboratory (LLNL)

2012-01-01T23:59:59.000Z

42

Measured improvement of global magnetohydrodynamic mode stability at high-beta, and in reduced collisionality spherical torus plasmas  

SciTech Connect (OSTI)

Global mode stability is studied in high-? National Spherical Torus Experiment (NSTX) plasmas to avoid disruptions. Dedicated experiments in NSTX using low frequency active magnetohydrodynamic spectroscopy of applied rotating n?=?1 magnetic fields revealed key dependencies of stability on plasma parameters. Observations from previous NSTX resistive wall mode (RWM) active control experiments and the wider NSTX disruption database indicated that the highest ?{sub N} plasmas were not the least stable. Significantly, here, stability was measured to increase at ?{sub N}?l{sub i} higher than the point where disruptions were found. This favorable behavior is shown to correlate with kinetic stability rotational resonances, and an experimentally determined range of measured E?×?B frequency with improved stability is identified. Stable plasmas appear to benefit further from reduced collisionality, in agreement with expectation from kinetic RWM stabilization theory, but low collisionality plasmas are also susceptible to sudden instability when kinetic profiles change.

Berkery, J. W.; Sabbagh, S. A.; Balbaky, A. [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States)] [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States); Bell, R. E.; Diallo, A.; Gerhardt, S. P.; LeBlanc, B. P.; Manickam, J.; Menard, J. E.; Podestà, M. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Betti, R. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)] [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)

2014-05-15T23:59:59.000Z

43

MARFE Stability and Movement in an ELMy H-mode NSTX Discharge  

SciTech Connect (OSTI)

The results of a comparison of Multifaceted Asymmetric Radiation From the Edge (MARFE) theory with experiment in the National Spherical Torus Experiment (NSTX) are presented. A variety of MARFE behavior was observed using a fast-framing camera. A basic MARFE theory was applied to NSTX Multi-Pulse Thomson scattering (MPTS) and charge-exchange recombination spectroscopy (CHERS) data. MARFE theory showed some limited agreement with experiment, but uncertainty in the separatrix location constrained the analysis. A method based on shifting iso-Te flux surfaces was used to estimate the separatrix location. The movements of MARFEs in NSTX are interpreted to result from diamagnetic heat flux driven drifts relative to the background plasma velocity and imply slowing edge poloidal rotation and/or changing edge profiles before a large ELM.

F. Kelly, R. Maingi, R. Maqueda, J. Menard, S. Paul

2009-02-23T23:59:59.000Z

44

Parametric Dependence Of Fast-ion Transport Events On The National Spherical Torus Experiment  

SciTech Connect (OSTI)

Neutral-beam heated tokamak plasmas commonly have more than one third of the plasma kinetic energy in the non-thermal energetic beam ion population. This population of fast ions heats the plasma, provides some of the current drive, and can affect the stability (positively or negatively) of magnetohydrodynamic instabilities. This population of energetic ions is not in thermodynamic equilibrium, thus there is free-energy available to drive instabilities, which may lead to redistribution of the fast ion population. Understanding under what conditions beam-driven instabilities arise, and the extent of the resulting perturbation to the fast ion population, is important for predicting and eventually demonstrating non-inductive current ramp-up and sustainment in NSTX-U, as well as the performance of future fusion plasma experiments such as ITER. This paper presents an empirical approach towards characterizing the stability boundaries for some common energetic-ion-driven instabilities seen on NSTX.

Fredrickson, Erik; Gorelenkov, N. N.; Podesta, M.; Gerhardt, S. P.; Bell, R. E.; Diallo, A.; LeBlanc, B. [Princeton Plasma Physics Lab., NJ (United States)] [Princeton Plasma Physics Lab., NJ (United States); Bortolon, A. [Univ. of Tennessee, Knoxville, TN (United States)] [Univ. of Tennessee, Knoxville, TN (United States)

2014-03-31T23:59:59.000Z

45

Liquid Lithium Divertor and Scrape-Off-Layer Interactions on the National Spherical Torus Experiment: 2010 ? 2013 Progress Report  

SciTech Connect (OSTI)

The implementation of the liquid Lithium Divertor (LLD) in NSTX presented a unique opportunity in plasma-material interactions studies. A high density Langmuir Probe (HDLP) array utilizing a dense pack of triple Langmuir probes was built at PPPL and the electronics designed and built by UIUC. It was shown that the HDLP array could be used to characterize the modification of the EEDF during lithium experiments on NSTX as well as characterize the transient particle loads during lithium experiments as a means to study ELMs. With NSTX being upgraded and a new divertor being installed, the HDLP array will not be used in NSTX-U. However UIUC is currently helping to develop two new systems for depositing lithium into NSTX-U, a Liquid Lithium Pellet Dripper (LLPD) for use with the granular injector for ELM mitigation and control studies as well as an Upward-Facing Lithium Evaporator (U-LITER) based on a flash evaporation system using an electron beam. Currently UIUC has Daniel Andruczyk Stationed at PPPL and is developing these systems as well as being involved in preparing the Materials Analysis Particle Probe (MAPP) for use in LTX and NSTX-U. To date the MAPP preparations have been completed. New sample holders were designed by UIUC?s Research Engineer at PPPL and manufactured at PPPL and installed. MAPP is currently being used on LTX to do calibration and initial studies. The LLPD has demonstrated that it can produce pellets. There is still some adjustments needed to control the frequency and particle size. Equipment for the U-LITER has arrived and initial test are being made of the electron beam and design of the U-LITER in progress. It is expected to have these ready for the first run campaign of NSTX-U.

None

2013-08-27T23:59:59.000Z

46

L-H Threshold Studies in NSTX  

SciTech Connect (OSTI)

Recent experiments in the low aspect ratio National Spherical Torus Experiment (NSTX) have been run in support of the high priority ITER and ITPA issue of access to the H-mode. Specifically, a series of experiments showed reduced power threshold values for deuterium vs helium plasmas, and for plasmas with lower current, lower triangularity and with lithium conditioning. Application of n=3 fields at the plasma edge resulted in higher power thresholds. To within the constraints of temporal and spatial resolutions, no systematic difference in T{sub e}, n{sub e}, p{sub e}, T{sub i}, v or their derivatives was found in discharges that transitioned into the H-mode versus those at slightly lower power that did not. Finally, H{sub 98y,2} {approx} 1 confinement quality could be achieved for powers just above the threshold power in ELM-free conditions.

Kaye, S M; Battaglia, D; Bell, R E; Chang, C S; Hosea, J; Kugel, H; LeBlanc, B P; Meyer, H; Park, G Y

2011-09-06T23:59:59.000Z

47

L-H Threshold Studies in NSTX  

SciTech Connect (OSTI)

Recent experiments in the low aspect ratio National Spherical Torus Experiment (NSTX) have been run in support of the high priority ITER and ITPA issue of access to the H-mode. Specifically, a series of experiments showed reduced power threshold values for deuterium versus helium plasmas, and for plasmas with lower current, lower triangularity and with lithium conditioning. Application of n = 3 fields at the plasma edge resulted in higher power thresholds. To within the constraints of temporal and spatial resolutions, no systematic difference in T(e), n(e), p(e), T(i), v or their derivatives was found in discharges that transitioned into the H-mode versus those at slightly lower power that did not. Finally, H(98y,2) similar to 1 confinement quality could be achieved for powers just above the threshold power in ELM-free conditions.

Kaye, S. M. [Princeton Plasma Physics Laboratory (PPPL); Maingi, Rajesh [ORNL; Battaglia, D. J. [Oak Ridge National Laboratory (ORNL); Bell, R. E. [Princeton Plasma Physics Laboratory (PPPL); Chang, C. S. [Princeton Plasma Physics Laboratory (PPPL); Hosea, J. [Princeton Plasma Physics Laboratory (PPPL); Kugel, H. W. [Princeton Plasma Physics Laboratory (PPPL); LaBlanc, B. P. [Princeton Plasma Physics Laboratory (PPPL); Meyer, H. [EURATOM / UKAEA, UK; Park, G-Y. [New York University; Wilson, J. R. [Princeton Plasma Physics Laboratory (PPPL)

2011-01-01T23:59:59.000Z

48

Modeling Results for Proposed NSTX 28 GHz and EBWH System  

SciTech Connect (OSTI)

A 28 GHz electron cyclotron heating (ECH) and electron Bernstein wave heating (EBWH) system has been proposed for installation on the National Spherical Torus Experiment (NSTX). A 350 kW gyrotron connected to a fixed horn antenna is proposed for ECH-assisted solenoid-free plasma startup. Modeling predicts strong first pass on-axis EC absorption, even for low electron temperature, Te ~ 20 eV, Coaxial Helicity Injection (CHI) startup plasmas. ECH will heat the CHI plasma to Te ~ 300 eV, providing a suitable target plasma for 30 MHz high-harmonic fast wave heating. A second gyrotron and steered O-X-B mirror launcher is proposed for EBWH experiments. Radiometric measurements of thermal EBW emission detected via B-X-O coupling on NSTX support implementation of the proposed system. 80% B-X-O coupling efficiency was measured in L-mode plasmas and 60% B-X-O coupling efficiency was recently measured in H-mode plasmas conditioned with evaporated lithium. Modeling predicts local on-axis EBW heating and current drive using 28 GHz power in ? ~ 20% NSTX plasmas should be possible, with current drive efficiencies ~ 40 kA/MW.

Taylor, G; Ellis, R A; Fredd, E; Greenough, N; Hosea, J C; Wilgen, J B; Harvey, R W; Smirnov, A P; Preinhaelter, J; Urban, J

2008-03-20T23:59:59.000Z

49

Extended Magnetohydrodynamic Simulations of the Helicity Injected Torus (HIT-SI) Spheromak Experiment with the NIMROD Code.  

E-Print Network [OSTI]

??A comparative study of 3-D pressureless resistive (single-fluid) magnetohydrodynamic (rMHD) and 3-D pressureless two-fluid magnetohydrodynamic (2fl-MHD) models of the Helicity Injected Torus experiment (HIT-SI) is… (more)

Akcay, Cihan

2013-01-01T23:59:59.000Z

50

Next step spherical torus design studies  

Science Journals Connector (OSTI)

Studies are underway to identify and characterize a design point for a next step spherical torus (NSST) experiment. This would be a ‘proof of performance’ device which would follow and build upon the successes of the national spherical torus experiment (NSTX) ‘proof of principle’ device which has operated at PPPL since 1999. With the decontamination and decommissioning (D&D) of the tokamak fusion test reactor (TFTR) nearly completed, the TFTR test cell and facility will soon be available for a device such as NSST. By utilizing the TFTR test cell, NSST can be constructed for a relatively low cost on a short time scale. In addition, while furthering spherical torus (ST) research, this device could achieve modest fusion power gain for short pulse lengths, a significant step toward future large burning plasma devices now under discussion in the fusion community. The selected design point is Q=2 at HH=1.4, Pfusion=60 MW, 5-s pulse, with R0=1.5 m, A=1.6, Ip=10 MA, Bt=2.6 T, CS flux=16 weber. Most of the research would be conducted in DD, with a limited DT campaign during the last years of the program.

C. Neumeyer; P. Heitzenroeder; C. Kessel; M. Ono; M. Peng; J. Schmidt; R. Woolley; I. Zatz

2003-01-01T23:59:59.000Z

51

Impact of Profile Variation on the Equilibrium and Stability of NSTX  

SciTech Connect (OSTI)

MHD equilibrium and stability analyses have been performed in support of the design and initial experimental operation of the National Spherical Torus Experiment (NSTX). Free-boundary equilibria have been generated to determine several aspects of the anticipated plasma configurations including the stability and shape domain. Boundary shape determination has been studied by considering random variations of modeled signals from the NSTX magnetic diagnostic set. The impact of equilibrium profile variations on the ideal low-n kink and ballooning stability of high-{beta} configurations was also determined to assess the robustness of the stable operating space of NSTX. The profiles used included local perturbations from previously reported optimization studies and experimental pressure profiles from the START spherical torus, the DIII-D tokamak, and TRANSP modeling. The largest {beta}-limits occur in plasmas with broader pressure profiles and are set by the n = 1 kink/ballooning mode. Values of {beta} = 38% are achieved in the presence of a conformal conducting wall at b/a = 0.25. The corresponding calculated no-wall {beta}-limit is 22%. The lowest limits ({beta} = 19%) were generated in plasmas with greater pressure peaking, and are set by high-n ballooning modes.

D. Gates; F. Paoletti; J. Manickam; S.A. Sabbagh; S.M. Kaye [and others

1999-06-01T23:59:59.000Z

52

Two-dimensional AXUV-based radiated power density diagnostics on NSTX-U  

SciTech Connect (OSTI)

A new set of radiated-power-density diagnostics for the National Spherical Torus Experiment Upgrade (NSTX-U) tokamak have been designed to measure the two-dimensional poloidal structure of the total photon emissivity profile in order to perform power balance, impurity transport, and magnetohydrodynamic studies. Multiple AXUV-diode based pinhole cameras will be installed in the same toroidal angle at various poloidal locations. The local emissivity will be obtained from several types of tomographic reconstructions. The layout and response expected for the new radially viewing poloidal arrays will be shown for different impurity concentrations to characterize the diagnostic sensitivity. The radiated power profile inverted from the array data will also be used for estimates of power losses during transitions from various divertor configurations in NSTX-U. The effect of in-out and top/bottom asymmetries in the core radiation from high-Z impurities will be addressed.

Faust, I.; Parker, R. R. [MIT - Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Delgado-Aparicio, L.; Bell, R. E.; Diallo, A.; Gerhardt, S. P.; LeBlanc, B.; Kozub, T. A. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States); Tritz, K. [The Johns Hopkins University, Baltimore, Maryland 21209 (United States); Stratton, B. C. [MIT - Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States)

2014-11-15T23:59:59.000Z

53

Physics Design Requirements for the National Spherical Torus Experiment Liquid Lithium Divertor  

SciTech Connect (OSTI)

Recent NSTX high power divertor experiments have shown significant and recurring benefits of solid lithium coatings on PFC's to the performance of divertor plasmas in both L- and H- mode confinement regimes heated by high-power neutral beams. The next step in this work is installation of a liquid lithium divertor (LLD) to achieve density control for inductionless current drive capability (e.g., about a 15-25% ne decrease from present highest non-inductionless fraction discharges which often evolve toward the density limit, ne/nGW~1), to enable ne scan capability (x2) in the H-mode, to test the ability to operate at significantly lower density for future ST-CTF reactor designs (e.g., ne/nGW = 0.25), and eventually to investigate high heat-flux power handling (10 MW/m2) with longpulse discharges (>1.5s). The first step (LLD-1) physics design encompasses the desired plasma requirements, the experimental capabilities and conditions, power handling, radial location, pumping capability, operating temperature, lithium filling, MHD forces, and diagnostics for control and characterization.

Kugel, W.; Bell, M.; Berzak,L.; Brooks, A.; Ellis, R.; Gerhardt, S.; Harjes, H.; Kaita, R.; Kallman, J.; Maingi, R.; Majeski, R.; Mansfield, D.; Menard, J.; Nygren,R. E.; Soukhanovskii, V.; Stotler, D.; Wakeland, P.; Zakharov L. E.

2008-09-26T23:59:59.000Z

54

Flow and shear behavior in the edge and scrape-off layer of L-mode plasmas in National Spherical Torus Experiment  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

Fluctuations in the edge and scrape-off layer (SOL) of L-mode plasmas in the National Spherical Torus Experiment (NSTX) [S. M. Kaye et al.,Phys. Plasmas 8, 1977 (2001)] as observed by the gas puff imaging (GPI) diagnostic are studied. Calculation of local, time resolved velocity maps using the Hybrid Optical Flow and Pattern Matching Velocimetry (HOP-V) code enables analysis of turbulent flow and shear behavior. Periodic reversals in the direction of the poloidal flow near the separatrix are observed. Also, poloidal velocities and their radial shearing rate are found to be well correlated with the fraction of D? light contained in the SOL, which acts as a measure of turbulent bursts. The spectra of GPI intensity and poloidal velocity both have a strong feature near 3 kHz, which appears to correspond with turbulent bursts. This mode exhibits a poloidal structure with poloidal wavenumber of 7.7 m-1 for GPI intensity and 3.4 m-1 for poloidal velocity, and the poloidal velocity fluctuations near 3 kHz remain coherent over length scales in excess of the turbulent scales. Furthermore, recent SOL Turbulence (SOLT) simulations find a parameter regime that exhibits periodic bursty transport and shares many qualitative similarities with the experimental data. Strong correlations between the shearing rate and the turbulent bursts are observed for time periods of ~ 2 ms, but the relationship is complicated by several factors. Finally, measurements of the radial profiles of the Reynolds shear stresses are reported. These radial profiles exhibit many similarities for several shots, and a region with positive radial gradient is seen to be coincident with local flow shear.

Sechrest, Y. [Univ. of Colorado, Boulder, CO (United States); Munsat, T. [Univ. of Colorado, Boulder, CO (United States); D’Ippolito, D. A. [Lodestar Research Corp., Boulder, CO (United States); Maqueda, R. J. [Princeton Plasma Physics Lab., NJ (United States); Myra, J. R. [Lodestar Research Corp., Boulder, CO (United States); Russell, D. [Lodestar Research Corp., Boulder, CO (United States); Zweben, S. J. [Princeton Plasma Physics Lab., NJ (United States)

2011-01-10T23:59:59.000Z

55

Properties of Alfven Eigenmodes in the TAE range on the National Spherical Torus Experiment-Upgrade  

SciTech Connect (OSTI)

A second Neutral Beam (NB) injection line is being installed on the NSTX Upgrade device, resulting in six NB sources with di erent tangency radii that will be available for heating and current drive. This work explores the properties of instabilities in the frequency range of the Toroidal Alfv#19;en Eigenmode (TAE) for NSTX-U scenarios with various NB injection geometries, from more perpendicular to more tangential, and with increased toroidal magnetic eld with respect to previous NSTX scenarios. Predictions are based on analysis through the ideal MHD code NOVA-K. For the scenarios considered in this work, modi cations of the Alfv#19;en continuum result in a frequency upshift and a broadening of the radial mode structure. The latter e ect may have consequences for fast ion transport and loss. Preliminary stability considerations indicate that TAEs are potentially unstable, with ion Landau damping representing the dominant damping mechanism

none,

2013-04-24T23:59:59.000Z

56

Modification of divertor heat and article flux profiles with applied 3D fields in NSTX H-mode plasmas  

SciTech Connect (OSTI)

Externally imposed non-axisymmetric magnetic perurbations are observed to alter divertor heat and particle flux profiles in the National Spherical Torus Experiment (NSTX). The divertor profiles are foud to have a modust level of multiple local peaks, characteristic of strike poimt splitting or the "magnetis lob" structure, even before the application of the 3D fields in some (but not all) NSTX discharges. This is thought to be due to the intrinsic error fields. The applied 3D fields augmented the intrinsic strike point splitting, making the ampliture of local peaks, and valleys larger in the divertor profile and striations at the divertor surface brighter. The measured heat flux profile shows that the radial location and spacing of the strations are qualitativel consistent witth a vacuum field tracing calcultion. 3D field application did not change the peak divertor heat and particle fluxes at the toroidal location of measurement. Spatial characteristics of the observed patterns are also reported in the paper.

Ahn, Joon-Wook [Oak Ridge National Laboratory (ORNL); Canik, John [ORNL; Soukhanovskii, V. A. [Lawrence Livermore National Laboratory (LLNL); Maingi, Rajesh [ORNL; Battaglia, D. J. [Oak Ridge National Laboratory (ORNL)

2010-04-01T23:59:59.000Z

57

Analysis of NSTX Upgrade OH Magnet and Center Stack  

SciTech Connect (OSTI)

The new ohmic heating (OH) coil and center stack for the National Spherical Torus Experiment (NSTX) upgrade are required to meet cooling and structural requirements for operation at the enhanced 1 Tesla toroidal field and 2 MA plasma current. The OH coil is designed to be cooled in the time between discharges by water flowing in the center of the coil conductor. We performed resistive heating and thermal hydraulic analyses to optimize coolant channel size to keep the coil temperature below 100 C and meet the required 20 minute cooling time. Coupled electromagnetic, thermal and structural FEA analyses were performed to determine if the OH coil meets the requirements of the structural design criteria. Structural response of the OH coil to its self-field and the field from other coils was analyzed. A model was developed to analyze the thermal and electromagnetic interaction of centerstack components such as the OH coil, TF inner legs and the Bellville washer preload mechanism. Torsional loads from the TF interaction with the OH and poloidal fields are transferred through the TF flag extensions via a torque transfer coupling to the rest of the tokamak structure. A 3D FEA analysis was performed to qualify this design. The results of these analyses, which will be presented in this paper, have led to the design of OH coil and centerstack components that meet the requirements of the NSTX-upgrade structural design criteria.

A. Zolfaghari, P. Titus, J. Chrzanowski, A. Salehzadeh, F. Dahlgren

2010-11-30T23:59:59.000Z

58

Recent Progress on Spherical Torus Research  

SciTech Connect (OSTI)

The spherical torus or spherical tokamak (ST) is a member of the tokamak family with its aspect ratio (A = R0/a) reduced to A ~ 1.5, well below the normal tokamak operating range of A ? 2.5. As the aspect ratio is reduced, the ideal tokamak beta ? (radio of plasma to magnetic pressure) stability limit increases rapidly, approximately as ? ~ 1/A. The plasma current it can sustain for a given edge safety factor q-95 also increases rapidly. Because of the above, as well as the natural elongation ?, which makes its plasma shape appear spherical, the ST configuration can yield exceptionally high tokamak performance in a compact geometry. Due to its compactness and high performance, the ST configuration has various near term applications, including a compact fusion neutron source with low tritium consumption, in addition to its longer term goal of attractive fusion energy power source. Since the start of the two megaampere class ST facilities in 2000, National Spherical Torus Experiment (NSTX) in the US and Mega Ampere Spherical Tokamak (MAST) in UK, active ST research has been conducted worldwide. More than sixteen ST research facilities operating during this period have achieved remarkable advances in all of fusion science areas, involving fundamental fusion energy science as well as innovation. These results suggest exciting future prospects for ST research both near term and longer term. The present paper reviews the scientific progress made by the worldwide ST research community during this new mega-ampere-ST era.

Ono, Masayuki [PPPL; Kaita, Robert [PPPL

2014-01-01T23:59:59.000Z

59

Use of the Far Infrared Tangential Interferometer/Polarimeter diagnostic for the study of rf driven plasma waves on NSTX  

SciTech Connect (OSTI)

A rf detection system for waves in the 30 MHz range has been constructed for the Far Infrared Tangential Interferometer/Polarimeter on National Spherical Torus Experiment (NSTX). It is aimed at monitoring high frequency density fluctuations driven by 30 MHz high harmonic fast wave fields. The levels of density fluctuations at various radial chords and antenna phase angles can be estimated using the electric field calculated by TORIC code and linearized continuity equation for the electron density. In this paper, the experimental arrangement for the detection of rf signal and preliminary results of simulation will be discussed.

Kim, J.; Park, H. [Department of Physics, POSTECH, Pohang, Gyeongbuk 790-784 (Korea, Republic of); Lee, K. C.; Domier, C. W.; Luhmann, N. C. Jr. [University of California at Davis, Davis, California 95616 (United States); Kaita, R.; Phillips, C. K.; Valeo, E. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Bonoli, P. T. [Plasma Science and Fusion Center, MIT, Cambridge, Massachusetts (United States)

2010-10-15T23:59:59.000Z

60

Characterization of Disruption Halo Currents in the National Spherical Torus Experiment  

SciTech Connect (OSTI)

This paper describes the general characteristics of disruptions halo currents in the National Spherical Torus Experiment [M. Ono, et al. Nuclear Fusion 40, 557 (2000)]. The commonly observed types of vertical motion and resulting halo current patterns are described, and it is shown that plasma discharges developing between components can facilitate halo current flow. The halo current fractions and toroidal peaking factors at various locations in the device are presented. The maximum product of these two metrics for localized halo current measurements is always significantly less than the worst-case expectations from conventional aspect ratio tokamaks (which are typically written in terms of the total halo current). The halo current fraction and impulse is often largest in cases with the fastest plasma current quenches and highest quench rates. The effective duration of the halo current pulse is comparable to or shorter than the plasma current quench time. The largest halo currents have tended to occur in lower ? and lower elongation plasmas. The sign of the poloidal halo current is reversed when the toroidal field direction is reversed.

S.P. Gerhardt, J. Menard, S. Sabbagh and F. Scotti

2012-04-25T23:59:59.000Z

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61

NSTX High Field Side Gas Fueling System  

SciTech Connect (OSTI)

Fueling National Spherical Torus Experiment (NSTX) plasmas with gas injected from the high field side (HFS) has produced earlier, more reliable transitions to the H-mode, longer H-mode durations, higher toroidal rotation, and higher edge electron temperature compared with similar discharges using the low field side (LFS) gas fueling injectors. The HFS gas fueling system consists of a Center Stack midplane injector, and an injector at the inner, upper corner of the Center Stack. The challenging design and installation constraints for the HFS gas system involved placing the control components as close as possible to the machine-vacuum interface, devising a special feed-through flange, traversing through vessel regions whose temperatures during bake-out range from 150 to 350 degrees Centigrade, adapting the gas transport tubing size and route to the small instrumentation wire channels behind the existing graphite plasma facing component tiles on the Center Stack, and providing output orifices shielded from excessive plasma power depositions while concentrating the output flow to facilitate fast camera viewing and analysis. Design, recent performance, and future upgrades will be presented.

H.W. Kugel; M. Anderson; G. Barnes; M. Bell; W. Blanchard; L. Dudek; D. Gates; R. Gernhardt; R. Maingi; D. Mueller; T. Provost; R. Raman; V. Soukhanovskii; J. Winston

2003-10-09T23:59:59.000Z

62

NSTX Weekly Report (Apr. 16, 2010) FY 2010 NSTX plasma operations  

E-Print Network [OSTI]

Experiment" by F.M. Poli, "L-H Threshold Studies in NSTX" by S. Kaye, "Reflectometry and Backscattering. Shot 137642 was made with 40kV NBI as needed for neutron detector calibration. The final shots needed

Princeton Plasma Physics Laboratory

63

An Overview of Recent Results from the National Spherical Torus Experiment  

E-Print Network [OSTI]

Hopkins U Los Alamos NL Lawrence Livermore NL Lodestar MIT Nova Photonics, Inc. New York U Old Dominion U U Hiroshima U Hyogo U Kyoto U Kyushu U Kyushu Tokai U NIFS Niigata U U Tokyo JAEA Hebrew U Ioffe, Garching ASCR, Czech Rep U Quebec Supported by #12;Bell / NIFS seminar / 080916 2 "Spherical Torus" Extends

Princeton Plasma Physics Laboratory

64

NSTX Program Overview andNSTX Program Overview and NSTX Upgrade Physics Design ProgressNSTX Upgrade Physics Design Progress  

E-Print Network [OSTI]

size and cost for PMI R&D High neutron flux at small size and cost for testing fusion nuclear) Science Facility ITER NSTX NSTX-U ST-based Fusion Nuclear Science (FNS) Facility #12;NSTXNSTX NSTX Program the current, control plasma profiles · High fnon-inductive 70% in NSTX (FW+NBI+BS), 100% NI + J(r) control

Princeton Plasma Physics Laboratory

65

Continuous Improvement of H-Mode Discharge Performance with Progressively Increasing Lithium Coatings in the National Spherical Torus Experiment  

SciTech Connect (OSTI)

Lithium wall coatings have been shown to reduce recycling, improve energy confinement, and suppress edge localized modes in the National Spherical Torus Experiment. Here, we show that these effects depend continuously on the amount of predischarge lithium evaporation.We observed a nearly monotonic reduction in recycling, decrease in electron transport, and modification of the edge profiles and stability with increasing lithium. These correlations challenge basic expectations, given that even the smallest coatings exceeded that needed for a nominal thickness of the order of the implantation range.

Maingi, Rajesh [ORNL; Kaye, S. [Princeton Plasma Physics Laboratory (PPPL); Skinner, C. H. [Princeton Plasma Physics Laboratory (PPPL); Boyle, D. P. [Princeton University; Canik, John [ORNL; Bell, M. G. [Princeton Plasma Physics Laboratory (PPPL); Bell, R. E. [Princeton Plasma Physics Laboratory (PPPL); Gray, Travis K [ORNL; Jaworski, M. A. [Princeton Plasma Physics Laboratory (PPPL); Kaita, R. [Princeton Plasma Physics Laboratory (PPPL); Kugel, H. W. [Princeton Plasma Physics Laboratory (PPPL); LaBlanc, B. P. [Princeton Plasma Physics Laboratory (PPPL); Mansfield, D.K. [Princeton Plasma Physics Laboratory (PPPL); Osborne, T. H. [General Atomics; Sabbagh, S. A. [Columbia University; Soukhanovskii, V. A. [Lawrence Livermore National Laboratory (LLNL)

2011-01-01T23:59:59.000Z

66

Full Toroidal Imaging of Non-axisymmetric Plasma Material Interaction in the National Spherical Torus eXperiment  

SciTech Connect (OSTI)

A pair of two dimensional fast cameras with a wide angle view (allowing a full radial and toroidal coverage of the lower divertor) was installed in the National Spherical Torus Experiment in order to monitor non-axisymmetric effects. A custom polar remapping procedure and an absolute photometric calibration enabled the easier visualization and quantitative analysis of non-axisymmetric plasma material interaction (e.g., strike point splitting due to application of 3D fields and effects of toroidally asymmetric plasma facing components).

Filippo Scotti, A.L. Roquemore, and V. A. Soukhanovskii

2012-07-11T23:59:59.000Z

67

European nuclear fusion: Torus takes summer break  

Science Journals Connector (OSTI)

... EUROPE'S collaborative experiment in nuclear fusion, the Joint European Torus (JET), produced "real plasma" for the first time ...

Robert Walgate

1983-08-04T23:59:59.000Z

68

Large Area Divertor Temperature Measurements Using A High-speed Camera With Near-infrared FiIters in NSTX  

SciTech Connect (OSTI)

Fast cameras already installed on the National Spherical Torus Experiment (NSTX) have be equipped with near-infrared (NIR) filters in order to measure the surface temperature in the lower divertor region. Such a system provides a unique combination of high speed (> 50 kHz) and wide fi eld-of-view (> 50% of the divertor). Benchtop calibrations demonstrated the system's ability to measure thermal emission down to 330 oC. There is also, however, signi cant plasma light background in NSTX. Without improvements in background reduction, the current system is incapable of measuring signals below the background equivalent temperature (600 - 700 oC). Thermal signatures have been detected in cases of extreme divertor heating. It is observed that the divertor can reach temperatures around 800 oC when high harmonic fast wave (HHFW) heating is used. These temperature profiles were fi t using a simple heat diffusion code, providing a measurement of the heat flux to the divertor. Comparisons to other infrared thermography systems on NSTX are made.

Lyons, B C; Zweben, S J; Gray, T K; Hosea, J; Kaita, R; Kugel, H W; Maqueda, R J; McLean, A G; Roquemore, A L; Soukhanovskii, V A

2011-04-05T23:59:59.000Z

69

Stochastic Orbit Loss of Neutral Beam Ions From NSTX Due to Toroidal Alfven Eigenmode Avalanches  

SciTech Connect (OSTI)

Short toroidal Alfven eigenmode (TAE) avalanche bursts in the National Spherical Torus Experiment (NSTX) cause a drop in the neutron rate and sometimes a loss of neutral beam ions at or near the full injection energy over an extended range of pitch angles. The simultaneous loss of wide ranges of pitch angle suggests stochastic transport of the beam ions occurs. When beam ion orbits are followed with a guiding center code that incorporates plasma's magnetic equilibrium plus the measured modes, the predicted ranges of lost pitch angle are similar to those seen in the experiment, with distinct populations of trapped and passing orbits lost. These correspond to domains where the stochasticity extends in the orbit phase space from the region of beam ion deposition to the loss boundary.

Darrow, D S; Fredrickson, E D; Gorelenkov, N N; Gorelenkova, M; Kubota, S; Medley, S S; Podesta, M; Shi, L

2012-07-11T23:59:59.000Z

70

Properties of Alfvén eigenmodes in the Toroidal Alfvén Eigenmode range on the National Spherical Torus Experiment-Upgrade  

SciTech Connect (OSTI)

A second Neutral Beam (NB) injection line is being installed on the NSTX Upgrade device, resulting in six NB sources with different tangency radii that will be available for heating and current drive. This work explores the properties of instabilities in the frequency range of the Toroidal Alfvén Eigenmode (TAE) for NSTX-U scenarios with various NB injection geometries, from more perpendicular to more tangential, and with increased toroidal magnetic field with respect to previous NSTX scenarios. Predictions are based on analysis through the ideal MHD code NOVA-K. For the scenarios considered in this work, modifications of the Alfvén continuum result in a frequency up-shift and a broadening of the radial mode structure. The latter effect may have consequences for fast ion transport and loss. Preliminary stability considerations indicate that TAEs are potentially unstable with ion Landau damping representing the dominant damping mechanism.

Podestà, M.; Gorelenkov, N. N.; White, R. B.; Fredrickson, E. D.; Gerhardt, S. P.; Kramer, G. J. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

2013-08-15T23:59:59.000Z

71

SciTech Connect: Comparison of Gas Puff Imaging Data in NSTX...  

Office of Scientific and Technical Information (OSTI)

measured and modeled D light emission for speci c NSTX experiments. Both the simulated spatial distribution and radiance of the D light emission agree well with the...

72

Double Bubble Experiments in the Three-Torus By Nicholas D. Brubaker, Stephen Carter, Sean M. Evans, Daniel E. Kravatz Jr.,  

E-Print Network [OSTI]

Double Bubble Experiments in the Three-Torus By Nicholas D. Brubaker, Stephen Carter, Sean M. Evans, Millersville University and Dr. Frank Morgan, Williams College Figure 1: The ten conjectured double bubble bubbles. This shape is a conse- quence of the fact that of all the ways of enclosing a given volume

Umble, Ron

73

Princeton Plasma Physics Laboratory NSTX Experimental Proposal  

E-Print Network [OSTI]

Review Board (designated by Run Coordinator) MINOR MODIFICATIONS (Approved by Experimental Research in NSTX and DIII-D. Because the physics of ELM mitigation by non- axisymmetric fields is not established, this experiment is somewhat exploratory in nature. For instance, plasma targets with various edge q

Princeton Plasma Physics Laboratory

74

Princeton Plasma Physics Laboratory NSTX Experimental Proposal  

E-Print Network [OSTI]

, the experiment will then attempt to determine the error-field penetration threshold scaling with B-field, shape, if some confidence can be gained that error fields have been minimized in NSTX, the penetration threshold ramp-rate to reach flat-top current at t=160ms for higher IP shots or use higher current reference

Princeton Plasma Physics Laboratory

75

Onset and Saturation of a Non-resonant Internal Mode in NSTX and Implications For AT Modes in ITER  

SciTech Connect (OSTI)

Motivated by experimental observations of apparently triggerless tearing modes, we have performed linear and nonlinear MHD analysis showing that a non-resonant mode with toroidal mode number n = 1 can develop in the National Spherical Torus eXperiment (NSTX) at moderate normalized ?N when the shear is low and the central safety factor q0 is close to but greater than one. This mode, which is related to previously identified ‘infernal’ modes, will saturate and persist, and can develop poloidal mode number m = 2 magnetic islands in agreement with experiments. We have also extended this analysis by performing a free-boundary transport simulation of an entire discharge and showing that, with reasonable assumptions, we can predict the time of mode onset. __________________________________________________

J.A. Breslau, M.S. Chance, J. Chen, G.Y. Fu, S,. Gerhardt, N. Gorelenkov, S.C. Jardin and J. Manickam

2011-08-01T23:59:59.000Z

76

Novel Use of Water Soluble "Aquapour" As A Temporary Spacer During Coil Winding For The NSTX-U Centerstack  

SciTech Connect (OSTI)

A major facility upgrade to the National Spherical Torus eXperiment (NSTX-U) is currently underway at Princeton Plasma Physics Laboratory (PPPL). A key component of NSTX-U is the fabrication of a new, higher field centerstack (CS). In order to simultaneously provide robust joints between the inner and outer legs of the Toroidal Field Coils (TF) and minimize radial build, the NSTX-U CS design requires that the Ohmic Heating solenoid (OH) be wound directly on the inner TF bundle. To protect the OH against thermal expansion stress during scenarios where the inner TF bundle is hot but the OH is relatively cool, the completed CS will have a 0.100 inch annular gap between the outer diameter of the TF bundle and the inner diameter of the OH solenoid. "Aquapour", a proprietary material produced by the Advanced Ceramics Manufacturing Company will be used during manufacture to produce this gap. After the TF bundle is vacuum pressure impregnated and cured, a cylindrical "clam shell" mold will be assembled around it, and a slurry of powdered Aquapour and water will be pumped into the annular space between the mold and TF bundle. Subsequent baking will turn the Aquapour solid, and a protective layer of wet lay-up fiberglass and resin will be added. The OH solenoid will be wound directly on this wet lay-up shell. After vacuum pressure impregnation of the OH, the water soluble Aquapour will be washed away, leaving the required radial clearance between the TF and OH. This paper will describe prototyping and testing of this process, and plans for use on the actual CS fabrication.

Mardenfeld, Michael

2013-07-01T23:59:59.000Z

77

Reduced model prediction of electron temperature profiles in microtearing-dominated National Spherical Torus eXperiment plasmas  

SciTech Connect (OSTI)

A representative H-mode discharge from the National Spherical Torus eXperiment is studied in detail to utilize it as a basis for a time-evolving prediction of the electron temperature profile using an appropriate reduced transport model. The time evolution of characteristic plasma variables such as ?{sub e},??{sub e}{sup ?}, the MHD ? parameter, and the gradient scale lengths of T{sub e}, T{sub i}, and n{sub e} were examined as a prelude to performing linear gyrokinetic calculations to determine the fastest growing micro instability at various times and locations throughout the discharge. The inferences from the parameter evolutions and the linear stability calculations were consistent. Early in the discharge, when ?{sub e} and ?{sub e}{sup ?} were relatively low, ballooning parity modes were dominant. As time progressed and both ?{sub e} and ?{sub e}{sup ?} increased, microtearing became the dominant low-k{sub ?} mode, especially in the outer half of the plasma. There are instances in time and radius, however, where other modes, at higher-k{sub ?}, may, in addition to microtearing, be important for driving electron transport. Given these results, the Rebut-Lallia-Watkins (RLW) electron thermal diffusivity model, which is based on microtearing-induced transport, was used to predict the time-evolving electron temperature across most of the profile. The results indicate that RLW does a good job of predicting T{sub e} for times and locations where microtearing was determined to be important, but not as well when microtearing was predicted to be stable or subdominant.

Kaye, S. M., E-mail: skaye@pppl.gov; Guttenfelder, W.; Bell, R. E.; Gerhardt, S. P.; LeBlanc, B. P.; Maingi, R. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)

2014-08-15T23:59:59.000Z

78

NSTX Failure Modes & Effects Analysis / NSTX-FMEA-71-10 / p. 1 of 115 FAILURE MODES AND EFFECTS ANALYSIS  

E-Print Network [OSTI]

NSTX Failure Modes & Effects Analysis / NSTX-FMEA-71-10 / p. 1 of 115 NSTX FAILURE MODES AND EFFECTS ANALYSIS (FMEA) Revision 10 Dated: November 2014 Prepared By: Name/WBS Signature Name: ________________________________________________ Ron Strykowsky, NSTX Upgrade Project Manager #12;NSTX Failure Modes & Effects Analysis / NSTX-FMEA-71

Princeton Plasma Physics Laboratory

79

Final Scientific/Technical Report, USDOE Award DE-FG-02ER54684, Recipient: CompX, Project Title: Fokker-Planck/Ray Tracing for Electron Bernstein and Fast Wave Modeling in Support of NSTX.  

SciTech Connect (OSTI)

This DOE grant supported fusion energy research, a potential long-term solution to the world's energy needs. Magnetic fusion, exemplified by confinement of very hot ionized gases, i.e., plasmas, in donut-shaped tokamak vessels is a leading approach for this energy source. Thus far, a mixture of hydrogen isotopes has produced 10's of megawatts of fusion power for seconds in a tokamak reactor at Princeton Plasma Physics Laboratory in New Jersey. The research grant under consideration, ER54684, uses computer models to aid in understanding and projecting efficacy of heating and current drive sources in the National Spherical Torus Experiment, a tokamak variant, at PPPL. The NSTX experiment explores the physics of very tight aspect ratio, almost spherical tokamaks, aiming at producing steady-state fusion plasmas. The current drive is an integral part of the steady-state concept, maintaining the magnetic geometry in the steady-state tokamak. CompX further developed and applied models for radiofrequency (rf) heating and current drive for applications to NSTX. These models build on a 30 year development of rf ray tracing (the all-frequencies GENRAY code) and higher dimensional Fokker-Planck rf-collisional modeling (the 3D collisional-quasilinear CQL3D code) at CompX. Two mainline current-drive rf modes are proposed for injection into NSTX: (1) electron Bernstein wave (EBW), and (2) high harmonic fast wave (HHFW) modes. Both these current drive systems provide a means for the rf to access the especially high density plasma--termed high beta plasma--compared to the strength of the required magnetic fields. The CompX studies entailed detailed modeling of the EBW to calculate the efficiency of the current drive system, and to determine its range of flexibility for driving current at spatial locations in the plasma cross-section. The ray tracing showed penetration into NSTX bulk plasma, relatively efficient current drive, but a limited ability to produce current over the whole radial plasma cross-section. The actual EBW experiment will cost several million dollars, and remains in the proposal stage. The HHFW current drive system has been experimentally implemented on NSTX, and successfully drives substantial current. The understanding of the experiment is to be accomplished in terms of general concepts of rf current drive, and also detailed modeling of the experiment which can discern the various competing processes which necessarily occur simultaneously in the experiment. An early discovery of the CompX codes, GENRAY and CQL3D, was that there could be significant interference between the neutral beam injection fast ions in the machine (injected for plasma heating) and the HHFW energy. Under many NSTX experimental conditions, power which could go to the fast ions would then be unavailable for current drive by the desired HHFW interaction with electrons. This result has been born out by experiments; the modeling helps in understanding difficulties with HHFW current drive, and has enabled adjustment of the experiment to avoid interaction with neutral beam injected fast ions thereby achieving stronger HHFW current drive. The detailed physics modeling of the various competing processes is almost always required in fusion energy plasma physics, to ensure a reasonably accurate and certain interpretation of the experiment, enabling the confident design of future, more advanced experiments and ultimately a commercial fusion reactor. More recent work entails detailed investigation of the interaction of the HHFW radiation for fast ions, accounting for the particularly large radius orbits in NSTX, and correlations between multiple HHFW-ion interactions. The spherical aspect of the NSTX experiment emphasized particular physics such as the large orbits which are present to some degree in all tokamaks, but gives clearer clues on the resulting physics phenomena since competing physics effects are reduced.

R.W. Harvey, CompX, Del Mar, CA 92014

2009-11-12T23:59:59.000Z

80

Fast wave heating in the NSTX-Upgrade device  

SciTech Connect (OSTI)

NSTX-Upgrade will operate with toroidal magnetic fields (B T) up to 1 T, nearly twice the value used in the experiments on NSTX, and the available NBI power will be doubled. The doubling of B T while retaining the 30 MHz RF source frequency has moved the heating regime from the high harmonic fast wave (HHFW) regime used in NSTX to the mid harmonic fast wave (MHFW) regime. By making use of the full wave code AORSA, this work shows that direct ion damping (mainly by thermal ions localized at the 5th harmonic resonance) might be significant in NSTX-Upgrade under TRANSP predicted full performance conditions and the electron and ion absorption is sensitive to the ratio of electron and ion temperature. Launching at high toroidal wave number appears to be one way to significantly reduce the ion damping. By using the extended AORSA code, which includes a detailed description of the scrape-off layer in the field solutions, we found a large electric field amplitude outside of the last closed flux surface as previously seen in NSTX from AORSA simulations (D. L. Green, et al, Phys. Rev. Lett. 107, 145001 (2011)). Preliminary results by introducing a collision damping in the scrape-off layer in the AORSA code to represent a damping process are presented, showing for the first time absorbed power in the scrape-off layer.

Bertelli, Nicola [Princeton Plasma Physics Laboratory (PPPL); Jaeger, E. F. [XCEL; Berry, Lee Alan [XCEL Engineering Inc., Oak Ridge; Bonoli, P. [Massachusetts Institute of Technology (MIT); Budny, R. V. [Princeton Plasma Physics Laboratory (PPPL); Fu, GuoYong [Princeton Plasma Physics Laboratory (PPPL); Gerhardt, S. [Princeton Plasma Physics Laboratory (PPPL); Green, David L [ORNL; Harvey, R. W. [CompX, Del Mar, CA; Hosea, J. [Princeton Plasma Physics Laboratory (PPPL); Kramer, G. [Princeton Plasma Physics Laboratory (PPPL); LeBlanc, B [Princeton Plasma Physics Laboratory (PPPL); Perkins, R. J. [Princeton Plasma Physics Laboratory (PPPL); Phillips, C. K. [Princeton Plasma Physics Laboratory (PPPL); Ryan, Philip Michael [ORNL; Taylor, G. [Princeton Plasma Physics Laboratory (PPPL); Valeo, E. J. [Princeton Plasma Physics Laboratory (PPPL); Wilson, J. R. [Princeton Plasma Physics Laboratory (PPPL); Wright, J. [Massachusetts Institute of Technology (MIT)

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "torus experiment nstx" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Rack Number Assignments Location TFTR TFTR NSTX NSTX  

E-Print Network [OSTI]

Rack Number Assignments Location TFTR TFTR NSTX NSTX Prefix Number range Prefix Number range-853 C-Site RF Balcony CRFB 900,901 CRFB 900,901 Most Safety Racks CSS 949-973 CSS 949-973 Oddball Control Room CCR 999 Pump Room CCI-IR 1-3 CCI-IR 1-3 Pump House CPH 1 CPH 1 Bakeout Racks VVS-ETC- 001

Princeton Plasma Physics Laboratory

82

HHFW absorption in Neutral-Beam heated NSTX plasmas  

E-Print Network [OSTI]

HHFW absorption in Neutral-Beam heated NSTX plasmas B. LeBlanc, M. Podestà, W. Heidbrink XP -1012 ions Need to characterize RF absorption as a function of RF phasing, L vs. H-mode plasmas, outer gap, optimized for FIDA measurements · Similar to 2008 FIDA experiment on RF absorption by fast ions · NB sources

Princeton Plasma Physics Laboratory

83

Progress In Understanding The Enhanced Petestal H-mode In NSTX  

SciTech Connect (OSTI)

ThIS paper describes the enhanced pedestal (EP) H-mode observed in the National Spherical Torus Experiment (NSTX). The defining characteristics of EP H-mode are given, namely i)transition after the L- to H-mode transition, ii) region of very steep ion temperature gradient, and iii) associated region of strong rotational shear. A newly observed long-pulse EP H-mode example shows quiescent behavior for as long as the heating and current drive sources are maintained. Cases are shown where the region of steep ion temperature gradient is located at the very edge, and cases where it is shifted up to 10 cm inward from the plasma edge; these cases are united by a common dependence of the ion temperature gradient on the toroidal rotation frequency shear. EP H-mode examples have been observed across a wide range of q95 and pedestal collisionality. No strong changes in the fluctuation amplitudes have been observed following the eP H-mode transition, and transport analysis indicates that the ion t hermal transport is comparable to or less than anticipated from a simple neoclassical transport model. Cases are shown where EP H-modes were reliably generated, through these low-q95 examples were difficult to sustain. A case where an externally triggered ELM precipitates the transition to EP H-mode is also shown, though an initial experiment designed to trigger EP-H-modes in this fashion was successful.

none,

2014-06-26T23:59:59.000Z

84

High Non-inductive Fraction H-mode Discharges Generated by High-harmonic Fast Wave Heating and Current Drive in the National Spherical Torus Experiment  

SciTech Connect (OSTI)

A deuterium H-mode discharge with a plasma current of 300 kA, an axial toroidal magnetic field of 0.55 T, and a calculated non-inductive plasma current fraction of 0.7 1 has been generated in the National Spherical Torus Experiment by 1.4MW of 30MHz high-harmonic fast wave (HHFW) heating and current drive. Seventy-five percent of the non-inductive current was generated inside an internal transport barrier that formed at a normalized minor radius 0.4. Three quarters of the non-inductive current was bootstrap current, and the remaining non-inductive current was generated directly by HHFW power inside a normalized minor radius 0.2. VC 2012 American Institute of Physics.

Taylor, G. [Princeton Plasma Physics Laboratory (PPPL); Hosea, J. [Princeton Plasma Physics Laboratory (PPPL); Kessel, C. E. [Princeton Plasma Physics Laboratory (PPPL); LeBlanc, B [Princeton Plasma Physics Laboratory (PPPL); Mueller, D. [Princeton Plasma Physics Laboratory (PPPL); Phillips, C. K. [Princeton Plasma Physics Laboratory (PPPL); Valeo, E. J. [Princeton Plasma Physics Laboratory (PPPL); Wilson, J. R. [Princeton Plasma Physics Laboratory (PPPL); Ryan, Philip Michael [ORNL; Bonoli, P. [Massachusetts Institute of Technology (MIT); Harvey, R. W. [CompX, Del Mar, CA

2012-01-01T23:59:59.000Z

85

Torus instability  

E-Print Network [OSTI]

The expansion instability of a toroidal current ring in low-beta magnetized plasma is investigated. Qualitative agreement is obtained with experiments on spheromak expansion and with essential properties of solar coronal mass ejections, unifying the two apparently disparate classes of fast and slow coronal mass ejections.

B. Kliem; T. Toeroek

2006-05-24T23:59:59.000Z

86

Torus Instability  

Science Journals Connector (OSTI)

The expansion instability of a toroidal current ring in low-beta magnetized plasma is investigated. Qualitative agreement is obtained with experiments on spheromak expansion and with essential properties of solar coronal mass ejections, unifying the two apparently disparate classes of fast and slow coronal mass ejections.

B. Kliem and T. Török

2006-06-26T23:59:59.000Z

87

Attachment 2 NSTX Data Usage and Publication Agreement  

E-Print Network [OSTI]

Attachment 2 NSTX Data Usage and Publication Agreement NSTX Research is carried out by a multi agrees to adhere to the following guidelines of the NSTX data usage and results publication. 1

Princeton Plasma Physics Laboratory

88

Attachment 2 NSTX Data Usage and Publication Agreement  

E-Print Network [OSTI]

Attachment 2 NSTX Data Usage and Publication Agreement NSTX is an open, fundamental research of the NSTX data usage and results publication. 1) No Research Team member will be given direct access

Princeton Plasma Physics Laboratory

89

NSTX Weekly Report (November 12, 2010) FY 2011 NSTX plasma operations started on October 4, 2010  

E-Print Network [OSTI]

. Sabbagh (Columbia U.), "Role of plasma edge region in global stability on NSTX" by J. Menard (PPPL of NSTX" by S. Zweben (PPPL), "Modification of divertor heat and particle flux profiles with 3-D fields-K. Park (PPPL), "Effects of Global Alfven Eigenmodes on Electron Thermal Transport in NSTX" by K. Tritz

Princeton Plasma Physics Laboratory

90

Integration of Microsoft Windows applications with \\{MDSplus\\} data acquisition on the National Spherical Torus Experiment at the Princeton Plasma Physics Laboratory  

Science Journals Connector (OSTI)

Data acquisition on the National Spherical Torus Experiment at the Princeton Plasma Physics Laboratory (PPPL) has increasingly involved the use of Personal Computers and specially developed ‘turn-key’ hardware and software systems to control diagnostics. Interaction with these proprietary software packages is accomplished through use of Visual Basic, or Visual C++ and Component Object Model (com) technology. com is a software architecture that allows the components made by different software vendors to be combined into a variety of applications. This technology is particularly well suited to these systems because of its programming language independence, standards for function calling between components, and ability to transparently reference remote processes. com objects make possible the creation of acquisition software that can control the experimental parameters of both the hardware and software. Synchronization of these applications for diagnostics, such as charged couple device cameras and residual gas analyzers, with the rest of the experiment event cycle at PPPL has been made possible by utilization of the \\{MDSplus\\} libraries for Windows. Instead of transferring large data files to remote disk space, Windows \\{MDSplus\\} events and I/O functions allow us to put raw data into \\{MDSplus\\} directly from interactive data language for Windows and Visual Basic. The combination of com technology and the \\{MDSplus\\} libraries for Windows provide the tools for many new possibilities in versatile acquisition applications and future diagnostics.

Dana M. Mastrovito

2002-01-01T23:59:59.000Z

91

Health and Safety Plan for NSTX Upgrade Project Tasks  

E-Print Network [OSTI]

Health and Safety Plan for NSTX Upgrade Project Tasks in the NSTX Test Cell PRINCETON PLASMA....~_____...L....,L....q..l:::::.......:.J Larry Dudek, NSTX Center Stack Manager Reviewed by: I( Jer evine, Environment, Safety, Health and S This document describes the structure and implementation of the Health and Safety Plan for the NSTX Upgrade

Princeton Plasma Physics Laboratory

92

Experimental studies on fast-ion transport by Alfven wave avalanches on the National Spherical Torus Experiment  

E-Print Network [OSTI]

-linearities may compromise a direct comparison between experiment and theory. PACS numbers: I. INTRODUCTION a linear magneto-hydrodynamics stability code. The comparison with experimental data suggests that non or neutral beams (NB), may open new avenues to control the behavior of a fusion reactor. Paper GI1 1, Bull

Princeton Plasma Physics Laboratory

93

Lithium Surface Coatings for Improved Plasma Performance in NSTX  

SciTech Connect (OSTI)

NSTX high-power divertor plasma experiments have shown, for the first time, significant and frequent benefits from lithium coatings applied to plasma facing components. Lithium pellet injection on NSTX introduced lithium pellets with masses 1 to 5 mg via He discharges. Lithium coatings have also been applied with an oven that directed a collimated stream of lithium vapor toward the graphite tiles of the lower center stack and divertor. Lithium depositions from a few mg to 1 g have been applied between discharges. Benefits from the lithium coating were sometimes, but not always seen. These improvements sometimes included decreases plasma density, inductive flux consumption, and ELM frequency, and increases in electron temperature, ion temperature, energy confinement and periods of MHD quiescence. In addition, reductions in lower divertor D, C, and O luminosity were measured.

Kugel, H W; Ahn, J -W; Allain, J P; Bell, R; Boedo, J; Bush, C; Gates, D; Gray, T; Kaye, S; Kaita, R; LeBlanc, B; Maingi, R; Majeski, R; Mansfield, D; Menard, J; Mueller, D; Ono, M; Paul, S; Raman, R; Roquemore, A L; Ross, P W; Sabbagh, S; Schneider, H; Skinner, C H; Soukhanovskii, V; Stevenson, T; Timberlake, J; Wampler, W R

2008-02-19T23:59:59.000Z

94

Snowflake Divertor Configuration in NSTX  

SciTech Connect (OSTI)

Steady-state handling of divertor heat flux is a critical issue for present and future conventional and spherical tokamaks with compact high power density divertors. A novel 'snowflake' divertor (SFD) configuration that takes advantage of magnetic properties of a second-order poloidal null has been predicted to have a larger plasma-wetted area and a larger divertor volume, in comparison with a standard first-order poloidal X-point divertor configuration. The SFD was obtained in 0.8 MA, 4-6 MW NBI-heated H-mode discharges in NSTX using two divertor magnetic coils. The SFD led to a partial detachment of the outer strike point even in low-collisionality scrape-off layer plasma obtained with lithium coatings in NSTX. Significant divertor peak heat flux reduction and impurity screening have been achieved simultaneously with good core confinement and MHD properties.

Soukhanovskii, V. A. [Lawrence Livermore National Laboratory (LLNL); Ahn, Joonwook [ORNL; Bell, R. E. [Princeton Plasma Physics Laboratory (PPPL); Gates, D.A. [Princeton Plasma Physics Laboratory (PPPL); Gerhardt, S. [Princeton Plasma Physics Laboratory (PPPL); Kaita, R. [Princeton Plasma Physics Laboratory (PPPL); Kolemen, E.. [Princeton Plasma Physics Laboratory (PPPL); Kugel, H. W. [Princeton Plasma Physics Laboratory (PPPL); LeBlanc, B [Princeton Plasma Physics Laboratory (PPPL); Maingi, Rajesh [ORNL; Maqueda, R. J. [Nova Photonics, Princeton, NJ; McLean, Adam G [ORNL; Menard, J. E. [Princeton Plasma Physics Laboratory (PPPL); Mueller, D. [Princeton Plasma Physics Laboratory (PPPL); Paul, S. F. [Princeton Plasma Physics Laboratory (PPPL); Raman, R [University of Washington, Seattle; Roquemore, L. [Princeton Plasma Physics Laboratory (PPPL); Ryutov, D. D. [Lawrence Livermore National Laboratory (LLNL); Scott, H A [Lawrence Livermore National Laboratory (LLNL)

2011-01-01T23:59:59.000Z

95

CHARTER OF THE NSTX PROGRAM ADVISORY COMMITTEE  

E-Print Network [OSTI]

.S. and world fusion programs. The PAC will provide this advice to the PPPL Director. The PAC will address key, and subsequently requested in writing by the PPPL Director. The NSTX Program Director is responsible for implementing the NSTX Program, with the guidance of the PPPL Office of the Director. III. Membership The PPPL

Princeton Plasma Physics Laboratory

96

Work Authorization Document NSTX Upgrade Project  

E-Print Network [OSTI]

Work Authorization Document NSTX Upgrade Project Control Account #: 1302 Title: WBS 1.1.11 Title Functional Manager P. Heitzenroeder Approvals Signature Date NSTX-U Project Manager R. Strykowsky 4- WBS and includes design modifications and upgrade of the coil assembly stand; procedures for assembling the Center

Princeton Plasma Physics Laboratory

97

Work Authorization Document NSTX Upgrade Project  

E-Print Network [OSTI]

Work Authorization Document NSTX Upgrade Project Control Account #: 7900 Title: WBS 1.7.3 Title Functional Manager L. Dudek Approvals Signature Date NSTX-U Project Manager R. Strykowsky 4- WBS Dictionary procedures and documents to support the integrated tests, and to support performance of the pre

Princeton Plasma Physics Laboratory

98

Investigation of Resistive Wall Mode Stabilization Physics in High-beta Plasmas Using Applied Non-axisymmetric Fields in NSTX  

SciTech Connect (OSTI)

The National Spherical Torus Experiment (NSTX) offers an operational space characterized by high-beta (?t = 39%, ?N > 7, ?N/?no-wall N > 1.5) and low aspect ratio (A > 1.27) to leverage the plasma parameter dependences of RWM stabilization and plasma rotation damping physics giving greater confidence for extrapolation to ITER. Significant new capability for RWM research has been added to the device with the commissioning of a set of six nonaxisymmetric magnetic field coils, allowing generation of fields with dominant toroidal mode number, n, of 1–3. These coils have been used to study the dependence of resonant field amplification on applied field frequency and RWMstabilization physics by reducing the toroidal rotation profile belowits steady-state value through non-resonant magnetic braking. Modification of plasma rotation profiles shows that rotation outside q = 2.5 is not required for passive RWM stability and there is large variation in the RWM critical rotation at the q = 2 surface, both of which are consistent with distributed dissipation models.

Sontag, A. C.; Sabbagh, S. A.; Zhu, W.; Menard, J. E.; Bell, R. E.; Bialek, J. M.; Bell, M. G.; Gates, D. A.; Glasser, A. H.; LeBlanc, B. P.; Shaing, K. C.; Stutman, D.; Tritz, K. L.

2009-06-16T23:59:59.000Z

99

The Dependence of H-mode Energy Confinement and Transport on Collisionality in NSTX  

SciTech Connect (OSTI)

Understanding the dependence of confi nement on collisionality in tokamaks is important for the design of next-step devices, which will operate at collisionalities at least one order of magnitude lower than in present generation. A wide range of collisionality has been obtained in the National Spherical Torus Experiment (NSTX) by employing two different wall conditioning techniques, one with boronization and between-shot helium glow discharge conditioning (HeGDC+B), and one using lithium evaporation (Li EVAP). Previous studies of HeGDC+B plasmas indicated a strong and favorable dependence of normalized con nement on collisionality. Discharges with lithium conditioning discussed in the present study gen- erally achieved lower collisionality, extending the accessible range of collisionality by almost an order of unity. While the confinement dependences on dimensional, engineering variables of the HeGDC+B and Li EVAP datasets differed, collisionality was found to unify the trends, with the lower collisionality lithium conditioned discharges extending the trend of increasing normalized confi nement time with decreasing collisionality when other dimension less variables were held as fi xed as possible. This increase of confi nement with decreasing collisionality was driven by a large reduction in electron transport in the outer region of the plasma. This result is consistent with gyrokinetic calculations that show microtearing and Electron Temperature Gradient modes to be more stable for the lower collisionality discharges. Ion transport, near neoclassical at high collisionality, became more anomalous at lower collisionality, possibly due to the growth of hybrid TEM/KBM modes in the outer regions of the plasma

S.M.. Kaye, S. Gerhardt, W. Guttenfelder, R. Maingi, R.E. Bell, A. Diallo, B.P. LeBlanc and M. Podesta

2012-11-28T23:59:59.000Z

100

The Dependence of H-mode Energy Confinement and Transport on Collisionality in NSTX  

SciTech Connect (OSTI)

Understanding the dependence of confi nement on collisionality in tokamaks is important for the design of next-step devices, which will operate at collisionalities at least one order of magnitude lower than in present generation. A wide range of collisionality has been obtained in the National Spherical Torus Experiment (NSTX) by employing two different wall conditioning techniques, one with boronization and between-shot helium glow discharge conditioning (HeGDC+B), and one using lithium evaporation (Li EVAP). Previous studies of HeGDC+B plasmas indicated a strong and favorable dependence of normalized con nement on collisionality. Discharges with lithium conditioning discussed in the present study gen- erally achieved lower collisionality, extending the accessible range of collisionality by almost an order of unity. While the confinement dependences on dimensional, engineering variables of the HeGDC+B and Li EVAP datasets differed, collisionality was found to unify the trends, with the lower collisionality lithium conditioned discharges extending the trend of increasing normalized confi nement time with decreasing collisionality when other dimension less variables were held as fi xed as possible. This increase of confi nement with decreasing collisionality was driven by a large reduction in electron transport in the outer region of the plasma. This result is consistent with gyrokinetic calculations that show microtearing and Electron Temperature Gradient modes to be more stable for the lower collisionality discharges. Ion transport, near neoclassical at high collisionality, became more anomalous at lower collisionality, possibly due to the growth of hybrid TEM/KBM modes in the outer regions of the plasma.

S.M.. Kaye, S. Gerhardt, W. Guttenfelder, R. Maingi, R.E. Bell, A. Diallo, B.P. LeBlanc and M. Podesta

2012-11-27T23:59:59.000Z

Note: This page contains sample records for the topic "torus experiment nstx" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Spherical torus fusion reactor  

DOE Patents [OSTI]

The object of this invention is to provide a compact torus fusion reactor with dramatic simplification of plasma confinement design. Another object of this invention is to provide a compact torus fusion reactor with low magnetic field and small aspect ratio stable plasma confinement. In accordance with the principles of this invention there is provided a compact toroidal-type plasma confinement fusion reactor in which only the indispensable components inboard of a tokamak type of plasma confinement region, mainly a current conducting medium which carries electrical current for producing a toroidal magnet confinement field about the toroidal plasma region, are retained.

Martin Peng, Y.K.M.

1985-10-03T23:59:59.000Z

102

Comparison of Gas Puff Imaging Data in NSTX with the DEGAS 2 Simulation  

SciTech Connect (OSTI)

Gas-Puff-Imaging (GPI) is a two dimensional diagnostic which measures the edge D? light emission from a neutral D2 gas puff nears the outer mid-plane of NSTX. DEGAS 2 is a 3-D Monte Carlo code used to model neutral transport and atomic physics in tokamak plasmas. In this paper we compare measurements of the D? light emission obtained by GPI on NSTX with DEGAS 2 simulations of D? light emission for specific experiments. Both the simulated spatial distribution and absolute intensity of the D? light emission agree well with the experimental data obtained between ELMs in H-mode. __________________________________________________

B. Cao, D.P. Stotler, S.J. Zweben, M. Bell, A. Diallo and B. Leblanc

2012-11-08T23:59:59.000Z

103

Comparison of Gas Puff Imaging Data in NSTX with the DEGAS 2 Simulation  

SciTech Connect (OSTI)

Gas-Puff-Imaging (GPI) is a two dimensional diagnostic which measures the edge D? light emission from a neutral D2 gas puff nears the outer mid-plane of NSTX. DEGAS 2 is a 3-D Monte Carlo code used to model neutral transport and atomic physics in tokamak plasmas. In this paper we compare measurements of the D? light emission obtained by GPI on NSTX with DEGAS 2 simulations of D? light emission for specific experiments. Both the simulated spatial distribution and absolute intensity of the D? light emission agree well with the experimental data obtained between ELMs in H-mode.

B. Cao, D.P. Stotler, S.J. Zweben, M. Bell, A. Diallo and B. Leblanc

2012-10-27T23:59:59.000Z

104

Princeton Plasma Physics Laboratory NSTX Experimental Proposal  

E-Print Network [OSTI]

and that this may effect the energy confinement time as well as provide current drive. Of course, other effects mayPrinceton Plasma Physics Laboratory NSTX Experimental Proposal Title: CHI into an ohmic discharge

Princeton Plasma Physics Laboratory

105

Princeton Plasma Physics Laboratory NSTX Experimental Proposal  

E-Print Network [OSTI]

-mode reflectometry. The electron density scale length (Ln) at the B-X mode conversion layer is an important parameter at the B-X conversion layer. The antenna includes a port for a gas injection valve. #12;NSTX Experimental the Conversion of EBWs to X-Mode on NSTX OP-XP-404 Revision: 0 Effective Date: December 10, 2003 (Ref. OP-AD-97

Princeton Plasma Physics Laboratory

106

Princeton Plasma Physics Laboratory NSTX Experimental Proposal  

E-Print Network [OSTI]

-mode reflectometry. The electron density scale length (Ln) at the B-X mode conversion layer is an important parameter at the B-X conversion layer. The antenna includes a port for a gas injection valve. #12;NSTX Experimental the Conversion of EBWs to X-Mode on NSTX OP-XP- 308 Revision: 3 Effective Date: February 10, 2003 (Ref. OP-AD-97

Princeton Plasma Physics Laboratory

107

NSTX Data Usage and Publication Agreement NSTX Research is carried out by a multi-institutional collaborative Research Team. All Research Team  

E-Print Network [OSTI]

NSTX Data Usage and Publication Agreement NSTX Research is carried out by a multi agrees to adhere to the following guidelines of the NSTX data usage and results publication. 1

Princeton Plasma Physics Laboratory

108

Recent Progress in the NSTX/NSTX-U Lithium Program and Prospects for Reactor-Relevant Liquid-Lithium Based Divertor Development  

SciTech Connect (OSTI)

Developing a reactor compatible divertor has been identified as a particularly challenging technology problem for magnetic confinement fusion. While tungsten has been identified as the most attractive solid divertor material, the NSTX/NSTX-U lithium (Li) program is investigating the viability of liquid lithium (LL) as a potential reactor compatible divertor plasma facing component (PFC) . In the near term, operation in NSTX-U is projected to provide reactor-like divertor heat loads < 40 MW/m^2 for 5 s. During the most recent NSTX campaign, ~ 0.85 kg of Li was evaporated onto the NSTX PFCs where a ~50% reduction in heat load on the Liquid Lithium Divertor (LLD) was observed, attributable to enhanced divertor bolometric radiation. This reduced divertor heat flux through radiation observed in the NSTX LLD experiment is consistent with the results from other lithium experiments and calculations. These results motivate an LL-based closed radiative divertor concept proposed here for NSTX-U and fusion reactors. With an LL coating, the Li is evaporated from the divertor strike point surface due to the intense heat. The evaporated Li is readily ionized by the plasma due to its low ionization energies, and the ionized Li ions can radiate strongly, resulting in a significant reduction in the divertor heat flux. Due to the rapid plasma transport in divertor plasma, the radiation values can be significantly enhanced up to ~ 11 MJ/cc of LL. This radiative process has the desired function of spreading the focused divertor heat load to the entire divertor chamber facilitating the divertor heat removal. The LL divertor surface can also provide a "sacrificial" surface to protect the substrate solid material from transient high heat flux such as the ones caused by the ELMs. The closed radiative LLD concept has the advantages of providing some degree of partition in terms of plasma disruption forces on the LL, Li particle divertor retention, and strong divertor pumping action from the Li-coated divertor chamber wall. By operating at a lower temperature than the first wall, the LLD can serve to purify the entire reactor chamber, as impurities generally migrate toward lower temperature Li-condensed surfaces. To maintain the LL purity, a closed LL loop system with a modest capacity (e.g., ~ 1 Liter/sec for ~ 1% level "impurities") is envisioned for a steady-state 1 GW-electric class fusion power plant.

M. Ono, et al.

2012-10-27T23:59:59.000Z

109

Health and Safety Plan for NSTX Upgrade Project Tasks  

E-Print Network [OSTI]

Draft 0 6/17/11 1 Health and Safety Plan for NSTX Upgrade Project Tasks in the NSTX Test Cell: _____________________________________________________________ Jerry Levine, Environment, Safety, Health and Security Head Reviewed by describes the structure and implementation of the Health and Safety Plan for the NSTX Upgrade Project work

Princeton Plasma Physics Laboratory

110

Spherical torus fusion reactor  

DOE Patents [OSTI]

A fusion reactor is provided having a near spherical-shaped plasma with a modest central opening through which straight segments of toroidal field coils extend that carry electrical current for generating a toroidal magnet plasma confinement fields. By retaining only the indispensable components inboard of the plasma torus, principally the cooled toroidal field conductors and in some cases a vacuum containment vessel wall, the fusion reactor features an exceptionally small aspect ratio (typically about 1.5), a naturally elongated plasma cross section without extensive field shaping, requires low strength magnetic containment fields, small size and high beta. These features combine to produce a spherical torus plasma in a unique physics regime which permits compact fusion at low field and modest cost.

Peng, Yueng-Kay M. (Oak Ridge, TN)

1989-01-01T23:59:59.000Z

111

NSTX plasma response to lithium coated divertor  

SciTech Connect (OSTI)

NSTX experiments have explored lithium evaporated on a graphite divertor and other plasma-facing components in both L- and H- mode confinement regimes heated by high-power neutral beams. Improvements in plasma performance have followed these lithium depositions, including a reduction and eventual elimination of the HeGDC time between discharges, reduced edge neutral density, reduced plasma density, particularly in the edge and the SOL, increased pedestal electron and ion temperature, improved energy confinement and the suppression of ELMs in the H-mode. However, with improvements in confinement and suppression of ELMs, there was a significant secular increase in the effective ion charge Z(eff) and the radiated power in H-mode plasmas as a result of increases in the carbon and medium-Z metallic impurities. Lithium itself remained at a very low level in the plasma core, < 0.1%. Initial results are reported from operation with a Liquid Lithium Divertor (LLD) recently installed. (C) 2010 Elsevier B.V. All rights reserved.

Kugel, H. W. [Princeton Plasma Physics Laboratory (PPPL); Bell, M. G. [Princeton Plasma Physics Laboratory (PPPL); Allain, J. P. [Purdue University; Bell, R. E. [Princeton Plasma Physics Laboratory (PPPL); Ding, S. [Academia Sinica, Institute of Plasma Physics, Hefei, China; Gerhardt, S. P. [Princeton Plasma Physics Laboratory (PPPL); Jaworski, M. A. [Princeton Plasma Physics Laboratory (PPPL); Kaita, R. [Princeton Plasma Physics Laboratory (PPPL); Kallman, J. [Princeton Plasma Physics Laboratory (PPPL); Kaye, S. M. [Princeton Plasma Physics Laboratory (PPPL); LeBlanc, B. P. [Princeton Plasma Physics Laboratory (PPPL); Maingi, Rajesh [ORNL; Majeski, R. [Princeton Plasma Physics Laboratory (PPPL); Maqueda, R. J. [Princeton Plasma Physics Laboratory (PPPL); Mansfield, D.K. [Princeton Plasma Physics Laboratory (PPPL); Mueller, D. [Princeton Plasma Physics Laboratory (PPPL); Nygren, R. E. [Sandia National Laboratories (SNL); Paul, S. F. [Princeton Plasma Physics Laboratory (PPPL); Raman, R [University of Washington, Seattle; Roquemore, A. L. [Princeton Plasma Physics Laboratory (PPPL); Sabbagh, S. A. [Columbia University; Schneider, H. [Princeton Plasma Physics Laboratory (PPPL); Skinner, C. H. [Princeton Plasma Physics Laboratory (PPPL); Soukhanovskii, V. A. [Lawrence Livermore National Laboratory (LLNL); Taylor, C. N. [Purdue University; Timberlake, J. [Princeton Plasma Physics Laboratory (PPPL); Wampler, W. R. [Sandia National Laboratories (SNL); Zakharov, L. E. [Princeton Plasma Physics Laboratory (PPPL); Zweben, S. J. [Princeton Plasma Physics Laboratory (PPPL)

2011-01-01T23:59:59.000Z

112

Overview of Innovative PMI Research on NSTX-U and Associated PMI Facilities at PPPL  

SciTech Connect (OSTI)

Developing a reactor compatible divertor and managing the associated plasma material interaction (PMI) has been identified as a high priority research area for magnetic confinement fusion. Accordingly on NSTXU, the PMI research has received a strong emphasis. With ~ 15 MW of auxiliary heating power, NSTX-U will be able to test the PMI physics with the peak divertor plasma facing component (PFC) heat loads of up to 40-60 MW/m2 . To support the PMI research, a comprehensive set of PMI diagnostic tools are being implemented. The snow-flake configuration can produce exceptionally high divertor flux expansion of up to ~ 50. Combined with the radiative divertor concept, the snow-flake configuration has reduced the divertor heat flux by an order of magnitude in NSTX. Another area of active PMI investigation is the effect of divertor lithium coating (both in solid and liquid phases). The overall NSTX lithium PFC coating results suggest exciting opportunities for future magnetic confinement research including significant electron energy confinement improvements, Hmode power threshold reduction, the control of Edge Localized Modes (ELMs), and high heat flux handling. To support the NSTX-U/PPPL PMI research, there are also a number of associated PMI facilities implemented at PPPL/Princeton University including the Liquid Lithium R&D facility, Lithium Tokamak Experiment, and Laboratories for Materials Characterization and Surface Chemistry.

M. Ono, M. Jaworski, R. Kaita, C. N. Skinner, J.P. Allain, R. Maingi, F. Scotti, V.A. Soukhanovskii, and the NSTX-U Team

2012-09-19T23:59:59.000Z

113

Reduction of plasma density in the Helicity Injected Torus with Steady Inductance experiment by using a helicon pre-ionization source  

SciTech Connect (OSTI)

A helicon based pre-ionization source has been developed and installed on the Helicity Injected Torus with Steady Inductance (HIT-SI) spheromak. The source initiates plasma breakdown by injecting impurity-free, unmagnetized plasma into the HIT-SI confinement volume. Typical helium spheromaks have electron density reduced from (2–3) × 10{sup 19} m{sup ?3} to 1 × 10{sup 19} m{sup ?3}. Deuterium spheromak formation is possible with density as low as 2 × 10{sup 18} m{sup ?3}. The source also enables HIT-SI to be operated with only one helicity injector at injector frequencies above 14.5 kHz. A theory explaining the physical mechanism driving the reduction of breakdown density is presented.

Hossack, Aaron C.; Jarboe, Thomas R.; Victor, Brian S. [Department of Aeronautics and Astronautics, University of Washington, Seattle, Washington 98195 (United States)] [Department of Aeronautics and Astronautics, University of Washington, Seattle, Washington 98195 (United States); Firman, Taylor; Prager, James R.; Ziemba, Timothy [Eagle Harbor Technologies, Inc., 119 W. Denny Way, Suite 210, Seattle, Washington 98119 (United States)] [Eagle Harbor Technologies, Inc., 119 W. Denny Way, Suite 210, Seattle, Washington 98119 (United States); Wrobel, Jonathan S. [979B West Moorhead Circle, Boulder, Colorado 80305 (United States)] [979B West Moorhead Circle, Boulder, Colorado 80305 (United States)

2013-10-15T23:59:59.000Z

114

NSTX Weekly Report (Mar. 12, 2010) FY 2010 NSTX plasma operations  

E-Print Network [OSTI]

for publication in Nuclear Fusion. The paper reviews recent 2009 results on L-H transition dependences-Japan Workshop / ITPA MHD meeting held at NIFS, Toki, Japan, March 8th - 12th, 2010. NSTX input to ITPA MHD joint

Princeton Plasma Physics Laboratory

115

NSTX Synchronization System Block Diagram Control Room  

E-Print Network [OSTI]

NSTX Synchronization System Block Diagram Clock Rack Control Room Junction Area MG FCPCRF Cage Test Cell West Patch Rack Test Cell East Patch Rack Darm Patch Rack CAMAC Crate CAMAC Crate CAMAC Crate' Level, and RF Balcony O 1,230 ft. 1.88 µsec Optic Rack 100 Control Room E 100 ft. .15µsec O 525 ft. .8

Princeton Plasma Physics Laboratory

116

Princeton Plasma Physics Laboratory NSTX Machine Proposal  

E-Print Network [OSTI]

-XMP-62 2 / 5 REVIEWERS (designated by RLM) Organization/Position Name Signature ATI Test Director designated by RLM NSTX Work Permit T-MOD (OP-AD-03) Independent Review ES&H Review MINOR MODIFICATIONS #12;OP Independent Reviewer NB RF Diagnostics TRAINING (designated by RLM) Training required: No Yes Instructor

Princeton Plasma Physics Laboratory

117

Princeton Plasma Physics Laboratory NSTX Machine Proposal  

E-Print Network [OSTI]

-XMP-58 2 / 5 REVIEWERS (designated by RLM) Organization/Position Name Signature ATI Test Director designated by RLM NSTX Work Permit T-MOD (OP-AD-03) Independent Review ES&H Review MINOR MODIFICATIONS #12;OP Independent Reviewer NB RF Diagnostics TRAINING (designated by RLM) Training required: No Yes Instructor

Princeton Plasma Physics Laboratory

118

Princeton Plasma Physics Laboratory NSTX Machine Proposal  

E-Print Network [OSTI]

MINOR MODIFICATIONS #12;OP-XMP-60 2 / 6 REVIEWERS (designated by RLM) Organization/Position Name Procedure Requirements designated by RLM NSTX Work Permit T-MOD (OP-AD-03) Independent Review ES&H Review Signature ATI D. Mueller Test Director D. Gates Independent Reviewer NB M. Cropper RF Diagnostics TRAINING

Princeton Plasma Physics Laboratory

119

Princeton Plasma Physics Laboratory NSTX Experimental Proposal  

E-Print Network [OSTI]

Princeton Plasma Physics Laboratory NSTX Experimental Proposal Title: Dependence of ELM size Thermonuclear Experimental Reactor (ITER) have yielded a pedestal energy loss fraction between 5% and 20 with resonant magnetic perturbations2 or by access to small ELM regimes. Fig. 1 from reference1 , where

Princeton Plasma Physics Laboratory

120

Princeton Plasma Physics Laboratory NSTX Experimental Proposal  

E-Print Network [OSTI]

Princeton Plasma Physics Laboratory NSTX Experimental Proposal Title: Dependence of ELM size Projections1 of the energy loss from Type I ELMs for the International Thermonuclear Experimental Reactor perturbations2 or by access to small ELM regimes. Fig. 1 from reference1 , where extrapolation to ITER is done

Princeton Plasma Physics Laboratory

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121

Improvement in Plasma Performance with Lithium Coatings in NSTX  

SciTech Connect (OSTI)

Lithium as a plasma-facing material has attractive features, including a reduction in the recycling of hydrogenic species and the potential for withstanding high heat and neutron fluxes in fusion reactors. Dramatic effects on plasma performance with lithium-coated plasma-facing components (PFCOs) have been demonstrated on many fusion devices, including TFTR, [1] T-11M, [2] and FT-U. [3] Using a liquid-lithium-filled tray as a limiter, the CDX-U device achieved very significant enhancement in the confinement time of ohmically heated plasmas. [4] The recent NSTX experiments reported here have demonstrated, for the first time, significant and recurring benefits of lithium PFC coatings on divertor plasma performance in both L- and H- mode regimes heated by neutral beams.

Kaita, R; Ahn, J -W; Allain, J P; Bell, M G; Bell, R; Boedo, J; Bush, C; Mansfield, D; Menard, J; Mueller, D; Ono, M; Paul, S; Raman, R; Roquemore, A L; Ross, P W; Sabbagh, S; Schneider, H; Skinner, C H; Soukhanovskii, V; Stevenson, T; Stotler, D; Timberlake, J; Wampler, W R; Wilgen, J B

2008-09-12T23:59:59.000Z

122

Improvement in Plasma Performance with Lithium Coatings in NSTX  

SciTech Connect (OSTI)

Lithium as a plasma-facing material has attractive features, including a reduction in the recycling of hydrogenic species and the potential for withstanding high heat and neutron fluxes in fusion reactors. Dramatic effects on plasma performance with lithium-coated plasma-facing components (PFC's) have been demonstrated on many fusion devices, including TFTR, T-11M, and FT-U. Using a liquid-lithium-filled tray as a limiter, the CDX-U device achieved very significant enhancement in the confinement time of ohmically heated plasmas. The recent NSTX experiments reported here have demonstrated, for the first time, significant and recurring benefits of lithium PFC coatings on divertor plasma performance in both L- and H- mode regimes heated by neutral beams.

Kaita, R

2009-02-17T23:59:59.000Z

123

Progress in Simulating Turbulent Electron Thermal Transport in NSTX  

SciTech Connect (OSTI)

Nonlinear simulations based on multiple NSTX discharge scenarios have progressed to help differentiate unique instability mechanisms and to validate with experimental turbulence and transport data. First nonlinear gyrokinetic simulations of microtearing (MT) turbulence in a high-beta NSTX H-mode discharge predict experimental levels of electron thermal transport that are dominated by magnetic flutter and increase with collisionality, roughly consistent with energy confinement times in dimensionless collisionality scaling experiments. Electron temperature gradient (ETG) simulations predict significant electron thermal transport in some low and high beta discharges when ion scales are suppressed by E x B shear. Although the predicted transport in H-modes is insensitive to variation in collisionality (inconsistent with confinement scaling), it is sensitive to variations in other parameters, particularly density gradient stabilization. In reversed shear (RS) Lmode discharges that exhibit electron internal transport barriers, ETG transport has also been shown to be suppressed nonlinearly by strong negative magnetic shear, s<<0. In many high beta plasmas, instabilities which exhibit a stiff beta dependence characteristic of kinetic ballooning modes (KBM) are sometimes found in the core region. However, they do not have a distinct finite beta threshold, instead transitioning gradually to a trapped electron mode (TEM) as beta is reduced to zero. Nonlinear simulations of this "hybrid" TEM/KBM predict significant transport in all channels, with substantial contributions from compressional magnetic perturbations. As multiple instabilities are often unstable simultaneously in the same plasma discharge, even on the same flux surface, unique parametric dependencies are discussed which may be useful for distinguishing the different mechanisms experimentally.

Guttenfelder, Walter; Kaye, S. M.; Ren, Y.; Bell, R. E.; Hammett, G. W.; LeBlanc, B. P.; Mikkelsen, D. R. [Princeton Plasma Physics Lab., Princeton, NJ (United States); Peterson, J. L.; Nevins, W. M. [Lawrence Livermore National Lab., Livermore, CA (United States); Candy, J. [General Atomics, San Diego, CA (United States); Yuh, H. [Nova Photonics, Princeton, NJ (United States)

2013-07-17T23:59:59.000Z

124

Solenoid-free Plasma Start-up in NSTX using Transient CHI  

SciTech Connect (OSTI)

Experiments in NSTX have now demonstrated the coupling of toroidal plasmas produced by the technique of Coaxial Helicity Injection (CHI) to inductive sustainment and ramp-up of the toroidal plasma current. In these discharges, the central Ohmic transformer was used to apply an inductive loop voltage to discharges with a toroidal current of about 100 kA created by CHI. The coupled discharges have ramped up to >700 kA and transitioned into an H-mode demonstrating compatibility of this startup method with conventional operation. The electron temperature in the coupled discharges reached over 800 eV and the resulting plasma had low inductance, which is preferred for long-pulse high performance discharges. These results from NSTX in combination with the previously obtained record 160 kA non-inductively-generated startup currents in an ST or tokamak in NSTX demonstrate that CHI is a viable solenoid-free plasma startup method for future STs and tokamaks.

Raman, R; Jarboe, T; Nelson, B; Mueller, D; Soukhanovskii, V A

2009-01-05T23:59:59.000Z

125

The use of \\{MDSplus\\} on NSTX at PPPL  

Science Journals Connector (OSTI)

The \\{MDSplus\\} data acquisition system has been used successfully since the 1999 startup of NSTX for control, data acquisition and analysis for diagnostic subsystems. For each plasma “shot” on NSTX about 75 \\{MBs\\} of data is acquired and loaded into \\{MDSplus\\} hierarchical data structures in 2–3 min. Physicists adapted to the \\{MDSplus\\} software tools with no real difficulty. Some locally developed tools are described. The support from the developers at MIT was timely and insightful. The use of \\{MDSplus\\} has resulted in significant cost savings for NSTX.

W. Davis; P. Roney; T. Carroll; T. Gibney; D. Mastrovito

2002-01-01T23:59:59.000Z

126

The torus instability  

E-Print Network [OSTI]

The expansion instability of a toroidal current ring in low-beta magnetized plasma is investigated. Qualitative agreement is obtained with experiments on spheromak expansion and with essential properties of solar coronal mass ejections (CMEs), unifying the two apparently disparate classes of fast and slow CMEs.

Kliem, B

2006-01-01T23:59:59.000Z

127

Relationship Between Onset Thresholds, Trigger Types, and Rotation Shear for the m/n=2/1 Neoclassical Tearing Mode in a High-? Spherical Torus  

SciTech Connect (OSTI)

The onset conditions for the m/n=2/1 neoclassical tearing mode (NTM) are studied in terms of neoclassical drive, triggering instabilities, and toroidal rotation or rotation shear, in the spherical torus NSTX [M. Ono, et al., Nuclear Fusion 40, 557 (2000)]. There are three typical onset conditions for these modes, given in order of increasing neoclassical drive required for mode onset: triggering by energetic particle modes, triggering by edge localized modes, and cases where the modes appear to grow without a trigger. In all cases, the required drive increases with toroidal rotation shear, implying a stabilizing effect from the shear.

Gerhardt, S. P.; Brennan, D. P.; Buttery, R.; La Haye, R. J.; Sabbagh, S.; Strait, E.; Bell, M.; Bell, R.; Fredrickson, E.; Gates, D.; LeBlanc, B.; Menard, J.; Stutman, D.; Tritz, K.; Yuh, H.

2009-02-24T23:59:59.000Z

128

Princeton Plasma Physics Laboratory Procedure Title: Access to NSTX Experimental Areas  

E-Print Network [OSTI]

NSTX D-Site Caretaking Vacuum Computer Tritium Quality Assurance/Quality Control AC Power Maintenance of this procedure is to delineate the rules and requirements for access to the NSTX experimental areas

Princeton Plasma Physics Laboratory

129

Plasma Performance Improvement with Lithium-Coated Plasma-Facing Components in NSTX  

SciTech Connect (OSTI)

Lithium as a plasma-facing material has many attractive features, including a reduction in the recycling of hydrogenic species and the potential for withstanding high heat and neutron fluxes in fusion reactors. Recent NSTX experiments have shown, for the first time, significant and recurring benefits of lithium coatings on plasma-facing components (PFC's) to the performance of divertor plasmas in both L- and H- mode confinement regimes heated by high-power neutral beams. They included decreases in the plasma density and inductive flux consumption, and increases in the electron temperature, ion temperature, energy confinement time, and DD neutron rate. Extended periods of MHD quiescence were also achieved, and measurements of the visible emission from the lower divertor showed a reduction in the deuterium, carbon, and oxygen line emission. Other salient results with lithium evaporation included a broadening of the electron temperature profile, and changes in edge density gradients that benefited electron Bernstein wave coupling. There was also a reduction in ELM frequency and amplitude, followed by a period of complete ELM suppression. In general, it was observed that both the best and the average confinement occurred after lithium deposition and that the increase in WMHD occurs mostly through an increase in We. In addition, a liquid lithium divertor (LLD) is being installed on NSTX this year. As the first fully-toroidal liquid metal divertor target, experiments with the LLD can provide insight into the behavior of metallic ITER PFC's should they liquefy during high-power divertor tokamak operations. The NSTX lithium coating and LLD experiments are important near-term steps in demonstrating the potential of liquid lithium as a solution to the first-wall problem for both magnetic and inertial fusion reactors.

Kaita, R; Kugel, H; Bell, M G; Bell, R; Boedo, J; Bush, C; Ellis, R; Gates, D; Gerhardt, S; Gray, T; Kallman, J; Kaye, S; LeBlanc, B; Majeski, R; Maingi, R; Mansfield, D; Menard, J; Mueller, D; Ono, M; Paul, S; Raman, R; Roquemore, A L; Ross, P W; Sabbagh, S; Schneider, H; Skinner, S H; Soukhanovskii, V; Stevenson, T; Stotler, D; Timberlake, J; Zakharov, L; Ahn, J; Allain, J P; Wampler, W R

2009-01-08T23:59:59.000Z

130

Plasma Performance Improvement with Lithium-Coated Plasma-Facing Components in NSTX  

SciTech Connect (OSTI)

Lithium as a plasma-facing material has many attractive features, including a reduction in the recycling of hydrogenic species and the potential for withstanding high heat and neutron fluxes in fusion reactors. Recent NSTX experiments have shown, for the first time, significant and recurring benefits of lithium coatings on plasma-facing components (PFC's) to the performance of divertor plasmas in both L- and H- mode confinement regimes heated by high-power neutral beams. They included decreases in the plasma density and inductive flux consumption, and increases in the electron temperature, ion temperature, energy confinement time, and DD neutron rate. Extended periods of MHD quiescence were also achieved, and measurements of the visible emission from the lower divertor showed a reduction in the deuterium, carbon, and oxygen line emission. Other salient results with lithium evaporation included a broadening of the electron temperature profile, and changes in edge density gradients that benefited electron Bernstein wave coupling. There was also a reduction in ELM frequency and amplitude, followed by a period of complete ELM suppression. In general, it was observed that both the best and the average confinement occurred after lithium deposition and that the increase in WMHD occurs mostly through an increase in We. In addition, a liquid lithium divertor (LLD) is being installed on NSTX this year. As the first fully-toroidal liquid metal divertor target, experiments with the LLD can provide insight into the behavior of metallic ITER PFC's should they liquefy during high-power divertor tokamak operations. The NSTX lithium coating and LLD experiments are important near-term steps in demonstrating the potential of liquid lithium as a solution to the first-wall problem for both magnetic and inertial fusion reactors.

Kaita, R., et. al.

2008-09-29T23:59:59.000Z

131

BPM, 3/12-13/02 NSTX Research Plan Supported by  

E-Print Network [OSTI]

BPM, 3/12-13/02 NSTX Research Plan Supported by Martin Peng Oak Ridge National Laboratory, UT to accelerate research in FY03-04 to meet the FESAC 5-year Objective on ST #12;BPM, 3/12-13/02 NSTX Research programs #12;BPM, 3/12-13/02 NSTX Research Plan U.S. Collaborative Team members make crucial contributions

Princeton Plasma Physics Laboratory

132

Turbo Pump Magnetic Shielding Analysis NSTX-CALC-24-04-00  

E-Print Network [OSTI]

NSTX Turbo Pump Magnetic Shielding Analysis NSTX-CALC-24-04-00 March 16, 2011 Prepared By turbo pump to reduce the fringe field from NSTX coils at the pump location to below 50 gauss shield is below 50 G and overall Lorentz force on the pump is below 50 pound. 3) Although the magnetic

Princeton Plasma Physics Laboratory

133

Design and Performance of NSTX Movable GDC Probe  

SciTech Connect (OSTI)

The NSTX GDC system has been improved by replacing one of the two fixed anodes with a Movable GDC Probe (MGP) anode that can be inserted 1.2 m to about midway between the inner and outer vessel walls. The purpose was to provide more spatially uniform HeGDC for improving discharge stability and reliability. The MGP has been used reliably between every discharge during the last two NSTX experimental campaigns. It has also been used to apply HeGDC assisted boronization, and more recently, HeGDC assisted lithiumization. The MGP has contributed to improved NSTX performance during long pulse and H-mode discharges, and enabled a faster discharge repetition rate.

Kugel, H W; Bell, M; Blanchard, W; Gates, D; Gernhardt, R; Holoman, T; Labik, G; Provost, T; Roquemore, A L

2007-06-14T23:59:59.000Z

134

MHD Induced Neutral Beam Ion Loss from NSTX Plasmas  

SciTech Connect (OSTI)

Bursts of ~60 kHz activity on Mirnov coils occur frequently in NSTX plasmas and these are accompanied by bursts of neutral beam ion loss over a range in pitch angles. These losses have been measured with a scintillator type loss probe imaged with a high speed (>10,000 frames/s) video camera, giving the evolution of the energy and pitch angle distributions of the lost neutral beam ions over the course of the events. The instability occurs below the TAE frequency in NSTX (~100 kHz) in high beta plasmas and may be a beta driven Alfvén acoustic (BAAE) mode.

D.S. Darrow, E.D. Fredrickson, N.N. Gorelenkov, A.L. Roquemore, and K. Shinohara

2007-12-13T23:59:59.000Z

135

Evaporated Lithium Surface Coatings in NSTX  

SciTech Connect (OSTI)

Two lithium evaporators were used to evaporate more than 100 g of lithium on to the NSTX lower divertor region. Prior to each discharge, the evaporators were withdrawn behind shutters, where they also remained during the subsequent HeGDC applied for periods up to 9.5 min. After the HeGDC, the shutters were opened and the LITERs were reinserted to deposit lithium on the lower divertor target for 10 min, at rates of 10-70 mg/min, prior to the next discharge. The major improvements in plasma performance from these lithium depositions include: (1) plasma density reduction as a result of lithium deposition; (2) suppression of ELMs; (3) improvement of energy confinement in a low-triangularity shape; (4) improvement in plasma performance for standard, high-triangularity discharges: (5) reduction of the required HeGDC time between discharges; (6) increased pedestal electron and ion temperature; (7) reduced SOL plasma density; and (8) reduced edge neutral density. (C) 2009 Elsevier B.V. All rights reserved

Kugel, H. W. [Princeton Plasma Physics Laboratory (PPPL); Mansfield, D. [Princeton Plasma Physics Laboratory (PPPL); Maingi, Rajesh [ORNL; Bell, M. G. [Princeton Plasma Physics Laboratory (PPPL); Bell, R. E. [Princeton Plasma Physics Laboratory (PPPL); Allain, J. P. [Purdue University; Gates, D. [Princeton Plasma Physics Laboratory (PPPL); Gerhardt, S. P. [Princeton Plasma Physics Laboratory (PPPL); Kaita, R. [Princeton Plasma Physics Laboratory (PPPL); Kallman, J. [Princeton Plasma Physics Laboratory (PPPL); Kaye, S. [Princeton Plasma Physics Laboratory (PPPL); LeBlanc, B. P. [Princeton Plasma Physics Laboratory (PPPL); Majeski, R. [Princeton Plasma Physics Laboratory (PPPL); Menard, J. [Princeton Plasma Physics Laboratory (PPPL); Mueller, D. [Princeton Plasma Physics Laboratory (PPPL); Ono, M. [Princeton Plasma Physics Laboratory (PPPL); Paul, S. [Princeton Plasma Physics Laboratory (PPPL); Raman, R. [University of Washington, Seattle; Roquemore, A. L. [Princeton Plasma Physics Laboratory (PPPL); Ross, P. W. [Princeton Plasma Physics Laboratory (PPPL); Sabbagh, S. A. [Columbia University; Schneider, H. [Princeton Plasma Physics Laboratory (PPPL); Skinner, C. H. [Princeton Plasma Physics Laboratory (PPPL); Soukhanovskii, V. [Lawrence Livermore National Laboratory (LLNL); Stevenson, T. [Princeton Plasma Physics Laboratory (PPPL); Timberlake, J. [Princeton Plasma Physics Laboratory (PPPL); Wampler, W. R. [Sandia National Laboratories (SNL); Wilgen, John B [ORNL; Zakharov, L. E. [Princeton Plasma Physics Laboratory (PPPL)

2009-01-01T23:59:59.000Z

136

Evaporated Lithium Surface Coatings in NSTX  

SciTech Connect (OSTI)

Two lithium evaporators were used to evaporate more than 100 g of lithium on to the NSTX lower divertor region. Prior to each discharge, the evaporators were withdrawn behind shutters, where they also remained during the subsequent HeGDC applied for periods up to 9.5 min. After the HeGDC, the shutters were opened and the LITERs were reinserted to deposit lithium on the lower divertor target for 10 min, at rates of 10-70 mg/min, prior to the next discharge. The major improvements in plasma performance from these lithium depositions include: 1) plasma density reduction as a result of lithium deposition; 2) suppression of ELMs; 3) improvement of energy confinement in a low-triangularity shape; 4) improvement in plasma performance for standard, high-triangularity discharges; 5) reduction of the required HeGDC time between discharges; 6) increased pedestal electron and ion temperature; 7) reduced SOL plasma density; and 8) reduced edge neutral density.

Kugel, H. W.; Mansfield, D.; Maingi, R.; Bel, M. G.; Bell, R. E.; Allain, J. P.; Gates, D.; Gerhardt, S.; Kaita, R.; Kallman, J.; Kaye, S.; LeBlanc, B.; Majeski, R.; Menard, J.; Mueller, D.; Ono, M.

2009-04-09T23:59:59.000Z

137

Evaporated lithium surface coatings in NSTX.  

SciTech Connect (OSTI)

Two lithium evaporators were used to evaporate more than 100 g of lithium on to the NSTX lower divertor region. Prior to each discharge, the evaporators were withdrawn behind shutters, where they also remained during the subsequent HeGDC applied for periods up to 9.5 min. After the HeGDC, the shutters were opened and the LITERs were reinserted to deposit lithium on the lower divertor target for 10 min, at rates of 10-70 mg/min, prior to the next discharge. The major improvements in plasma performance from these lithium depositions include: (1) plasma density reduction as a result of lithium deposition; (2) suppression of ELMs; (3) improvement of energy confinement in a low-triangularity shape; (4) improvement in plasma performance for standard, high-triangularity discharges; (5) reduction of the required HeGDC time between discharges; (6) increased pedestal electron and ion temperature; (7) reduced SOL plasma density; and (8) reduced edge neutral density.

Zakharov, L. (Princeton Plasma Physics Laboratory, Princeton, NJ); Gates, D. (Princeton Plasma Physics Laboratory, Princeton, NJ); Menard, J. (Princeton Plasma Physics Laboratory, Princeton, NJ); Maingi, R. (Oak Ridge National Laboratory, Oak Ridge, TN); Schneider, H. (Princeton Plasma Physics Laboratory, Princeton, NJ); Mueller, D. (Princeton Plasma Physics Laboratory, Princeton, NJ); Wampler, William R.; Roquemore, A. L. (Princeton Plasma Physics Laboratory, Princeton, NJ); Kallman, Jeffrey K. (Princeton Plasma Physics Laboratory, Princeton, NJ); Sabbagh, S. (Columbia University, New York, NY); LeBlanc, B. (Princeton Plasma Physics Laboratory, Princeton, NJ); Raman, R. (University of Washington, Seattle, WA); Ono, M. (Princeton Plasma Physics Laboratory, Princeton, NJ); Wilgren, J. (Oak Ridge National Laboratory, Oak Ridge, TN); Allain, J.P. (Purdue University, West Lafayette, IN); Timberlake, J. (Princeton Plasma Physics Laboratory, Princeton, NJ); Stevenson, T. (Princeton Plasma Physics Laboratory, Princeton, NJ); Ross, P. W. (Princeton Plasma Physics Laboratory, Princeton, NJ); Majeski, R. (Princeton Plasma Physics Laboratory, Princeton, NJ); Kugel, Henry W. (Princeton Plasma Physics Laboratory, Princeton, NJ); Skinner, C. H. (Princeton Plasma Physics Laboratory, Princeton, NJ); Gerhardt, S. (Princeton Plasma Physics Laboratory, Princeton, NJ); Paul, S. (Princeton Plasma Physics Laboratory, Princeton, NJ); Bell, R. (Princeton Plasma Physics Laboratory, Princeton, NJ); Kaye, S. M. (Princeton Plasma Physics Laboratory, Princeton, NJ); Kaita, R. (Princeton Plasma Physics Laboratory, Princeton, NJ); Soukhanovskii, V. (Lawrence Livermore National Laboratory, Livermore, CA); Bell, Michael G. (Princeton Plasma Physics Laboratory, Princeton, NJ); Mansfield, D. (Princeton Plasma Physics Laboratory, Princeton, NJ)

2008-08-01T23:59:59.000Z

138

Deuterium Retention in NSTX with Lithium Conditioning  

SciTech Connect (OSTI)

High (approximate to 90%) deuterium retention was observed in NSTX gas balance measurements both with- and without lithiumization of the carbon plasma-facing components. The gas retained in ohmic discharges was measured by comparing the vessel pressure rise after a discharge to that of a gas-only pulse with the pumping valves closed. For neutral beam heated discharges the gas input and gas pumped by the NB cryopanels were tracked. The discharges were followed by outgassing of deuterium that reduced the retention. The relationship between retention and surface chemistry was explored with a new plasma-material interface probe connected to an in vacuo surface science station that exposed four material samples to the plasma. XPS and TDS analysis demonstrated that binding of D atoms in graphite is fundamentally changed by lithium - in particular atoms are weakly bonded in regions near lithium atoms bound to either oxygen or the carbon matrix. This is in contrast to the strong ionic bonding that occurs between D and pure Li. (C) 2010 Elsevier B.V. All rights reserved.

Skinner, C. H. [Princeton Plasma Physics Laboratory (PPPL); Allain, J. P. [Purdue University; Blanchard, W. [Princeton Plasma Physics Laboratory (PPPL); Kugel, H. W. [Princeton Plasma Physics Laboratory (PPPL); Maingi, Rajesh [ORNL; Roquemore, L. [Princeton Plasma Physics Laboratory (PPPL); Soukhanovskii, V. A. [Lawrence Livermore National Laboratory (LLNL); Taylor, C. N. [Purdue University

2011-01-01T23:59:59.000Z

139

3D TORUS V1.0  

Energy Science and Technology Software Center (OSTI)

002440MLTPL00 3D Torus Routing Engine Module for OFA OpenSM v. 1.0  http://www.openfabrics.org/git?p=sashak/management.git;a=sum 

140

http://NSTX.pppl.gov/nstx/Software/IDL/setupidl.html How to Setup IDL at PPPL Monday, February 1, 1999 How to Setup IDL at PPPL  

E-Print Network [OSTI]

http://NSTX.pppl.gov/nstx/Software/IDL/setupidl.html How to Setup IDL at PPPL Monday, February 1, 1999 Page: 1 How to Setup IDL at PPPL As with any X-windows application, IDL needs to know the TCP it manually. For example, on UNIX: orion.pppl.gov% setenv DISPLAY mything.pppl.gov:0 on VMS you would type

Princeton Plasma Physics Laboratory

Note: This page contains sample records for the topic "torus experiment nstx" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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141

Implications of NSTX Lithium Results for Magnetic Fusion Research  

SciTech Connect (OSTI)

Lithium wall coating techniques have been experimentally explored on NSTX for the last five years. The lithium experimentation on NSTX started with a few milligrams of lithium injected into the plasma as pellets and it has evolved to a lithium evaporation system which can evaporate up to ~ 100 g of lithium onto the lower divertor plates between lithium reloadings. The unique feature of the lithium research program on NSTX is that it can investigate the effects of lithium in H-mode divertor plasmas. This lithium evaporation system thus far has produced many intriguing and potentially important results; the latest of these are summarized in a companion paper by H. Kugel. In this paper, we suggest possible implications and applications of the NSTX lithium results on the magnetic fusion research which include electron and global energy confinement improvements, MHD stability enhancement at high beta, ELM control, H-mode power threshold reduction, improvements in radio frequency heating and non-inductive plasma start-up performance, innovative divertor solutions and improved operational efficiency.

M. Ono, M.G. Bell, R.E. Bell, R. Kaita, H.W. Kugel, B.P. LeBlanc, J.M. Canik, S. Diem, S.P.. Gerhardt, J. Hosea, S. Kaye, D. Mansfield, R. Maingi, J. Menard, S. F. Paul, R. Raman, S.A. Sabbagh, C.H. Skinner, V. Soukhanovskii, G. Taylor, and the NSTX Research Team

2010-01-14T23:59:59.000Z

142

The role of parallel heat transport in the relation between upstream scrape-off layer widths and target heat flux width in H-mode plasmas of NSTX.  

SciTech Connect (OSTI)

The physics of parallel heat transport was tested in the Scrape-off Layer (SOL) plasma of the National Spherical Torus Experiment (NSTX) [M. Ono, et al., Nucl. Fusion 40, 557 (2000) and S. M. Kaye, et al., Nucl. Fusion 45, S168 (2005)] tokamak by comparing the upstream electron temperature (T{sub e}) and density (n{sub e}) profiles measured by the mid-plane reciprocating probe to the heat flux (q{sub {perpendicular}}) profile at the divertor plate measured by an infrared (IR) camera. It is found that electron conduction explains the near SOL width data reasonably well while the far SOL, which is in the sheath limited regime, requires an ion heat flux profile broader than the electron one to be consistent with the experimental data. The measured plasma parameters indicate that the SOL energy transport should be in the conduction-limited regime for R-R{sub sep} (radial distance from the separatrix location) < 2-3 cm. The SOL energy transport should transition to the sheath-limited regime for R-R{sub sep} > 2-3cm. The T{sub e}, n{sub e}, and q{sub {perpendicular}} profiles are better described by an offset exponential function instead of a simple exponential. The conventional relation between mid plane electron temperature decay length ({lambda}{sub Te}) and target heat flux decay length ({lambda}{sub q}) is {lambda}{sub Te} = 7/2{lambda}{sub q}, whereas the newly-derived relation, assuming offset exponential functional forms, implies {lambda}{sub Te} = (2-2.5){lambda}{sub q}. The measured values of {lambda}{sub Te}/{lambda}{sub q} differ from the new prediction by 25-30%. The measured {lambda}{sub q} values in the far SOL (R-R{sub sep} > 2-3cm) are 9-10cm, while the expected values are 2.7 < {lambda}{sub q} < 4.9 cm (for sheath-limited regime). We propose that the ion heat flux profile is substantially broader than the electron heat flux profile as an explanation for this discrepancy in the far SOL.

Ahn, J W; Boedo, J A; Maingi, R; Soukhanovskii, V A

2009-01-05T23:59:59.000Z

143

Neutral-Beam-Heating Results from the Princeton Large Torus  

Science Journals Connector (OSTI)

Experimental results from high-power neutral-beam-injection experiments on the Princeton Large Torus tokamak are reported. At the highest beam powers (2.4 MW) and lowest plasma densities [ne(0)=5×1013 cm-3], ion temperatures of 6.5 keV are achieved. The ion collisionality ?i* drops below 0.1 over much of the radial profile. Electron heating of ?TeTe?50% has also been observed, consistent with the gross energy-confinement time of the Ohmically heated plasma, but indicative of enhanced electron-energy confinement in the core of the plasma.

H. Eubank et al.

1979-07-23T23:59:59.000Z

144

HHFW Heating and Current Drive Studies of NSTX H-Mode Plasmas  

SciTech Connect (OSTI)

30 MHz high-harmonic fast wave (HHFW) heating and current drive are being developed to assist fully non-inductive plasma current (I{sub p}) ramp-up in NSTX. The initial approach to achieving this goal has been to heat I{sub p} = 300 kA inductive plasmas with current drive antenna phasing in order to generate an HHFW H-mode with significant bootstrap and RF-driven current. Recent experiments, using only 1.4 MW of RF power (P{sub RF}), achieved a noninductive current fraction, f{sub NI} {approx} 0.65. Improved antenna conditioning resulted in the generation of I{sub p} = 650 kA HHFW H-mode plasmas, with f{sub NI} {approx} 0.35, when P{sub RF} {ge} 2.5 MW. These plasmas have little or no edge localized mode (ELM) activity during HHFW heating, a substantial increase in stored energy and a sustained central electron temperature of 5-6 keV. Another focus of NSTX HHFW research is to heat an H-mode generated by 90 keV neutral beam injection (NBI). Improved HHFW coupling to NBI-generated H-modes has resulted in a broad increase in electron temperature profile when HHFW heating is applied. Analysis of a closely matched pair of NBI and HHFW+NBI H-mode plasmas revealed that about half of the antenna power is deposited inside the last closed flux surface (LCFS). Of the power damped inside the LCFS about two-thirds is absorbed directly by electrons and one-third accelerates fast-ions that are mostly promptly lost from the plasma. At longer toroidal launch wavelengths, HHFW+NBI H-mode plasmas can have an RF power flow to the divertor outside the LCFS that significantly reduces RF power deposition to the core. ELMs can also reduce RF power deposition to the core and increase power deposition to the edge. Recent full wave modeling of NSTX HHFW+NBI H-mode plasmas, with the model extended to the vessel wall, predicts a coaxial standing mode between the LCFS and the wall that can have large amplitudes at longer launch wavelengths. These simulation results qualitatively agree with HHFW+NBI H-mode data that show decreasing core RF heating efficiency and increasing RF power flow to the lower divertor at longer launch wavelengths.

G. Taylor, P.T. Bonoli, D.L. Green, R.W. Harvey, J.C. Hosea, E.F. Jaeger, B.P. LeBlanc, R. Maingi, C.K. Phillips, P.M. Ryan, E.J. Valeo, J.R. Wilson, J.C. Wright, and the NSTX Team

2011-06-08T23:59:59.000Z

145

HHFW Heating and Current Drive Studies of NSTX H-Mode Plasmas  

SciTech Connect (OSTI)

30 MHz high-harmonic fast wave (HHFW) heating and current drive are being developed to assist fully non-inductive plasma current (I{sub p}) ramp-up in NSTX. The initial approach to achieving this goal has been to heat I{sub p} = 300 kA inductive plasmas with current drive antenna phasing in order to generate an HHFW H-mode with significant bootstrap and RF-driven current. Recent experiments, using only 1.4 MW of RF power (P{sub RF}), achieved a non-inductive current fraction, f{sub NI}{approx}0.65. Improved antenna conditioning resulted in the generation of I{sub p} = 650 kA HHFW H-mode plasmas, with f{sub NI}{approx}0.35, when P{sub RF}{>=}2.5 MW. These plasmas have little or no edge localized mode (ELM) activity during HHFW heating, a substantial increase in stored energy and a sustained central electron temperature of 5-6 keV. Another focus of NSTX HHFW research is to heat an H-mode generated by 90 keV neutral beam injection (NBI). Improved HHFW coupling to NBI-generated H-modes has resulted in a broad increase in electron temperature profile when HHFW heating is applied. Analysis of a closely matched pair of NBI and HHFW+NBI H-mode plasmas revealed that about half of the antenna power is deposited inside the last closed flux surface (LCFS). Of the power damped inside the LCFS about two-thirds is absorbed directly by electrons and one-third accelerates fast-ions that are mostly promptly lost from the plasma. At longer toroidal launch wavelengths, HHFW+NBI H-mode plasmas can have an RF power flow to the divertor outside the LCFS that significantly reduces RF power deposition to the core. ELMs can also reduce RF power deposition to the core and increase power deposition to the edge. Recent full wave modeling of NSTX HHFW+NBI H-mode plasmas, with the model extended to the vessel wall, predicts a coaxial standing mode between the LCFS and the wall that can have large amplitudes at longer launch wavelengths. These simulation results qualitatively agree with HHFW+NBI H-mode data that show decreasing core RF heating efficiency and increasing RF power flow to the lower divertor at longer launch wavelengths.

Taylor, G.; Hosea, J. C.; LeBlanc, B. P.; Phillips, C. K.; Valeo, E. J.; Wilson, J. R. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Bonoli, P. T.; Wright, J. C. [MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Green, D. L.; Jaeger, E. F.; Maingi, R.; Ryan, P. M. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Harvey, R. W. [CompX, PO Box 2672, Del Mar, California 92014 (United States)

2011-12-23T23:59:59.000Z

146

Upward-facing Lithium Flash Evaporator for NSTX-U  

SciTech Connect (OSTI)

NSTX plasma performance has been significantly enhanced by lithium conditioning [1]. To date, the lower divertor and passive plates have been conditioned by downward facing lithium evaporators (LITER) as appropriate for lower null plasmas. The higher power operation expected from NSTX-U requires double null plasma operation in order to distribute the heat flux between the upper and lower divertors making it desirable to coat the upper divertor region with Li as well. An upward aiming LITER (U-LITER) is presently under development and will be inserted into NSTX-U using a horizontal probe drive located in a 6" upper midplane port. In the retracted position the evaporator will be loaded with up to 300 mg of Li granules utilizing one of the calibrated NSTX Li powder droppers[2]. The evaporator will then be inserted into the vessel in a location within the shadow of the RF limiters and will remain in the vessel during the discharge. About 10 seconds before a discharge, it will be rapidly heated and the lithium completely evaporated onto the upper divertor, thus avoiding the complication of a shutter that prevents evaporation during the shot when the diagnostic shutters are open. The minimal time interval between the evaporation and the start of the discharge will avoid the passivation of the lithium by residual gases and enable the study of the conditioning effects of un-passivated Li surfaces [3]. Two methods are being investigated to accomplish the rapid (few second) heating of the lithium. A resistive method relies on passing a large current through a Li filled crucible. A second method requires using a 3 kW e-beam gun to heat the Li. In this paper the evaporator systems will be described and the pros and cons of each heating method will be discussed.

Roquemore, A. L.

2013-07-09T23:59:59.000Z

147

A note on geodesic foliations on the torus Pierre Mounoud  

E-Print Network [OSTI]

A note on geodesic foliations on the torus Pierre Mounoud R´esum´e : Nous ´etudions les propri´et´es de leur feuilletages orthogonaux. Abstract: We look at geodesic foliations on the Lorentzian torus with leaves of different kind. We prove that they do not exist if the torus is geodesically

Mounoud, Pierre

148

Imaging of high-speed dust particle trajectories on NSTX  

SciTech Connect (OSTI)

Imaging of high-speed incandescent dust particle trajectories in a tokamak plasma has been accomplished on NSTX using up to three high-speed cameras each viewing the same plasma volume from different locations and operating at speeds up to 68 000 frames/s with exposure times varying from 2 to 300 {mu}s. The dynamics of the dust trajectories can be quite complex exhibiting a large variation in both speed (10-200 m/s) and direction. Simulations of these trajectories will be utilized to ascertain the role dust may play in future machines such as ITER where significant dust production from wall erosion is expected. NSTX has numerous view ports including both tangential as well as radial views in both the midplane and lower divertors. Several vertical ports are also available so that a few specific regions in NSTX may be viewed simultaneously from several different camera positions. The cameras can be operated in the full visible spectrum but near-infrared filters can be utilized to enhance the observation of incandescent particles against a bright background. A description of the cameras and required optics is presented.

Roquemore, A. L.; Davis, W.; Kaita, R.; Skinner, C. H.; Maqueda, R.; Nishino, N. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Nova Photonics, Inc., Princeton, New Jersey 08540 (United States); Hiroshima University, Hiroshima 739-8527 (Japan)

2006-10-15T23:59:59.000Z

149

Plasma Facing Surface Composition During NSTX Li Experiments  

SciTech Connect (OSTI)

Lithium conditioned plasma facing surfaces have lowered recycling and enhanced plasma performance on many fusion devices. However, the nature of the plasma-lithium surface interaction has been obscured by the difficulty of in-tokamak surface analysis. We report laboratory studies of the chemical composition of lithium surfaces exposed to typical residual gases found in tokamaks. Solid lithium and a molybdenum alloy (TZM) coated with lithium has been examined using x-ray photoelectron spectroscopy, temperature programmed desorption, and Auger electron spectroscopy both in ultrahigh vacuum conditions and after exposure to trace gases. Lithium surfaces near room temperature were oxidized after exposure to 1-2 Langmuirs of oxygen or water vapor. The oxidation rate by carbon monoxide was four times less. Lithiated PFC surfaces in tokamaks will be oxidized in about 100 s depending on the tokamak vacuum conditions.

C.H. Skinner, R. Sullenberger, B.E. Koel, M.A. Jaworski and H.W. Kugel

2012-07-20T23:59:59.000Z

150

Exploration of the Equilibrium Operating Space For NSTX-Upgrade  

SciTech Connect (OSTI)

This paper explores a range of high-performance equilibrium scenarios available in the NSTX-Upgrade device [J.E. Menard, submitted for publication to Nuclear Fusion]. NSTX-Upgrade is a substantial upgrade to the existing NSTX device [M. Ono, et al., Nuclear Fusion 40, 557 (2000)], with significantly higher toroidal field and solenoid capabilities, and three additional neutral beam sources with significantly larger current drive efficiency. Equilibria are computed with freeboundary TRANSP, allowing a self consistent calculation of the non-inductive current drive sources, the plasma equilibrium, and poloidal field coil current, using the realistic device geometry. The thermal profiles are taken from a variety of existing NSTX discharges, and different assumptions for the thermal confinement scalings are utilized. The no-wall and idealwall n=1 stability limits are computed with the DCON code. The central and minimum safety factors are quite sensitive to many parameters: they generally increases with large outer plasmawall gaps and higher density, but can have either trend with the confinement enhancement factor. In scenarios with strong central beam current drive, the inclusion of non-classical fast ion diffusion raises qmin, decreases the pressure peaking, and generally improves the global stability, at the expense of a reduction in the non-inductive current drive fraction; cases with less beam current drive are largely insensitive to additional fast ion diffusion. The non-inductive current level is quite sensitive to the underlying confinement and profile assumptions. For instance, for BT=1.0 T and Pinj=12.6 MW, the non-inductive current level varies from 875 kA with ITER-98y,2 thermal confinement scaling and narrow thermal profiles to 1325 kA for an ST specific scaling expression and broad profiles. This sensitivity should facilitate the determination of the correct scaling of transport with current and field to use for future fully non-inductive ST devices. Scenarios are presented which can be sustained for 8-10 seconds, or (20-30)?CR, at ?N=3.8-4.5, facilitating, for instance, the study of disruption avoidance for very long pulse. Scenarios have been documented which can operate with ?T~25% and equilibrated qmin>1. The value of qmin can be controlled at either fixed non-inductive fraction of 100% or fixed plasma current, by varying which beam sources are used, opening the possibility for feedback qmin control. In terms of quantities like collisionality, neutron emission, non-inductive fraction, or stored energy, these scenarios represent a significant performance extension compared to NSTX and other present spherical torii.

S.P. Gerhardt, R. Andre and J.E. Menard

2012-04-25T23:59:59.000Z

151

Performance characterization of the Caltech corn act torus injector P. K. Loewenhardt,a) M. R. Browqb) J. Yee, and P. M. Bellan  

E-Print Network [OSTI]

A compact torus (CT), or spheromak, is a toroidal mag- netofluid configuration in which plasma is cot tokamak by the Caltech Spheromak Ijec- tion experiment to study helicity injection and refueling,3

Brown, Michael R.

152

Bridge Numbers of Torus Knots Jennifer Schultens  

E-Print Network [OSTI]

contained proof of the following result of H. Schubert: If K is a (p, q)-torus knot, then the bridge number below all maxima of h|K, then we say that K is in bridge position with respect to h. The bridge number of whether or not we require K to be in bridge position. Indeed, if h|K has n maxima, then the maxima of h

Schultens, Jennifer

153

Results from the NSTX X-ray Crystal Spectrometer  

SciTech Connect (OSTI)

A high-resolution X-ray crystal spectrometer has recently been installed at the National Spherical Torus Experiment to record the satellite spectra of helium-like argon, ArXVII, in the wavelength range from 3.94 to 4.00 {angstrom} for measurements of ion and electron temperatures, and measurements of the ionization equilibrium of argon, which is of interest for studies of ion transport. The instrument presently consists of a spherically bent quartz crystal and a conventional one-dimensional position-sensitive multi-wire proportional counter, but it will soon be upgraded to a new type of X-ray imaging crystal spectrometer by the installation of a large size (10 cm x 30 cm) two-dimensional position-sensitive detector that will allow us to obtain temporally and spatially resolved spectra from an 80 cm high cross-section of the plasma. In its present configuration, the spectrometer has been optimized for high throughput so that it is possible to record spectra with small statistical errors with a time resolution of 10 ms by adding only small, nonperturbing amounts of argon to the plasma. The spectrometer is most valuable for measurements of the ion temperature in the absence of a neutral beam in ohmically heated and radio-frequency heated discharges, when charge exchange recombination spectroscopy does not function. Electron temperature measurements from the satellite-to-resonance line ratios have been important for a quantitative comparison with (and verification of) the Thomson scattering data. The paper will describe the instrumental details of the present and future spectrometer configurations, and present recent experimental results.

M. Bitter; K. Hill; L. Roquemore; P. Beiersdorfer; D. Thorn; Ming Feng Gu

2003-01-14T23:59:59.000Z

154

"Stellar" progress on NSTX-U highlights strong year for PPPL...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

"Stellar" progress on NSTX-U highlights strong year for PPPL, Lab Director Stewart Prager says By Jeanne Jackson DeVoe May 5, 2014 Tweet Widget Google Plus One Share on Facebook...

155

Conceptual design of a divertor Thomson scattering diagnostic for NSTX-U  

SciTech Connect (OSTI)

A conceptual design for a divertor Thomson scattering (DTS) diagnostic has been developed for the NSTX-U device to operate in parallel with the existing multipoint Thomson scattering system. Higher projected peak heat flux in NSTX-U will necessitate application of advanced magnetics geometries and divertor detachment. Interpretation and modeling of these divertor scenarios will depend heavily on local measurement of electron temperature, T{sub e}, and density, n{sub e}, which DTS provides in a passive manner. The DTS design for NSTX-U adopts major elements from the successful DIII-D DTS system including 7-channel polychromators measuring T{sub e} to 0.5 eV. If implemented on NSTX-U, the divertor TS system would provide an invaluable diagnostic for the boundary program to characterize the edge plasma.

McLean, A. G., E-mail: mclean@fusion.gat.com; Soukhanovskii, V. A.; Allen, S. L. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States); Carlstrom, T. N. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); LeBlanc, B. P.; Ono, M.; Stratton, B. C. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

2014-11-15T23:59:59.000Z

156

Second Peer Review for New MGI Valves for NSTX-U  

E-Print Network [OSTI]

Second Peer Review for New MGI Valves for NSTX-U (Update on Valve Tes · Characterize this valve upto 1000 Torr.L · Describe results in Peer Review (Jan, 2014

Princeton Plasma Physics Laboratory

157

Princeton Plasma Physics Laboratory NSTX Experimental Proposal  

E-Print Network [OSTI]

in a "fixed wall" device is key for management of plasma-wall (i.e., divertor) interactions. In particular-H transition. The early times after this transition being generally blob-less. The proposed experiment intends

Princeton Plasma Physics Laboratory

158

Easy web interfaces to IDL code for NSTX Data Analysis  

Science Journals Connector (OSTI)

Reusing code is a well-known Software Engineering practice to substantially increase the efficiency of code production, as well as to reduce errors and debugging time. A variety of “Web Tools” for the analysis and display of raw and analyzed physics data are in use on NSTX [1], and new ones can be produced quickly from existing IDL [2] code. A Web Tool with only a few inputs, and which calls an IDL routine written in the proper style, can be created in less than an hour; more typical Web Tools with dozens of inputs, and the need for some adaptation of existing IDL code, can be working in a day or so. Efficiency is also increased for users of Web Tools because of the familiar interface of the web browser, and not needing X-windows, or accounts and passwords, when used within our firewall. Web Tools were adapted for use by PPPL physicists accessing EAST data stored in \\{MDSplus\\} with only a few man-weeks of effort; adapting to additional sites should now be even easier. An overview of Web Tools in use on NSTX, and a list of the most useful features, is also presented.

W.M. Davis

2012-01-01T23:59:59.000Z

159

Global Bifurcation Destroying The Experimental Torus T2  

E-Print Network [OSTI]

We show experimentally the scenario of a two-frequency torus $T^2$ breakdown, in which a global bifurcation occurs due to the collision of a torus with an unstable periodic orbit, creating a heteroclinic saddle connection, followed by an intermittent behavior.

T. Pereira; M. S. Baptista; M. B. Reyes; I. L. Caldas; J. C. Sartorelli; J. Kurths

2007-06-22T23:59:59.000Z

160

Arithmetic functions in torus and tree networks  

DOE Patents [OSTI]

Methods and systems for performing arithmetic functions. In accordance with a first aspect of the invention, methods and apparatus are provided, working in conjunction of software algorithms and hardware implementation of class network routing, to achieve a very significant reduction in the time required for global arithmetic operation on the torus. Therefore, it leads to greater scalability of applications running on large parallel machines. The invention involves three steps in improving the efficiency and accuracy of global operations: (1) Ensuring, when necessary, that all the nodes do the global operation on the data in the same order and so obtain a unique answer, independent of roundoff error; (2) Using the topology of the torus to minimize the number of hops and the bidirectional capabilities of the network to reduce the number of time steps in the data transfer operation to an absolute minimum; and (3) Using class function routing to reduce latency in the data transfer. With the method of this invention, every single element is injected into the network only once and it will be stored and forwarded without any further software overhead. In accordance with a second aspect of the invention, methods and systems are provided to efficiently implement global arithmetic operations on a network that supports the global combining operations. The latency of doing such global operations are greatly reduced by using these methods.

Bhanot, Gyan (Princeton, NJ); Blumrich, Matthias A. (Ridgefield, CT); Chen, Dong (Croton On Hudson, NY); Gara, Alan G. (Mount Kisco, NY); Giampapa, Mark E. (Irvington, NY); Heidelberger, Philip (Cortlandt Manor, NY); Steinmacher-Burow, Burkhard D. (Mount Kisco, NY); Vranas, Pavlos M. (Bedford Hills, NY)

2007-12-25T23:59:59.000Z

Note: This page contains sample records for the topic "torus experiment nstx" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Sensitivity to Error Fields in NSTX High Beta Plasmas  

SciTech Connect (OSTI)

It was found that error field threshold decreases for high ? in NSTX, although the density correlation in conventional threshold scaling implies the threshold would increase since higher ? plasmas in our study have higher plasma density. This greater sensitivity to error field in higher ? plasmas is due to error field amplification by plasmas. When the effect of amplification is included with ideal plasma response calculations, the conventional density correlation can be restored and threshold scaling becomes more consistent with low ? plasmas. However, it was also found that the threshold can be significantly changed depending on plasma rotation. When plasma rotation was reduced by non-resonant magnetic braking, the further increase of sensitivity to error field was observed.

Jong-Kyu Park, Jonathan E. Menard, Stefan P. Gerhardt, Richard J. Buttery, Steve A. Sabbagh, Ronald E. Bell and Benoit P. LeBlanc

2011-11-07T23:59:59.000Z

162

Local Effects of Biased Electrodes in the Divertor of NSTX  

SciTech Connect (OSTI)

The goal of this paper is to characterize the effects of small non-axisymmetric divertor plate electrodes on the local scrape-off layer plasma. Four small rectangular electrodes were installed into the outer divertor plates of NSTX. When the electrodes were located near the outer divertor strike point and biased positively, there was an increase in the nearby probe currents and probe potentials and an increase in the LiI light emission at the large major radius end of these electrodes. When an electrode located farther outward from the outer divertor strike point was biased positively, there was sometimes a significant decrease in the LiI light emission at the small major radius end of this electrode, but there were no clear effects on the nearby probes. No non-local effects were observed with the biasing of these electrodes.

: S. Zweben, M.D. Campanell, B.C. Lyons, R.J. Maqueda, Y. Raitses, A.L. Roquemore and F. Scotti

2012-05-07T23:59:59.000Z

163

Observation of EHO in NSTX and Theoretical Study of its Active Control Using HHFW Antenna  

SciTech Connect (OSTI)

Two important topics in the tokamak ELM control, using the non-axisymmetric (3D) magnetic perturbations, are studied in NSTX and combined envisioning ELM control in the future NSTX-U operation: Experimental observations of the edge harmonic oscillation in NSTX (not necessarily the same as EHOs in DIII-D), and theoretical study of its external drive using the high harmonic fast wave (HHFW) antenna as a 3D field coil. Edge harmonic oscillations were observed particularly well in NSTX ELM-free operation with low n core modes, with various diagnostics confirming n = 4 ~#24; 6 edge-localized and coherent oscillations in 2 ~#24; 8kHz frequency range. These oscillations seem to have a favored operational window in rotational shear, similarly to EHOs in DIII-D QH modes . However, in NSTX, they are not observed to provide particle or impurity control, possibly due to their weak amplitudes, of a few mm displacements, as measured by reflectometry. The external drive of these modes has been proposed in NSTX, by utilizing audio-frequency currents in the HHFW antenna straps. Analysis shows that the HHFW straps can be optimized to maximize n = 4 ~#24; 6 while minimizing n = 1 ~#24; 3. Also, IPEC calculations show that the optimized configuration with only 1kAt current can produce comparable or larger displacements than the observed internal modes. If this optimized external drive can be constructively combined, or further resonated with the internal modes, the edge harmonic oscillations in NSTX may be able to produce sufficient particle control to modify ELMs.

J.-K. Park, et. al.

2013-01-14T23:59:59.000Z

164

AGENDA for Review of NSTX 5 Year Plan for 2009-2013 July 28-30, 2008  

E-Print Network [OSTI]

AGENDA for Review of NSTX 5 Year Plan for 2009-2013 July 28-30, 2008 Conference Room LSB-B318, PPPL session) 1:30PM Chair, Panel Debriefing from 5-year plan review committee (open) 2:30PM Adjourn #12; Agenda and plan, panel member introduction 9:30AM Jon Menard Overview of NSTX Research Program for 2009

Princeton Plasma Physics Laboratory

165

Torus knot polynomials and susy Wilson loops  

E-Print Network [OSTI]

We give, using an explicit expression obtained in [V. Jones, Ann. of Math. 126, 335 (1987)], a basic hypergeometric representation of the HOMFLY polynomial of $(n,m)$ torus knots, and present a number of equivalent expressions, all related by Heine's transformations. Using this result the $(m,n)\\leftrightarrow (n,m)$ symmetry and the leading polynomial at large $N$ are explicit. We show the latter to be the Wilson loop of 2d Yang-Mills theory on the plane. In addition, after taking one winding to infinity, it becomes the Wilson loop in the zero instanton sector of the 2d Yang-Mills theory, which is known to give averages of Wilson loops in $\\mathcal{N}$=4 SYM theory. We also give, using matrix models, an interpretation of the HOMFLY polynomial and the corresponding Jones-Rosso representation in terms of $q$-harmonic oscillators.

Georgios Giasemidis; Miguel Tierz

2014-01-31T23:59:59.000Z

166

Torus knot polynomials and susy Wilson loops  

E-Print Network [OSTI]

We give, using an explicit expression obtained in [V. Jones, Ann. of Math. 126, 335 (1987)], a basic hypergeometric representation of the HOMFLY polynomial of $(n,m)$ torus knots, and present a number of equivalent expressions, all related by Heine's transformations. Using this result the $(m,n)\\leftrightarrow (n,m)$ symmetry and the leading polynomial at large $N$ are explicit. We show the latter to be the Wilson loop of 2d Yang-Mills theory on the plane. In addition, after taking one winding to infinity, it becomes the Wilson loop in the zero instanton sector of the 2d Yang-Mills theory, which is known to give averages of Wilson loops in $\\mathcal{N}$=4 SYM theory. We also give, using matrix models, an interpretation of the HOMFLY polynomial and the corresponding Jones-Rosso representation in terms of $q$-harmonic oscillators.

Giasemidis, Georgios

2014-01-01T23:59:59.000Z

167

NSTX Protection And Interlock Systems For Coil And Powers Supply Systems  

SciTech Connect (OSTI)

NSTX at Princeton Plasma Physics Laboratory (PPPL) requires sophisticated plasma positioning control system for stable plasma operation. TF magnetic coils and PF magnetic coils provide electromagnetic fields to position and shape the plasma vertically and horizontally respectively. NSTX utilizes twenty six coil power supplies to establish and initiate electromagnetic fields through the coil system for plasma control. A power protection and interlock system is utilized to detect power system faults and protect the TF coils and PF coils against excessive electromechanical forces, overheating, and over current. Upon detecting any fault condition the power system is restricted, and it is either prevented from initializing or suppressed to de-energize coil power during pulsing. Power fault status is immediately reported to the computer system. This paper describes the design and operation of NSTX's protection and interlocking system and possible future expansion.

X. Zhao, S. Ramakrishnan, J. Lawson, C.Neumeyer, R. Marsala, H. Schneider, Engineering Operations

2009-09-24T23:59:59.000Z

168

Collective fast ion instability-induced losses in National Spherical Tokamak Experiment  

SciTech Connect (OSTI)

A wide variety of fast ion driven instabilities are excited during neutral beam injection (NBI) in the National Spherical Torus Experiment (NSTX) [Nucl. Fusion 40, 557 (2000)] due to the large ratio of fast ion velocity to Alfven velocity, V{sub fast}/V{sub Alfven}, and high fast ion beta. The ratio V{sub fast}/V{sub Alfven} in ITER [Nucl. Fusion 39, 2137 (1999)] and NSTX is comparable. The modes can be divided into three categories: chirping energetic particle modes (EPM) in the frequency range 0 to 120 kHz, the toroidal Alfven eigenmodes (TAE) with a frequency range of 50 kHz to 200 kHz, and the compressional and global Alfven eigenmodes (CAE and GAE, respectively) between 300 kHz and the ion cyclotron frequency. Fast ion driven modes are of particular interest because of their potential to cause substantial fast ion losses. In all regimes of NBI heated operation we see transient neutron rate drops, correlated with bursts of TAE or fishbone-like EPMs. The fast ion loss events are predominantly correlated with the EPMs, although losses are also seen with bursts of multiple, large amplitude TAE. The latter is of particular significance for ITER; the transport of fast ions from the expected resonance overlap in phase space of a 'sea' of large amplitude TAE is the kind of physics expected in ITER. The internal structure and amplitude of the TAE and EPMs has been measured with quadrature reflectometry and soft x-ray cameras. The TAE bursts have internal amplitudes of n-tilde/n=1% and toroidal mode numbers 21 and can have a toroidal mode number n>1. The range of the frequency chirp can be quite large and the resonance can be through a fishbone-like precessional drift resonance, or through a bounce resonance.

Fredrickson, E.D.; Bell, R.E.; Darrow, D.S.; Fu, G.Y.; Gorelenkov, N.N.; LeBlanc, B.P.; Medley, S.S.; Menard, J.E.; Park, H.; Roquemore, A.L.; Heidbrink, W.W.; Sabbagh, S.A.; Stutman, D.; Tritz, K.; Crocker, N.A.; Kubota, S.; Peebles, W.; Lee, K.C.; Levinton, F.M. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); University of California, Irvine, California 92697 (United States); Columbia University, New York, New York 10027-6902 (United States); Johns Hopkins University, Baltimore, Maryland 21218 (United States); University of California, Los Angeles, California 90095-1354 (United States); University of California, Davis, California 95616 (United States); Nova Photonics, Princeton, New Jersey 08543 (United States)

2006-05-15T23:59:59.000Z

169

Interaction between Faraday rotation and Cotton-Mouton effects in polarimetry modeling for NSTX  

SciTech Connect (OSTI)

The evolution of electromagnetic wave polarization is modeled for propagation in the major radial direction in the National Spherical Torus Experiment with retroreflection from the center stack of the vacuum vessel. This modeling illustrates that the Cotton-Mouton effect-elliptization due to the magnetic field perpendicular to the propagation direction-is shown to be strongly weighted to the high-field region of the plasma. An interaction between the Faraday rotation and Cotton-Mouton effects is also clearly identified. Elliptization occurs when the wave polarization direction is neither parallel nor perpendicular to the local transverse magnetic field. Since Faraday rotation modifies the polarization direction during propagation, it must also affect the resultant elliptization. The Cotton-Mouton effect also intrinsically results in rotation of the polarization direction, but this effect is less significant in the plasma conditions modeled. The interaction increases at longer wavelength and complicates interpretation of polarimetry measurements.

Zhang, J.; Crocker, N. A.; Carter, T. A.; Kubota, S.; Peebles, W. A. [Department of Physics and Astronomy, UCLA, Los Angeles, California 90095-1547 (United States)

2010-10-15T23:59:59.000Z

170

LM-MHD free-surface flow experiments in MTOR  

E-Print Network [OSTI]

LM-MHD free-surface flow experiments in MTOR Neil Morley for the APEX Participants VLT Conference concentrators · Free jet · Recirculating cell · Soaker Hose (not discussed here) Slide 5 #12;LM In LM Out #12;LM Jet test for NSTX module simulation · Jet flow is introduced into the high field region between

California at Los Angeles, University of

171

Magnetic Diagnostics For Equilibrium Reconstruction And Realtime Plasma Control In NSTX-Upgrade  

SciTech Connect (OSTI)

This paper describes aspects of magnetic diagnostics for realtime control in NSTX-U. The sensor arrangement on the upgraded center column is described. New analog and digital circuitry for processing the plasma current rogowski data are presented. An improved algorithm for estimating the plasma vertical velocity for feedback control is presented.

Gerhardt, Stefan P. [PPPL; Erickson, Keith [PPPL; Kaita, Robert [PPPL; Lawson, John [PPPL; Mozulay, Robert [PPPL; Mueller, Dennis [PPPL; Que, Weiguo [PPPL; Rahman, Nabidur [PPPL; Schneider, Hans [PPPL; Smalley, Gustav [PPPL; Tresemer, Kelsey [PPPL

2014-06-01T23:59:59.000Z

172

Fast 2-D Camera Control, Data Acquisition, and Database Techniques for Edge Studies on NSTX  

E-Print Network [OSTI]

. Scotti1, M. K. Ko3 1Princeton Plasma Physics Laboratory, Princeton, NJ 08540 2 Lodestar Research Corporation, Boulder, CO 80301 3 Princeton H.S., Princeton, NJ 08540 Poster P3-01 Abstract Number ???? #12;NSTX-U 9th IAEA TM ­ Fast 2-D Camera Plasma Edge Studies (W. Davis) May 6-10, 2013 Abstract 2 Fast 2-D

Princeton Plasma Physics Laboratory

173

Raman spectroscopy of carbon dust samples from NSTX Y. Raitses a,*, C.H. Skinner a  

E-Print Network [OSTI]

.S. Duffy b a Princeton Plasma Physics Laboratory, Princeton, NJ 08543, USA b Department of Geosciences, Princeton University, NJ 08544, USA Received 13 November 2007; accepted 17 January 2008 Abstract The Raman spectrum of dust particles exposed to the NSTX plasma is different from the spectrum of unexposed particles

Duffy, Thomas S.

174

Cascade of torus doubling bifurcations in a detuned laser  

SciTech Connect (OSTI)

By using a simplified system of Maxwell-Bloch equations (with the adiabatically excluded polarisation of the medium), we studied the processes proceeding in the cross section of a light wave propagating in a wide-aperture laser emitting at the frequency detuned from the transition-line centre. It is shown that in the model under study the passage to the chaotic regime during a change in the wave propagation velocity across the aperture occurs via the doubling bifurcations of an ergodic two-dimensional torus. The spectrum of Lyapunov exponents is found and it is established that at bifurcation points a structurally unstable three-dimensional torus is produced, which gives rise to a stable doubled ergodic torus. (nonlinear optical phenomena)

Krents, A A [S.P. Korolev Samara State Aerospace University, Samara (Russian Federation); Molevich, N E [Samara Branch of the P.N. Lebedev Physical Institute, Russian Academy of Sciences, Samara (Russian Federation)

2009-08-31T23:59:59.000Z

175

ccsd-00003224,version1-4Nov2004 Clifton-Pohl torus and geodesic completeness  

E-Print Network [OSTI]

ccsd-00003224,version1-4Nov2004 Clifton-Pohl torus and geodesic completeness by a 'complex' point generalization of the idea of completeness guarantee geodesic completeness of Clifton- Pohl torus; we explicitely compute all of its geodesics. Keywords: Clifton-Pohl torus, geodesic completeness, holomorphic metric

Paris-Sud XI, Université de

176

Analytic solutions and conserved quantities of wave equation on torus  

Science Journals Connector (OSTI)

This paper discusses the wave equation on torus in terms of classical Lie theory. The symmetry algebra is computed and found solvable. A general element of one-dimensional Lie algebra is used to compute similarity variables. Further invariant solutions ... Keywords: Conservation law, Lie algebra, Lie symmetries

Adil Jhangeer; M. N. Qureshi; S. Sial; S. Sharif

2012-09-01T23:59:59.000Z

177

Torus-Margo Pits Help Conifers Compete with Angiosperms  

E-Print Network [OSTI]

. The reduction in resistivity achieved by the torus-margo pit membrane is equivalent to a 7.7-fold increase the number of times water must flow through high-resistance pits that link conduits end-to-end. Accordingly, the tracheid-based wood of conifers should have much higher flow resistance per length (resistivity) than

Hacke, Uwe

178

Three-dimensional Reconstruction of Dust Particle Trajectories in the NSTX  

SciTech Connect (OSTI)

Highly mobile incandescent dust particles are routinely observed on NSTX using two fast cameras operating in the visible region. An analysis method to reconstruct dust particle trajectories in space using two fast cameras is presented in this paper. Position accuracies of a few millimeters depending on the particle's location have been achieved and particle velocities between 10 and 200 m/s have been observed. 2008 American Institute of Physics. __________________________________________________

W.U. Boeglin, A.L. Roquemore, and R. Maqueda

2009-03-06T23:59:59.000Z

179

Three-dimensional reconstruction of dust particle trajectories in the NSTX  

SciTech Connect (OSTI)

Highly mobile incandescent dust particles are routinely observed on NSTX using two fast cameras operating in the visible region. An analysis method to reconstruct dust particle trajectories in space using two fast cameras is presented in this paper. Position accuracies of a few millimeters depending on the particle's location have been achieved and particle velocities between 10 and 200 m/s have been observed.

Boeglin, W. U. [Physics Department, Florida International University, 11200 SW 8th Street, Miami, Florida 33199 (United States); Roquemore, A. L. [Princeton Plasma Physics Laboratory, James Forrestal Campus, Rt. 1 N at Sayre Dr., Princeton, New Jersey 08543 (United States); Maqueda, R. [NOVA Photonics, P.O. Box 451, Princeton, New Jersey 08543-0451 (United States)

2008-10-15T23:59:59.000Z

180

Recent Developments in High-Harmonic Fast Wave Physics in NSTX  

SciTech Connect (OSTI)

Understanding the interaction between ion cyclotron range of frequency (ICRF) fast waves and the fast-ions created by neutral beam injection (NBI) is critical for future devices such as ITER, which rely on a combination ICRF and NBI. Experiments in NSTX which use 30 MHz High-Harmonic Fast-Wave (HHFW) ICRF and NBI heating show a competition between electron heating via Landau damping and transit-time magnetic pumping, and radio-frequency wave acceleration of NBI generated fast ions. Understanding and mitigating some of the power loss mechanisms outside the last closed flux surface (LCFS) has resulted in improved HHFW heating inside the LCFS. Nevertheless a significant fraction of the HHFW power is diverted away from the enclosed plasma. Part of this power is observed locally on the divertor. Experimental observations point toward the radio-frequency (RF) excitation of surface waves, which disperse wave power outside the LCFS, as a leading loss mechanism. Lithium coatings lower the density at the antenna, thereby moving the critical density for perpendicular fast-wave propagation away from the antenna and surrounding material surfaces. Visible and infrared imaging reveal flows of RF power along open field lines into the divertor region. In L-mode -- low average NBI power -- conditions, the fast-ion D-alpha (FIDA) diagnostic measures a near doubling and broadening of the density profile of the upper energetic level of the fast ions concurrent with the presence of HHFW power launched with k// =-8m-1. We are able to heat NBI-induced H-mode plasmas with HHFW. The captured power is expected to be split between absorption by the electrons and absorption by the fast ions, based on TORIC calculation. In the case discussed here the Te increases over the whole profile when ~2MW of HHFW power with antenna k// =13m-1 is applied after the H-mode transition.. But somewhat unexpectedly fast-ion diagnostics do not observe a change between the HHFW heated NBI discharge and the reference NBI only plasma, although an increase in neutron production is measured. __________________________________________________

B.P. LeBlanc, R.E. Bell, P. Bonoli, R. Harvey, W.W. Heidbrink, J.C. Hosea, S.M. Kaye, D. Liu, R. Maingi, S.S. Medley, M. Ono, M. Podestà, C.K. Phillips, P.M. Ryan, A.L. Roquemore, G. Taylor, J.R. Wilson and the NSTX Team

2010-10-06T23:59:59.000Z

Note: This page contains sample records for the topic "torus experiment nstx" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Disruption Analysis and Response Implicattions of Passive Plates for the NSTX Upgrade  

SciTech Connect (OSTI)

The NSTX upgrade project requires analysis qualifications of existing vacuum vessel and passive stabilizing plates for increased plasma performance. Vertical stability is critically dependent on the passive conducting structure that surrounds the plasma. In this paper, the passive conducting structure is analyzed for the upgrade condition during plasma disruption to ensure the level of stress in the stabilizing plates and the fastener is within its design limits. The counter-bore of the passive plates for bolting is evaluated in details and counter-bore bushing is redesigned to prevent shear failure during disruptions as a result of high pulling and pushing forces, particularly for support at the corner bolts

Yuhu Zhai, Peter Titus, Art Brooks, and Ron Hatcher

2012-08-27T23:59:59.000Z

182

Predicting HHFW Heating Efficiency on NSTX via Whole-Device Full-Wave Simulation  

SciTech Connect (OSTI)

We present a qualitative comparison of NSTX HHFW heating efficiency observations with results from the AORSA whole-device, linear simulation. The simulation retains a realistic geometry and core plasma kinetic physics such that scrape-off plasma linear RF fields can be calculated. By examining L-mode and neutral beam heated H-mode scenarios we quantify the conditions that result in a fast-wave coaxial mode in the scrape-off plasma. These large amplitude coaxial modes are expected to damp on collisions or couple to non-linear damping mechanisms and be correlated to an observed drop in core heating efficiency.

Green, D. L.; Berry, L. A.; Ryan, P. M. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831-6169 (United States); Jaeger, E. F. [XCEL Engineering Inc., 1066 Commerce Park Dr., Oak Ridge, TN 37830 (United States)

2011-12-23T23:59:59.000Z

183

HHFW Power Flow Along Magnetic Field Lines In The Scrape-off Layer of NSTX  

SciTech Connect (OSTI)

A significant fraction of high-harmonic fast-wave (HHFW) power applied to NSTX can be lost to the scrape-off layer (SOL) and deposited in bright and hot spirals on the divertor rather than in the core plasma. We show that the HHFW power flows to these spirals along magnetic field lines passing through the SOL in front of the antenna, implying that the HHFW power couples across the entire width of the SOL rather than mostly at the antenna face. This result will help guide future efforts to understand and minimize these edge losses in order to maximize fast wave heating and current drive.

Rory Perkins, et. al.

2012-02-27T23:59:59.000Z

184

Dependence of recycling and edge profiles on lithium evaporation in high triangularity, high performance NSTX H-mode discharges  

E-Print Network [OSTI]

1 Dependence of recycling and edge profiles on lithium evaporation in high triangularity, high between discharges in NSTX, partly to reduce recycling. Reduced D emissions from the lower and upper of the recycling light, improvements in global confinement16-19 , along with the appearance of ELM-free regimes20

Princeton Plasma Physics Laboratory

185

White Paper for Developing Electromagnetic Particle Injector system for ITER on NSTX-U University of Washington (19 July 2012)  

E-Print Network [OSTI]

White Paper for Developing Electromagnetic Particle Injector system for ITER on NSTX-U University of Washington (19 July 2012) 1/2 White Paper@aa.washington.edu This white paper describes our plans for developing a new system for safely

186

Spherical torus plasma interactions with large-area liquid lithium surfaces in CDX-U  

Science Journals Connector (OSTI)

The current drive experiment-upgrade (CDX-U) device at the Princeton Plasma Physics Laboratory (PPPL) is a spherical torus (ST) dedicated to the exploration of liquid lithium as a potential solution to reactor first-wall problems such as heat load and erosion, neutron damage and activation, and tritium inventory and breeding. Initial lithium limiter experiments were conducted with a toroidally-local liquid lithium rail limiter (L3) from the University of California at San Diego (UCSD). Spectroscopic measurements showed a clear reduction of impurities in plasmas with the L3, compared to discharges with a boron carbide limiter. The evidence for a reduction in recycling was less apparent, however. This may be attributable to the relatively small area in contact with the plasma, and the presence of high-recycling surfaces elsewhere in the vacuum chamber. This conclusion was tested in subsequent experiments with a fully toroidal lithium limiter that was installed above the floor of the vacuum vessel. The new limiter covered over ten times the area of the L3 facing the plasma. Experiments with the toroidal lithium limiter have recently begun. This paper describes the conditioning required to prepare the lithium surface for plasma operations, and effect of the toroidal liquid lithium limiter on discharge performance.

R Kaita; R Majeski; M Boaz; P Efthimion; B Jones; D Hoffman; H Kugel; J Menard; T Munsat; A Post-Zwicker; V Soukhanovskii; J Spaleta; G Taylor; J Timberlake; R Woolley; L Zakharov; M Finkenthal; D Stutman; G Antar; R Doerner; S Luckhardt; R Maingi; M Maiorano; S Smith

2002-01-01T23:59:59.000Z

187

Fast ion absorption of the high harmonic fast wave in the National Spherical Torus Experimenta...  

E-Print Network [OSTI]

Fast ion absorption of the high harmonic fast wave in the National Spherical Torus Experimenta... A; published online 23 April 2004 Ion absorption of the high harmonic fast wave in a spherical torus Y.-K. M profile, which promotes greater off-axis absorption where the fast ion population is small. Ion loss codes

Egedal, Jan

188

Experiences  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Experiences Experiences with 100Gbps Network Applications Mehmet Balman, Eric Pouyoul, Yushu Yao, E. Wes Bethel Burlen Loring, Prabhat, John Shalf, Alex Sim, and Brian L. Tierney Lawrence Berkeley National Laboratory One Cyclotron Road Berkeley, CA, 94720, USA {mbalman,epouyoul,yyao,ewbethel,bloring,prabhat,jshalf,asim,btierney}@lbl.gov ABSTRACT 100Gbps networking has finally arrived, and many research and educational institutions have begun to deploy 100Gbps routers and services. ESnet and Internet2 worked together to make 100Gbps networks available to researchers at the Supercomputing 2011 con- ference in Seattle Washington. In this paper, we describe two of the first applications to take advantage of this network. We demon- strate a visualization application that enables remotely located sci- entists to gain insights from large datasets. We also demonstrate climate

189

Towards identifying the mechanisms underlying field-aligned edge-loss of HHFW power on NSTX  

SciTech Connect (OSTI)

Fast-wave heating will be a major heating scheme on ITER, as it can heat ions directly and is relatively unaffected by the large machine size unlike neutral beams. However, fast-wave interactions with the plasma edge can lead to deleterious effects such as, in the case of the high-harmonic fast-wave (HHFW) system on NSTX, large losses of fast-wave power in the scrape off layer (SOL) under certain conditions. In such scenarios, a large fraction of the lost HHFW power is deposited on the upper and lower divertors in bright spiral shapes. The responsible mechanism(s) has not yet been identified but may include fast-wave propagation in the scrape off layer, parametric decay instability, and RF currents driven by the antenna reactive fields. Understanding and mitigating these losses is important not only for improving the heating and current-drive on NSTX-Upgrade but also for understanding fast-wave propagation across the SOL in any fast-wave system. This talk summarizes experimental results demonstrating that the flow of lost HHFW power to the divertor regions largely follows the open SOL magnetic field lines. This lost power flux is relatively large close to both the antenna and the last closed flux surface with a reduced level in between, so the loss mechanism cannot be localized to the antenna. At the same time, significant losses also occur along field lines connected to the inboard edge of the bottom antenna plate. The power lost within the spirals is roughly estimated, showing that these field-aligned losses to the divertor are significant but may not account for the total HHFW loss. To elucidate the role of the onset layer for perpendicular fast-wave propagation with regards to fast-wave propagation in the SOL, a cylindrical cold-plasma model is being developed. This model, in addition to advanced RF codes such as TORIC and AORSA, is aimed at identifying the underlying mechanism(s) behind these SOL losses, to minimize their effects in NSTX-U, and to predict their importance in ITER.

Perkins, R. J.; Bell, R. E.; Bertelli, N.; Diallo, A.; Gerhardt, S.; Hosea, J. C.; Jaworski, M. A.; LeBlanc, B. P.; Kramer, G. J.; Maingi, R.; Phillips, C. K.; Podestà, M.; Roquemore, L.; Scotti, F.; Taylor, G.; Wilson, J. R. [Princeton Plasma Physics Laboratory, Princeton, NJ (United States); Ahn, J-W.; Gray, T. K.; Green, D. L.; McLean, A. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); and others

2014-02-12T23:59:59.000Z

190

Towards identifying the mechanisms underlying field-aligned edge-loss of HHFW power on NSTX  

SciTech Connect (OSTI)

Fast-wave heating will be a major heating scheme on ITER, as it can heat ions directly and is relatively unaffected by the large machine size unlike neutral beams. However, fast-wave interactions with the plasma edge can lead to deleterious effects such as, in the case of the high-harmonic fast-wave (HHFW) system on NSTX, large losses of fast-wave power in the scrape off layer (SOL) under certain conditions. In such scenarios, a large fraction of the lost HHFW power is deposited on the upper and lower divertors in bright spiral shapes. The responsible mechanism(s) has not yet been identified but may include fast-wave propagation in the scrape off layer, parametric decay instability, and RF currents driven by the antenna reactive fields. Understanding and mitigating these losses is important not only for improving the heating and current-drive on NSTX-Upgrade but also for understanding fast-wave propagation across the SOL in any fast-wave system. This talk summarizes experimental results demonstrating that the flow of lost HHFW power to the divertor regions largely follows the open SOL magnetic field lines. This lost power flux is relatively large close to both the antenna and the last closed flux surface with a reduced level in between, so the loss mechanism cannot be localized to the antenna. At the same time, significant losses also occur along field lines connected to the inboard edge of the bottom antenna plate. The power lost within the spirals is roughly estimated, showing that these field-aligned losses to the divertor are significant but may not account for the total HHFW loss. To elucidate the role of the onset layer for perpendicular fast-wave propagation with regards to fast-wave propagation in the SOL, a cylindrical cold-plasma model is being developed. This model, in addition to advanced RF codes such as TORIC and AORSA, is aimed at identifying the underlying mechanism(s) behind these SOL losses, to minimize their effects in NSTX-U, and to predict their importance in ITER.

Perkins, R. J. [Princeton Plasma Physics Laboratory (PPPL); Ahn, Joonwook [ORNL; Bell, R. E. [Princeton Plasma Physics Laboratory (PPPL); Bertelli, Nicola [Princeton Plasma Physics Laboratory (PPPL); Diallo, A. [Princeton Plasma Physics Laboratory (PPPL); Gerhardt, S. [Princeton Plasma Physics Laboratory (PPPL); Gray, T. K. [Oak Ridge National Laboratory (ORNL); Green, David L [ORNL; Jaeger, E. F. [XCEL; Hosea, J. [Princeton Plasma Physics Laboratory (PPPL); Jaworski, M. A. [Princeton Plasma Physics Laboratory (PPPL); LeBlanc, B [Princeton Plasma Physics Laboratory (PPPL); Kramer, G. [Princeton Plasma Physics Laboratory (PPPL); McLean, Adam G [ORNL; Maingi, Rajesh [ORNL; Phillips, C. K. [Princeton Plasma Physics Laboratory (PPPL); Podesta, M. [Princeton Plasma Physics Laboratory (PPPL); Ryan, Philip Michael [ORNL; Sabbagh, S. A. [Columbia University; Scotti, F. [Princeton Plasma Physics Laboratory (PPPL); Taylor, G. [Princeton Plasma Physics Laboratory (PPPL); Wilson, J. R. [Princeton Plasma Physics Laboratory (PPPL)

2013-01-01T23:59:59.000Z

191

A tangentially viewing fast ion D-alpha diagnostic for NSTX  

SciTech Connect (OSTI)

A second fast ion D-alpha (FIDA) installation is planned at NSTX to complement the present perpendicular viewing FIDA diagnostics. Following the present diagnostic scheme, the new diagnostic will consist of two instruments: a spectroscopic diagnostic that measures fast ion spectra and profiles at 16 radial points with 5-10 ms resolution and a system that uses a band pass filter and photomultiplier to measure changes in FIDA light with 50 kHz sampling rate. The new pair of FIDA instruments will view the heating beams tangentially. The viewing geometry minimizes spectral contamination by beam emission or edge sources of background emission. The improved velocity-space resolution will provide detailed information about neutral-beam current drive and about fast ion acceleration and transport by injected radio frequency waves and plasma instabilities.

Bortolon, A.; Heidbrink, W. W. [University of California, Irvine, California 92697 (United States); Podesta, M. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

2010-10-15T23:59:59.000Z

192

Analysis of High-Te Plasmas Heated by HHFW in NSTX  

SciTech Connect (OSTI)

The implementation in TRANSP of a recent version of TORIC capable of calculating power deposition for HHFW conditions is used to analyze NSTX plasma under different operating conditions. The power deposition profile into the electrons is obtained for high-Te conditions - Te ? 5keV - obtained in He and D plasmas with ITB. HHFW heating of NBI-induced H-mode plasmas is discussed. At the RF onset the RF power is divided evenly between the electrons and the fast particles, but as the latter thermalize and the electron density increases, the HHFW power repartition shifts progressively toward the electrons. Power deposition profiles for the electrons and for the fast particles are shown.

LeBlanc, P.; Bell, R. E.; Bonoli, P.; Hosea, J. C.; Mazzucato, E.; Phillips, C. K.; Roquemore, A. L.; Ryan, P. M.; Taylor, G.; Wilson, J. R.; Yuh, H.

2009-06-26T23:59:59.000Z

193

Effect of Deuterium Gas Puff On The Edge Plasma In NSTX  

SciTech Connect (OSTI)

This paper describes a detailed examination of the effects of a relatively small pulsed deuterium gas puff on the edge plasma and edge turbulence in NSTX. This gas puff caused little or no change in the line-averaged plasma density or total stored energy, or in the edge density and electron temperature up to the time of the peak of the gas puff. The radial profile of the D? light emission and the edge turbulence within this gas puff did not vary significantly over its rise and fall, implying that these gas puffs did not significantly perturb the local edge plasma or edge turbulence. These measurements are compared with modeling by DEGAS 2, UEDGE, and with simplified estimates for the expected effects of this gas puff.

Zweben, S. J.

2014-02-20T23:59:59.000Z

194

E-Print Network 3.0 - advanced bumpy torus Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

results for: advanced bumpy torus Page: << < 1 2 3 4 5 > >> 1 COMPARISON OF ELECTRON CYCLOTRON HEATING IN VARIOUS DEVICES Summary: is low (WW2 0.01) . This paper will com...

195

Princeton Uni ' 'rsi y Plasma Physics Laboratory James Forrestal Campus  

E-Print Network [OSTI]

(PPPL), D-Site Dear Mr. Makiel: This letter is in response to your letter to me, dated May 7. Williams Associate Director for Engineering #12;cc: Erik D. Perry, PPPL Masayuki Ono, PPPL Raymond M, PPPL SUBJECT: SECURITY VUNERABILITY ASSESSMENT FOR THE NATIONAL SPHERICAL TORUS EXPERIMENT (NSTX

Princeton Plasma Physics Laboratory

196

THE CLASSIFICATION OF DEHN FILLINGS ON THE OUTER TORUS OF A 1-BRIDGE BRAID  

E-Print Network [OSTI]

THE CLASSIFICATION OF DEHN FILLINGS ON THE OUTER TORUS OF A 1-BRIDGE BRAID EXTERIOR WHICH PRODUCE SOLID TORI Ying-Qing Wu1 Abstract. Let K = K(w, b, t) be a 1-bridge braid in a solid torus V , and let for such Dehn fillings. 1. Introduction A knot K in a 3-manifold M is a 0-bridge knot if it is isotopic

Wu, Ying-Qing

197

Current Projects | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

Current Current Projects Princeton Site Office (PSO) PSO Home About Current Projects Contract Management Environment, Safety and Health (ES&H) Contact Information Princeton Site Office U.S. Department of Energy P.O. Box 102 Princeton, NJ 08543 P: (609) 243-3700 F: (609) 243-2032 Current Projects Print Text Size: A A A RSS Feeds FeedbackShare Page National Spherical Torus Experiment (NSTX) The National Spherical Torus Experiment (NSTX) at the U.S. Department of Energy's Princeton Plasma Physics Laboratory (PPPL) is yielding research results that may open an attractive path towards developing fusion energy as an abundant, safe, affordable and environmentally sound means of generating electricity. The NSTX device is exploring a novel structure for the magnetic field used to contain the hot ionized gas, called

198

Ideal magnetohydrodynamic equilibrium in a non-symmetric topological torus  

SciTech Connect (OSTI)

An alternative representation of an ideal magnetohydrodynamic equilibrium is developed. The representation is a variation of one given by A. Salat, Phys. Plasmas 2, 1652 (1995). The system of equations is used to study the possibility of non-symmetric equilibria in a topological torus, here an approximate rectangular parallelopiped, with periodicity in two of the three rectangular coordinates. An expansion is carried out in the deviation of pressure surfaces from planes. Resonances are manifest in the process. Nonetheless, provided the magnetic shear is small, it is shown that it is possible to select the magnetic fields and flux surfaces in such a manner that no singularities appear on resonant surfaces. One boundary surface of the parallelopiped is not arbitrary but is dependent on the equilibrium in question. A comparison of the solution sets of axisymmetric and non-axisymmetric equilibria suggests that the latter have a wider class of possible boundary shapes but more restrictive rotational transform profiles. No proof of convergence of the series is given.

Weitzner, Harold [Courant Institute of Mathematical Sciences, New York University, New York, New York 10012 (United States)] [Courant Institute of Mathematical Sciences, New York University, New York, New York 10012 (United States)

2014-02-15T23:59:59.000Z

199

NSTX presentation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

to maintain pressure t time confinemen pressure P P Q heat fusion Fusion gain loss heat volume pressure t time confinemen 36 What determines the power loss?...

200

Calculation of the Non-Inductive Current Profile in High-Performance NSTX Plasmas  

SciTech Connect (OSTI)

The constituents of the current profile have been computed for a wide range of high-performance plasmas in NSTX [M. Ono, et al., Nuclear Fusion 40, 557 (2000)]; these include cases designed to maximize the non-inductive fraction, pulse length, toroidal-?, or stored energy. In the absence of low-frequency MHD activity, good agreement is found between the reconstructed current profile and that predicted by summing the independently calculated inductive, pressure-driven, and neutral beam currents, without the need to invoke any anomalous beam ion diffusion. Exceptions occur, for instance, when there are toroidal Alfven eigenmode avalanches or coupled m/n=1/1+2/1 kink-tearing modes. In these cases, the addition of a spatially and temporally dependent fast ion diffusivity can reduce the core beam current drive, restoring agreement between the reconstructed profile and the summed constituents, as well as bringing better agreement between the simulated and measured neutron emission rate. An upper bound on the fast ion diffusivity of ~0.5-1 m2/sec is found in “MHD-free” discharges, based on the neutron emission, time rate of change of the neutron signal when a neutral beam is stepped, and reconstructed on-axis current density.

Gerhardt, S P; Gates, D; Kaye, S; Menard, J; Bell, M G; Bell, R E; Le Blanc, B P; Kugel, H; Sabbagh, S A

2011-02-09T23:59:59.000Z

Note: This page contains sample records for the topic "torus experiment nstx" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Operating the Upgraded NSTX HHFW Antenna Array in an Environment with Li-coated Surfaces  

SciTech Connect (OSTI)

The single-feed, end-grounded straps of the NSTX 12-strap HHFW antenna array have been replaced with double-feed, center-grounded straps to reduce the voltages in the vicinity of the Faraday shield (FS) for a given strap current. The strap spacings to the FS and to the back plate were increased by 3 mm to decrease the electric fields for a given voltage. The electric fields near the FS have been roughly halved for the same strap currents, permitting a direct examination of the roles that internal fields play in determining antenna power limits in plasmas. Extensive RF/plasma conditioning of the antenna was required to remove enough of the evaporated Li deposits from prior wall conditioning to permit coupling in excess of 4 MW to L- and H-mode plasmas in 2009. Most arcs were associated with expulsion of Li from the FS/antenna frame surfaces. The center-grounded straps were less susceptible to arcing during ELMing Hmode plasmas. Reliable operation above 2 MW was difficult after the installation of the Liquid Lithium Divertor (LLD) in 2010. Li-compound dust was found in the antennas after this run and is believed to have contributed to the reduced power limit.

Ryan, Philip Michael [ORNL] [ORNL; Ellis, R. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Hosea, J. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Kung, C. C. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); LeBlanc, B [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Pinsker, R. [General Atomics] [General Atomics; Taylor, G. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); Wilson, J. R. [Princeton Plasma Physics Laboratory (PPPL)] [Princeton Plasma Physics Laboratory (PPPL); NSTX Team, [Multiple Institutions

2011-01-01T23:59:59.000Z

202

High-resolution tangential absolute extreme ultraviolet arrays for radiated power density measurements on NSTX-U  

SciTech Connect (OSTI)

The radiated-power-density diagnostic on the equatorial midplane for the NSTX-U tokamak will be upgraded to measure the radial structure of the photon emissivity profile with an improved radial resolution. This diagnostic will enhance the characterization and studies of power balance, impurity transport, and MHD. The layout and response expected of the new system is shown for different plasma conditions and impurity concentrations. The effect of toroidal rotation driving poloidal asymmetries in the core radiation from high-Z impurities is also addressed.

Delgado-Aparicio, L.; Bell, R. E.; Diallo, A.; Gerhardt, S. P.; Kozub, T. A.; LeBlanc, B. P.; Stratton, B. C. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States); Faust, I. [MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Tritz, K. [The Johns Hopkins University, Baltimore, Maryland 21209 (United States)

2014-11-15T23:59:59.000Z

203

High-Harmonic Fast-Wave Power Flow along Magnetic Field Lines in the Scrape-Off Layer of NSTX  

Science Journals Connector (OSTI)

A significant fraction of high-harmonic fast-wave (HHFW) power applied to NSTX can be lost to the scrape-off layer (SOL) and deposited in bright and hot spirals on the divertor rather than in the core plasma. We show that the HHFW power flows to these spirals along magnetic field lines passing through the SOL in front of the antenna, implying that the HHFW power couples across the entire width of the SOL rather than mostly at the antenna face. This result will help guide future efforts to understand and minimize these edge losses in order to maximize fast-wave heating and current drive.

R. J. Perkins; J. C. Hosea; G. J. Kramer; J.-W. Ahn; R. E. Bell; A. Diallo; S. Gerhardt; T. K. Gray; D. L. Green; E. F. Jaeger; M. A. Jaworski; B. P. LeBlanc; A. McLean; R. Maingi; C. K. Phillips; L. Roquemore; P. M. Ryan; S. Sabbagh; G. Taylor; J. R. Wilson

2012-07-27T23:59:59.000Z

204

Comparison of Measurement And Modeling Of Current Profile Changes Due To Neutral Bean Ion Redistribution During TAE Avalanches in NSTX  

SciTech Connect (OSTI)

Brief "avalanches" of toroidal Alfven eigenmodes (TAEs) are observed in NSTX plasmas with several different n numbers simultaneously present. These affect the neutral beam ion distribution as evidenced by a concurrent drop in the neutron rate and, sometimes, beam ion loss. Guiding center orbit modeling has shown that the modes can transiently render portions of the beam ion phase space stochastic. The resulting redistribution of beam ions can also create a broader beam-driven current profile and produce other changes in the beam ion distribution function

Darrow, Douglas

2013-07-09T23:59:59.000Z

205

High-Harmonic Fast-Wave Power Flow Along Magnetic Field Lines in the Scrape-Off Layer of NSTX  

SciTech Connect (OSTI)

A significant fraction of high-harmonic fast-wave (HHFW) power applied to NSTX can be lost to the scrape-off layer (SOL) and deposited in bright and hot spirals on the divertor rather than in the core plasma. We show that the HHFW power flows to these spirals along magnetic field lines passing through the SOL in front of the antenna, implying that the HHFW power couples across the entire width of the SOL rather than mostly at the antenna face. This result will help guide future efforts to understand and minimize these edge losses in order to maximize fast-wave heating and current drive.

Perkins, R. J. [Princeton Plasma Physics Laboratory (PPPL); Hosea, J. [Princeton Plasma Physics Laboratory (PPPL); Kramer, G. [Princeton Plasma Physics Laboratory (PPPL); Ahn, Joonwook [ORNL; Bell, R. E. [Princeton Plasma Physics Laboratory (PPPL); Diallo, A. [Princeton Plasma Physics Laboratory (PPPL); Gerhardt, S. [Princeton Plasma Physics Laboratory (PPPL); Gray, T. K. [Oak Ridge National Laboratory (ORNL); Green, David L [ORNL; Jaeger, Erwin Frederick [ORNL; Jaworski, M. A. [Princeton Plasma Physics Laboratory (PPPL); LeBlanc, B [Princeton Plasma Physics Laboratory (PPPL); McLean, Adam G [ORNL; Maingi, Rajesh [ORNL; Phillips, C. K. [Princeton Plasma Physics Laboratory (PPPL); Roquemore, L. [Princeton Plasma Physics Laboratory (PPPL); Ryan, Philip Michael [ORNL; Sabbagh, S. A. [Columbia University; Taylor, G. [Princeton Plasma Physics Laboratory (PPPL); Wilson, J. R. [Princeton Plasma Physics Laboratory (PPPL)

2012-01-01T23:59:59.000Z

206

Design and Construction of the NSTX Bakeout, Cooling and Vacuum Systems L. E. Dudek, W. Blanchard, M. Kalish, R. Gernhardt and R. F. Parsells  

E-Print Network [OSTI]

to 50 °C. The system uses a low viscosity heat transfer oil which is capable of high temperature low and a Roots blower pump. A PLC is used as the control system to provide remote monitoring, control of the design requirements for the NSTX auxiliary systems was to use as much of the existing equipment

207

White Paper for Massive Gas Injection studies in NSTX-U in support of ITER research University of Washington (19 July 2012)  

E-Print Network [OSTI]

White Paper for Massive Gas Injection studies in NSTX-U in support of ITER research University of Washington (19 July 2012) 1/2 White Paper@aa.washington.edu , Jarboe@aa.washington.edu , dstotler@pppl.gov, tabrams@pppl.gov This white paper describes

208

E-Print Network 3.0 - advanced torus experiment Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Sciences 6 Perceiving translucent materials Roland W. Fleming1 Summary: transport Recent advances in computer graphics Jensen et al. 2001 allow us to simulate...

209

Galileo Plasma Wave Observations in the Io Plasma Torus and Near Io  

Science Journals Connector (OSTI)

...Hz to 5.6 MHz (1). During...frequencies above 1 MHz (Fig. 1...electrons (9). Large variations in...the electron plasma frequency and...factor of 2 larger than the Voyager...of the torus plasma, may now...thermally cool areas abound...assuming average atmospheric radiances...

D. A. Gurnett; W. S. Kurth; A. Roux; S. J. Bolton; C. F. Kennel

1996-10-18T23:59:59.000Z

210

LARGE SCALE CHANGES IN THE HIGHLY ENERGETIC CHARGED PARTICLES IN THE REGION OF THE IO TORUS  

E-Print Network [OSTI]

that they are caused by energetic trapped particles. On the C22 pass through the torus region the count rates were pass, the background count rate was low until inside the orbit of Io with a dip in the count rate 1 Institute of Geophysics and Planetary Physics, University of California Los Angeles, CA 90095

Russell, Christopher T.

211

An Inexpensive Ohmic Transformer Firing Circuit for the CDXU Spherical Torus  

E-Print Network [OSTI]

1 An Inexpensive Ohmic Transformer Firing Circuit for the CDX­U Spherical Torus T. Munsat, R designed and modeled a simple, efficient circuit for delivering power to the CDX­U ohmic transformer, spherical tori) have traditionally driven plasma current by using the transformer action of a centrally

212

An Inexpensive Ohmic Transformer Firing Circuit for the CDX-U Spherical Torus  

E-Print Network [OSTI]

1 An Inexpensive Ohmic Transformer Firing Circuit for the CDX-U Spherical Torus T. Munsat, R designed and modeled a simple, efficient circuit for delivering power to the CDX-U ohmic transformer, spherical tori) have traditionally driven plasma current by using the transformer action of a centrally

213

Toroidal Plasma Rotation in the Princeton Large Torus Induced by Neutral-Beam Injection  

Science Journals Connector (OSTI)

Toroidal plasma rotation, generated by toroidally unbalanced neutral-beam injection into the Princeton Large Torus, has been measured by Doppler shifts of several atomic spectral lines. These measurements produce the time evolution and spatial distribution of the rotation from which a momentum confinement time, comparable to the ion energy confinement time, is deduced.

S. Suckewer; H. P. Eubank; R. J. Goldston; E. Hinnov; N. R. Sauthoff

1979-07-16T23:59:59.000Z

214

Calculation of Neoclassical Toroidal Viscosity with a Particle Simulation in the Tokamak Magnetic Breaking Experiments  

SciTech Connect (OSTI)

Accurate calculation of perturbed distribution function #14;?f and perturbed magnetic fi eld #14;?B is essential to achieve prediction of non-ambipolar transport and neoclassical toroidal viscosity (NTV) in perturbed tokamaks. This paper reports a study of the NTV with a #14;?f particle code (POCA) and improved understanding of magnetic braking in tokamak experiments. POCA calculates the NTV by computing #14;f with guiding-center orbit motion and using #14;B from the ideal perturbed equilibrium code (IPEC). POCA simulations are compared with experimental estimations for NTV, which are measured from angular momentum balance (DIII-D) and toroidal rotational damping rate (NSTX). The calculation shows good agreement in total NTV torque for the DIII-D discharge, where an analytic neoclassical theory also gives a consistent result thanks to relatively large aspect-ratio and slow toroidal rotations. In NSTX discharges, where the aspect-ratio is small and the rotation is fast, the theory only gives a qualitative guide for predicting NTV. However, the POCA simulation largely improves the quantitative NTV prediction for NSTX. It is discussed that a self- consistent calculation of ?#14;B using general perturbed equilibria is eventually necessary since a non-ideal plasma response can change the perturbed eld and thereby the NTV torque.

Kimin Kim, et al

2013-04-23T23:59:59.000Z

215

FORMATION OF A COMPACT TORUS USING A TOROIDAL PLASMA GUN  

E-Print Network [OSTI]

USING A TOROIDAL PLASMA GUN Morton A. Levine and Philip A.bounce back toward the gun. If this experiment is successfulUSING A TOROIDAL PLASMA GUN Morton A. Levine and Philip A.

Levine, Morton A.

2013-01-01T23:59:59.000Z

216

A Star on Earth  

ScienceCinema (OSTI)

At the Energy Department's Princeton Plasma Physics Lab, scientists are trying to accomplish what was once considered the realm of science fiction: create a star on Earth. The National Spherical Torus Experiment (NSTX) is a magnetic fusion device that is used to study the physics principles of spherically shaped plasmas -- hot ionized gases in which, under the right conditions, nuclear fusion will occur. Fusion is the energy source of the sun and all of the stars. Not just limited to theoretical work, the NSTX is enabling cutting-edge research to develop fusion as a future energy source.

Prager, Stewart; Zwicker, Andrew; Hammet, Greg; Tresemer, Kelsey; Diallo, Ahmed

2014-06-06T23:59:59.000Z

217

A Star on Earth  

SciTech Connect (OSTI)

At the Energy Department's Princeton Plasma Physics Lab, scientists are trying to accomplish what was once considered the realm of science fiction: create a star on Earth. The National Spherical Torus Experiment (NSTX) is a magnetic fusion device that is used to study the physics principles of spherically shaped plasmas -- hot ionized gases in which, under the right conditions, nuclear fusion will occur. Fusion is the energy source of the sun and all of the stars. Not just limited to theoretical work, the NSTX is enabling cutting-edge research to develop fusion as a future energy source.

Prager, Stewart; Zwicker, Andrew; Hammet, Greg; Tresemer, Kelsey; Diallo, Ahmed

2014-03-05T23:59:59.000Z

218

Time-resolved spectra in the 80–340-Å wavelength region from Princeton Large Torus tokamak plasmas  

Science Journals Connector (OSTI)

High-resolution spectra from the Princeton Large Torus plasma have been recorded by a 2-m Schwob–Fraenkel soft-x-ray multichannel spectrometer. Spectra covering a wavelength range of...

Wouters, A; Davé, J H; Feldman, U; Seely, J F; Suckewer, S; Hinnov, E; Schwob, J L

1987-01-01T23:59:59.000Z

219

Emission in the 50–80-Å region from highly ionized silver in Princeton Large Torus tokamak plasmas  

Science Journals Connector (OSTI)

The spectrum of silver emitted by Princeton Large Torus tokamak plasmas has been recorded in the 25–150-Å region by a multichannel time-resolving grazing-incidence spectrometer. Silver...

Schwob, J L; Finkenthal, M; Wouters, A; Suckewer, S; Cohen, S A

1986-01-01T23:59:59.000Z

220

Charles L Neumeyer | Princeton Plasma Physics Lab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Charles L Neumeyer Charles L Neumeyer ITER Steady State Electrical Systems WBS Manager, NSTX Project Engineer Charles Neumeyer Jr. is a registered professional engineer with more than 30 years experience in advanced technology research and project management. His experience covers functions ranging from design to procurement and conditioning. Neumeyer has managerial roles in activities associated with ITER and the National Spherical Torus Experiment Upgrade (NSTX-U). He is responsible for U.S. equipment contributions for the ITER Steady State Electrical Network, which will supply AC power to all ITER plant systems. As systems engineer for the NSTX-U, he is responsible for systems integration of the upgrade project. Interests Electromagnetic and high voltage engineering AC/DC power conditioning systems

Note: This page contains sample records for the topic "torus experiment nstx" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Existence of exotic torus configuration in high-spin excited states of $^{40}$Ca  

E-Print Network [OSTI]

We investigate the possibility of the existence of the exotic torus configuration in the high-spin excited states of $^{40}$Ca. We here consider the spin alignments about the symmetry axis. To this end, we use a three-dimensional cranked Skyrme Hartree-Fock method and search for stable single-particle configurations. We find one stable state with the torus configuration at the total angular momentum $J=$ 60 $\\hbar$ and an excitation energy of about 170 MeV in all calculations using various Skyrme interactions. The total angular momentum J=60 $\\hbar$ consists of aligned 12 nucleons with the orbital angular momenta $\\Lambda=+4$, +5, and +6 for spin up-down neutrons and protons. The obtained results strongly suggest that a macroscopic amount of circulating current breaking the time-reversal symmetry emerges in the high-spin excited state of $^{40}$Ca.

T. Ichikawa; J. A. Maruhn; N. Itagaki; K. Matsuyanagi; P. -G. Reinhard; S. Ohkubo

2012-07-26T23:59:59.000Z

222

Ordinary-Mode Fundamental Electron-Cyclotron Resonance Absorption and Emission in the Princeton Large Torus  

Science Journals Connector (OSTI)

Fundamental electron-cyclotron resonance damping for 4-mm waves with ordinary polarization as well as blackbody emission is measured along the midplane of the plasma in the Princeton Large Torus. Optical depths obtained from the data are in good agreement with those predicted by hot-plasma theory. The use of ordinary-mode fundamental electron-cyclotron resonance heating in existing and future toroidal devices is supported by these results.

P. C. Efthimion; V. Arunasalam; J. C. Hosea

1980-02-11T23:59:59.000Z

223

Critical temperature gradient length signatures in heat wave propagation across internal transport barriers in the Joint European Torus  

SciTech Connect (OSTI)

New results on electron heat wave propagation using ion cyclotron resonance heating power modulation in the Joint European Torus (JET) [P. H. Rebut et al., Nucl. Fusion 25, 1011 (1985)] plasmas characterized by internal transport barriers (ITBs) are presented. The heat wave generated outside the ITB, and traveling across it, always experiences a strong damping in the ITB layer, demonstrating a low level of transport and loss of stiffness. In some cases, however, the heat wave is strongly inflated in the region just outside the ITB, showing features of convective-like behavior. In other cases, a second maximum in the perturbation amplitude is generated close to the ITB foot. Such peculiar types of behavior can be explained on the basis of the existence of a critical temperature gradient length for the onset of turbulent transport. Convective-like features appear close to the threshold (i.e., just outside the ITB foot) when the value of the threshold is sufficiently high, with a good match with the theoretical predictions for the trapped electron mode threshold. The appearance of a second maximum is due to the oscillation of the temperature profile across the threshold in the case of a weak ITB. Simulations with an empirical critical gradient length model and with the theory based GLF23 [R. E. Waltz et al., Phys. Plasmas, 4, 2482 (1997)] model are presented. The difference with respect to previous results of cold pulse propagation across JET ITBs is also discussed.

Casati, Alessandro [Istituto di Fisica del Plasma 'P. Caldirola', Associazione Euratom-ENEA-CNR, Via Cozzi 53, 20125 Milano (Italy); Dipartimento di Ingegneria Nucleare, Politecnico di Milano, Via Ponzio 34/3, 20133 Milano (Italy); Mantica, P. [Istituto di Fisica del Plasma 'P. Caldirola', Associazione Euratom-ENEA-CNR, Via Cozzi 53, 20125 Milano (Italy); Eester, D. van [LPP-ERM/KMS, Association Euratom-Belgian State, TEC, B-1000 Brussels (Belgium); Hawkes, N.; De Vries, P. [Culham Science Centre, EURATOM/UKAEA Fusion Association, Abingdon OX14 3DB (United Kingdom); Imbeaux, F.; Joffrin, E. [Association Euratom-CEA, CEA-DSM-DRFC Cadarache, 13108, St. Paul-lez-Durance Cedex (France); Marinoni, A. [Association Euratom-Confederation Suisse, CRPP, EPFL, CH 1015, Lausanne (Switzerland); Ryter, F. [Max-Planck Insitut fur Plasmaphysik, Euratom Association, 85748 Garching (Germany); Salmi, A. [Helsinki University of Technology, Association Euratom-TEKES, P.O. Box 2200 (Finland); Tala, T. [Association Euratom-TEKES, VTT, P.O. Box 1000, FIN-02044 VTT (Finland)

2007-09-15T23:59:59.000Z

224

Tomographic analysis of neutron and gamma pulse shape distributions from liquid scintillation detectors at Joint European Torus  

SciTech Connect (OSTI)

The Joint European Torus (JET, Culham, UK) is the largest tokamak in the world devoted to nuclear fusion experiments of magnetic confined Deuterium (D)/Deuterium-Tritium (DT) plasmas. Neutrons produced in these plasmas are measured using various types of neutron detectors and spectrometers. Two of these instruments on JET make use of organic liquid scintillator detectors. The neutron emission profile monitor implements 19 liquid scintillation counters to detect the 2.45 MeV neutron emission from D plasmas. A new compact neutron spectrometer is operational at JET since 2010 to measure the neutron energy spectra from both D and DT plasmas. Liquid scintillation detectors are sensitive to both neutron and gamma radiation but give light responses of different decay time such that pulse shape discrimination techniques can be applied to identify the neutron contribution of interest from the data. The most common technique consists of integrating the radiation pulse shapes within different ranges of their rising and/or trailing edges. In this article, a step forward in this type of analysis is presented. The method applies a tomographic analysis of the 3-dimensional neutron and gamma pulse shape and pulse height distribution data obtained from liquid scintillation detectors such that n/? discrimination can be improved to lower energies and additional information can be gained on neutron contributions to the gamma events and vice versa.

Giacomelli, L. [JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom) [JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Department of Physics, Università degli Studi di Milano-Bicocca, Milano (Italy); Conroy, S. [JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom) [JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Department of Physics and Astronomy, Uppsala University, Uppsala (Sweden); Gorini, G. [Department of Physics, Università degli Studi di Milano-Bicocca, Milano (Italy)] [Department of Physics, Università degli Studi di Milano-Bicocca, Milano (Italy); Horton, L.; Murari, A.; Popovichev, S.; Syme, D. B. [JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom)] [JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom)

2014-02-15T23:59:59.000Z

225

Torus Formation in Neutron Star Mergers and Well-Localized Short Gamma-Ray Bursts  

E-Print Network [OSTI]

Merging neutron stars (NSs) are hot candidates for the still enigmatic sources of short gamma-ray bursts (GRBs). If the central engines of the huge energy release are accreting relic black holes (BHs) of such mergers, it is important to understand how the properties of the BH-torus systems, in particular disc masses and mass and rotation rate of the compact remnant, are linked to the characterizing parameters of the NS binaries. For this purpose we present relativistic smoothed particle hydrodynamics simulations with conformally flat approximation of the Einstein field equations and a physical, non-zero temperature equation of state. Thick disc formation is highlighted as a dynamical process caused by angular momentum transfer through tidal torques during the merging process of asymmetric systems or in the rapidly spinning triaxial post-merger object. Our simulations support the possibility that the first well-localized short and hard GRBs 050509b, 050709, 050724, 050813 have originated from NS merger events and are powered by neutrino-antineutrino annihilation around a relic BH-torus system. Using model parameters based on this assumption, we show that the measured GRB energies and durations lead to estimates for the accreted masses and BH mass accretion rates which are compatible with theoretical expectations. In particular, the low energy output and short duration of GRB 050509b set a very strict upper limit of less than 100 ms for the time interval after the merging until the merger remnant has collapsed to a BH, leaving an accretion torus with a small mass of only about 0.01 solar masses. This favors a (nearly) symmetric NS+NS binary with a typical mass as progenitor system.

R. Oechslin; H. -Th. Janka

2005-07-05T23:59:59.000Z

226

Conformal perturbation theory and higher spin entanglement entropy on the torus  

E-Print Network [OSTI]

We study the free fermion theory in 1+1 dimensions deformed by chemical potentials for holomorphic, conserved currents at finite temperature and on a spatial circle. For a spin-three chemical potential \\mu, the deformation is related at high temperatures to a higher spin black hole in hs[0] theory on AdS_3 spacetime. We calculate the order \\mu^2 corrections to the single interval Renyi and entanglement entropies on the torus using the bosonized formulation. A consistent result, satisfying all checks, emerges upon carefully accounting for both perturbative and winding mode contributions in the bosonized language. The order \\mu^2 corrections involve integrals that are finite but potentially sensitive to contact term singularities. We propose and apply a prescription for defining such integrals which matches the Hamiltonian picture and passes several non-trivial checks for both thermal corrections and the Renyi entropies at this order. The thermal corrections are given by a weight six quasi-modular form, whilst the Renyi entropies are controlled by quasi-elliptic functions of the interval length with modular weight six. We also point out the well known connection between the perturbative expansion of the partition function in powers of the spin-three chemical potential and the Gross-Taylor genus expansion of large-N Yang-Mills theory on the torus. We note the absence of winding mode contributions in this connection, which suggests qualitatively different entanglement entropies for the two systems.

Shouvik Datta; Justin R. David; S. Prem Kumar

2014-12-12T23:59:59.000Z

227

Stefan Gerhardt | Princeton Plasma Physics Lab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

the NSTX organization. He operates numerous diagnostics on NSTX, along with designing plasma control schemes and running physics experiments. He has previously worked on a wide...

228

Fast-Wave Heating of Two-Ion Plasmas in the Princeton Large Torus through Minority-Cyclotron-Resonance Damping  

Science Journals Connector (OSTI)

Strong minority proton heating is produced in the Princeton Large Torus through ioncyclotron resonance damping of fast waves at moderate rf power levels. In addition to demonstrating good proton confinement, the proton energy distribution is consistent with Fokker-Planck theory which provides the prescription for extrapolation of this heating regime to higher rf power levels and other minority species.

J. Hosea; S. Bernabei; P. Colestock; S. L. Davis; P. Efthimion; R. J. Goldston; D. Hwang; S. S. Medley; D. Mueller; J. Strachan; H. Thompson

1979-12-10T23:59:59.000Z

229

Hydrogen atom in crossed electric and magnetic fields: Phase space topology and torus quantization via periodic orbits  

E-Print Network [OSTI]

Hydrogen atom in crossed electric and magnetic fields: Phase space topology and torus quantization for the periodic orbits in a strongly coupled multidimen- sional Hamiltonian system, namely the hydrogen atom.15.Gy, 05.45.-a, 45.20.Jj I. INTRODUCTION The hydrogen atom in crossed electric and magnetic fields

230

FPA Meeting, 10/11-12/05 Status of World ST Research Status of World Spherical Torus Research  

E-Print Network [OSTI]

ST to Explore Plasma Limits as A 1 Pegasus (US) #12;FPA Meeting, 10/11-12/05 Status of World STFPA Meeting, 10/11-12/05 Status of World ST Research Status of World Spherical Torus Research and Energy Policy October 11-12, 2005, Washington, DC Supported by Office of Science College W&M Colorado Sch

231

Statistical analysis of variations in impurity ion heating at reconnection events in the Madison Symmetric Torus  

SciTech Connect (OSTI)

The connection between impurity ion heating and other physical processes in the plasma is evaluated by studying variations in the amount of ion heating at reconnection events in the Madison Symmetric Torus (MST). Correlation of the change in ion temperature with individual tearing mode amplitudes indicates that the edge-resonant modes are better predictors for the amount of global ion heating than the core-resonant modes. There is also a strong correlation between ion heating and current profile relaxation. Simultaneous measurements of the ion temperature at different toroidal locations reveal, for the first time, a toroidal asymmetry to the ion heating in MST. These results present challenges for existing heating theories and suggest a stronger connection between edge-resonant tearing modes, current profile relaxation, and ion heating than has been previously thought.

Cartolano, M. S.; Craig, D., E-mail: darren.craig@wheaton.edu [Wheaton College, Wheaton, Illinois 60187 (United States); Den Hartog, D. J.; Kumar, S. T. A.; Nornberg, M. D. [University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States) [University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Center for Magnetic Self-Organization in Laboratory and Astrophysical Plasmas, Madison, Wisconsin 53706 (United States)

2014-01-15T23:59:59.000Z

232

Fast-wave power flow along SOL field lines in NSTX and the associated power deposition profile across the SOL in front of the antenna  

Science Journals Connector (OSTI)

Fast-wave heating and current drive efficiencies can be reduced by a number of processes in the vicinity of the antenna and in the scrape-off layer (SOL). On NSTX from around 25% to more than 60% of the high-harmonic fast-wave power can be lost to the SOL regions, and a large part of this lost power flows along SOL magnetic field lines and is deposited in bright spirals on the divertor floor and ceiling. We show that field-line mapping matches the location of heat deposition on the lower divertor, albeit with a portion of the heat outside of the predictions. The field-line mapping can then be used to partially reconstruct the profile of lost fast-wave power at the midplane in front of the antenna, and the losses peak close to the last closed flux surface as well as the antenna. This profile suggests a radial standing-wave pattern formed by fast-wave propagation in the SOL, and this hypothesis will be tested on NSTX-U. RF codes must reproduce these results so that such codes can be used to understand this edge loss and to minimize RF heat deposition and erosion in the divertor region on ITER.

R.J. Perkins; J.-W. Ahn; R.E. Bell; A. Diallo; S. Gerhardt; T.K. Gray; D.L. Green; E.F. Jaeger; J.C. Hosea; M.A. Jaworski; B.P. LeBlanc; G.J. Kramer; A. McLean; R. Maingi; C.K. Phillips; M. Podestà; L. Roquemore; P.M. Ryan; S. Sabbagh; F. Scotti; G. Taylor; J.R. Wilson

2013-01-01T23:59:59.000Z

233

Fast-wave Power Flow Along SOL Field Lines In NSTX nd The Associated Power Deposition Profile Across The SOL In Front Of The Antenna  

SciTech Connect (OSTI)

Fast-wave heating and current drive efficiencies can be reduced by a number of processes in the vicinity of the antenna and in the scrape off layer (SOL). On NSTX from around 25% to more than 60% of the high-harmonic fast-wave power can be lost to the SOL regions, and a large part of this lost power flows along SOL magnetic field lines and is deposited in bright spirals on the divertor floor and ceiling. We show that field-line mapping matches the location of heat deposition on the lower divertor, albeit with a portion of the heat outside of the predictions. The field-line mapping can then be used to partially reconstruct the profile of lost fast-wave power at the midplane in front of the antenna, and the losses peak close to the last closed flux surface (LCFS) as well as the antenna. This profile suggests a radial standing-wave pattern formed by fast-wave propagation in the SOL, and this hypothesis will be tested on NSTX-U. Advanced RF codes must reproduce these results so that such codes can be used to understand this edge loss and to minimize RF heat deposition and erosion in the divertor region on ITER.

Perkins, Roy

2013-06-21T23:59:59.000Z

234

Simulation of non-resonant internal kink mode with toroidal rotation in the National Spherical Torus Experiment  

SciTech Connect (OSTI)

Plasmas in spherical and conventional tokamaks, with weakly reversed shear q profile and minimum q above but close to unity, are susceptible to an non-resonant (m,n) = (1,1) internal kink mode. This mode can saturate and persist and can induce a (2,1) seed island for Neoclassical Tearing Mode. [Breslau et al. Nucl. Fusion 51, 063027 (2011)]. The mode can also lead to large energetic particle transport and significant broadening of beam-driven current. Motivated by these important effects, we have carried out extensive nonlinear simulations of the mode with finite toroidal rotation using parameters and profiles of an NTSX plasma with a weakly reversed shear profile. The numerical results show that, at the experimental level, plasma rotation has little effect on either equilibrium or linear stability. However, rotation can significantly influence the nonlinear dynamics of the (1,1) mode and the induced (2,1) magnetic island. The simulation results show that a rotating helical equilibrium is formed and maintained in the nonlinear phase at finite plasma rotation. In contrast, for non-rotating cases, the nonlinear evolution exhibits dynamic oscillations between a quasi-2D state and a helical state. Furthermore, the effects of rotation are found to greatly suppress the (2,1) magnetic island even at a low level.

Wang, Feng; Liu, J. Y. [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Fu, G. Y.; Breslau, J. A. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Tritz, Kevin [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States)] [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States)

2013-07-15T23:59:59.000Z

235

Hydrogen atom in crossed electric and magnetic fields: Phase space topology and torus quantization via periodic orbits  

E-Print Network [OSTI]

A hierarchical ordering is demonstrated for the periodic orbits in a strongly coupled multidimensional Hamiltonian system, namely the hydrogen atom in crossed electric and magnetic fields. It mirrors the hierarchy of broken resonant tori and thereby allows one to characterize the periodic orbits by a set of winding numbers. With this knowledge, we construct the action variables as functions of the frequency ratios and carry out a semiclassical torus quantization. The semiclassical energy levels thus obtained agree well with exact quantum calculations.

Stephan Gekle; Jörg Main; Thomas Bartsch; T. Uzer

2006-10-02T23:59:59.000Z

236

ACCRETION AND OUTFLOW FROM A MAGNETIZED, NEUTRINO COOLED TORUS AROUND THE GAMMA-RAY BURST CENTRAL ENGINE  

SciTech Connect (OSTI)

We calculate the structure and short-term evolution of a gamma-ray burst (GRB) central engine in the form of a turbulent torus accreting onto a stellar mass black hole. Our models apply to the short GRB events, in which a remnant torus forms after the neutron star-black hole or a double neutron star merger and is subsequently accreted. We study the two-dimensional, relativistic models and concentrate on the effects of the black hole and flow parameters as well as the neutrino cooling. We compare the resulting structure and neutrino emission to the results of our previous one-dimensional simulations. We find that the neutrino cooled torus launches a powerful mass outflow, which contributes to the total neutrino luminosity and mass loss from the system. The neutrino luminosity may exceed the Blandford-Znajek luminosity of the polar jets and the subsequent annihilation of neutrino-antineutrino pairs will provide an additional source of power to the GRB emission.

Janiuk, Agnieszka; Mioduszewski, Patryk [Center for Theoretical Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Moscibrodzka, Monika, E-mail: agnes@cft.edu.pl [Department of Physics, University of Nevada Las Vegas, 4505 South Maryland Parkway, Las Vegas, NV 89154 (United States)

2013-10-20T23:59:59.000Z

237

An axisymmetric hydrodynamical model for the torus wind in AGN. II: X-ray excited funnel flow  

E-Print Network [OSTI]

We have calculated a series of models of outflows from the obscuring torus in active galactic nuclei (AGN). Our modeling assumes that the inner face of a rotationally supported torus is illuminated and heated by the intense X-rays from the inner accretion disk and black hole. As a result of such heating a strong biconical outflow is observed in our simulations. We calculate 3-dimensional hydrodynamical models, assuming axial symmetry, and including the effects of X-ray heating, ionization, and radiation pressure. We discuss the behavior of a large family of these models, their velocity fields, mass fluxes and temperature, as functions of the torus properties and X-ray flux. Synthetic warm absorber spectra are calculated, assuming pure absorption, for sample models at various inclination angles and observing times. We show that these models have mass fluxes and flow speeds which are comparable to those which have been inferred from observations of Seyfert 1 warm absorbers, and that they can produce rich absorption line spectra.

A. Dorodnitsyn; T. Kallman; D. Proga

2008-06-23T23:59:59.000Z

238

An axisymmetric hydrodynamical model for the torus wind in AGN. II: X-ray excited funnel flow  

E-Print Network [OSTI]

We have calculated a series of models of outflows from the obscuring torus in active galactic nuclei (AGN). Our modeling assumes that the inner face of a rotationally supported torus is illuminated and heated by the intense X-rays from the inner accretion disk and black hole. As a result of such heating a strong biconical outflow is observed in our simulations. We calculate 3-dimensional hydrodynamical models, assuming axial symmetry, and including the effects of X-ray heating, ionization, and radiation pressure. We discuss the behavior of a large family of these models, their velocity fields, mass fluxes and temperature, as functions of the torus properties and X-ray flux. Synthetic warm absorber spectra are calculated, assuming pure absorption, for sample models at various inclination angles and observing times. We show that these models have mass fluxes and flow speeds which are comparable to those which have been inferred from observations of Seyfert 1 warm absorbers, and that they can produce rich absorp...

Dorodnitsyn, A; Proga, D

2008-01-01T23:59:59.000Z

239

A Description of the Full Particle Orbit Following SPIRAL Code for Simulating Fast-ion Experiments in Tokamaks  

SciTech Connect (OSTI)

The numerical methods used in the full particle-orbit following SPIRAL code are described and a number of physics studies performed with the code are presented to illustrate its capabilities. The SPIRAL code is a test-particle code and is a powerful numerical tool to interpret and plan fast-ion experiments in Tokamaks. Gyro-orbit effects are important for fast ions in low-field machines such as NSTX and to a lesser extent in DIII-D. A number of physics studies are interlaced between the description of the code to illustrate its capabilities. Results on heat loads generated by a localized error-field on the DIII-D wall are compared to measurements. The enhanced Triton losses caused by the same localized error-field are calculated and compared to measured neutron signals. MHD activity such as tearing modes and Toroidicity-induced Alfven Eigenmodes (TAEs) have a profound effect on the fast-ion content of Tokamak plasmas and SPIRAL can calculate the effects of MHD activity on the confined and lost fast-ion population as illustrated for a burst of TAE activity in NSTX. The interaction between Ion Cyclotron Range of Frequency (ICRF) heating and fast ions depends solely on the gyro-motion of the fast ions and is captured exactly in the SPIRAL code. A calculation of ICRF absorption on beam ions in ITER is presented. The effects of high harmonic fast wave heating on the beam-ion slowing-down distribution in NSTX is also studied.

Kramer, G.J.; Budny, R.V.; Bortolon, A.; Fredrickson, E.D.; Fu, G.Y.; Heidbrink, W.W.; Nazikian, R.; Valeo, E.; Van Zeeland, M.A.

2012-07-27T23:59:59.000Z

240

Interplay between MacDonald and Hall-Littlewood expansions of extended torus superpolynomials  

E-Print Network [OSTI]

In arXiv:1106.4305 extended superpolynomials were introduced for the torus links T[m,mk+r], which are functions on the entire space of time variables and, at expense of reducing the topological invariance, possess additional algebraic properties, resembling those of the matrix model partition functions and the KP/Toda tau-functions. Not surprisingly, being a suitable extension it actually allows one to calculate the superpolynomials. These functions are defined as expansions into MacDonald polynomials, and their dependence on k is entirely captured by the action of the cut-and-join operator, like in the HOMFLY case. We suggest a simple description of the coefficients in these character expansions, by expanding the initial (at k=0) conditions for the k-evolution into the new auxiliary basis, this time provided by the Hall-Littlewood polynomials, which, hence, play a role in the description of the dual m-evolution. For illustration we list manifest expressions for a few first series, mk\\pm 1, mk\\pm 2, mk\\pm 3, mk\\pm 4. Actually all formulas were explicitly tested up to m=17 strands in the braid.

A. Mironov; A. Morozov; Sh. Shakirov; A. Sleptsov

2012-02-17T23:59:59.000Z

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241

Observations of giant recombination edges on the Princeton Large Torus tokamak induced by particle transport  

Science Journals Connector (OSTI)

In this paper we report on the observation of characteristic "steps" in the continuum spectrum of high-temperature tokamak plasmas associated with recombination radiation from impurity ions. During special argon-seeded discharges on the Princeton Large Torus tokamak the x-ray spectrum exhibited large enhancements over the bremsstrahlung continuum beginning with energies of 4.1 keV. This corresponds to the radiative capture of free electrons by hydrogenlike argon into the ground state of heliumlike argon. The size of these edges increased to unexpectedly large values with minor radius (decreasing electron temperature), consistent with a departure of the hydrogenlike species from the predictions of corona equilibrium. Hence, the coronal equilibrium equations must be modified to account for the radial transport of argon. A simple particle diffusion model is proposed, with the Ar XVIII radial profiles evaluated from the size of the recombination edges. For the case of moderate density (?ne??3×1013 cm-3) and temperature (Te(0)?1.5 keV) discharges the outward radial transport velocity is found to be approximately 10 m/sec.

K. Brau; S. von Goeler; M. Bitter; R. D. Cowan; D. Eames; K. Hill; N. Sauthoff; E. Silver; W. Stodiek

1980-12-01T23:59:59.000Z

242

Ideal MHD Stability Characteristics of Advanced Operating Regimes in Spherical Torus Plasmas and the Role of High Harmonic Fast Waves  

SciTech Connect (OSTI)

The ARIES reactor study group has found an economically attractive ST-based reactor configuration with: A = 1.6, {kappa} = 3.4, {delta} = 0.65, {beta} = 50%, {beta}{sub N} = 7.3, f{sub BS} = 0.95, R{sub 0} = 3.2 meters, B{sub t0} = 2.08 Tesla, and I{sub P} = 28.5 MA which yields a cost of electricity of approximately 80mils/kWh. MHD stability analysis finds that a broad pressure profile is optimal for wall-stabilizing the pressure driven kink modes typical of such configurations, and that wall stabilization is crucial to achieving the high {beta} needed for an economical power plant. The 6MW high-harmonic fast wave system presently being installed on NSTX should allow real-time control of the plasma {beta}, and in combination with NBI may permit experimental investigations of the effect of pressure profile peaking on MHD stability in the near-term. In the longer term, ejection of ions through resonant interaction with HHFW might be used to induce a controllable edge radial electric field with potentially interesting effects on edge MHD and confinement.

C.E. Kessel; J. Manickam; J.E. Menard; S.C. Jardin; S.M. Kaye [and others

1999-06-01T23:59:59.000Z

243

Nanoparticle shape reconstruction by solving the direct and inverse small-angle scattering problems for a unit potential localized inside a torus  

SciTech Connect (OSTI)

The simplest doubly connected surface of revolution (torus) is used as an example to demonstrate the possibility of stable reconstruction a three-dimensional homogeneous body defined by a unit potential U(r) using a spherically averaged small-angle scattering (SAS) curve I(s). Annealing Monte Carlo simulations are performed without using prior information about nanoparticle shape and size. Exact and approximate expressions are obtained for the form factor of a torus. It is shown graphically that the exact and approximate SAS form-factor curves agree for an experimentally accessible scattering region. Examples are given.

Amarantov, S. V. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)], E-mail: amarantov_s@mail.ru

2009-04-15T23:59:59.000Z

244

David W Johnson | Princeton Plasma Physics Lab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

W Johnson W Johnson Principal Research Physicist, Head, ITER Fabrication David Johnson is a principal research physicist with broad experience in techniques and instrumentation for measuring the characteristics of magnetic fusion plasmas. He has specific expertise in laser Thomson scattering systems, and has installed and operated such systems on many fusion devices around the world. He managed a division of plasma diagnostic experts for the Tokamak Fusion Test Reactor (TFTR) and National Spherical Torus Experiment (NSTX) projects, more recently becoming the Work Breakdown Structure Team Leader for US ITER Diagnostics. He has served on numerous national and international committees related to diagnostic development. Interests Plasma diagnostics techniques and instrumentation

245

Accurate evolutions of unequal-mass neutron-star binaries: properties of the torus and short GRB engines  

E-Print Network [OSTI]

We present new results from accurate and fully general-relativistic simulations of the coalescence of unmagnetized binary neutron stars with various mass ratios. The evolution of the stars is followed through the inspiral phase, the merger and prompt collapse to a black hole, up until the appearance of a thick accretion disk, which is studied as it enters and remains in a regime of quasi-steady accretion. Although a simple ideal-fluid equation of state with \\Gamma=2 is used, this work presents a systematic study within a fully general relativistic framework of the properties of the resulting black-hole--torus system produced by the merger of unequal-mass binaries. More specifically, we show that: (1) The mass of the torus increases considerably with the mass asymmetry and equal-mass binaries do not produce significant tori if they have a total baryonic mass M_tot >~ 3.7 M_sun; (2) Tori with masses M_tor ~ 0.2 M_sun are measured for binaries with M_tot ~ 3.4 M_sun and mass ratios q ~ 0.75-0.85; (3) The mass of the torus can be estimated by the simple expression M_tor(q, M_tot) = [c_1 (1-q) + c_2](M_max-M_tot), involving the maximum mass for the binaries and coefficients constrained from the simulations, and suggesting that the tori can have masses as large as M_tor ~ 0.35 M_sun for M_tot ~ 2.8 M_sun and q ~ 0.75-0.85; (4) Using a novel technique to analyze the evolution of the tori we find no evidence for the onset of non-axisymmetric instabilities and that very little, if any, of their mass is unbound; (5) Finally, for all the binaries considered we compute the complete gravitational waveforms and the recoils imparted to the black holes, discussing the prospects of detection of these sources for a number of present and future detectors.

Luciano Rezzolla; Luca Baiotti; Bruno Giacomazzo; David Link; Jose A. Font

2010-05-13T23:59:59.000Z

246

THE COMPTON-THICK SEYFERT 2 NUCLEUS OF NGC 3281: TORUS CONSTRAINTS FROM THE 9.7 {mu}m SILICATE ABSORPTION  

SciTech Connect (OSTI)

We present mid-infrared (mid-IR) spectra of the Compton-thick Seyfert 2 galaxy NGC 3281, obtained with the Thermal-Region Camera Spectrograph at the Gemini-South telescope. The spectra present a very deep silicate absorption at 9.7 {mu}m, and [S IV] 10.5 {mu}m and [Ne II] 12.7 {mu}m ionic lines, but no evidence of polycyclic aromatic hydrocarbon emission. We find that the nuclear optical extinction is in the range 24 mag {<=} A{sub V} {<=} 83 mag. A temperature T = 300 K was found for the blackbody dust continuum component of the unresolved 65 pc nucleus and the region at 130 pc SE, while the region at 130 pc NW reveals a colder temperature (200 K). We describe the nuclear spectrum of NGC 3281 using a clumpy torus model that suggests that the nucleus of this galaxy hosts a dusty toroidal structure. According to this model, the ratio between the inner and outer radius of the torus in NGC 3281 is R{sub 0}/R{sub d} = 20, with 14 clouds in the equatorial radius with optical depth of {tau}{sub V} = 40 mag. We would be looking in the direction of the torus equatorial radius (i = 60{sup 0}), which has outer radius of R{sub 0} {approx} 11 pc. The column density is N{sub H} {approx} 1.2 x 10{sup 24} cm{sup -2} and the iron K{alpha} equivalent width ({approx}0.5-1.2 keV) is used to check the torus geometry. Our findings indicate that the X-ray absorbing column density, which classifies NGC 3281 as a Compton-thick source, may also be responsible for the absorption at 9.7 {mu}m providing strong evidence that the silicate dust responsible for this absorption can be located in the active galactic nucleus torus.

Sales, Dinalva A.; Pastoriza, M. G.; Riffel, R. [Departamento de Astronomia, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, Porto Alegre, RS (Brazil); Winge, C. [Gemini Observatory, c/o Aura, Inc., Casilla 603, La Serena (Chile); RodrIguez-Ardila, A. [Laboratorio Nacional de Astrofisica/MCT, Rua dos Estados Unidos 154, Itajuba, MG (Brazil); Carciofi, A. C., E-mail: dinalva.aires@ufrgs.br [Instituto de Astronomia, Geofisica e Ciencias Atmosfericas, Universidade de Sao Paulo, Rua do Matao 1226, Cidade Universitaria, Sao Paulo, SP (Brazil)

2011-09-01T23:59:59.000Z

247

Observational evidence of torus instability as trigger mechanism for coronal mass ejections: the 2011 August 4 filament eruption  

E-Print Network [OSTI]

Solar filaments are magnetic structures often observed in the solar atmosphere and consist of plasma that is cooler and denser than their surroundings. They are visible for days -- and even weeks -- which suggests that they are often in equilibrium with their environment before disappearing or erupting. Several eruption models have been proposed that aim to reveal what mechanism causes (or triggers) these solar eruptions. Validating these models through observations represents a fundamental step in our understanding of solar eruptions. We present an analysis of the observation of a filament eruption that agrees with the torus instability model. This model predicts that a magnetic flux rope embedded in an ambient field undergoes an eruption when the axis of the flux rope reaches a critical height that depends on the topology of the ambient field. We use the two vantage points of SDO and STEREO to reconstruct the three-dimensional shape of the filament, to follow its morphological evolution and to determine its...

Zuccarello, Francesco P; Mierla, Marilena; Poedts, Stefaan; Rachmeler, Laurel A; Romano, Paolo; Zuccarello, Francesca

2014-01-01T23:59:59.000Z

248

Determination of the minimum value of the safety factor from geodesic Alfven eigenmodes in Joint European Torus  

SciTech Connect (OSTI)

An analysis of the experimental conditions under which low-frequency (70-150 kHz) Alfven eigenmodes (AE) are excited during the monster sawtooth in Joint European Torus [F. Romanelli et al., Proceedings of the 22nd IAEA Fusion Energy Conference, Geneva, Switzerland, 2008] is presented for the specific case of a discharge with ion cyclotron heating (5 MW). Using a simplified AE model for modes excited at the Alfven wave continuum maximum with geodesic corrections taken into account, the temporal evolution of the value of the safety factor q{sub 0} at the magnetic axis is determined. We describe a new scheme to determine the time variation of q{sub 0} that works under conditions in which other standard diagnostics, such as the motional Stark effect do not give reliable results such as during a monster sawtooth.

Elfimov, A. G. [Institute of Physics, University of Sao Paulo, 05508-090 Sao Paulo (Brazil); Galvao, R. M. O. [Institute of Physics, University of Sao Paulo, 05508-090 Sao Paulo (Brazil); Centro Brasileiro de Pesquisas em Fisica, Rua Xavier Sigaud 150, BR-22290180 Rio de Janeiro (Brazil); Sharapov, S. E. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)

2010-11-15T23:59:59.000Z

249

Experimental evidence of charge-exchange recombination of highly ionized iron and titanium in Princeton large torus  

Science Journals Connector (OSTI)

The observed behavior of the emissivitives of boronlike Fe xxii, lithiumlike Fe xxiv and Ti xx, and the heliumlike Fe xxv ions in the Princeton large torus tokamak during high-power neutral (H0 or D0) beam heating is described. A substantial lowering of the dominant ionization state in the center of the discharge, while the electron temperature is rising, is attributed primarily to increased recombination rate of the ions through charge exchange with neutral hydrogen. This interpretation is supported by the different space and time behavior or the lithiumlike and boronlike ions of comparable ionization potentials, and by comparisons of neutral beam heating of the plasma with ion cyclotron resonance heating, which does not appreciably change the neutral hydrogen concentration. The observations are compared with approximate zero-dimensional model calculations, using experimental plasma conditions and estimated charge-exchange rates.

S. Suckewer; E. Hinnov; M. Bitter; R. Hulse; D. Post

1980-08-01T23:59:59.000Z

250

Power balance in ELMO Bumpy Torus: bulk electrons and ions in a 37 kW discharge  

SciTech Connect (OSTI)

The power balance of the bulk electrons and ions in discharges with 37 kW of applied microwave power in the ELMO Bumpy Torus (EBT) is examined in a zero-dimensional model using data on the intensity and linewidth of the molecular and atomic hydrogen emission. At least 60% of the applied power is ultimately dissipated by processes involving the neutral particles, including dissociation of molecules, ionization of and radiation from atoms, and heating of cold electrons produced during atomic ionization. The molecular influx rate and the density of atoms are used independently to determine the bulk electron particle confinement time, and an upper bound estimate is made of the diffusional power loss from the bulk plasma electrons. Parameters derived from the basic spectroscopic data presented in this paper include the neutral atom density 2 - 5x10/sup 10/ cm/sup -3/, incident molecular flux 3 - 5x10/sup 15/ cm/sup -2/s/sup -1/, bulk ion temperature approx. =3 eV, and particle confinement time <1.1 ms. The bulk electron energy confinement time is 0.7 ms or less in the standard operating regime. Published data on the nonthermal electron and ion populations in the plasma are used to evaluate approximately the overall energy flow in the discharge. 54 refs.

McNeill, D.H.

1985-10-01T23:59:59.000Z

251

Non-stationary hyperaccretion of stellar-mass black holes in three dimensions: Torus evolution and neutrino emission  

E-Print Network [OSTI]

We present three-dimensional hydrodynamic simulations of the evolution of selfgravitating, thick accretion discs around hyperaccreting stellar-mass black holes. The black hole-torus systems are considered to be remnants of compact object mergers, in which case the disc is not fed by an external mass reservoir and the accretion is non-stationary. Our models take into account viscous dissipation, described by an alpha-law, a detailed equation of state for the disc gas, and an approximate treatment of general relativistic effects on the disc structure by using a pseudo-Newtonian potential for the black hole including its possible rotation and spin-up during accretion. Magnetic fields are ignored. The neutrino emission of the hot disc is treated by a neutrino-trapping scheme, and the neutrino-antineutrino annihilation near the disc is evaluated in a post-processing step. Our simulations show that the neutrino emission and energy deposition by neutrino-antineutrino annihilation increase sensitively with the disc mass, with the black hole spin in case of a disc in corotation, and in particular with the alpha-viscosity. We find that for sufficiently large alpha-viscosity neutrino-antineutrino annihilation can be a viable energy source for gamma-ray bursts.

S. Setiawan; M. Ruffert; H. -Th. Janka

2004-02-20T23:59:59.000Z

252

Determination of Fe charge-state distributions in the Princeton large torus by Bragg crystal x-ray spectroscopy  

Science Journals Connector (OSTI)

A curved-crystal Bragg x-ray spectrometer has been used to measure K? or 1s-2p radiation from highly stripped Fexviii-Fexxv impurity ions in the Princeton large torus tokamak. The spectrometer has sufficient energy resolution (?4 eV at 6400 eV) to distinguish between the different ionization states of iron by measuring the energy shift of the K? x rays. The measured wavelengths agree well with theory and with spectra from solar flares and from laser-produced plasmas. The distribution of Fe charge states in the center of the discharge has been inferred from a comparison of the measured x-ray spectrum with theory. The shape of the spectrum depends strongly on electron temperature (Te) in the range Te=800-1500 eV. Within the factor of 2 uncertainty in L-shell ionization cross sections, measured intensities agree with theory, which is based on coronal equilibrium, indicating that the ion lifetime in the center of the plasma is approximately equal to or greater than the equilibration time.

K. W. Hill; S. von Goeler; M. Bitter; L. Campbell; R. D. Cowan; B. Fraenkel; A. Greenberger; R. Horton; J. Hovey; W. Roney; N. R. Sauthoff; W. Stodiek

1979-04-01T23:59:59.000Z

253

A Compact Torus Fusion Reactor Utilizing a Continuously Generated Strings of CT's. The CT String Reactor, CTSR.  

SciTech Connect (OSTI)

A fusion reactor is described in which a moving string of mutually repelling compact toruses (alternating helicity, unidirectional Btheta) is generated by repetitive injection using a magnetized coaxial gun driven by continuous gun current with alternating poloidal field. An injected CT relaxes to a minimum magnetic energy equilibrium, moves into a compression cone, and enters a conducting cylinder where the plasma is heated to fusion-producing temperature. The CT then passes into a blanketed region where fusion energy is produced and, on emergence from the fusion region, the CT undergoes controlled expansion in an exit cone where an alternating poloidal field opens the flux surfaces to directly recover the CT magnetic energy as current which is returned to the formation gun. The CT String Reactor (CTSTR) reactor satisfies all the necessary MHD stability requirements and is based on extrapolation of experimentally achieved formation, stability, and plasma confinement. It is supported by extensive 2D, MHD calculations. CTSTR employs minimal external fields supplied by normal conductors, and can produce high fusion power density with uniform wall loading. The geometric simplicity of CTSTR acts to minimize initial and maintenance costs, including periodic replacement of the reactor first wall.

Hartman, C W; Reisman, D B; McLean, H S; Thomas, J

2007-05-30T23:59:59.000Z

254

SciDAC Center for Simulation of Wave-Plasma Interactions - Iterated Finite-Orbit Monte Carlo Simulations with Full-Wave Fields for Modeling Tokamak ICRF Wave Heating Experiments - Final Report  

SciTech Connect (OSTI)

This final report describes the work performed under U.S. Department of Energy Cooperative Agreement DE-FC02-08ER54954 for the period April 1, 2011 through March 31, 2013. The goal of this project was to perform iterated finite-orbit Monte Carlo simulations with full-wall fields for modeling tokamak ICRF wave heating experiments. In year 1, the finite-orbit Monte-Carlo code ORBIT-RF and its iteration algorithms with the full-wave code AORSA were improved to enable systematical study of the factors responsible for the discrepancy in the simulated and the measured fast-ion FIDA signals in the DIII-D and NSTX ICRF fast-wave (FW) experiments. In year 2, ORBIT-RF was coupled to the TORIC full-wave code for a comparative study of ORBIT-RF/TORIC and ORBIT-RF/AORSA results in FW experiments.

Choi, Myunghee [Retired] [Retired; Chan, Vincent S. [General Atomics] [General Atomics

2014-02-28T23:59:59.000Z

255

Ignition Experiments  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Ignition Experiments The goal of many NIF experiments is to create a self-sustaining "burn" of fusion fuel (the hydrogen isotopes deuterium and tritium) that produces as much or...

256

Observation of a Forbidden Line of Fe xx and Its Application for Ion Temperature Measurements in the Princeton Large Torus Tokamak  

Science Journals Connector (OSTI)

A spectrum line in the Princeton Large Torus (PLT) tokamak discharges, with wave-length measured as 2665.1 ± 0.3 Å, has been identified as the 2s22p3 D522?D322 magnetic dipole transition in Fe xx ground configuration. A variety of localized spectroscopic diagnostics, e.g., ion temperature and density distribution measurements in the high-temperature interior of the plasma, are feasible by means of forbidden lines of this type. The 2665-Å line has been used to measure near-central ion temperature in a discharge with auxiliary neutral-beam heating.

S. Suckewer and E. Hinnov

1978-09-11T23:59:59.000Z

257

Digestion Experiments  

E-Print Network [OSTI]

Blank in Bulletin] BULLETIN NO. 291 FEBRUARY, 1922 DIGESTION EXPERIMENTS This is the sixth bulletin in a series whose object is to ascertain the Aceding value of Texas feeding stuffs by means of digestion experiments. Previous bulletins... The productive values and the values for digestible protein in t Bulletin have been calculated from the results of digestion esperiine? with sheep. The method of conducting the experiments is described Bulletins Nos. 147 and 166 of this Station. The production...

Fraps, G. S. (George Stronach)

1922-01-01T23:59:59.000Z

258

Electric-magnetic Duality of Abelian Gauge Theory on the Four-torus, from the Fivebrane on T2 x T4, via their Partition Functions  

E-Print Network [OSTI]

We compute the partition function of four-dimensional abelian gauge theory on a general four-torus T4 with flat metric using Dirac quantization. In addition to an SL(4, Z) symmetry, it possesses SL(2,Z) symmetry that is electromagnetic S-duality. We show explicitly how this SL(2, Z) S-duality of the 4d abelian gauge theory has its origin in symmetries of the 6d (2,0) tensor theory, by computing the partition function of a single fivebrane compactified on T2 x T4, which has SL(2,Z) x SL(4,Z) symmetry. If we identify the couplings of the abelian gauge theory \\tau = {\\theta\\over 2\\pi} + i{4\\pi\\over e^2} with the complex modulus of the T2 torus, \\tau = \\beta^2 + i {R_1\\over R_2}, then in the small T2 limit, the partition function of the fivebrane tensor field can be factorized, and contains the partition function of the 4d gauge theory. In this way the SL(2,Z) symmetry of the 6d tensor partition function is identified with the S-duality symmetry of the 4d gauge partition function. Each partition function is the product of zero mode and oscillator contributions, where the SL(2,Z) acts suitably. For the 4d gauge theory, which has a Lagrangian, this product redistributes when using path integral quantization.

Louise Dolan; Yang Sun

2014-11-10T23:59:59.000Z

259

Hydronuclear experiments  

SciTech Connect (OSTI)

Hydronuclear experiments, a method for assessing some aspects of nuclear weapon safety, were conducted at Los Alamos during the 1958 to 1961 moratorium on nuclear testing. The experiments resulted in subcritical multiplying assemblies or a very slight degree of supercriticality and, in some cases, involved a slight, but insignificant, fission energy release. These experiments helped to identify so-called one-point safety problems associated with some of the nuclear weapons systems of that time. The need for remedial action was demonstrated, although some of the necessary design changes could not be made until after the resumption of weapons testing at the end of 1961.

Thorn, R.N.; Westervelt, D.R.

1987-02-01T23:59:59.000Z

260

Emplacing experience  

Science Journals Connector (OSTI)

We propose that understandings of the role of space and place in everyday life are of value to designing the environment of Role Playing Games (RPGs). We compare aspects of space and place in spatial experiences while moving through terrains in physical ... Keywords: place, space, video games

David Browning; Steven Stanley; Michael Fryer; Nicola J Bidwell

2006-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "torus experiment nstx" from the National Library of EnergyBeta (NLEBeta).
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261

Fusion scientists gear up to learn how to harness plasma energy | Princeton  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Living on the edge Living on the edge Fusion scientists gear up to learn how to harness plasma energy By Kitta MacPherson March 30, 2011 Tweet Widget Facebook Like Google Plus One Researchers working on an advanced experimental fusion machine are readying experiments that will investigate a host of scientific puzzles, including how heat escapes as hot magnetized plasma, and what materials are best for handling intense plasma powers. Scientists conducting research on the National Spherical Torus Experiment (NSTX) at the U.S. Department of Energy's Princeton Plasma Physics Laboratory (PPPL) have mapped out a list of experiments to start in July and run for eight months. The experimental machine is designed to deepen understanding of how plasmas can be mined for energy. A major topic of investigation by scientists for the coming round of

262

Experimental studies on fast-ion transport by Alfvn wave avalanches on the National Spherical Torus Experimenta...  

E-Print Network [OSTI]

disagreement suggests that nonlinearities may compromise a direct comparison between experiment and linear for reactors such as ITER, where alpha particles originate from fusion reac- tions with an energy of 3.5 Me the behavior of a fusion reactor. Waves in the Alfvén frequency range are well known for their potential

Heidbrink, William W.

263

SUZAKU VIEW OF THE SWIFT/BAT ACTIVE GALACTIC NUCLEI. V. TORUS STRUCTURE OF TWO LUMINOUS RADIO-LOUD ACTIVE GALACTIC NUCLEI (3C 206 AND PKS 0707-35)  

SciTech Connect (OSTI)

We present the results from broadband X-ray spectral analysis of 3C 206 and PKS 0707-35 with Suzaku and Swift/BAT, two of the most luminous unobscured and obscured radio-loud active galactic nuclei (AGNs) with hard X-ray luminosities of 10{sup 45.5} erg s{sup -1} and 10{sup 44.9} erg s{sup -1} (14-195 keV), respectively. Based on the radio core luminosity, we estimate that the X-ray spectrum of 3C 206 contains a significant ({approx}60% in the 14-195 keV band) contribution from the jet, while it is negligible in PKS 0707-35. We can successfully model the spectra with the jet component (for 3C 206), the transmitted emission, and two reflection components from the torus and the accretion disk. The reflection strengths from the torus are found to be R{sub torus}({identical_to} {Omega}/2{pi}) = 0.29 {+-} 0.18 and 0.41 {+-} 0.18 for 3C 206 and PKS 0707-35, respectively, which are smaller than those in typical Seyfert galaxies. Utilizing the torus model by Ikeda et al., we quantify the relation between the half-opening angle of a torus ({theta}{sub oa}) and the equivalent width of an iron-K line. The observed equivalent width of 3C 206, < 71 eV, constrains the column density in the equatorial plane to N{sub H}{sup eq} <10{sup 23} cm{sup -2}, or the half-opening angle to {theta}{sub oa} > 80 Degree-Sign if N{sub H}{sup eq} =10{sup 24} cm{sup -2} is assumed. That of PKS 0707-35, 72 {+-} 36 eV, is consistent with N{sub H}{sup eq} {approx}10{sup 23} cm{sup -2}. Our results suggest that the tori in luminous radio-loud AGNs are only poorly developed. The trend is similar to that seen in radio-quiet AGNs, implying that the torus structure is not different between AGNs with jets and without jets.

Tazaki, Fumie; Ueda, Yoshihiro [Department of Astronomy, Kyoto University, Kyoto 606-8502 (Japan); Terashima, Yuichi [Department of Physics, Ehime University, Matsuyama 790-8577 (Japan); Mushotzky, Richard F.; Tombesi, Francesco [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States)

2013-07-20T23:59:59.000Z

264

Liquid Lithium Limiter Experiments in CDX-U  

SciTech Connect (OSTI)

Recent experiments in the Current Drive Experiment-Upgrade provide a first-ever test of large area liquid lithium surfaces as a tokamak first wall, to gain engineering experience with a liquid metal first wall, and to investigate whether very low recycling plasma regimes can be accessed with lithium walls. The CDX-U is a compact (R = 34 cm, a = 22 cm, B{sub toroidal} = 2 kG, I{sub P} = 100 kA, T{sub e}(0) = 100 eV, n{sub e}(0) {approx} 5 x 10{sup 19} m{sup -3}) spherical torus at the Princeton Plasma Physics Laboratory. A toroidal liquid lithium tray limiter with an area of 2000 cm{sup 2} (half the total plasma limiting surface) has been installed in CDX-U. Tokamak discharges which used the liquid lithium limiter required a fourfold lower loop voltage to sustain the plasma current, and a factor of 5-8 increase in gas fueling to achieve a comparable density, indicating that recycling is strongly reduced. Modeling of the discharges demonstrated that the lithium-limited discharges are consistent with Z{sub effective} < 1.2 (compared to 2.4 for the pre-lithium discharges), a broadened current channel, and a 25% increase in the core electron temperature. Spectroscopic measurements indicate that edge oxygen and carbon radiation are strongly reduced.

R. Majeski; S. Jardin; R. Kaita; T. Gray; P. Marfuta; J. Spaleta; J. Timberlake; L. Zakharov; G. Antar; R. Doerner; S. Luckhardt; R. Seraydarian; V. Soukhanovskii; R. Maingi; M. Finkenthal; D. Stutman; D. Rodgers

2004-10-28T23:59:59.000Z

265

Robert Kaita | Princeton Plasma Physics Lab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Kaita Kaita Principal Research Physicist, P.I., LTX Robert (Bob) Kaita is the head of plasma diagnostic operations and acting head of boundary physics operations for the National Spherical Torus Experiment (NSTX). Kaita is also a co-principal investigator of the Lithium Tokamak Experiment (LTX). He is a Fellow of the American Physical Society and a recipient of the Kaul Foundation Prize for Excellence in Plasma Physics Research. He has supervised the research of many students in the PPPL Program in Plasma Physics in the Department of Astrophysical Sciences at Princeton University. Interests Neutral beam and radiofrequency plasma heating Plasma diagnostics Plasma-surface interactions Solid and liquid plasma-facing components Contact Information Phone: 609-243-3275

266

On the LINER nuclear obscuration, Compton-thickness and the existence of the dusty torus; Clues from Spitzer/IRS spectra  

E-Print Network [OSTI]

Most of the optically classified low ionisation narrow emission-line regions (LINERs) nuclei host an active galactic nuclei (AGN). However, how they fit into the unified model (UM) of AGN is still an open question. The aims of this work are to study at mid-infrared (mid-IR) (1) the Compton-thick nature of LINERs; and (2) the disappearance of the dusty torus in LINERs predicted from theoretical arguments. We have compiled all the available low spectral resolution mid-IR spectra of LINERs from the IRS/Spitzer (40 LINERs). We have complemented this sample with Spitzer/IRS spectra of PGQSOs, S1s, S2s, and SBs nuclei. We have studied the AGN versus the starburst content in our sample using different indicators: the EW(PAH 6.2um), the strength of the silicate feature at 9.7um, and the steepness of the mid-IR spectra. In 25 out of the 40 LINERs (i.e., 62.5%) the mid-IR spectra are not SB-dominated, similar to the comparison S2 sample (67.7%). The average spectra of both SB-dominated LINERs and S2s are very similar t...

Gonzalez-Martin, O; Marquez, I; Rodríguez-Espinosa, J M; Acosta-Pulido, J A; Ramos-Almeida, C; Dultzin, D; Hernandez-Garcia, L; Ruschel-Dutra, D; Alonso-Herrero, A

2015-01-01T23:59:59.000Z

267

Iterated finite-orbit Monte Carlo simulations with full-wave fields for modeling tokamak ion cyclotron resonance frequency wave heating experiments  

SciTech Connect (OSTI)

The five-dimensional finite-orbit Monte Carlo code ORBIT-RF[M. Choi et al., Phys. Plasmas 12, 1 (2005)] is successfully coupled with the two-dimensional full-wave code all-orders spectral algorithm (AORSA) [E. F. Jaeger et al., Phys. Plasmas 13, 056101 (2006)] in a self-consistent way to achieve improved predictive modeling for ion cyclotron resonance frequency (ICRF) wave heating experiments in present fusion devices and future ITER [R. Aymar et al., Nucl. Fusion 41, 1301 (2001)]. The ORBIT-RF/AORSA simulations reproduce fast-ion spectra and spatial profiles qualitatively consistent with fast ion D-alpha [W. W. Heidbrink et al., Plasma Phys. Controlled Fusion 49, 1457 (2007)] spectroscopic data in both DIII-D [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] and National Spherical Torus Experiment [M. Ono et al., Nucl. Fusion 41, 1435 (2001)] high harmonic ICRF heating experiments. This work verifies that both finite-orbit width effect of fast-ion due to its drift motion along the torus and iterations between fast-ion distribution and wave fields are important in modeling ICRF heating experiments.

Choi, M.; Chan, V. S.; Lao, L. L.; Pinsker, R. I. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Green, D.; Berry, L. A.; Jaeger, F.; Park, J. M. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States); Heidbrink, W. W.; Liu, D.; Podesta, M. [University of California-Irvine, Irvine, California 92697 (United States); Harvey, R. [CompX, P.O. Box 2672, Del Mar, California 92014-5672 (United States); Smithe, D. N. [Tech-X Corporation, Boulder, Colorado 80303 (United States); Bonoli, P. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2010-05-15T23:59:59.000Z

268

Simulation of the shape of chaperonins using the small-angle x-ray scattering curves and torus form factor  

SciTech Connect (OSTI)

The inverse scattering problem has been solved for protein complexes whose surfaces can be described by a set of the simplest doubly connected surfaces in the uniform approximation (a scattering potential inside the molecule is a constant). Solutions of two proteins-well-known GroEL bacterial chaperonin and poor-studied bacteriophage chaperonin, which is a product of 146 gene (gp146)-were taken for the experiment. The shapes of protein complexes have been efficiently reconstructed from the experimental scattering curves. The shell method, the method of the rotation of amino acid sequences with the use of the form factor of an amino acid, and the method of seeking the model parameters of a protein complex with the preliminarily obtained form factor of the model have been used to reconstruct the shape of these particles.

Amarantov, S. V., E-mail: amarantov_s@mail.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Naletova, I. N. [Moscow State University, Belozerskii Institute of Molecular Biology and Bioorganic Chemistry (Russian Federation); Kurochkina, L. P. [Russian Academy of Sciences, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry (Russian Federation)

2011-08-15T23:59:59.000Z

269

Low-recycling conditions and improved core confinement in steady-state operation scenarios in JET (Joint European Torus)  

Science Journals Connector (OSTI)

In this paper, we discuss the phenomena that link particle recycling from the vessel walls in the L-mode during discharge start-up and the core confinement in the H-mode during the subsequent main heating phase. We consider available data of JET experiments that aimed at approaching fully non-inductive ITER-relevant steady-state conditions and show that the high electron temperature produced at the edge by a low recycling during start-up tends to favour the build-up of high normalized ?(?N) regimes in the H-mode, the confinement being improved in a large plasma volume. To provide an insight into this complex phenomenon we have modelled the relation between particle recycling in the scrape-off layer and the evolution of plasma transport, plasma current density and shear as well as the stability properties for such experimental conditions. The results confirm the existence of a link between the confinement in the H-mode phase and the values at the edge of electron temperature, bootstrap current density and local magnetic shear during start-up. Such a link could favour these regimes to be self-sustained in time.

R Cesario; L Amicucci; A Fonseca; I T Chapman; F Jenko; M Marinucci; S Saarelma; P Smeulders; D Told; R Zagorski; Y Baranov; M Beurskens; R De Angelis; D Mc Donald; C Challis; A Galli; J Mailloux; V Pericoli; M Zerbini; the EFDA-JET Contributors

2013-01-01T23:59:59.000Z

270

Recent Liquid Lithium Limiter Experiments in CDX-U  

SciTech Connect (OSTI)

Recent experiments in the Current Drive eXperiment-Upgrade (CDX-U) provide a first-ever test of large area liquid lithium surfaces as a tokamak first wall, to gain engineering experience with a liquid metal first wall, and to investigate whether very low recycling plasma regimes can be accessed with lithium walls. The CDX-U is a compact (R=34 cm, a=22 cm, B{sub toroidal} = 2 kG, I{sub P} =100 kA, T{sub e}(0) {approx} 100 eV, n{sub e}(0) {approx} 5 x 10{sup 19} m{sup -3}) spherical torus at the Princeton Plasma Physics Laboratory. A toroidal liquid lithium pool limiter with an area of 2000 cm{sup 2} (half the total plasma limiting surface) has been installed in CDX-U. Tokamak discharges which used the liquid lithium pool limiter required a fourfold lower loop voltage to sustain the plasma current, and a factor of 5-8 increase in gas fueling to achieve a comparable density, indicating that recycling is strongly reduced. Modeling of the discharges demonstrated that the lithium limited discharges are consistent with Z{sub effective} < 1.2 (compared to 2.4 for the pre-lithium discharges), a broadened current channel, and a 25% increase in the core electron temperature. Spectroscopic measurements indicate that edge oxygen and carbon radiation are strongly reduced.

R. Majeski; S. Jardin; R. Kaita; T. Gray; P. Marfuta; J. Spaleta; J. Timberlake; L. Zakharov; G. Antar; R. Doerner; S. Luckhardt; R. Seraydarian; V. Soukhanovskii; R. Maingi; M. Finkenthal; D. Stutman; D. Rodgers; S. Angelini

2005-05-03T23:59:59.000Z

271

Recent results from the HIT-SI experiment  

Science Journals Connector (OSTI)

New understanding and improved parameters have been achieved on the Helicity Injected Torus with Steady Inductive helicity injection current drive (HIT-SI) experiment. The experiment has a bowtie-shaped spheromak confinement region with two helicity injectors. The inductive injectors are 180° segments of a small, oval cross section toroidal pinch. Spheromaks with currents up to 38?kA and current amplification of 2 have been achieved with only 6?MW of injector power. The Taylor-state model is shown to agree with HIT-SI surface and internal magnetic profile measurements. Helicity balance predicts the peak magnitude of toroidal spheromak current and the threshold for spheromak formation. The model also accurately predicts the division of the applied loop voltage between the injector and spheromak regions. Single injector operation shows that the two injectors have opposing, preferred spheromak current directions. An electron locking relaxation model is consistent with the preferred direction, with ion Doppler data and with bolometric data. Results from higher frequency operation are given. The impact of the new understanding on the future direction of the HIT programme is discussed.

T.R. Jarboe; C. Akcay; M.A. Chilenski; D.A. Ennis; C.J. Hansen; N.K. Hicks; R.Z. Aboul Hosn; A.C. Hossack; G.J. Marklin; B.A. Nelson; R.G. O'Neill; P.E. Sieck; R.J. Smith; B.S. Victor; J.S. Wrobel; M. Nagata

2011-01-01T23:59:59.000Z

272

PPPL wins R&D 100 Award | Princeton Plasma Physics Lab  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

right) Jon Menard, the NSTX program director, and Vlad Soukhanovskii, who designed and led the experiments. (Photo by Elle Starkman, PPPL Office of Communications) Award winners:...

273

FES Science Network Requirements - Report of the Fusion Energy Sciences Network Requirements Workshop Conducted March 13 and 14, 2008  

E-Print Network [OSTI]

18 Princeton Plasma Physics Laboratory (PPPL), Princeton,Laboratory (ORNL), the Princeton Plasma Physics Laboratory (Experiment (NSTX) at the Princeton Plasma Physics Laboratory

Dart, Eli

2008-01-01T23:59:59.000Z

274

Facilities | U.S. DOE Office of Science (SC)  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Facilities Facilities Fusion Energy Sciences (FES) FES Home About Research Facilities ITER External link DIII-D External link National Spherical Torus Experiment (NSTX) External link Alcator C-Mod External link Science Highlights Benefits of FES Funding Opportunities Fusion Energy Sciences Advisory Committee (FESAC) News & Resources Contact Information Fusion Energy Sciences U.S. Department of Energy SC-24/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-4941 F: (301) 903-8584 E: sc.fes@science.doe.gov More Information » Facilities Print Text Size: A A A RSS Feeds FeedbackShare Page ITER ITER (Latin for "the way") is a critical step between today's studies of plasma physics and tomorrow's fusion power plants producing electricity and hydrogen. An unprecedented international collaboration of scientists

275

Ongoing Projects | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

Current Projects Current Projects Project Assessment (OPA) OPA Home About Project Management SC Projects Review Dates (updated November 2013) Project Construction Photos Completed Projects Current Projects Other Links SC Federal Project Directors (FPD) and FPD Resources Contact Information Project Assessment U.S. Department of Energy SC-28/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-4840 F: (301) 903-8520 E: sc.opa@science.doe.gov Project Construction Photos Current Projects Print Text Size: A A A RSS Feeds FeedbackShare Page Photos of current SC Projects 12 GeV CEBAF Upgrade .pdf file (3.2MB) Daya Bay .pdf file (1.0MB) National Spherical Torus Experiment (NSTX) .pdf file (841KB) National Synchrotron Light Source II (NSLS II) .pdf file (6.4MB)

276

He Puff System For Dust Detector Upgrade  

SciTech Connect (OSTI)

Local detection of surface dust is needed for the safe operation of next-step magnetic fusion devices such as ITER. An electrostatic dust detector, based on a 5 cm x 5 cm grid of interlocking circuit traces biased to 50 V, has been developed to detect dust on remote surfaces and was successfully tested for the first time on the National Spherical Torus Experiment (NSTX). We report on a helium puff system that clears residual dust from this detector and any incident debris or fibers that might cause a permanent short circuit. The entire surface of the detector was cleared of carbon particles by two consecutive helium puffs delivered by three nozzles of 0.45 mm inside diameter. The optimal configuration was found to be with the nozzles at an angle of 30o with respect to the surface of the detector and a helium backing pressure of 6 bar. __________________________________________________

B. Rais, C.H. Skinner A.L. Roquemore

2010-10-01T23:59:59.000Z

277

Spontaneous three-dimensional magnetic reconnection in merging toroidal plasma experiment  

SciTech Connect (OSTI)

We investigated a new phenomenon of three-dimensional (3D) magnetic reconnection in TS-4 torus plasma merging experiments by directly measuring the 3D structures of the current sheet. Removal of all toroidal asymmetry of the device reveals that a strong external drive of reconnection inflow increases the toroidal asymmetry of the current sheet only during the reconnection. This spontaneous 3D deformation of the current sheet increases the reconnection outflow as well as the reconnection electric field, probably because local compression of the current sheet to a thickness less than the ion gyroradius triggers its strong dissipation of the current sheet, responsible for the onset of 3D reconnection. These mechanisms indicate that the 3D reconnection is a newly observed spontaneous process of fast reconnection.

Ii, Toru [Graduate School of Engineering, University of Tokyo, Tokyo 113-8656 (Japan); Ono, Yasushi [Graduate School of Frontier Sciences, University of Tokyo, Chiba 277-8561 (Japan)

2013-01-15T23:59:59.000Z

278

71-970820-CLN-01 TO: DISTRIBUTION  

E-Print Network [OSTI]

. This memo presents an initial plan subject to approval by the NSTX project management as well as PPPL of D-site responsibilities from the overall PPPL point of view is needed. Overall construction and the assembly and installation of all Torus Systems (WBS 1). Modifications to other PPPL facilities, components

Princeton Plasma Physics Laboratory

279

COR Summary of Experience  

Broader source: Energy.gov (indexed) [DOE]

COR SUMMARY OF EXPERIENCE COR SUMMARY OF EXPERIENCE Effective January 1, 2012 CORs who are applying for certification must demonstrate past contracting, acquisition, procurement, program/project management, and general business experience. This experience is based on a set of competencies. Some of the competencies are listed below to use as a reference when you are documenting your previous experience. Use this template to document your experience. Experience should be supported by a written confirmation from the cognizant Contracting Officer/Contract Specialist showing the contract number, title and date(s) to which the experience applied. Once you have completed this document, please forward it and its supporting statement(s) to your Site Acquisition Career Manager (SACM) as part of your application for COR certification.

280

Energetic Particle Physics In Fusion Research In Preparation For Burning Plasma Experiments  

SciTech Connect (OSTI)

The area of energetic particle (EP) physics of fusion research has been actively and extensively researched in recent decades. The progress achieved in advancing and understanding EP physics has been substantial since the last comprehensive review on this topic by W.W. Heidbrink and G.J. Sadler [1]. That review coincided with the start of deuterium-tritium (DT) experiments on Tokamak Fusion Test reactor (TFTR) and full scale fusion alphas physics studies. Fusion research in recent years has been influenced by EP physics in many ways including the limitations imposed by the "sea" of Alfven eigenmodes (AE) in particular by the toroidicityinduced AEs (TAE) modes and reversed shear Alfven (RSAE). In present paper we attempt a broad review of EP physics progress in tokamaks and spherical tori since the first DT experiments on TFTR and JET (Joint European Torus) including helical/stellarator devices. Introductory discussions on basic ingredients of EP physics, i.e. particle orbits in STs, fundamental diagnostic techniques of EPs and instabilities, wave particle resonances and others are given to help understanding the advanced topics of EP physics. At the end we cover important and interesting physics issues toward the burning plasma experiments such as ITER (International Thermonuclear Experimental Reactor).

Gorelenkov, Nikolai N [PPPL

2013-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "torus experiment nstx" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Princeton Plasma Physics Laboratory NSTX Experimental Proposal  

E-Print Network [OSTI]

-mode plasmas, using Neon injection and the (diode based) USXR poloidal arrays. While thermal ion transport in H H- modes by using deuterated-methane and neon gas puffs as well as vitreous carbon pellet injection. We will first attempt injection into ELM-free H-modes by applying brief (50-200 ms) gas puffs

Princeton Plasma Physics Laboratory

282

Princeton Plasma Physics Laboratory NSTX Experimental Proposal  

E-Print Network [OSTI]

plan 1. Assume previous XP ends with standard He-GDC 2. 2-3 Gas only shots 2 puff (128266) and 4 puff - Run Coordinator: Date Responsible Division: Experimental Research Operations Chit Review Board AUTHORS: C. H. Skinner, R. Maingi, V. Soukhanovski, W. Blanchard DATE: 4/9/08 1. Overview of planned

Princeton Plasma Physics Laboratory

283

Princeton Plasma Physics Laboratory NSTX Machine Proposal  

E-Print Network [OSTI]

conditions, promoting reliability in future experimental operations. 3. Plan: Establish standard HHFW plasma-AD-63) Independent Review Master Equip. List Mod (OP-AD-112) ES&H Review (NEPA, IH, etc) MINOR MODIFICATIONS #12;REVIEWERS (designated by RLM) ATI Test Director Independent Reviewer D-Site Shift Supervisor

Princeton Plasma Physics Laboratory

284

Princeton Plasma Physics Lab - NSTX-U  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

certified safe to operate. At the U.S. Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL), the task of evaluating the safety of the 94 million upgrade...

285

Princeton Plasma Physics Laboratory NSTX Experimental Proposal  

E-Print Network [OSTI]

Operations Chit Review Board (designated by Run Coordinator) MINOR MODIFICATIONS (Approved by Experimental and detailed nature of the inertial effects and dissipation mechanisms have yet to be determined. The strength, and neoclassical effects. Active braking of the plasma rotation by externally applied fields will be used to alter

Princeton Plasma Physics Laboratory

286

Princeton Plasma Physics Laboratory NSTX Experimental Proposal  

E-Print Network [OSTI]

Chit Review Board (designated by Run Coordinator) MINOR MODIFICATIONS (Approved by Experimental helical field, resonant electromagnetic coupling of rational surfaces to error fields or the conducting global nature of toroidal rotation damping at N / Nno-wall > 1 2) The observed dependence of rotation

Princeton Plasma Physics Laboratory

287

Princeton Plasma Physics Laboratory NSTX Experimental Proposal  

E-Print Network [OSTI]

Responsible Division: Experimental Research Operations Chit Review Board (designated by Run Coordinator) MINOR redistribution and loss of fast ions resulting from the bursts. In addition, eternal braking fields eigenfunctions. Comparison with calculated BAAE eigenfunctions will improve understanding of the exact nature

Princeton Plasma Physics Laboratory

288

Princeton Plasma Physics Laboratory NSTX Machine Proposal  

E-Print Network [OSTI]

designated by RLM MINOR MODIFICATIONS #12;OP-XMP-59 2 / 6 REVIEWERS (designated by RLM) Organization/Position Name Signature ATI D. Mueller Test Director M. Podestà Independent Reviewer NB M. Cropper RF Diagnostics TRAINING (designated by RLM) Training required: No Yes Instructor

Princeton Plasma Physics Laboratory

289

Work Authorization Document NSTX Upgrade Project  

E-Print Network [OSTI]

-NBI-Control & Instm 5 08JUN10A 08JUN10A 14JUN10A 14JUN10A 0 0.00 100 0.00 0.00 2475-0004 FMEA Analysis

Princeton Plasma Physics Laboratory

290

Work Authorization Document NSTX Upgrade Project  

E-Print Network [OSTI]

01JUN10A 0 0.00 100 0.00 0.00 1000-0008 Fault, FMEA evaluation and analyses 21 03MAY10A 03MAY10A 0110A 25FEB11 18MAY11 -58 147 18,651.56 75 13,823.15 18,430.86 1000-0017 Fault, FMEA analyses (LOE) 220

Princeton Plasma Physics Laboratory

291

Princeton Plasma Physics Laboratory NSTX Experimental Proposal  

E-Print Network [OSTI]

the optimal sequencing of H-mode, heating, and current ramp rate to reliably access qmin >> 1 at the end/ empirical justification Rapid penetration of the current density during the current ramp phase of a tokamak operation. Such rapid current penetration can be caused by either high plasma resistivity or plasma

Princeton Plasma Physics Laboratory

292

Princeton Plasma Physics Laboratory NSTX Experimental Proposal  

E-Print Network [OSTI]

and height are determined by neutral penetration length. We would like to document SGI and CGI fueled pedestal conditions so that analytical models of neutral penetration can be applied. 3. Experimental run-mode discharge (1-2 shots) Repeat with LFS injector (Injector # 2) at identical rate and timing Use MPTS relative

Princeton Plasma Physics Laboratory

293

EBW PHYSICS OF ECE IN NSTX  

SciTech Connect (OSTI)

Topics covered include: ray tracing and Fokker-Planck coupling; relativistic and electromagnetic effects in EBW damping (ray-tracing); O-X-EBW mode conversion efficiency limit due to finite beam divergence; general prospects for electron Bernstein wave heating and current drive in spherical tokamaks; sensitivity of EBW H&CD; collisional effects on EBW coupling; and EBW propagation in a high-temperature plasma.

Linda Vahala

2012-06-26T23:59:59.000Z

294

Work Authorization Document NSTX Upgrade Project  

E-Print Network [OSTI]

heating system. The system will be composed of an AC/DC power conversion system, gyrotron source or other operational characteristic for the system will require upgrade. Only disruption qualification The Electron Cyclotron Heating System provides breakdown and startup assist through an electron cyclotron

Princeton Plasma Physics Laboratory

295

Fertilizer Experiments with Cotton.  

E-Print Network [OSTI]

LIBRARY. A & M COLLEGE, CAMPUS I TEXAS AGRICULTURAL EXPERIMENT STATION A. B. CONNER, DIRECTOR COLLEGE STATION, BRAZOS COUNTY, TEXAS BULLETIN NO. 469 DIVISION OF AGRONOMY Fertilizer Experiments with Cotton AGRICULTURAL AND MECHANICAL COLLEGE... of seven years experiments with fertilizers on cotton at Troup, Nacogdoches, Angleton, College Station, Beeville, Tem- ple, and Denton, Texas, are reported in this Bulletin. The Kirvin fine sandy loam at Troup and the Nacogdoches and Ruston fine sandy...

Reynolds, E. B. (Elbert Brunner)

1932-01-01T23:59:59.000Z

296

Irish Potato Fertilizer Experiments.  

E-Print Network [OSTI]

S AGRICULTURAL EXPERIMENT STATIONS. BULLETIN NO 101 January, 1908. ish Potato Fertilizer Experiments - Postoffice, COLLEGE STATION, BRAZOS COUNTY, TEXAS. TEXAS AGRICULTURAL EXPERIMENT STATIONS OFFICERS. GOVERNING BOARD. (Board of Directors... was sc Be Irish Potato Fl nents W. S. Hotchkiss and E. J. Kyle. e fertilizer work with the Irish potato at Troupe was first planned fall of 1902. The results which were gotten upon harvesting the the spring of 1903 were so opposed, especially...

Hotchkiss, W.S.; Kyle, E. J. (Edwin Jackson)

1908-01-01T23:59:59.000Z

297

A Simple Eclipse Experiment  

Science Journals Connector (OSTI)

... the experiment above cited may be produced in one of three ways: first, by roughening the surface of the pin's head; secondly, by dust on the edges of ...

W. G. ROYAL-DAWSON

1912-06-06T23:59:59.000Z

298

CASL Test Stand Experience  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Industry Test Stand Experience Stephen Hess, EPRI Heather Feldman, EPRI Brenden Mervin, EPRI Martin Pytel, EPRI Rose Montgomery, TVA Bill Bird, TVA Fausto Franceschini,...

299

Operating Experience Committee Charter  

Broader source: Energy.gov (indexed) [DOE]

and the ability to learn from experience are attributes consistently evident in High Reliability Organizations. These organizations are learning organizations, which have...

300

The path to fusion power  

Science Journals Connector (OSTI)

...cost-effective neutron and plasma source for a component...at Culham and NSTX at Princeton, are beginning to reach...that requires no driven plasma current to confine the...achieved near fusion plasma conditions at very modest...Experiment (NSTX) at Princeton in the USA also operates...

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "torus experiment nstx" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

The DITE Tokamak Experiment  

Science Journals Connector (OSTI)

...April 1981 research-article The DITE Tokamak Experiment J. W. M. Paul W. H. M...magnetic containment of hot plasma in the tokamak toroidal configuration, and plasma heating...these concepts in the Divertor Injection Tokamak Experiment (DITE) at Culham Laboratory...

1981-01-01T23:59:59.000Z

302

Practical Experiments in Statistics  

Science Journals Connector (OSTI)

An simple and inexpensive experiment in radioactive decay that can be applied to any field that requires a knowledge of statistics; the primary goal is to familiarize students with probability distributions. ... A Didactic Experience of Statistical Analysis for the Determination of Glycine in a Nonaqueous Medium Using ANOVA and a Computer Program ...

Craig A. Stone; Lorin D. Mumaw

1995-01-01T23:59:59.000Z

303

Conference: Synergy Between Experiment  

E-Print Network [OSTI]

Kaxiras (Harvard) Synopsis ­ Society's ceaseless demand for clean, renewable energy resources on rapidly developing areas of nanoscale computation, will hold a conference on energy research, experimentAn NNIN/C Conference: Synergy Between Experiment and Computation in Energy ­ Looking to 2030. Yu

Heller, Eric

304

COR Summary of Experience  

Broader source: Energy.gov (indexed) [DOE]

COR SUMMARY OF EXPERIENCE Effective January 1, 2012, the Office of Federal Procurement Policy (OFPP) added a requirement for past COR experience to qualify for FAC-COR Level II (journeyman level) and III (senior/expert level). At least 1 year of COR experience is required to qualify for Level II; 2 years for Level III. OFPP strongly advises that applicants for Level III have prior experience at Level II. Applicants with no prior experience as an appointed COR must demonstrate proficiency in the specific competencies listed below for the same time period, validated by a cognizant Contracting Officer or Contract Specialist by signature below or an accompanying e-mail. Submit this form to your Site Acquisition Career Manager (SACM) as part of your application

305

Study of Thermonuclear Alfven Instabilities in Next Step Burning Plasma Experiments  

SciTech Connect (OSTI)

A study is presented for the stability of alpha-particle driven shear Alfven Eigenmodes (AE) for the normal parameters of the three major burning plasma proposals, ITER (International Thermonuclear Experimental Reactor), FIRE (Fusion Ignition Research Experiment), and IGNITOR (Ignited Torus). A study of the JET (Joint European Torus) plasma, where fusion alphas were generated in tritium experiments, is also included to attempt experimental validation of the numerical predictions. An analytic assessment of Toroidal AE (TAE) stability is first presented, where the alpha particle beta due to the fusion reaction rate and electron drag is simply and accurately estimated in 7-20 keV plasma temperature regime. In this assessment the hot particle drive is balanced against ion-Landau damping of the background deuterons and electron collision effects and stability boundaries are determined. Then two numerical studies of AE instability are presented. In one the High-n stability code HINST is used . This code is capable of predicting instabilities of low and moderately high frequency Alfven modes. HINST computes the non-perturbative solution of the Alfven eigenmodes including effects of ion finite Larmor radius, orbit width, trapped electrons etc. The stability calculations are repeated using the global code NOVAK. We show that for these tokamaks the spectrum of the least stable AE modes are TAE that appear at medium-/high-n numbers. In HINST TAEs are locally unstable due to the alphas pressure gradient in all the devices under the consideration except IGNITOR. However, NOVAK calculations show that the global mode structure enhances the damping mechanisms and produces stability in all configurations considered here. A serious question remains whether the perturbation theory used in NOVAK overestimates the stability predictions, so that it is premature to conclude that the nominal operation of all three proposals are stable to AEs. In addition NBI ions produce a strong stabilizing effect for JET. However, in ITER the beam energies needed to penetrate to the core must be high so that a diamagnetic drift frequency comparable to that of the alpha particles is produced by the beam ions which induces a destabilizing effect.

N.N. Gorelenkov; H.L. Berk; R. Budny; C.Z. Cheng; G.-Y. Fu; W.W. Heidbrink; G. Kramer; D. Meade; and R. Nazikian

2002-07-02T23:59:59.000Z

306

The Neutron EDM Experiment  

E-Print Network [OSTI]

The neutron EDM experiment has played an important part over many decades in shaping and constraining numerous models of CP violation. This review article discusses some of the techniques used to calculate EDMs under various theoretical scenarios, and highlights some of the implications of EDM limits upon such models. A pedagogical introduction is given to the experimental techniques employed in the recently completed ILL experiment, including a brief discussion of the dominant systematic uncertainties. A new and much more sensitive version of the experiment, which is currently under development, is also outlined.

P. G. Harris

2007-09-19T23:59:59.000Z

307

BNL | Completed ATF Experiments  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Completed / Terminated ATF Experiments Completed / Terminated ATF Experiments AE01 - Micro-undulator FEL Experiment. Spokesperson: I. Ben-Zvi, BNL. (1992 - 1997) AE02. - Inverse FEL Accelerator. Spokesperson: A. van Steenbergen, BNL. [Yale, Columbia]. (1992-1997) AE03 - Laser Grating Accelerator Experiment. Spokesperson: R. Fernow, BNL. [Princeton, LANL]. (1992- 1996) AE05 - Nonlinear-Compton Scattering. Spokesperson: K. McDonald, Princeton (1992-) AE06 - Inverse Cherenkov Acceleration. Spokesperson: W. Kimura, STI Optronics. [UCSB,BNL]. (1992-1997) AE08 - Far Infrared Radiation Source. Spokesperson J. Walsh, Dartmouth. [Oxford, BNL]. (1992 - 1994) AE09. - Photocathode R&D. Spokesperson: T. Rao, BNL. (1992 - ) AE10. - High Gain Harmonic Generation FEL. Spokesperson: L.H. Yu, BNL. [ANL] (1992 - 2001)

308

The Colorado FRC Experiment  

Science Journals Connector (OSTI)

A new experiment is under development for the study of turbulence, flow, and cross-field transport in a field-reversed configuration. The facility is a merged-spheromak device driven by magnetized coaxial plasma ...

T. Munsat; C. L. Ellison; A. Light; J. Nuger; W. Willcockson…

2008-06-01T23:59:59.000Z

309

Corporate Operating Experience Program  

Broader source: Energy.gov [DOE]

The DOE Corporate Operating Experience Program helps to prevent the recurrence of significant adverse events/trends by sharing performance information, lessons learned and good practices across the DOE complex.

310

General relativity and experiment  

E-Print Network [OSTI]

The confrontation between Einstein's theory of gravitation and experiment is summarized. Although all current experimental data are compatible with general relativity, the importance of pursuing the quest for possible deviations from Einstein's theory is emphasized.

T. Damour

1994-12-08T23:59:59.000Z

311

Some Experiments in Magnetism  

Science Journals Connector (OSTI)

1 January 1904 research-article Some Experiments in Magnetism T. C. Porter The Royal Society is collaborating with JSTOR to digitize, preserve, and extend access to Proceedings of the Royal Society of London. www.jstor.org

1904-01-01T23:59:59.000Z

312

Solar neutrino experiments  

Science Journals Connector (OSTI)

The main results of solar neutrino experiments are presented, ranging from the pioneering Cl - Ar experiment up to the most recent Borexino data. Solar neutrino fluxes and spectra are given for two versions of the standard solar model, and radiochemical and electronic detectors are briefly described. The results of Be- and pep-neutrino detection by Borexino are presented. The LMA-MSW oscillation solution of the solar neutrino problem is considered.

A V Derbin

2014-01-01T23:59:59.000Z

313

The MAJORANA Experiment  

E-Print Network [OSTI]

The MAJORANA collaboration is actively pursuing research and development aimed at a tonne-scale 76Ge neutrinoless double-beta decay) experiment. The current, primary focus is the construction of the MAJORANA DEMONSTRATOR experiment, an R&D effort that will field approximately 40kg of germanium detectors with mixed enrichment levels. This article provides a status update on the construction of the DEMONSTRATOR.

The MAJORANA Collaboration

2011-09-22T23:59:59.000Z

314

Complete Experiment Safety Documentation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Complete Experiment Safety Documentation Print Complete Experiment Safety Documentation Print User Safety Overview The steps for authorization of your experiment are described below. The ALS Experiment Coordinators are available to support you through this process. Please This e-mail address is being protected from spambots. You need JavaScript enabled to view it at any stage if you have questions or need more information. Prior to Your Arrival at the ALS 1. Complete or Update and Experiment Safety Sheet If you did not submit a General User Proposal, you must submit an ESS one month prior to arrival at the ALS. 2. Biological, Radioactive, Hazardous, and Electrical Materials, and Lasers If your experiment involves the use of any of the above materials-no matter how small the quantities are or how innocuous the sample may be-additional authorization may be required. Please submit your ESS early and clearly identify your materials. Our staff will assess the hazards and contact you about any necessary supplementary documentation.

315

Complete Experiment Safety Documentation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Complete Experiment Safety Documentation Print Complete Experiment Safety Documentation Print User Safety Overview The steps for authorization of your experiment are described below. The ALS Experiment Coordinators are available to support you through this process. Please This e-mail address is being protected from spambots. You need JavaScript enabled to view it at any stage if you have questions or need more information. Prior to Your Arrival at the ALS 1. Complete or Update and Experiment Safety Sheet If you did not submit a General User Proposal, you must submit an ESS one month prior to arrival at the ALS. 2. Biological, Radioactive, Hazardous, and Electrical Materials, and Lasers If your experiment involves the use of any of the above materials-no matter how small the quantities are or how innocuous the sample may be-additional authorization may be required. Please submit your ESS early and clearly identify your materials. Our staff will assess the hazards and contact you about any necessary supplementary documentation.

316

Complete Experiment Safety Documentation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Complete Experiment Safety Documentation Print Complete Experiment Safety Documentation Print User Safety Overview The steps for authorization of your experiment are described below. The ALS Experiment Coordinators are available to support you through this process. Please This e-mail address is being protected from spambots. You need JavaScript enabled to view it at any stage if you have questions or need more information. Prior to Your Arrival at the ALS 1. Complete or Update and Experiment Safety Sheet If you did not submit a General User Proposal, you must submit an ESS one month prior to arrival at the ALS. 2. Biological, Radioactive, Hazardous, and Electrical Materials, and Lasers If your experiment involves the use of any of the above materials-no matter how small the quantities are or how innocuous the sample may be-additional authorization may be required. Please submit your ESS early and clearly identify your materials. Our staff will assess the hazards and contact you about any necessary supplementary documentation.

317

Complete Experiment Safety Documentation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Complete Experiment Safety Documentation Print Complete Experiment Safety Documentation Print User Safety Overview The steps for authorization of your experiment are described below. The ALS Experiment Coordinators are available to support you through this process. Please This e-mail address is being protected from spambots. You need JavaScript enabled to view it at any stage if you have questions or need more information. Prior to Your Arrival at the ALS 1. Complete or Update and Experiment Safety Sheet If you did not submit a General User Proposal, you must submit an ESS one month prior to arrival at the ALS. 2. Biological, Radioactive, Hazardous, and Electrical Materials, and Lasers If your experiment involves the use of any of the above materials-no matter how small the quantities are or how innocuous the sample may be-additional authorization may be required. Please submit your ESS early and clearly identify your materials. Our staff will assess the hazards and contact you about any necessary supplementary documentation.

318

Hershey-Chase experiment  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Hershey-Chase experiment Hershey-Chase experiment Name: pei01 Location: N/A Country: N/A Date: N/A Question: I would like to know the characteristics of Griffth's experiment, and Hershey-Chase experiment. Replies: For the H-C experiment: It was designed to show that the type of virus known as a bacteriophage infected bacteria by injecting its DNA, and not by incorporating the entire virus into the bacterium. This was important because it showed that the entire replication of the virus could be coded for in the DNA of the virus, and not in the coat protein. They labeled with radioactivity the coat of the virus using one type of label 35-S, and the DNA with another, 32-P and then infected bacteria. After infection, the bacteria contained only 32-P, and no 35-S. The viruses went on to destroy the bacteria and reproduce, and the new viruses contained no 35-S in their coats. Source: Biology, 3rd ed., by Solomon et al., although the same information is in almost all texts at the college level

319

KISMET tungsten dispersal experiment  

SciTech Connect (OSTI)

Results of the KISMET tungsten dispersal experiment indicate a relatively small degree of wall-rock contamination caused by this underground explosive experiment. Designed as an add-on to the KISMET test, which was performed in the U-1a.02 drift of the LYNER facility at Nevada Test Site on 1 March 1995, this experiment involved recovery and analysis of wall-rock samples affected by the high- explosive test. The chemical, high-explosive blast drove tungsten powder, placed around the test package as a plutonium analog, into the surrounding wall- rock alluvium. Sample analyses by an analytical digital electron microscope (ADEM) show tungsten dispersed in the rock as tiny (<10 {mu}m) particles, agglomerates, and coatings on alluvial clasts. Tungsten concentrations, measured by energy dispersive spectral analysis on the ADEM, indicate penetration depths less than 0.1 m and maximum concentrations of 1.5 wt % in the alluvium.

Wohletz, K.; Kunkle, T.; Hawkins, W.

1996-12-01T23:59:59.000Z

320

AGS experiments, 1988, 1989, 1990  

SciTech Connect (OSTI)

This report contains: experimental areas layout; table of beam parameters and fluxes; experiment schedule as run''; experiment long range schedule; a listing of experiments by number; two-page summaries of each experiment begin here, also ordered by number; publications of AGS experiments; and list of experimenters.

Depken, J.C.

1991-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "torus experiment nstx" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

A demonstration mobility experiment  

E-Print Network [OSTI]

Corporation, Albuquerque& New Nhxico& for his assl. stance and advice in the preparation of the crystslsl snd my wife, Ellen, who corrected gram&asr& typed, proofread& and offered sncouragesmnt throughout the comple- tion of this thesis, I I I 8 I w... Shockley Haynes mobil. ty experiment. Tp Fig, 2. Sketch of oscilloscope trace from asr1y version of tha Shoo'klay Hagrnes momlity experiment, drift toward the eollsotor point with e velocity~? whereMLO the h ~ ability of a boles Ths Current tlsw...

Martin, Howard Lawrence

1961-01-01T23:59:59.000Z

322

NSTX Weekly Report (Feb. 12, 2009) FY 2010 NSTX plasma operations  

E-Print Network [OSTI]

Detector diagnostic was installed. The neutral beam helium refrigerator has been cooled to cryogenic

Princeton Plasma Physics Laboratory

323

NSTX OH Conductor Fatigue, Calc # NSTXU CALC 133-09-00 Page No. 1 NSTX Upgrade  

E-Print Network [OSTI]

: ___________________________________ Peter Titus, PPPL Mechanical Engineering Reviewed By: ________________________________________ Irving Cognizant Engineer Peter Titus Digitally signed by Peter Titus DN: cn=Peter Titus, o, ou, email=ptitus@pppl=Irving Zatz, o=PPPL, ou, email=zatz@pppl.gov, c=US Date: 2011.02.23 17:07:03 -05'00' Jim Chrzanowski Digitally

Princeton Plasma Physics Laboratory

324

NSTX Weekly Report (September 24, 2010) FY 2010 NSTX plasma operations completed on September 24, 2010  

E-Print Network [OSTI]

in the PPPL Theory Department 5 year plan review held September 21-22. They presented highlights of theory, 2010 Planned: Total - 15 run weeks (Base - 14 run weeks, ARRA - 1 run week) Total completed ­ 15.43 run "Snowflake" divertor configurations for divertor peak heat flux reduction. In this part of XP, the standard

Princeton Plasma Physics Laboratory

325

NSTX Weekly Report (Jan. 22, 2009) FY 2010 NSTX plasma operations  

E-Print Network [OSTI]

in Tokamaks," and Vsevolod Soukhanovskii of Lawrence Livermore National Laboratory on "Advanced High Heat Flux research team attended the 2nd NIFS-CRF International Symposium on Plasma-Surface Interactions on Jan. 18 - 20, 2010 at NIFS, Gifu, Japan and the presented following three invited and two contributed oral

Princeton Plasma Physics Laboratory

326

NSTX Weekly Report (November 19, 2010) FY 2011 NSTX plasma operations started on October 4, 2010  

E-Print Network [OSTI]

of lithium carbonate to water soluble lithium acetate was drafted and is under review. · Lithium Evaporators and photographs. A temporary floor has now been installed in the vessel, and lithium clean-up operations as well) Boundary Physics Operations (H. Kugel) · Liquid Lithium Divertor (LLD) - Initial inspection of the LLD

Princeton Plasma Physics Laboratory

327

NSTX Weekly Report (Feb. 19, 2010) FY 2010 NSTX plasma operations  

E-Print Network [OSTI]

of safety interlocks for the field coil power, variable frequency, and neutral beam systems was started of the probe drive position controls for units F2 and K2. - An improved liquid lithium metering technique

Princeton Plasma Physics Laboratory

328

Venus Fly Trap Experiment  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Venus Fly Trap Experiment Venus Fly Trap Experiment Name: Jeremy Bailey Status: N/A Age: N/A Location: N/A Country: N/A Date: N/A Question: My name is Jeremy Bailey, and I am a student of Dorseyville Middle School. I have been working on a science project about Venus' Fly Traps. A recent addition to the project involved designing an experiment about something I found interesting about them. However, I don't know where to get them or how to grow them in the moderate climate of Pittsburgh. Also, I don't know how a successful experiment could be designed. Replies: Jeremy, I believe Venus Fly traps can be found 'in the wild' in the coastal floodplain of the Carolinas. As far as where to buy them, look in the phonebook yellow pages under plants or houseplants and do some calling. I live in eastern Pennsylvania, and over here they even sell them in hardware stores like Hechinger's and Home Depot (in their garden departments). I don't think you will have luck trying to grow them outside, our winters here are a bit too harsh for them. From what I recall they require substantial moisture and more moderate climes. You might try looking for houseplant books at your local library for more detailed information.

329

ATA beam director experiment  

SciTech Connect (OSTI)

This report describes beam director elements for an experiment at the Advanced Test Accelerator. The elements described include a vernier magnet for beam aiming, an achromat magnet, and an isolation system for the beam interface. These components are built at small scale for concept testing. (JDH)

Lee, E.P.; Younger, F.C.; Cruz, G.E.; Nolting, E.

1986-06-23T23:59:59.000Z

330

The MAJORANA Experiment  

SciTech Connect (OSTI)

The Majorana Collaboration is assembling an array of HPGe detectors to search for neutrinoless double-beta decay in {sup 76}Ge. Initially, Majorana aims to construct a prototype module to demonstrate the potential of a future 1-tonne experiment. The design and potential reach of this prototype Demonstrator module are presented.

Guiseppe, V.E. [Univ S Dakota; Keller, C. [Univ S Dakota; Mei, D-M [Univ S Dakota; Perevozchikov, O. [Univ S Dakota; Perumpilly, G. [Univ S Dakota; Thomas, K. [Univ S Dakota; Xiang, W. [Univ S Dakota; Zhang, C. [Univ S Dakota; Aalseth, C.E. [Pacific NW Natl Lab Richland, WA; Aguayo, E. [Pacific NW Natl Lab Richland, WA; Ely, J. [Pacific NW Natl Lab Richland, WA; Fast, J.E. [Pacific NW Natl Lab Richland, WA; Hoppe, E.W. [Pacific NW Natl Lab Richland, WA; Hossbach, T.W. [Pacific NW Natl Lab Richland, WA; Keillor, M. [Pacific NW Natl Lab Richland, WA; Kephart, J.D. [Pacific NW Natl Lab Richland, WA; Kouzes, R. [Pacific NW Natl Lab Richland, WA; Miley, H.S. [Pacific NW Natl Lab Richland, WA; Mizouni, L. [Pacific NW Natl Lab Richland, WA; Myers, A.W. [Pacific NW Natl Lab Richland, WA; Reid, D. [Pacific NW Natl Lab Richland, WA; Amman, M. [Lawrence Berkeley National Laboratory (LBNL); Bergevin, M. [Lawrence Berkeley National Laboratory (LBNL); Chan, Y-D [Lawrence Berkeley National Laboratory (LBNL); Detwiler, J.A. [Lawrence Berkeley National Laboratory (LBNL); Loach, J.C. [Lawrence Berkeley National Laboratory (LBNL); Luke, P.N. [Lawrence Berkeley National Laboratory (LBNL); Martin, R.D. [Lawrence Berkeley National Laboratory (LBNL); Poon, A.W.P. [Lawrence Berkeley National Laboratory (LBNL); Prior, G. [Lawrence Berkeley National Laboratory (LBNL); Vetter, K. [Lawrence Berkeley National Laboratory (LBNL); Yaver, H. [Lawrence Berkeley National Laboratory (LBNL); Avignone, F.T. III [University of South Carolina; Creswick, R. [University of South Carolina; Farach, H. [University of South Carolina; Mizouni, L. [University of South Carolina; Avignone, Frank Titus [ORNL; Bertrand Jr, Fred E [ORNL; Capps, Gregory L [ORNL; Cooper, Reynold J [ORNL; Radford, David C [ORNL; Varner Jr, Robert L [ORNL; Wilkerson, John F [University of North Carolina, Chapel Hill; Yu, Chang-Hong [ORNL; Back, H.O. [University of North Carolina; Leviner, L. [North Carolina State University; Young, A.R. [North Carolina State University; Back (et al.), H.O. [Triangle Universities Nuclear Laboratory, Durham, NC; Bai, X. [South Dakota School of Mines and Technology; Hong, H. [South Dakota School of Mines and Technology; Howard, S. [South Dakota School of Mines and Technology; Medlin, D. [South Dakota School of Mines and Technology; Sobolev, V. [South Dakota School of Mines and Technology; Barabash, A.S. [Inst Theort & Expt Phys, Moscow, Russia; Konovalov, S.I. [Inst Theort & Expt Phys, Moscow, Russia; Vanyushin, I. [Inst Theort & Expt Phys, Moscow, Russia; Yumatov, V. [Inst Theort & Expt Phys, Moscow, Russia; Barbeau, P.S. [University of Chicago; Collar, J.I. [University of Chicago; Fields, N. [University of Chicago; Boswell (et al.), M. [Los Alamos National Laboratory (LANL); Brudanin, V. [Joint Institute for Nuclear Research, Dubna, Russia; Egorov, V. [Joint Institute for Nuclear Research, Dubna, Russia; Gusey, K. [Joint Institute for Nuclear Research, Dubna, Russia; Kochetov, O. [Joint Institute for Nuclear Research, Dubna, Russia; Shirchenko, M. [Joint Institute for Nuclear Research, Dubna, Russia; Timkin, V. [Joint Institute for Nuclear Research, Dubna, Russia; Yakushev, E. [Joint Institute for Nuclear Research, Dubna, Russia; Bugg, W. [University of Tennessee, Knoxville (UTK); Efremenko, M. [University of Tennessee, Knoxville (UTK); Burritt (et al.), T.H. [University of Washington, Ctr Expt Nucle Phys & Astrophys; Burritt (et al.), T.H. [University of Washington, Dept Phys, Seattle, WA; Busch, M. [Duke University; Esterline, J. [Duke University; Swift, G. [Duke University; Tornow, W. [Duke University/TUNL; Ejiri, H. [Osaka University; Hazama, R. [Osaka University; Nomachi, M. [Osaka University; Shima, T. [Osaka University; Finnerty (et al.), P. [University of North Carolina; et al.

2011-01-01T23:59:59.000Z

331

FLORIDA TOWER FOOTPRINT EXPERIMENTS  

SciTech Connect (OSTI)

The Florida Footprint experiments were a series of field programs in which perfluorocarbon tracers were released in different configurations centered on a flux tower to generate a data set that can be used to test transport and dispersion models. These models are used to determine the sources of the CO{sub 2} that cause the fluxes measured at eddy covariance towers. Experiments were conducted in a managed slash pine forest, 10 km northeast of Gainesville, Florida, in 2002, 2004, and 2006 and in atmospheric conditions that ranged from well mixed, to very stable, including the transition period between convective conditions at midday to stable conditions after sun set. There were a total of 15 experiments. The characteristics of the PFTs, details of sampling and analysis methods, quality control measures, and analytical statistics including confidence limits are presented. Details of the field programs including tracer release rates, tracer source configurations, and configuration of the samplers are discussed. The result of this experiment is a high quality, well documented tracer and meteorological data set that can be used to improve and validate canopy dispersion models.

WATSON,T.B.; DIETZ, R.N.; WILKE, R.; HENDREY, G.; LEWIN, K.; NAGY, J.; LECLERC, M.

2007-01-01T23:59:59.000Z

332

The Majorana Experiment  

E-Print Network [OSTI]

The Majorana Collaboration is assembling an array of HPGe detectors to search for neutrinoless double-beta decay in Ge-76. Initially, Majorana aims to construct a prototype module to demonstrate the potential of a future 1-tonne experiment. The design and potential reach of this prototype Demonstrator module are presented.

V. E. Guiseppe; for the Majorana Collaboration

2010-12-30T23:59:59.000Z

333

Overview of CHS experiments  

Science Journals Connector (OSTI)

Recent experimental results are summarized. One of them is the bifurcation phenomenon of the electric potential which manifests itself in various aspects of CHS plasmas. Here, electrons heated with ECH play an essential role. The CHS will be operated, after being moved to the Toki site, so as to perform complementary experiments to LHD.

K Matsuoka; R Akiyama; A Fujisawa; K Ida; H Iguchi; M Isobe; S Kado; K Khlopenkov; T Kondo; Y Liang; G Matsunaga; T Minami; S Nishimura; I Nomura; K Ohkuni; S Okamura; M Osakabe; R Pavlichenko; M Sasao; A Shimizu; S Sudo; C Suzuki; C Takahashi; S Takagi; M Takechi; K Tanaka; K Toi; T Yamamoto; Y Yoshimura

2000-01-01T23:59:59.000Z

334

THE ARGUS EXPERIMENT  

Science Journals Connector (OSTI)

...first experiment which occurred to me stemmed out of my main field of endeavor in the last five years, namely, the Astron thermonuclear device. In this device it is contemplated to establish a cylindrical layer of relativistic electrons between two mirror...

N. C. Christofilos

1959-01-01T23:59:59.000Z

335

ORISE: Graduate Student Research Experiences  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Graduate Student Research Experiences The Oak Ridge Institute for Science and Education (ORISE) provides well-rounded laboratory experiences that expand graduate students'...

336

POLARIZED TARGET EXPERIMENT AT FERMILAB  

E-Print Network [OSTI]

on Experiment 61 at Fermilab, which is a large collaborationBernie Sandler, From From Fermilab. Alan Jonckheere andTARGET EXPERIMENT AT FERMILAB Owen Chamberlain January 1977

Chamberlain, O.

2010-01-01T23:59:59.000Z

337

ORISE: Faculty Research Experiences  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Faculty Research Experiences Faculty Research Experiences The Oak Ridge Institute for Science and Education (ORISE) provides short- and long-term programs for either faculty or faculty-student teams to collaborate with ORISE's science and engineering partners. The length of the faculty programs can vary-from summer internships to year-long sabbaticals-but all programs enable faculty members to broaden their professional outlook beyond the classroom to the application of laboratory research. For example, these researchers have taken advantage of ORISE opportunities: Dr. Miguel Castro Dr. Miguel Castro Dr. Miguel Castro, of the University of Puerto Rico in Mayaguez, spent three months conducting research on surface tension in Oak Ridge National Laboratory's Faculty Student Team Research program.

338

Gross decontamination experiment report  

SciTech Connect (OSTI)

A Gross Decontamination Experiment was conducted on various levels and surfaces of the TMI - Unit 2 reactor building in March 1982. The polar crane, D-rings, missile shields, refueling canals, refueling bridges, equipment, and elevations 305' and 347'-6'' were flushed with low pressure water. Additionally, floor surfaces on elevation 305' and floor surfaces and major pieces of equipment on elevation 347'-6'' were sprayed with high pressure water. Selective surfaces were decontaminated with a mechanical scrubber and chemicals. Strippable coating was tested and evaluated on equipment and floor surfaces. The effectiveness, efficiency, and safety of several decontamination techniques were established for the large, complex decontamination effort. Various decontamination equipment was evaluated and its effectiveness was documented. Decontamination training and procedures were documented and evaluated, as were the support system and organization for the experiment.

Mason, R.; Kinney, K.; Dettorre, J.; Gilbert, V.

1983-07-01T23:59:59.000Z

339

Electronics for Satellite Experiments  

SciTech Connect (OSTI)

The tracking detector for the LAT science instrument on the GLAST mission is an example of a large-scale particle detection system built primarily by particle physicists for space flight within the context of a NASA program. The design and fabrication model in most ways reflected practice and experience from particle physics, but the quality assurance aspects were guided by NASA. Similarly, most of the electronics in the LAT as a whole were designed and built by staff at a particle physics lab. This paper reports on many of the challenges and lessons learned in the experience of designing and building the tracking detector and general LAT electronics for use in the NASA GLAST mission.

Johnson, Robert P.; /UC, Santa Cruz

2006-05-16T23:59:59.000Z

340

Physics Experiments on NIF  

Broader source: Energy.gov (indexed) [DOE]

work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 ! LLNL Progress towards Ignition & Weapons Physics Experiments on NIF Presentation to: SEAB October 12, 2011 Ed Moses Director, NIF and Photon Science LLNL-PRES-506751 May 30, 2011 Moses_BOG_92811 NIF has broad array of technical and operational capabilities Moses_BOG_92811 Moses_BOG_92811 Laser bay NIF-0210-18489.ppt Moses presentation to Professor Mohamed Abdou, Neil Morley, Alice Ying, Robert Reed UCLA 5 Moses_All_Hands_100511 We are steadily increasing the laser energy and power available for ignition experiments: fy09 Moses_All_Hands_100511 We are steadily increasing the laser energy and power available for ignition experiments: fy10

Note: This page contains sample records for the topic "torus experiment nstx" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

AGS Experiments: 1989, 1990, 1991  

SciTech Connect (OSTI)

This report contains: Experimental areas layout; table of beam parameters and fluxes; experiment schedule as run''; proposed 1992 schedule; a listing of experiments by number; two-page summaries of each experiment begin here, also ordered by number; publications of AGS Experiments begin here; and list of AGS Experimenters begins here.

Depken, J.C.

1992-02-01T23:59:59.000Z

342

AGS Experiments: 1989, 1990, 1991  

SciTech Connect (OSTI)

This report contains: Experimental areas layout; table of beam parameters and fluxes; experiment schedule ``as run``; proposed 1992 schedule; a listing of experiments by number; two-page summaries of each experiment begin here, also ordered by number; publications of AGS Experiments begin here; and list of AGS Experimenters begins here.

Depken, J.C.

1992-02-01T23:59:59.000Z

343

APS Experiment Safety Review Board  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Charter for the APS Experiment Safety Review Board May 12, 2011 1. Purpose The APS Experiment Safety Review Board (ESRB) advises the AES Division Director on the safe implementation of experiments performed by APS users on the experiment hall floor. The ESRB reviews each experiment that is submitted to the APS via the APS Experiment Safety Assessment System (ESAF). These experiments are conducted in beamline endstations in the APS Experiment Hall. 2. Membership The ESRB members are appointed by the AES Division Director. The current members of the ESRB are: Bruce Glagola AES - Chair Edmund Chang AES Paul Rossi XSD Nena Moonier AES Tom Barkalow PSC Patricia Pedergnana AES Wendy VanWingeren AES 3. Method After an experiment is submitted to the APS Experiment Safety Review system

344

The NEXT experiment  

E-Print Network [OSTI]

NEXT (Neutrino Experiment with a Xenon TPC) is an experiment to search neutrinoless double beta decay processes (bb0nu) in Xe136. The NEXT technology is based in the use of time projection chambers operating at a typical pressure of 15 bar and using electroluminescence to amplify the signal (HPXE). The main advantages of the experimental technique are: a) excellent energy resolution; b) the ability to reconstruct the trajectory of the two electrons emitted in the decays, which further contributes to the suppression of backgrounds; c) scalability to large masses; and d) the possibility to reduce the background to negligible levels thanks to the barium tagging technology (BATA). The NEXT roadmap was designed in four stages: i) Demonstration of the HPXE technology with prototypes deploying a mass of natural xenon in the range of 1 kg, using the NEXT-DEMO (IFIC) and NEXT-DBDM (Berkeley) prototypes; ii) Characterisation of the backgrounds to the bb0nu signal and measurement of the bb2nu signal with the NEW detector, deploying 10 kg of enriched xenon and operating at the LSC; iii) Search for bb0nu decays with the NEXT-100 detector, which deploys 100 kg of enriched xenon; iv) Search for bb0nu decays with the BEXT detector, which will deploy masses in the range of the ton and will introduce two additional handles, only possible in a HPXE: a) A magnetic field, capable of further enhancing the topological signal of NEXT; and b) barium-tagging (a technique pioneered by the EXO experiment which is also accessible to NEXT).

Juan Jose Gomez-Cadenas

2014-11-10T23:59:59.000Z

345

APT radionuclide production experiment  

SciTech Connect (OSTI)

Tritium ({sup 3}H, a heavy isotope of hydrogen) is produced by low energy neutron-induced reactions on various elements. One such reaction is n+{sup 3}He {yields}>{sup 3}H+{sup 1}H in which {sup 3}He is transmuted to tritium. Another reaction, which has been used in reactor production of tritium, is the n+{sup 6}Li {yields}> {sup 3}H+{sup 4}He reaction. Accelerator Production of Tritium relies on a high-energy proton beam to produce these neutrons using the spallation reaction, in which high-energy proton beam to produce these neutrons using the spallation reaction, in which high-energy protons reacting with a heavy nucleus produce a shower of low-energy neutrons and a lower-mass residual nucleus. It is important to quantify the residual radionuclides produced in the spallation target for two reasons. From an engineering point of view, one must understand short-lived isotopes that may contribute to decay heat. From a safety viewpoint, one must understand what nuclei and decay gammas are produced in order to design adequate shielding, to estimate ultimate waste disposal problems, and to predict possible effects due to accidental dispersion during operation. The authors have performed an experiment to measure the production of radioisotopes in stopping-length W and Pb targets irradiated by a 800 MeV proton beam, and are comparing the results to values obtained from calculations using LAHET and MCNP. The experiment was designed to pay particular attention to the short half-life radionuclides, which have not been previously measured. In the following, they present details of the experiment, explain how they analyzed the data and obtain the results, how they perform the calculations, and finally, how the experimental data agree with the calculations.

Ullmann, J.L.; Gavron, A.; King, J.D. [and others

1994-07-02T23:59:59.000Z

346

ATLAS APPROVED EXPERIMENTS  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

8MAY98 8MAY98 Exp # Spokesperson Experiment Title Days 433-9 Miller Ion Irradiations of Anisotropic High-Tc Superconductors: Probing Dynamics of Magnetic Vortices 2 651-2 Paul Accelerator-Mass-Spectrometry Measurements of Natural 236U Concentrations with the ECR-ATLAS System 4 667-2 Janssens Unsafe Coulex of the 238,239Pu Nuclei 4 669-2 Carpenter Excited States Associated with Different Shapes in 178Hg and Neighboring Odd-A Nuclei 4 673-2 Lister A Study of Radiative Decay from High Lying States in 24Mg 5 689-2 Freeman Spectroscopy of Odd Tin Isotopes Approaching 100Sn 5 693-2 Reiter Structure and Formation Mechanism of Heavy Elements - Request for additional beam time for Experiment 693 - 6 706 Kwok Heavy-Ion Lithography on High Temperature Superconductors 2 708 Yu In-Beam Spectroscopy Study of the Proton Emitter 109I with Recoil-Decay Tagging Technique

347

HPCToolsExperiences.pptx  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Experiences Experiences w ith T ools a t N ERSC Richard G erber NERSC User Services Programming w eather, c limate, a nd e arth---system m odels on h eterogeneous m ul>---core p la?orms September 7 , 2 011 a t t he N a>onal C enter f or A tmospheric R esearch i n B oulder, C olorado 2 * Thanks f or t he i nvita>on * My p rofessional g oal i s t o e nable s cien>sts t o u se H PC easily a nd e ffec>vely * Contribute t o i mportant d iscoveries a bout h ow o ur natural w orld w orks * Make a d ifference * So i t i s a n h onor & m eaningful t o m e t o p ar>cipate i n this c onference * One o f m y p rimary r oles i s a s d eputy o n o ur n ext procurement t eam & w e a re e xtremely i nterested i n learning a bout y our e xperiences w ith h ybrid s ystems and p rogramming 3 * Recent e xperiences p roviding t ools *

348

The NEXT experiment  

E-Print Network [OSTI]

NEXT (Neutrino Experiment with a Xenon TPC) is an experiment to search neutrinoless double beta decay processes (bb0nu) in Xe136. The NEXT technology is based in the use of time projection chambers operating at a typical pressure of 15 bar and using electroluminescence to amplify the signal (HPXE). The main advantages of the experimental technique are: a) excellent energy resolution; b) the ability to reconstruct the trajectory of the two electrons emitted in the decays, which further contributes to the suppression of backgrounds; c) scalability to large masses; and d) the possibility to reduce the background to negligible levels thanks to the barium tagging technology (BATA). The NEXT roadmap was designed in four stages: i) Demonstration of the HPXE technology with prototypes deploying a mass of natural xenon in the range of 1 kg, using the NEXT-DEMO (IFIC) and NEXT-DBDM (Berkeley) prototypes; ii) Characterisation of the backgrounds to the bb0nu signal and measurement of the bb2nu signal with the NEW detecto...

Gomez-Cadenas, Juan Jose

2014-01-01T23:59:59.000Z

349

Research Experience Bibliography  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Research Programs Research Programs Found in Profiling Teacher Research Participation Programs: An Approach to Formative Evaluation, The National Center for Improving Science Edcuation of the NETWORK, Inc. with support from the United States Department of Energy, November, 1993. Gottfried, S.: Brown, C.; Markovits, P.; and Changar, J. Undated. "Scientific Work Experience Programs for Science Teachers: A Focus on Research-Related Internships." Unpublished Manuscript. The authors found five factors related to effective implementation of a research internship program: (1) mentors, project staff, and teachers share goals and expectations, have open, frequent communication; (2) teachers have articulated project or research assignment; (3) curriculum development component facilitated by expert, focus on process rather than product; (4)

350

The Cibola flight experiment  

SciTech Connect (OSTI)

The Cibola Flight Experiment (CFE) is an experimental small satellite carrying a reconfigurable processing instrument developed at the Los Alamos National Laboratory that demonstrates the feasibility of using FPGA-based high-performance computing for sensor processing in the space environment. The CFE satellite was launched on March 8, 2007 in low-earth orbit and has operated extremely well since its deployment. The nine Xilinx Virtex FPGAs used in the payload have been used for several high-throughput sensor processing applications and for single-event upset (SEU) monitoring and mitigation. This paper will describe the CFE system and summarize its operational results. In addition, this paper will describe the results from several SEU detection circuits that were performed on the spacecraft.

Caffrey, Michael Paul [Los Alamos National Laboratory; Nelson, Anthony [Los Alamos National Laboratory; Salazar, Anthony [Los Alamos National Laboratory; Roussel - Dupre, Diane [Los Alamos National Laboratory; Katko, Kim [Los Alamos National Laboratory; Palmer, Joseph [ISE-3; Robinson, Scott [Los Alamos National Laboratory; Wirthlin, Michael [BRIGHAM YOUNG UNIV; Howes, William [BRIGHAM YOUNG UNIV; Richins, Daniel [BRIGHAM YOUNG UNIV

2009-01-01T23:59:59.000Z

351

The SNO+ Experiment  

E-Print Network [OSTI]

The SNO+ experiment is the follow-up to the Sudbury Neutrino Observatory (SNO). The heavy water that was in SNO will be replaced with a liquid scintillator of linear alkylbenzene (plus fluor). SNO+ has many physics goals including detecting pep and CNO solar neutrinos, detecting geo-neutrinos, studying reactor neutrino oscillations, serving as a supernova neutrino detector and carrying out a search for neutrinoless double beta decay by adding neodymium to the liquid scintillator. Since a large amount of 150Nd isotope can be added to SNO+, a competitive search would be possible, with sensitivity below 100 meV using natural Nd and sensitivity below 40 meV with enriched neodymium.

Mark C. Chen; for the SNO+ collaboration

2008-10-20T23:59:59.000Z

352

Assessment of Project Management Experience  

Broader source: Energy.gov (indexed) [DOE]

Assessment of Project Management Experience PMCDP for CEG Competency 1.12.2 Assessment of Project Management Experience PMCDP for CEG Competency 1.12.2 Applicant Name: Applicant Supervisor: Date (mm/dd/yyyy): Directions: Step 1: Use this template to show project management experience for CEG competency 1.12.2. Rate your experience (0 - 5) in the following project management related activities using the scale below. Step 2: Sign the completed form and have your supervisor review and sign it. Step 3: Once approved by your supervisor, submit the form as part of your Level I certification package. Note: Project management experience is distinguished from FPD experience and applies to general project management activities and experience. Positions that do not count towards experience in project management include: program manager, property manager, health, safety and security (HSS) positions, and

353

LCA experiences in Danish industry  

Science Journals Connector (OSTI)

A study has been performed on Danish industry’s experiences with LCA. Twenty-six enterprises from different sectors conpleted ... learning phase, and experiences with full-blown LCA’s are sparse. Expectations of ...

Ole Broberg; Per Christensen

1999-09-01T23:59:59.000Z

354

Technological Transformation of Human Experience  

Science Journals Connector (OSTI)

This article was inspired by Don Ihde's work on the experience of technology in human-machine relations. (See Don Ihde. "The Experience of Technology," Cultural Hermeneutics, Vol. 2, 1974, pp. 267-279.)

Arun Kumar Tripathi

2008-07-01T23:59:59.000Z

355

The Tokamak Physics Experiment  

SciTech Connect (OSTI)

The mission of the Tokamak Physics Experiment (TPX) [Nevins {ital et} {ital al}., {ital Plasma} {ital Physics} {ital and} {ital Controlled} {ital Nuclear} {ital Fusion}, Wuerzburg (International Atomic Energy Agency, Vienna, 1992), Vol. 3, p. 279] is to develop the scientific basis for an economically competitive and continuously operating tokamak fusion power source. This complements the primary mission of the International Thermonuclear Experimental Reactor (ITER) [ITER Document Ser. No. 18 (International Atomic Energy Agency, Vienna, 1991)], the demonstration of ignition and long-pulse burn, and the integration of nuclear technologies. The TPX program is focused on making the demonstration power plant that follows ITER as compact and attractive as possible, and on permitting ITER to achieve its ultimate goal of steady-state operation. This mission of TPX requires the development of steady-state regimes with high beta, good confinement, and a high fraction of a self-driven bootstrap current. These regimes must be compatible with plasma stability, strong heat-flux dispersion in the divertor region, and effective particle control.

Davidson, R.C.; Goldston, R.J. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Neilson, G.H. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)] [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Thomassen, K.I. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)] [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

1995-06-01T23:59:59.000Z

356

Nuclear Reactor Severe Accident Experiments  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Nuclear Reactor Severe Accident Experiments Nuclear Reactor Severe Accident Experiments Capabilities Engineering Experimentation Reactor Safety Testing and Analysis Overview Nuclear Reactor Severe Accident Experiments MAX NSTF SNAKE Aerosol Experiments System Components Laser Applications Robots Applications Other Facilities Other Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Nuclear Reactor Severe Accident Experiments 1 2 3 4 5 6 7 We perform experiments simulating reactor core melt phenomena in which molten core debris ("corium") erodes the concrete floor of a containment building. This occurred during the Fukushima nuclear power plant accident though the extent of concrete damage is yet unknown. This video shows the top view of a churning molten pool of uranium oxide at 2000°C (3600°F) seen during an experiment at Argonne. Corium behaves much like lava.

357

Experiment Hazard Class 11 - Hydrogen  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

1 - Hydrogen 1 - Hydrogen Applicability This hazard classification applies to all experiments and processes involving the use of gaseous hydrogen. This class includes work performed in the Experiment Hall Beamline Stations and any preparatory/setup/testing work performed in the LOM laboratories. Other hazard controls such as fire protection and life safety regulations may apply to experiments of this hazard class. A summary of controls for hydrogen use is available in the hydrogen summary document. Experiment Category Experiments involving previously reviewed hazard controls qualify for categorized as medium risk. Experiments involving new equipment or modified hazard control schemes are categorized as high risk. Experiment Hazard Control Verification Statements Engineered Controls - Applicable controls for storage and use of

358

Magnetostatics of the uniformly polarized torus  

Science Journals Connector (OSTI)

...obvious. In any case, one does not get any wiser before one...simply connected apple. This does not preclude that some peculiarities...Abramowitz, M. , and I. Stegun1964 Handbook of mathematical functionsWashington...Feshbach1953 Methods of theoretical physics part IINew York, NYMcGraw-Hill...

2009-01-01T23:59:59.000Z

359

Electron Bernstein waves in spherical torus plasmas  

SciTech Connect (OSTI)

Propagation and absorption of the electron Bernstein waves (EBWs) in spherical tokamaks (STs) have been intensively discussed in recent years because the EBWs coupled with an externally launched electromagnetic beam seem to be the only opportunity for microwave plasma heating and current drive in the electron cyclotron (EC) frequency range in the STs. The whole problem of the electron Bernstein heating and current drive (EBWHCD) in spherical plasmas is naturally divided into three major parts: coupling of incident electromagnetic waves (EMWs) to the EBWs near the upper hybrid resonance (UHR) surface, propagation and absorption of the EBWs in the plasma interior and generation of noninductive current driven by the EBWs. The present paper is a brief survey of the most important theoretical and numerical results on the issue of EBWs.

Saveliev, A. N. [A.F.Ioffe Physico-Technical Institute, Politekhnicheskaya 26, 194021 St. Petersburg (Russian Federation)

2006-11-30T23:59:59.000Z

360

On compressing discs of torus knots  

Science Journals Connector (OSTI)

......a (ba) n or vice versa). + Email: mtg@uk.radan.com mail: bertw@pims...boxes can be cancelled as indicated - this process may create some simple closed curves...box as indicated in Fig. 7. (If this process creates any simple closed curves then......

Michael T. Greene; Bert Wiest

2001-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "torus experiment nstx" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Princeton Plasma Physics Laboratory D-SITE Procedure  

E-Print Network [OSTI]

Refrigerator Operator Attachment 12 ­ NSTX NB Ion Source Operator #12;NSTX PRINCETON PLASMA PHYSICS LABORATORY

Princeton Plasma Physics Laboratory

362

ADVANCES IN DUST DETECTION AND REMOVAL FOR TOKAMAKS  

SciTech Connect (OSTI)

Dust diagnostics and removal techniques are vital for the safe operation of next step fusion devices such as ITER. In the tokamak environment, large particles or fi bers can fall on the electrostatic detector potentially causing a permanent short. An electrostatic dust detector developed in the laboratory is being applied to the National Spherical Torus Experiment (NSTX). We report on the development of a gas puff system that uses helium to clear such particles from the detector. Experiments at atmospheric pressure with varying nozzle designs, backing pressures, puff durations and exit fl ow orientations have given an optimal confi guration that effectively removes particles from a 25 cm² area. Similar removal effi ciencies were observed under a vacuum base pressure of 1 mTorr. Dust removal from next step tokamaks will be required to meet regulatory dust limits. A tri-polar grid of fi ne interdigitated traces has been designed that generates an electrostatic traveling wave for conveying dust particles to a “drain.” First trials with only two working electrodes have shown particle motion in optical microscope images.

Campos, A.; Skinner, C.H.

2009-01-01T23:59:59.000Z

363

Overview of LHD Experiments  

SciTech Connect (OSTI)

Experimental studies on the Large Helical Device during the last two years are reviewed. After the start of LHD experiment in 1998, the magnetic field has been gradually raised up to 2.89 T. The heating power has been increased, up to 4.2 MW for NBI, 1.3 MW for ICRF, and 0.9 MW for ECRH. Upgrading the key hardware systems has led to the extension of the plasma parameters to (i) higher Te [ Te(0) = 4.4 keV at = 5.3 x 1018 m-3 and Pabs = 1.8 MW ], (ii) higher confinement [ tE = 0.3 s, Te(0) = 1.1 keV at = 6.5 x 1019 m-3 and Pabs = 2.0 MW ] and (iii) higher stored energy Wp dia = 880 kJ. High performance plasmas have been realized in the inward shifted magnetic axis configuration (R=3.6m) where the helical symmetry is recovered and the particle orbit properties are improved by trade off of MHD stability properties due to the appearance of the magnetic hill. The energy confinement was systematically higher than that predicted by the International Stellerator Scaling 95 up to a factor of 1.6 and was comparable with ELMy H-mode confinement capability in tokamaks. This confinement improvement is attributed to the configuration control (the inward shift of magnetic axis) and to the formation of the high edge temperature. The achieved average beta value reached 2.4 % at B=1.3 T, the highest beta value ever obtained in helical devices, and so far no degradation of confinement by MHD phenomenon is observed. The inward shifted configuration has also led to successful ICRF minority ion heating. ICRF power up to 1.3 MW was reliably injected into the plasma without significant impurity contamination and a plasma with a stored energy of 200 kJ was sustained for 5 sec by ICRF alone. As another important result long pulse discharges of more than 1 minute were successfully achieved separately with NBI heating of 0.5 MW and with ICRF heating of 0.85 MM.

Fujiwara, M. [National Institute for Fusion Science, Toki, Japan; Kawahata, K. [National Institute for Fusion Science, Toki, Japan; Ohyabu, N. [National Institute for Fusion Science, Toki, Japan; Kaneko, O. [National Institute for Fusion Science, Toki, Japan; Komori, A. [National Institute for Fusion Science, Toki, Japan; Yamada, H. [National Institute for Fusion Science, Toki, Japan; Ashikawa, N. [Graduate University for Advanced Studies, Japan; Baylor, Larry R [ORNL; Combs, Stephen Kirk [ORNL; DeVries, P. [National Institute for Fusion Science, Toki, Japan; Emoto, M. [National Institute for Fusion Science, Toki, Japan; Ejiri, E. [University of Tokyo, Tokyo, Japan; Fisher, Paul W [ORNL; Funaba, H. [National Institute for Fusion Science, Toki, Japan; Goto, M. [National Institute for Fusion Science, Toki, Japan; Hartmann, D. [Max Planck Institute for Plasma Physics, Garching, Germany; Ida, K. [National Institute for Fusion Science, Toki, Japan; Idei, H. [National Institute for Fusion Science, Toki, Japan; Iio, S. [Tokyo Institute of Technology; Ikeda, K. [National Institute for Fusion Science, Toki, Japan; Inagaki, S. [National Institute for Fusion Science, Toki, Japan; Inoue, N. [National Institute for Fusion Science, Toki, Japan; Isobe, M. [National Institute for Fusion Science, Toki, Japan; Kado, S, [University of Tokyo, Tokyo, Japan; Khlopenkov, K. [National Institute for Fusion Science, Toki, Japan; Kobuchi, T. [Graduate University for Advanced Studies, Japan; Krasilnikov, A. V. [Troitsk Institute of Nuclear Physics (TRINITI), Russia; Kubo, S. [National Institute for Fusion Science, Toki, Japan; Kumazawa, R. [National Institute for Fusion Science, Toki, Japan; Leuterer, F. [Max Planck Institute for Plasma Physics, Garching, Germany; Liang, Y. [Graduate University for Advanced Studies, Japan; Lyon, James F [ORNL; Masuzaki, S. [National Institute for Fusion Science, Toki, Japan; Minami, T. [National Institute for Fusion Science, Toki, Japan; Miyajima, J. [National Institute for Fusion Science, Toki, Japan; Morisaki, T. [National Institute for Fusion Science, Toki, Japan; Morita, S. [National Institute for Fusion Science, Toki, Japan; Murakami, S. [National Institute for Fusion Science, Toki, Japan; Muto, S. [National Institute for Fusion Science, Toki, Japan; Mutoh, T. [National Institute for Fusion Science, Toki, Japan; Nagayama, Y. [National Institute for Fusion Science, Toki, Japan; Nakajima, N. [National Institute for Fusion Science, Toki, Japan; Nakamura, Y. [National Institute for Fusion Science, Toki, Japan; Nakanishi, H. [National Institute for Fusion Science, Toki, Japan; Narihara, K. [National Institute for Fusion Science, Toki, Japan; Nishimura, K. [National Institute for Fusion Science, Toki, Japan; Noda, N. [National Institute for Fusion Science, Toki, Japan; Notake, T. [Nagoya University, Japan; Ohdachi, S. [National Institute for Fusion Science, Toki, Japan; Oka, Y. [National Institute for Fusion Science, Toki, Japan; Okajima, S. [Chuba University, Japan; Okamoto, M. [National Institute for Fusion Science, Toki, Japan; Osakabe, M. [National Institute for Fusion Science, Toki, Japan; Ozaki, T. [National Institute for Fusion Science, Toki, Japan; Pavlichenko, R. O. [National Institute for Fusion Science, Toki, Japan; Peterson, B. J. [National Institute for Fusion Science, Toki, Japan; Sagara, A. [National Institute for Fusion Science, Toki, Japan; Saito, K. [Nagoya University, Japan; Sakakibara, S. [National Institute for Fusion Science, Toki, Japan; Sakamoto, R. [National Institute for Fusion Science, Toki, Japan; Sanuki, H. [National Institute for Fusion Science, Toki, Japan; Sasao, H. [Graduate University for Advanced Studies, Japan; Sasao, M. [National Institute for Fusion Science, Toki, Japan; Sato, K. [National Institute for Fusion Science, Toki, Japan; et al.

2001-01-01T23:59:59.000Z

364

Results from Neutrino Oscillations Experiments  

SciTech Connect (OSTI)

The interpretation of the results of early solar and atmospheric neutrino experiments in terms of neutrino oscillations has been verified by several recent experiments using both, natural and man-made sources. The observations provide compelling evidence in favor of the existence of neutrino masses and mixings. These proceedings give a general description of the results from neutrino oscillation experiments, the current status of the field, and some possible future developments.

Aguilar-Arevalo, Alexis [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, Mexico, D.F., 04510 (Mexico)

2010-09-10T23:59:59.000Z

365

Neutron activation experiments in radiochemistry  

Science Journals Connector (OSTI)

Neutron activation experiments in radiochemistry ... Describes experimentation involving the neutron activation of a variety of samples irradiated in a subcritical reactor and a paraffin-moderated source. ...

Karl S. Vorres

1960-01-01T23:59:59.000Z

366

Future Cosmic Microwave Background Experiments  

E-Print Network [OSTI]

We summarise some aspects of experiments currently being built or planned, and indulge in wild speculation about possibilities on the more distant horizon.

Mark Halpern; Douglas Scott

1999-04-19T23:59:59.000Z

367

Chemistry: Mechanism and Experiment - Combustion Energy Frontier...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Chemistry: Mechanism and Experiment Chemistry: Mechanism and Experiment The Mechanism and Experiment DWG uses an array of advanced experimental apparatus to probe the combustion...

368

Producing reliable software: an experiment  

Science Journals Connector (OSTI)

A customer of high assurance software recently sponsored a software engineering experiment in which a small real-time software system was developed concurrently by two popular software development methodologies. One company specialized in the state-of-the-practice ... Keywords: capability maturity model, cleanroom certification, formal methods, software development methodologies, software engineering experiment, software process and product metrics, software reliability

Carol Smidts; Xin Huang; James C. Widmaier

2002-04-01T23:59:59.000Z

369

Experiments in Physics Physics 1291  

E-Print Network [OSTI]

and Conservation of Energy 97 1-9 Standing Waves 105 1-10 Specific Heat and Mechanical Equivalent of Heat 115 #12;#12;Introduction 1-0 General Instructions 1 Purpose of the Laboratory The laboratory experiments described in this manual are an important part of your physics course. Most of the experiments are designed to illustrate

Columbia University

370

LANL | Physics | Dynamic Plutonium Experiments  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Dynamic plutonium experiments Dynamic plutonium experiments Since the end of nuclear testing the nation has had to rely on sophisticated computer models to ensure the safety and reliability of the nuclear weapons stockpile. This program is known as science-based stockpile stewardship. Despite possessing the world's fastest computers and most advanced modeling capability, the behavior of materials under dynamic loads that occur in a nuclear weapon are difficult to accurately model. The Dynamic Plutonium experimental program carries out experiments at the Nevada National Security Site on plutonium driven by high explosives. These experiments are needed to measure and understand the behavior of plutonium under extreme conditions. Physics Division has unique capabilities in high-speed x-ray imaging and velocimetry (measuring the

371

Crucial Experiments in Climate Science  

Science Journals Connector (OSTI)

This article discusses the interplay between computational experiments and scientific advancement in dynamical meteorology and climate dynamics. In doing so, the emphasis is on the dual role of computations in prediction and experimentation, ...

A. Navarra; J. L. Kinter III; J. Tribbia

2010-03-01T23:59:59.000Z

372

Essays in macroeconomics and experiments  

E-Print Network [OSTI]

This dissertation consists of four chapters on empirical and experimental macroeconomics and other experimental topics. Chapter 1 uses a laboratory experiment to test the predictions of a dynamic global game designed to ...

Shurchkov, Olga

2008-01-01T23:59:59.000Z

373

DOE Corporate Operating Experience Program  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

The Order institutes a DOE wide program for the management of operating experience to prevent adverse operating incidents and facilitate the sharing of good work practices among DOE sites. Cancels DOE O 210.2.

2011-04-08T23:59:59.000Z

374

Introductory Experiment in Electrical Measurements  

Science Journals Connector (OSTI)

The author has felt that the transition from the elementary to the intermediate laboratory may sometimes be too abrupt and that while the student is getting accustomed to the more advanced laboratory he misses some of the important points in the early experiments he performs. The experiment described is designed to accustom the student to the new level of experiments and give him some insight into some fundamental principles of experimentation. The experiment consists of measuring a resistance by several different methods. The results are then compared and the relative merits of the methods are discussed. The methods used are the ohmmeter the voltmeter-ammeter method the Wheatstone bridge the potentiometer and the substitution method. Details of these measurements will be discussed.

Francis T. Worrell

1957-01-01T23:59:59.000Z

375

An experiment on wind energy  

Science Journals Connector (OSTI)

We discuss an experiment on wind energy performed with home-made apparatus. The experiment reproduces a laboratory windmill, which can pump water from a lower level to a higher one. By measuring the gain of the gravitational potential energy of the pumped water, one can determine the power extracted from the wind. The activity was carried out with high-school students, in the framework of the Italian National Plan for Scientific Degrees—Physics. The proposed experiment allows teachers to discuss renewable energy sources with students whose knowledge of physics is limited to mechanics. It gives students the possibility to gain experience with energy and to increase their awareness of this renewable energy source.

Vincenzo Lombardo; Emilio Fiordilino; Aurelio Agliolo Gallitto; Pasquale Aglieco

2012-01-01T23:59:59.000Z

376

Experiments on Cryogenic Complex Plasma  

SciTech Connect (OSTI)

Experiments on a cryogenic complex plasma have been performed. Preliminary experiments include production of a plasma in a liquid helium or in a cryogenic helium gas by a pulsed discharge. The extended production of a plasma has been realized in a vapor of liquid helium or in a cryogenic helium gas by rf discharge. The charge of dust particles injected in such a plasma has been studied in detail.

Ishihara, O.; Sekine, W.; Kubota, J.; Uotani, N.; Chikasue, M.; Shindo, M. [Faculty of Engineering, Yokohama National University Yokohama, 240-8501 (Japan)

2009-11-10T23:59:59.000Z

377

GCFR thermal-hydraulic experiments  

SciTech Connect (OSTI)

The thermal-hydraulic experimental studies performed and planned for the Gas-Cooled Fast Reactor (GCFR) core assemblies are described. The experiments consist of basic studies performed to obtain correlations, and bundle experiments which provide input for code validation and design verification. These studies have been performed and are planned at European laboratories, US national laboratories, Universities in the US, and at General Atomic Company

Schlueter, G.; Baxi, C.B.; Dalle Donne, M.; Gat, U.; Fenech, H.; Hanson, D.; Hudina, M.

1980-01-01T23:59:59.000Z

378

Experiment  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Prescott, AZ 86301 C. Bhat, S. J. Brice, B. C. Brown, L. Bugel, B. T. Fleming, R. Ford, F. G. Garcia, P. Kasper, T. Kobilarcik, I. Kourbanis, A. Malensek, W. Marsh, P....

379

Retail Choice Experiments: Comparing Early-AdopterExperience  

SciTech Connect (OSTI)

This paper reviews the experience with retail choice of non-residential electricity customers during the period from early 1998 through the first few months of 2000. Key findings include: (1) customers in California received a significantly smaller discount from utility tariffs than customers in other competitive markets; (2) this sample of large commercial/industrial customers believed they were benefiting significantly more from commodity savings from contracts with retail electricity service providers (RESP) than from value-added services; and,(3) market rules appear to be critical to customer experiences with retail competition, yet the relationship between market rules and market development is inadequately understood.

Golove, William

2003-03-01T23:59:59.000Z

380

Optimizing New Dark Energy Experiments  

SciTech Connect (OSTI)

Next generation “Stage IV” dark energy experiments under design during this grant, and now under construction, will enable the determination of the properties of dark energy and dark matter to unprecedented precision using multiple complementary probes. The most pressing challenge in these experiments is the characterization and understanding of the systematic errors present within any given experimental configuration and the resulting impact on the accuracy of our constraints on dark energy physics. The DETF and the P5 panel in their reports recommended “Expanded support for ancillary measurements required for the long-term program and for projects that will improve our understanding and reduction of the dominant systematic measurement errors.” Looking forward to the next generation Stage IV experiments we have developed a program to address the most important potential systematic errors within these experiments. Using data from current facilities it has been feasible and timely to undertake a detailed investigation of the systematic errors. In this DOE grant we studied of the source and impact of the dominant systematic effects in dark energy measurements, and developed new analysis tools and techniques to minimize their impact. Progress under this grant is briefly reviewed in this technical report. This work was a necessary precursor to the coming generations of wide-deep probes of the nature of dark energy and dark matter. The research has already had an impact on improving the efficiencies of all Stage III and IV dark energy experiments.

Tyson, J. Anthony [University of California, Davis

2013-08-26T23:59:59.000Z

Note: This page contains sample records for the topic "torus experiment nstx" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

UNIRIB Participant Experiences: Ron Goans  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Ron Goans Ron Goans Ron Goans Ron Goans Ron Goans is a graduate research assistant working on the thesis component of his master's degree in physics while performing experiments at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory (ORNL). His thesis research specifically relates to the field of radioactive ion beam development. The purpose of radioactive ion beam development is to study and produce high-intensity, high-purity beams of radioactive nuclides. These beams are used by nuclear physicists to study the structure of short-lived nuclei. Below is a question and answer dialog about Goans' experience in Oak Ridge. The video featured on the right side of this page also spotlights his experience with the University Radioactive Ion Beam (UNIRIB)

382

Neutrino interactions in oscillation experiments  

Science Journals Connector (OSTI)

We calculate the neutrino induced cross sections relevant for oscillation experiments, including the ?-lepton threshold for quasielastic, resonance and deep-inelastic scattering. In addition to threshold effects, we include nuclear corrections for heavy targets which are moderate for quasielastic and large for single pion production. The nuclear effects for deep-inelastic reactions are small. We present cross sections together with their nuclear corrections for various channels which are useful for interpreting the experimental results and for determining parameters of the neutrino sector. Finally, we calculate the ?-lepton event rates for the OPERA LBL experiment.

E. A. Paschos and J. Y. Yu

2002-01-07T23:59:59.000Z

383

A Home Experiment in Elasticity  

E-Print Network [OSTI]

We analyze a simple problem in elasticity: the \\emph{initial} motion of an elastic bar that after being hanged from an end is suddenly released. In a second problem a point mass is attached on the top of the bar. The analytical solutions uncover some unexpected properties, which can be checked, with a digital camera or camcorder, in an alternative setup in which a spring is substituted for the bar. The theoretical model and the experiments are useful to understand the similarities and differences between the elastic properties of bar and spring. Students can take advantage of the home experiments to improve their understanding of elastic waves.

J. M. Aguirregabiria; A. Hernández; M. Rivas

2006-07-06T23:59:59.000Z

384

Ring Bolted Joint NSTX-CALC-132-11  

E-Print Network [OSTI]

: ___________________________________ Peter Rogoff, PPPL Mechanical Engineering Reviewed By: ________________________________________ Irv Zatz, PPPL Mechanical Engineer Reviewed By: _______________________________________ Mark Smith, PPPL Physics Lab, ou=Mechanical Engineering, email=progoff@pppl.gov, c=US Date: 2011.04.12 10:58:22 -04

Princeton Plasma Physics Laboratory

385

NSTX Upgrade TF Flex Joint and TF Bundle Stub  

E-Print Network [OSTI]

Engineer Thomas Willard Digitally signed by Thomas Willard DN: cn=Thomas Willard, o=Engineering, ou=PPPL, email=twillard@pppl.gov, c=US Date: 2011.02.03 11:20:42 -05'00' Ali Zolfaghari Digitally signed by Ali Zolfaghari DN: cn=Ali Zolfaghari, o=PPPL, ou=Engineering, email=azolfagh@pppl. gov, c=US Date: 2011.02.03 11

Princeton Plasma Physics Laboratory

386

NSTX Scientific Organization for FY2008 Run Coordinator Deputy  

E-Print Network [OSTI]

Raman mbell@pppl.gov rraman@pppl.gov 609-243-3282 609-243-2855 Topical Science Group Leader Deputy/Co-leader Theory & Modeling Boundary Physics Vlad Soukhanovskii Rajesh Maingi Daren Stotler vlad@pppl.gov rmaingi@pppl.gov dstotler@pppl.gov 609-243-2064 609-243-3176 609-243-2063 Macroscopic Stability Steve Sabbagh Stefan

Princeton Plasma Physics Laboratory

387

NSTX Upgrade Project STRUCTURAL CALCULATION OF THE TF FLAG KEY  

E-Print Network [OSTI]

, 2010 Prepared By: ___________________________________ Ali Zolfaghari, PPPL Mechanical Engineering=Ali Zolfaghari, o=PPPL, ou=Engineering, email=azolfagha@pppl.gov, c=US Date: 2011.01.18 12:59:35 -05'00' Thomas Willard Digitally signed by Thomas Willard DN: cn=Thomas Willard, o=Engineering, ou=PPPL, email=twillard@pppl

Princeton Plasma Physics Laboratory

388

NSTX Upgrade Vessel Rework for the Neutral Beam and Thomson  

E-Print Network [OSTI]

=Thomas Willard, o=Engineering, ou=PPPL, email=twillard@pppl.gov, c=US Date: 2011.02.02 13:45:19 -05'00' Ali Zolfaghari Digitally signed by Ali Zolfaghari DN: cn=Ali Zolfaghari, o=PPPL, ou=Engineering, email=azolfagh@pppl, o=PPPL, ou=FOM, email=msmith@pppl.gov, c=US Date: 2011.02.02 16:49:16 -05'00' George Labik Digitally

Princeton Plasma Physics Laboratory

389

Objective Criteria for Assessing Safe NSTX-U Startup  

E-Print Network [OSTI]

) and Failure Modes and Effects Analysis (FMEA) reviews. SAD/FMEA Author and Activity Certification Committee-U facility and systems adequately described in the SAD? 1. Review SAD Chapter 3 and associated FMEAs FMEAs, and review SAD Chapter 4. Consider follow up interviews with cognizant systems engineers, SAD

Princeton Plasma Physics Laboratory

390

NSTX-U PRINCETON PLASMA D-NSTXU-??-??-???  

E-Print Network [OSTI]

Management Division Water Neutral Beam (Heating Systems Branch of Electrical Engineering) Radiofrequency (Heating Systems Branch of Electrical Engineering) Diagnostics: Brent Stratton Environmental, Safety conditions, diagnostics, and heating systems required for an Experimental Proposal. Experimental proposals

Princeton Plasma Physics Laboratory

391

NSTX Program Governance, Research Support and Facility Operation  

E-Print Network [OSTI]

· Milestone performance history · Scheduling operation, maintenance & upgrades · Managing environment, safety of the proposed research environment and resources. Do the collaborative arrangements achieve the goal Program Director Jon Menard Deputy: S. Kaye Engineering Ops Al von Halle Project Engineer Charles Neumeyer

Princeton Plasma Physics Laboratory

392

Reactor accelerator coupling experiments: a feasability study  

E-Print Network [OSTI]

The Reactor Accelerator Coupling Experiments (RACE) are a set of neutron source driven subcritical experiments under temperature feedback conditions. These experiments will involve coupling an accelerator driven neutron source to a TRIGA reactor...

Woddi Venkat Krishna, Taraknath

2006-08-16T23:59:59.000Z

393

David Bohms EPR Gedanken Experiment Frank Rioux  

E-Print Network [OSTI]

David Bohms EPR Gedanken Experiment Frank Rioux In 1951 David Bohm proposed a gedanken experiment, Podolsky and Rosen (EPR) in 1935. In this thought experiment a spin1/2 pair is prepared in a singlet state

Rioux, Frank

394

Comparing PRAs with operating experience  

SciTech Connect (OSTI)

Probabilistic Risk Assessment is widely used to estimate the frequencies of rare events, such as nuclear power plant accidents. An obvious question concerns the extent to which PRAs conform to operating experience--that is, do PRAs agree with reality? The authors discuss a formal methodology to address this issue and examine its performance using plant-specific data.

Picard, R.R.; Martz, H.F.

1998-12-01T23:59:59.000Z

395

DOE Corporate Operating Experience Program  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

The Order establishes a DOE wide program for management of operating experience to prevent adverse operating incidents and to expand the sharing of good work practices among DOE sites. Canceled by DOE O 210.2A. Does not cancel other directives.

2006-06-12T23:59:59.000Z

396

BUILDING MOBILE EXPERIENCES Frank Bentley  

E-Print Network [OSTI]

BUILDING MOBILE EXPERIENCES Frank Bentley Principal Staff Research Scientist Motorola Mobility of teaching mobile apps class at MIT ! Strong believer in user-inspired innovation ! Have brought several new? ! Investigating the interaction between people and mobile computing devices ! Creating compelling mobile

Glinz, Martin

397

Current Direct Neutrino Mass Experiments  

E-Print Network [OSTI]

In this contribution we review the status and perspectives of direct neutrino mass experiments. These experiments investigate the kinematics of $\\beta$-decays of specific isotopes ($^3$H, $^{187}$Re, $^{163}$Ho) to derive model-independent information on the averaged electron (anti-) neutrino mass, which is formed by the incoherent sum of the neutrino mass eigenstates contributing to the electron neutrino. We first review the kinematics of $\\beta$-decay and the determination of the neutrino mass, before giving a brief overview of past neutrino mass measurements (SN1987a-ToF studies, Mainz and Troitsk experiments for $^3$H, cryo-bolometers for $^{187}$Re). We then describe the Karlsruhe Tritium Neutrino (KATRIN) experiment which is currently under construction at Karlsruhe Institute of Technology. The large-scale setup will use the MAC-E-Filter principle pioneered earlier to push the sensitivity down to a value of 200 meV(90% C.L.). KATRIN faces many technological challenges that have to be resolved with regar...

Drexlin, G; Mertens, S; Weinheimer, C

2013-01-01T23:59:59.000Z

398

Strange experiments at the AGS  

SciTech Connect (OSTI)

The purpose of this review is to report recent progress in nuclear experiments involving strangeness which have been carried out at the Brookhaven Alternating Gradient Synchrotron over the past three years. These recent developments are noted in three areas: few body systems and dibaryons; strange probes of the nucleus; and associated production of hypernuclei. 9 refs., 3 figs.

Chrien, R.

1990-01-01T23:59:59.000Z

399

apply skills & experience build skills  

E-Print Network [OSTI]

senior apply skills & experience junior build skills sophomore research & execute freshman explore options1 2 3 4 s u p p o r t4-year career action plan parent about the center for career development Remind your student that it is never too soon or too late to seek an internship or summer job. build

Alvarez, Pedro J.

400

Neutrino Oscillations Experiments at Fermilab  

E-Print Network [OSTI]

Neutrino oscillations provide an unique opportunity to probe physics beyond the Standard Model. Fermilab is constructing two new neutrino beams to provide a decicive test of two of the recent positive indications for neutrino oscillations: MiniBOONE experiment will settle the LSND controversy, MINOS will provide detailed studies of the region indicated by the SuperK results.

Adam Para

2000-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "torus experiment nstx" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Experiments in Physics Physics 1291  

E-Print Network [OSTI]

of the Laboratory The laboratory experiments described in this manual are an important part of your physics course-3 Velocity, Acceleration, and g 35 1-4 Projectile Motion and Conservation of Energy 45 1-5 Conservation. Whenever possible, the material will have been discussed in lecture before you come to the laboratory

Columbia University

402

Experiments in Physics Physics 1291  

E-Print Network [OSTI]

The laboratory experiments described in this manual are an important part of your physics course. Most-8 Projectile Motion and Conservation of Energy 97 1-9 Standing Waves 105 1-10 Specific Heat and Mechanical Equivalent of Heat 115 #12;#12;Introduction 1-0 General Instructions 1 Purpose of the Laboratory

Columbia University

403

Development of a low-energy and high-current pulsed neutral beam injector with a washer-gun plasma source for high-beta plasma experiments  

SciTech Connect (OSTI)

We have developed a novel and economical neutral-beam injection system by employing a washer-gun plasma source. It provides a low-cost and maintenance-free ion beam, thus eliminating the need for the filaments and water-cooling systems employed conventionally. In our primary experiments, the washer gun produced a source plasma with an electron temperature of approximately 5 eV and an electron density of 5 Multiplication-Sign 10{sup 17} m{sup -3}, i.e., conditions suitable for ion-beam extraction. The dependence of the extracted beam current on the acceleration voltage is consistent with space-charge current limitation, because the observed current density is almost proportional to the 3/2 power of the acceleration voltage below approximately 8 kV. By optimizing plasma formation, we successfully achieved beam extraction of up to 40 A at 15 kV and a pulse length in excess of 0.25 ms. Its low-voltage and high-current pulsed-beam properties enable us to apply this high-power neutral beam injection into a high-beta compact torus plasma characterized by a low magnetic field.

Ii, Toru [Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656 (Japan); Gi, Keii; Umezawa, Toshiyuki; Inomoto, Michiaki; Ono, Yasushi [Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8561 (Japan); Asai, Tomohiko [College of Science and Technology, Nihon University, Tokyo 101-8308 (Japan)

2012-08-15T23:59:59.000Z

404

MiniCLEAN Dark Matter Experiment  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

MiniCLEAN MiniCLEAN Dark Matter Experiment Investigating the field of high energy physics through experiments that strengthen our fundamental understanding of matter, energy,...

405

Hydrogen Embrittlement Fundamentals, Modeling, and Experiment...  

Broader source: Energy.gov (indexed) [DOE]

Embrittlement Fundamentals, Modeling, and Experiment Hydrogen Embrittlement Fundamentals, Modeling, and Experiment Embrittlement, under static load could be a result of the...

406

Diesel Engine Emission Reduction (DEER) Experiment | Department...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Emission Reduction (DEER) Experiment Diesel Engine Emission Reduction (DEER) Experiment Presentation given at DEER 2006, August 20-24, 2006, Detroit, Michigan. Sponsored by the...

407

Fermilab | Science at Fermilab | Experiments & Projects  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Experiments & Projects icon: Energy Frontier Energy Frontier Particle physics experiments at the Energy Frontier explore the fundamental constituents and architecture of the...

408

MagLab Audio Dictionary: Magnet Experiments  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Experiments with Magnets Now Playing: Experiments with Magnets Enable Javascript and Flash to stream the Magnet Minute Greg Boebinger Associated Links Science Highlights: Research...

409

The Compass Experiment at CERN  

SciTech Connect (OSTI)

The COMPASS experiment at the CERN SPS has a broad physics program focused on the study of the spin structure of the nucleon and on hadron spectroscopy. Key measurements for the spin program are the gluon contribution to the spin of the nucleon, flavor dependent quark spin distribution, and the measurement of the transverse spin structure function. The apparatus consists of a two-stage spectrometer designed for high data rates and equipped with high-resolution tracking, particle identification, electromagnetic and hadronic calorimetry. Data taking has started in 2002. Following the CERN SPS shut down in 2005, the experiment will resume data taking in 2006 and is planned to continue (at least) until 2010. Few hundreds of Terabytes of data are put on tape each year. Out of this large amount of data first important physics results have been obtained.

Magnon, A. [DAPNIA/SPhN, CEA-Saclay, F91191 Gif-Sur-Yvette Cedex (France)

2005-02-10T23:59:59.000Z

410

Human Radiation Experiments: Related Sites  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Experiment Experiment Related Sites Related Links Home Roadmap What's New Search HREX Multimedia Related Sites Federal DOE DOE Sites & National Laboratories Federal Other The following are organizations which provide related information and links to databases, electronic documents, and servers. FEDERAL - DOE U.S. Department of Energy (DOE) homepage (http://www.doe.gov/)contains information on DOE's Departmental Resources, Programs, Offices, National Labs and other DOE related topics. DOE's Environment, Safety and Health (ES&H) Technical Information Services (TIS) homepage (http://nattie.eh.doe.gov/) is a collection of information services designed to provide safety and health professionals with reliable, accurate and current information to assist them in performing their jobs.

411

UNIRIB Participant Experiences: Cara Jost  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Cara Jost Cara Jost Cara Jost Cara Jost Cara Jost is a Ph.D. student in chemistry from the University of Mainz in Germany, and is involved with ion source development at the University Radioactive Ion Beam (UNIRIB) consortium as a research scholar. Jost and UNIRIB team members are researching new ways to develop radioactive ion beams for the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory. Below is a question and answer dialog about Jost's experience in Oak Ridge. The video featured on the right side of this page also spotlights Jost's experience with UNIRIB. What is your research focus at UNIRIB? My focus is on chemical reactions in the transfer line of the target-ion source, which can be used to improve the purity of radioactive beams.

412

Practical experience with Title V  

SciTech Connect (OSTI)

Having prepared numerous Title V permit applications and applications for synthetic minor status, the do`s and don`ts of this experience are evaluated. The philosophy for what goes into the application is reviewed, with special regard to the EPA {open_quotes}White Paper{close_quotes} on streamlining the process. The pros and cons of accepting and applying for synthetic minor status are evaluated.

Hoffnagle, G.F. [TRC Environmental, Windsor, CT (United States)

1996-12-31T23:59:59.000Z

413

Final Report: Levitated Dipole Experiment  

SciTech Connect (OSTI)

Since the very first experiments with the LDX, research progress was rapid and significant. Initial experiments were conducted with the high-field superconducting coil suspended by three thin rods. These experiments produced long-pulse, quasi-steady-state microwave discharges, lasting more than 10 s, having peak beta values of 20% [Garnier et al., Physics of Plasmas, 13 (2006) 056111]. High- beta, near steady-state discharges have been maintained in LDX for more than 20 seconds, and this capability made LDX the longest pulse fusion confinement experiment operating in the U.S. fusion program. A significant measure of progress in the LDX research program was the routine investigation of plasma confinement with a magnetically-levitated dipole and the resulting observations of confinement improvement. In both supported and levitated configurations, detailed measurements were made of discharge evolution, plasma dynamics and instability, and the roles of gas fueling, microwave power deposition profiles, and plasma boundary shape. High-temperature plasma was created by multi frequency electron cyclotron resonance heating at 2.45 GHz, 6.4 GHz, 10.5 GHz and 28 GHz allowing control of heating profiles. Depending upon neutral fueling rates, the LDX discharges contain a fraction of energetic electrons, with mean energies above 50 keV. Depending on whether or not the superconducting dipole was levitated or supported, the peak thermal electron temperature was estimated to exceed 500 eV and peak densities to approach 1e18 m?3. We have found that levitation causes a strong inwards density pinch [Boxer et al., Nature Physics, 6 (2010) 207] and we have observed the central plasma density increase dramatically indicating a significant improvement in the confinement of a thermal plasma species.

Kesner, Jay [Massachusetts Institute of Technology; Mauel, Michael [Columbia University

2013-03-10T23:59:59.000Z

414

AMIE (ACRF MJO Investigation Experiment)  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AMIE AMIE (ACRF MJO Investigation Experiment) Planning Meeting AMIE Science Steering Committee Chuck Long, Tony DelGenio, Bill Gustafson, Bob Houze, Mike Jensen, Steve Klein, Ruby Leung, Xaihong Liu, Ed Luke, Peter May, Sally McFarlane, Pat Minnis, Courtney Schumacher, Andy Vogelmann, Yi Wang, Xiaoqing Wu, Shaohong Xie Agenda * Proposal due May 1 !!!!!! * Primary purpose of this meeting is discussions and planning in support of

415

AGS experiments: 1990, 1991, 1992. Ninth edition  

SciTech Connect (OSTI)

This report contains a description of the following: AGS Experimental Area - High Energy Physics FY 1993 and Heavy Ion Physics FY 1993; Table of Beam Parameters and Fluxes; Experiment Schedule ``as run``; Proposed 1993 Schedule; A listing of experiments by number; Two-page summaries of each experiment begin here, also ordered by number; Publications of AGS Experiments; and List of AGS Experimenters.

Depken, J.C.

1993-04-01T23:59:59.000Z

416

HFIR Experiment Facilities | ORNL Neutron Sciences  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Experiment Facilities Experiment Facilities HFIR Experiment Facilities Neutron Scattering Facilities Target Positions Experiment Facilities in the Beryllium Reflector Large Removable Beryllium Facilities Small Removable Beryllium Facilities Control-Rod Access Plug Facilities Small Vertical Experiment Facilities Large Vertical Experiment Facilities Hydraulic Tube Facility Peripheral Target Positions Neutron Activation Analysis (NAA) Laboratory and Pneumatic Tube Facilities Slant Engineering Facilities Gamma Irradiation Facility Quality Assurance Requirements Contact Information Neutron Scattering Facilities The fully instrumented HFIR will eventually include 15 state-of-the-art neutron scattering instruments, seven of which will be designed exclusively for cold neutron experiments, located in a guide hall south of the reactor

417

Ramsey Experiments Using Neutron Beams  

Science Journals Connector (OSTI)

Abstract Ramsey's technique of separated oscillatory fields adapted to cold neutron beams is a very sensitive method to probe for spin- dependent interactions of neutrons with magnetic and pseudomagnetic fields. In the last couple of years several distinctive experiments using this technique have been performed, e.g. to determine the incoherent neutron scattering length of the deuteron, to perform polarized neutron imaging of magnetic fields and samples, and lately, to search for new light spin-1 bosons. Here, some of these results are reviewed and possible future measurements with respect to a pulsed neutron source are presented.

Florian M. Piegsa

2014-01-01T23:59:59.000Z

418

Physics with the ALICE experiment  

E-Print Network [OSTI]

ALICE experiment at LHC collects data in pp collisions at $\\sqrt{s}$=0.9, 2.76 and 7 TeV and in PbPb collisions at 2.76 TeV. Highlights of the detector performance and an overview of experimental results measured with ALICE in pp and AA collisions are presented in this paper. Physics with proton-proton collisions is focused on hadron spectroscopy at low and moderate $p_T$. Measurements with lead-lead collisions are shown in comparison with those in pp collisions, and the properties of hot quark matter are discussed.

Yuri Kharlov; for the ALICE collaboration

2012-03-09T23:59:59.000Z

419

Introduction of the CDEX experiment  

E-Print Network [OSTI]

Weakly Interacting Massive Particles (WIMPs) are the candidates of dark matter in our universe. Up to now any direct interaction of WIMP with nuclei has not been observed yet. The exclusion limits of the spin-independent cross section of WIMP-nucleon which have been experimentally obtained is about 10^{-7}pb at high mass region and only 10^{-5}pb} at low mass region. China Jin-Ping underground laboratory CJPL is the deepest underground lab in the world and provides a very promising environment for direct observation of dark matter. The China Dark Matter Experiment (CDEX) experiment is going to directly detect the WIMP flux with high sensitivity in the low mass region. Both CJPL and CDEX have achieved a remarkable progress in recent two years. The CDEX employs a point-contact germanium semi-conductor detector PCGe whose detection threshold is less than 300 eV. We report the measurement results of Muon flux, monitoring of radioactivity and Radon concentration carried out in CJPL, as well describe the structure ...

Kang, Ke-Jun; Li, Jin; Li, Yuan-Jing; Yue, Qian; Bai, Yang; Bi, Yong; Chang, Jian-Ping; Chen, Nan; Chen, Ning; Chen, Qing-Hao; Chen, Yun-Hua; Deng, Zhi; Du, Qiang; Gong, Hui; Hao, Xi-Qing; He, Hong-Jian; He, Qing-Ju; Hu, Xin-Hui; Huang, Han-Xiong; Jiang, Hao; Li, Jian-Min; Li, Xia; Li, Xin-Ying; Li, Xue-Qian; Li, Yu-Lan; Liu, Shu-Kui; Liu, Ya-Bin; Lu, Lan-Chun; Ma, Hao; Qin, Jian-Qiang; Ren, Jie; Ren, Jing; Ruan, Xi-Chao; Shen, Man-Bin; Su, Jian; Tang, Chang-Jian; Tang, Zhen-Yu; Wang, Ji-Min; Wang, Qing; Wang, Xu-Feng; Wu, Shi-Yong; Wu, Yu-Cheng; Xianyu, Zhong-Zhi; Xing, Hao-Yang; Xu, Xun-Jie; Xu, Yin; Xue, Tao; Yang, Li-Tao; Yi, Nan; Yu, Hao; Yu, Chun-Xu; Zeng, Xiong-Hui; Zeng, Zhi; Zhang, Lan; Zhang, Guang-Hua; Zhao, Ming-Gang; Zhong, Su-Ning; Zhou, Jin; Zhou, Zu-Ying; Zhu, Jing-Jun; Zhu, Wei-Bin; Zhu, Xue-Zhou; Zhu, Zhong-Hua

2013-01-01T23:59:59.000Z

420

Special Experiments: AES-UES  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Special Experiments at the APS Special note is made of the following experimental activities. (Updated 2/19/2012 17:00) BEAMLINE DATES SPOKESPERSON COMMENTS 2BM-B rad #92404 2/24- 2/27 Patrick LaReviere U of C *Approvals pending *No special procedure, samples must be surveyed before and after experiment by APS-HP. 10ID-B #92409 2/29- 3/05 Ken Kemner ANL-203 *Approvals pending *Samples may be left unattended for up to 12 hours with beam ON when hutch door is secured with lock and chain. 10BM-B rad #92408 3/01- 3/06 Ken Kemner ANL-203 *Approvals Pending *Samples may be left unattended for up to 12 hours with beam ON when hutch door is secured with lock and chain. 1ID-B rad #91277 3/07- 3/12 Don Brown- LANL Mark Daymond Queen's University *Approvals Pending 3ID-B #92107 3/10- 3/19 Valentin Iota UNLV

Note: This page contains sample records for the topic "torus experiment nstx" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Experiment Design and Analysis Guide - Neutronics & Physics  

SciTech Connect (OSTI)

The purpose of this guide is to provide a consistent, standardized approach to performing neutronics/physics analysis for experiments inserted into the Advanced Test Reactor (ATR). This document provides neutronics/physics analysis guidance to support experiment design and analysis needs for experiments irradiated in the ATR. This guide addresses neutronics/physics analysis in support of experiment design, experiment safety, and experiment program objectives and goals. The intent of this guide is to provide a standardized approach for performing typical neutronics/physics analyses. Deviation from this guide is allowed provided that neutronics/physics analysis details are properly documented in an analysis report.

Misti A Lillo

2014-06-01T23:59:59.000Z

422

ARM MJO Investigation Experiment on  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

5 5 ARM MJO Investigation Experiment on Gan Island (AMIE-Gan) Science Plan October 2011-March 2012 C Long Principal Investigator A Del Genio P May M Deng S McFarlane X Fu P Minnis W Gustafson C Schumacher R Houze A Vogelmann C Jakob Y Wang M Jensen P Webster R Johnson S Xie X Liu C Zhang E Luke April 2011 DISCLAIMER This report was prepared as an account of work sponsored by the U.S. Government. Neither the United States nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights.

423

AMIE (ARM MJO Investigation Experiment):  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

7 7 AMIE (ARM MJO Investigation Experiment): Observations of the Madden-Julian Oscillation for Modeling Studies Science Plan ARM Climate Research Facility Tropical Western Pacific Manus Site October 2011-March 2012 C Long Principal Investigator A DelGenio P May W Gustafson S McFarlane R Houze P Minnis C Jakob C Schumacher M Jensen A Vogelmann S Klein Y Wang L Ruby Leung X Wu X Liu S Xie E Luke March 2010 DISCLAIMER This report was prepared as an account of work sponsored by the U.S Government Neither the United States nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed,

424

Experiment Profile: Mu2e  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Mu2e Mu2e NAME: Muon-to-electron conversion, or Mu2e WHAT IS THE EXPERIMENT LOOKING FOR? A muon that does not follow the traditional weak- force decay pattern into a lighter electron and two neutrinos, but converts wholly into an electron. WHAT WILL THIS TELL US ABOUT THE WORLD? * Observing Mu2e conversion would point the way to a unification of all the forces of nature controlling the interactions of matter. This unification of the four existing forces we observe today - gravity, the electromagnetic force, and the weak and strong forces - is considered Albert Einstein's dream of "grand unification. * Finding signs of this "grand unification" could explain how the universe evolved from being

425

Rationalization of EPR Coincidence Experiments  

E-Print Network [OSTI]

Coincidence experiments on EPR pairs show strong violations of Bell's Inequalities at certain filter settings which is widely believed to mean that local hidden variable models cannot explain these results. In this paper it is shown that the 'non-separable' singlet density matrix can be represented as a sum of separable density matrices which are products of individual non-hermitian spin operator states. This decomposition is consistent with the intuitive notion that after separation from the singlet the two physical systems should be described by a product state. In spite of the non-hermiticity, the values of the relevant spin observables are real. A new local hidden variable model inspired by this decomposition is discussed.

B. C. Sanctuary

2007-10-10T23:59:59.000Z

426

The INEL beryllium multiplication experiment  

SciTech Connect (OSTI)

The experiment to measure the multiplication of 14-MeV neutrons in bulk beryllium has been completed. The experiment consists of determining the ratio of {sup 56}Mn activities induced in a large manganese bath by a central 14-MeV neutron source, with and without a beryllium sample surrounding the source. In the manganese bath method a neutron source is placed at the center of a totally-absorbing aqueous solution of MnSo{sub 4}. The capture of neutrons by Mn produces a {sup 56}Mn activity proportional to the emission rate of the source. As applied to the measurement of the multiplication of 14- MeV neutrons in bulk beryllium, the neutron source is a tritium target placed at the end of the drift tube of a small deuteron accelerator. Surrounding the source is a sample chamber. When the sample chamber is empty, the neutrons go directly to the surrounding MnSO{sub 4} solution, and produce a {sup 56}Mn activity proportional to the neutron emission rate. When the chamber contains a beryllium sample, the neutrons first enter the beryllium and multiply through the (n,2n) process. Neutrons escaping from the beryllium enter the bath and produce a {sup 56}Mn activity proportional to the neutron emission rate multiplied by the effective value of the multiplication in bulk beryllium. The ratio of the activities with and without the sample present is proportional to the multiplication value. Detailed calculations of the multiplication and all the systematic effects were made with the Monte Carlo program MCNP, utilizing both the Young and Stewart and the ENDF/B-VI evaluations for beryllium. Both data sets produce multiplication values that are in excellent agreement with the measurements for both raw and corrected values of the multiplication. We conclude that there is not real discrepancy between experimental and calculated values for the multiplication of neutrons in bulk beryllium. 12 figs., 11 tabs., 18 refs.

Smith, J.R.; King, J.J.

1991-03-01T23:59:59.000Z

427

Suspended sediment erosion in laboratory flume experiments  

E-Print Network [OSTI]

Laboratory flume experiments are used to examine the role of suspended sediment abrasion in bedrock channel erosion. A range of topographies was used, from a planar bed to a sinuous and scalloped inner channel. Experiments ...

Cornell, Katrina Muir

2007-01-01T23:59:59.000Z

428

Building Knowledge through Families of Experiments  

E-Print Network [OSTI]

Building Knowledge through Families of Experiments Victor R. Basili, Fellow, IEEE, Forrest Shull, and build models that represent the common observations about the discipline. This paper discusses building knowledge in an incremental manner through the replication of experiments within families

Basili, Victor R.

429

Status of the MAJORANA DEMONSTRATOR experiment  

SciTech Connect (OSTI)

The MAJORANA DEMONSTRATOR neutrinoless double beta-decay experiment is currently under construction at the Sanford Underground Research Facility in South Dakota, USA. An overview and status of the experiment are given.

Martin, R. D. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA and Department of Physics, University of South Dakota, Vermillion, SD (United States); Abgrall, N.; Chan, Y-D.; Hegai, A.; Mertens, S.; Poon, A. W. P.; Vetter, K. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Aguayo, E.; Fast, J. E.; Hoppe, E. W.; Kouzes, R. T.; LaFerriere, B. D.; Orrell, J. L.; Overman, N. R.; Soin, A. [Pacific Northwest National Laboratory, Richland, WA (United States); Avignone III, F. T. [Department of Physics and Astronomy, University of South Carolina, Columbia, SC, USA and Oak Ridge National Laboratory, Oak Ridge, TN (United States); Barabash, A. S.; Konovalov, S. I.; Yumatov, V. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Bertrand, F. E. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); and others

2014-06-24T23:59:59.000Z

430

The discriminative power of patient experience surveys  

Science Journals Connector (OSTI)

Comparisons of patient experiences between providers are increasingly used as an index of performance. The present study describes the ability of patient experience surveys to discriminate between healthcare p...

Dolf de Boer; Diana Delnoij; Jany Rademakers

2011-12-01T23:59:59.000Z

431

Fermilab at Work | Experiments and Projects  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Contacts (PDF) Current Experiments CDF CDMS (E891) COUPP Experiment (E961) Dark Energy Survey DarkSide (E1000) DZero Holometer (E990) MicroBooNE MINERvA (E938) MINOSMINOS+...

432

Solar energy experiment for beginning chemistry  

Science Journals Connector (OSTI)

Solar energy experiment for beginning chemistry ... This article introduces an experiment that incorporates chemical applications of solar energy into the curriculum. ... Involving Students in a Collaborative Project To Help Discover Inexpensive, Stable Materials for Solar Photoelectrolysis ...

Clyde E. Davis

1983-01-01T23:59:59.000Z

433

Solar energy storage: A demonstration experiment  

Science Journals Connector (OSTI)

Solar energy storage: A demonstration experiment ... A demonstration of a phase transition that can be used for heat storage. ...

Howard S. Kimmel; Reginald P. T. Tomkins

1979-01-01T23:59:59.000Z

434

Current experiments in elementary particle physics. Revision  

SciTech Connect (OSTI)

This report contains summaries of 568 current and recent experiments in elementary particle physics. Experiments that finished taking data before 1988 are excluded. Included are experiments at BEPC (Beijing), BNL, CEBAF, CERN, CESR, DESY, FNAL, INS (Tokyo), ITEP (Moscow), IUCF (Bloomington), KEK, LAMPF, Novosibirsk, PNPI (St. Petersburg), PSI, Saclay, Serpukhov, SLAC, and TRIUMF, and also several underground and underwater experiments. Instructions are given for remote searching of the computer database (maintained under the SLAC/SPIRES system) that contains the summaries.

Galic, H. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Armstrong, F.E. [Lawrence Berkeley Lab., CA (United States); von Przewoski, B. [Indiana Univ. Cyclotron Facility, Bloomington, IN (United States)] [and others

1994-08-01T23:59:59.000Z

435

Experiments with Wind to Produce Energy  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Nat EXPERIMENTS WITH WIND TO PRODUCE ENERGY Curriculum: Wind Power (simple machines, weatherclimatology, aerodynamics, leverage, mechanics, atmospheric pressure, and energy...

436

SYNCHROTRONS FOR HEAVY IONS - BEVALAC EXPERIENCE  

E-Print Network [OSTI]

and nuclear science applications. Then we shall talk about our experience in interleaving these on two research programs,

Grunder, H.A.

2010-01-01T23:59:59.000Z

437

Janus Experiments: Data from Mouse Irradiation Experiments 1972 - 1989  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

The Janus Experiments, carried out at Argonne National Laboratory from 1972 to 1989 and supported by grants from the US Department of Energy, investigated the effects of neutron and gamma radiation on mouse tissues primarily from B6CF1 mice. 49,000 mice were irradiated: Death records were recorded for 42,000 mice; gross pathologies were recorded for 39,000 mice; and paraffin embedded tissues were preserved for most mice. Mouse record details type and source of radiation [gamma, neutrons]; dose and dose rate [including life span irradiation]; type and presence/absence of radioprotector treatment; tissue/animal morphology and pathology. Protracted low dose rate treatments, short term higher dose rate treatments, variable dose rates with a same total dose, etc. in some cases in conjunction with radioprotectors, were administered. Normal tissues, tumors, metastases were preserved. Standard tissues saved were : lung, liver, spleen, kidney, heart, any with gross lesions (including mammary glands, Harderian gland with eye, adrenal gland, gut, ovaries or testes, brain and pituitary, bone). Data are searchable and specimens can be obtained by request.

438

AGS experiments -- 1991, 1992, 1993. Tenth edition  

SciTech Connect (OSTI)

This report contains: (1) FY 1993 AGS schedule as run; (2) FY 1994--95 AGS schedule; (3) AGS experiments {ge} FY 1993 (as of 30 March 1994); (4) AGS beams 1993; (5) AGS experimental area FY 1991 physics program; (6) AGS experimental area FY 1992 physics program; (7) AGS experimental area FY 1993 physics program; (8) AGS experimental area FY 1994 physics program (planned); (9) a listing of experiments by number; (10) two-page summaries of each experiment; (11) listing of publications of AGS experiments; and (12) listing of AGS experiments.

Depken, J.C.

1994-04-01T23:59:59.000Z

439

Today and Future Neutrino Experiments at Krasnoyarsk Nuclear Reactor  

E-Print Network [OSTI]

The results of undergoing experiments and new experiment propositions at Krasnoyarsk underground nuclear reactor are presented

Yu. V. Kozlov; S. V. Khalturtsev; I. N. Machulin; A. V. Martemyanov; V. P. Martemyanov; A. A. Sabelnikov; V. G. Tarasenkov; E. V. Turbin; V. N. Vyrodov; L. A. Popeko; A. V. Cherny; G. A. Shishkina

1999-12-21T23:59:59.000Z

440

Experience with hydrotreater computer control  

SciTech Connect (OSTI)

Part of a series of articles on actual operating experience with computer control, this article describes the control strategies and results of a hydrotreater computer control project. A new computer-based control system was installed in Gulf Canada's lube oil plant at Clarkson, Ontario. This plant is designed to produce 10 Mbpd of high quality lubricating oils using Gulf's new lube hydrotreating process. The following sections present a process description, a description of the control objectives, the control functions designed to meet those objectives, and a summary of the performance documented to date. In June 1980, Gulf conducted a feasibility study for computer control of their lube oil process, and the results of that study indicated that control of the heart of the process, the hydrotreater reactor and fractionation section, would yield significant economic benefit. In October 1980, Gulf reviewed a detailed design based on the control functions defined in the earlier study. After the desired functions were refined to Gulf's specification, control programming began at the Houston computer staging site. The applications software was demonstrated in Houston in May 1981, and integrated into the same computer on-site at Clarkson in July 1981. The system linked to an existing microprocessorbased hardware data acquisition and control system. Control commissioning and initial tuning were finished by mid-December 1981. Final tuning and testing were done in mid-January 1982, when the project was completed successfully, within budget and ahead of schedule.

Martin, G.D.; Cassaday, K.M.; VanHorn, L.D.

1984-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "torus experiment nstx" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

SAFT-UT field experience  

SciTech Connect (OSTI)

This paper reports on a three-year program at the Battelle Pacific Northwest Laboratory to transfer the synthetic aperture focusing technique (SAFT) technology that was developed at the University of Michigan into the field. A brief overview is given of the program and the field system is described. The main portion of the paper is devoted to the experience of using the SAFT system in a third-party role to aid in resolving inspection inconsistencies between several different UT inservice inspections results for intergranular stress corrosion cracks (IGSCC) in boiling water reactor (BWR) piping. A new method of scanning using a modified tandem technique (called TSAFT) was also developed and successfully employed in the field. The SAFT images made cracks easy to identify and the TSAFT data were easy to interpret for depth sizing. However, the most significant fact about the system is that it did work very well under field conditions even though a number of improvements were identified as a result of each field trip. These improvements are discussed in the paper. 6 refs., 15 figs.

Doctor, S.R.; Crawford, S.L.; Hall, T.E.

1985-03-01T23:59:59.000Z

442

Yuan T. Lee's Crossed Molecular Beam Experiment  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Yuan T. Lee's Crossed Molecular Beam Experiment Yuan T. Lee's Crossed Molecular Beam Experiment Home | Staff | Search | Advisory Committee | User Facilities | Laboratories | Congress | Budget Yuan T. Lee's Crossed Molecular Beam Experiment http://web.archive.org/web/20000902074635/www.er.doe.gov/production/bes/YuanLee_Exp.html (1 of 4)4/7/2006 2:46:13 PM Yuan T. Lee's Crossed Molecular Beam Experiment The above illustration was drawn by Professor Yuan T. Lee, who shared the 1986 Nobel Prize in Chemistry. It shows the design for his crossed molecular beam experiment described in the story beginning on page 27 of "Basic Energy Sciences: Summary of Accomplishments" (DOE/ER-0455P, May 1990); the story is also copied below. The purpose of this experiment was to study the chemical reaction of sodium atoms with oxygen molecules. In the experiment, a beam of sodium atoms (green,

443

LCLS CDR Chapter 3 - Scientific Experiments  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

3 3 Scientific Basis for Optical Systems TECHNICAL SYNOPSIS The LCLS Scientific Advisory Committee (SAC) has recommended experiments in five scientific disciplines for the initial operation of the LCLS. These experiments cover a variety of scientific disciplines: atomic physics, plasma physics, chemistry, biology and materials science. The x-ray optics and detectors needed to verify the LCLS capability to address these five disciplines will be constructed and installed as part of the LCLS project. The experiments are described in detail in the document "LCLS: The First Experiments" referenced earlier. Two classes of experiments are proposed for the LCLS. The first class consists of experiments where the x-ray beam is used to probe the sample, as is done in most experiments at current

444

Deuterium accelerator experiments for APT.  

SciTech Connect (OSTI)

Sandia National Laboratories in California initiated an experimental program to determine whether tritium retention in the tube walls and permeation through the tubes into the surrounding coolant water would be a problem for the Accelerator Production of Tritium (APT), and to find ways to mitigate the problem, if it existed. Significant holdup in the tube walls would limit the ability of APT to meet its production goals, and high levels of permeation would require a costly cleanup system for the cooling water. To simulate tritium implantation, a 200 keV accelerator was used to implant deuterium into Al 6061-T and SS3 16L samples at temperatures and particle fluxes appropriate for APT, for times varying between one week and five months. The implanted samples were characterized to determine the deuterium retention and Permeation. During the implantation, the D(d,p)T nuclear reaction was used to monitor the build-up of deuterium in the implant region of the samples. These experiments increased in sophistication, from mono-energetic deuteron implants to multi-energetic deuteron and proton implants, to more accurately reproduce the conditions expected in APT. Micron-thick copper, nickel, and anodized aluminum coatings were applied to the front surface of the samples (inside of the APT walls) in an attempt to lower retention and permeation. The reduction in both retention and permeation produced by the nickel coatings, and the ability to apply them to the inside of the APT tubes, indicate that both nickel-coated Al 6061-T6 and nickel-coated SS3 16L tubes would be effective for use in APT. The results of this work were submitted to the Accelerator Production of Tritium project in document number TPO-E29-Z-TNS-X-00050, APT-MP-01-17.

Causey, Rion A. (Sandia National Laboratories, Livermore, CA); Hertz, Kristin L. (Sandia National Laboratories, Livermore, CA); Cowgill, Donald F. (Sandia National Laboratories, Livermore, CA)

2005-08-01T23:59:59.000Z

445

Cygnus Performance in Subcritical Experiments  

SciTech Connect (OSTI)

The Cygnus Dual Beam Radiographic Facility consists of two identical radiographic sources with the following specifications: 4-rad dose at 1 m, 1-mm spot size, 50-ns pulse length, 2.25-MeV endpoint energy. The facility is located in an underground tunnel complex at the Nevada Test Site. Here SubCritical Experiments (SCEs) are performed to study the dynamic properties of plutonium. The Cygnus sources were developed as a primary diagnostic for these tests. Since SCEs are single-shot, high-value events - reliability and reproducibility are key issues. Enhanced reliability involves minimization of failure modes through design, inspection, and testing. Many unique hardware and operational features were incorporated into Cygnus to insure reliability. Enhanced reproducibility involves normalization of shot-to-shot output also through design, inspection, and testing. The first SCE to utilize Cygnus, Armando, was executed on May 25, 2004. A year later, April - May 2005, calibrations using a plutonium step wedge were performed. The results from this series were used for more precise interpretation of the Armando data. In the period February - May 2007 Cygnus was fielded on Thermos, which is a series of small-sample plutonium shots using a one-dimensional geometry. Pulsed power research generally dictates frequent change in hardware configuration. Conversely, SCE applications have typically required constant machine settings. Therefore, while operating during the past four years we have accumulated a large database for evaluation of machine performance under highly consistent operating conditions. Through analysis of this database Cygnus reliability and reproducibility on Armando, Step Wedge, and Thermos is presented.

G. Corrow, M. Hansen, D. Henderson, S. Lutz, C. Mitton, et al.

2008-02-01T23:59:59.000Z

446

Current Experiments in Particle Physics (September 1996)  

SciTech Connect (OSTI)

This report contains summaries of current and recent experiments in Particle Physics. Included are experiments at BEPC (Beijing), BNL, CEBAF, CERN, CESR, DESY, FNAL, Frascati, ITEP (Moscow), JINR (Dubna), KEK, LAMPF, Novosibirsk, PNPI (St. Petersburg), PSI, Saclay, Serpukhov, SLAC, and TRIUMF, and also several proton decay and solar neutrino experiments. Excluded are experiments that finished taking data before 1991. Instructions are given for the World Wide Web (WWW) searching of the computer database (maintained under the SLAC-SPIRES system) that contains the summaries. This report contains full summaries of 180 approved current and recent experiments in elementary particle physics. The focus of the report is on selected experiments which directly contribute to our better understanding of elementary particles and their properties such as masses, widths or lifetimes, and branching fractions.

Galic, H.; Lehar, F.; Klyukhin, V.I.; Ryabov, Yu.G.; Bilak, S.V.; Illarionova, N.S.; Khachaturov, B.A.; Strokovsky, E.A.; Hoffman, C.M.; Kettle, P.-R.; Olin, A.; Armstrong, F.E.

1996-09-01T23:59:59.000Z

447

Initial conditions of radiative shock experiments  

SciTech Connect (OSTI)

We performed experiments at the Omega Laser Facility to characterize the initial, laser-driven state of a radiative shock experiment. These experiments aimed to measure the shock breakout time from a thin, laser-irradiated Be disk. The data are then used to inform a range of valid model parameters, such as electron flux limiter and polytropic ?, used when simulating radiative shock experiments using radiation hydrodynamics codes. The characterization experiment and the radiative shock experiment use a laser irradiance of ?7 × 10{sup 14} W cm{sup ?2} to launch a shock in the Be disk. A velocity interferometer and a streaked optical pyrometer were used to infer the amount of time for the shock to move through the Be disk. The experimental results were compared with simulation results from the Hyades code, which can be used to model the initial conditions of a radiative shock system using the CRASH code.

Kuranz, C. C.; Drake, R. P.; Krauland, C. M.; Marion, D. C.; Grosskopf, M. J.; Rutter, E.; Torralva, B.; Holloway, J. P. [Department of Atmospheric, Oceanic and Space Science, University of Michigan, Center for Radiative Shock Hydrodynamics, 2455 Hayward Dr., Ann Arbor, Michigan 48109 (United States)] [Department of Atmospheric, Oceanic and Space Science, University of Michigan, Center for Radiative Shock Hydrodynamics, 2455 Hayward Dr., Ann Arbor, Michigan 48109 (United States); Bingham, D.; Goh, J. [Department of Statistics and Actuarial Science, Simon Fraser University, Burnaby, BC, Canada V5A 1S6 (Canada)] [Department of Statistics and Actuarial Science, Simon Fraser University, Burnaby, BC, Canada V5A 1S6 (Canada); Boehly, T. R.; Sorce, A. T. [Laboratory for Laser Energetics, University of Rochester, New York 14623 (United States)] [Laboratory for Laser Energetics, University of Rochester, New York 14623 (United States)

2013-05-15T23:59:59.000Z

448

Information Gains from Cosmic Microwave Background Experiments  

E-Print Network [OSTI]

To shed light on the fundamental problems posed by Dark Energy and Dark Matter, a large number of experiments have been performed and combined to constrain cosmological models. We propose a novel way of quantifying the information gained by updates on the parameter constraints from a series of experiments which can either complement earlier measurements or replace them. For this purpose, we use the Kullback-Leibler divergence or relative entropy from information theory to measure differences in the posterior distributions in model parameter space from a pair of experiments. We apply this formalism to a historical series of Cosmic Microwave Background experiments ranging from Boomerang to WMAP, SPT, and Planck. Considering different combinations of these experiments, we thus estimate the information gain in units of bits and distinguish contributions from the reduction of statistical errors and the `surprise' corresponding to a significant shift of the parameters' central values. For this experiment series, we...

Seehars, Sebastian; Refregier, Alexandre; Paranjape, Aseem; Akeret, Joël

2014-01-01T23:59:59.000Z

449

Laboratory experiments with silicon solar cells  

Science Journals Connector (OSTI)

The uses of silicon solar cells as subjects of experiments in undergraduate teaching laboratories are discussed. The basic theory of these cells is presented including equivalent circuits and characteristic equations. Fundamental experiments on the power output and efficiency which are appropriate for non?science majors’ courses are detailed as well as more advanced experiments on cell parameters. Experimental results and agreement with theory are presented for a typical inexpensive cell.

D. W. Kammer; M. A. Ludington

1977-01-01T23:59:59.000Z

450

Magnet operating experience review for fusion applications  

SciTech Connect (OSTI)

This report presents a review of magnet operating experiences for normal-conducting and superconducting magnets from fusion, particle accelerator, medical technology, and magnetohydrodynamics research areas. Safety relevant magnet operating experiences are presented to provide feedback on field performance of existing designs and to point out the operational safety concerns. Quantitative estimates of magnet component failure rates and accident event frequencies are also presented, based on field experience and on performance of similar components in other industries.

Cadwallader, L.C.

1991-11-01T23:59:59.000Z

451

Oak Ridge Critical Experiment Facility (Building 9213)  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

9213) Joe Lenhard, retired Department of Energy official, had responsibility for the Oak Ridge Critical Experi- ment Facility. Joe has continued to hold up this facility as...

452

Oneida's utopia: a religious and scientific experiment.  

E-Print Network [OSTI]

??Abstract of ONEIDA?S UTOPIA: A RELIGIOUS AND SCIENTIFIC EXPERIMENT by Katherine Anne Heim The Oneida Community was a Perfectionist communal venture undertaken in Madison County,… (more)

Heim, Katherine Anne

2010-01-01T23:59:59.000Z

453

Current experiments in elementary particle physics  

SciTech Connect (OSTI)

This report contains summaries of 720 recent and current experiments in elementary particle physics (experiments that finished taking data before 1980 are excluded). Included are experiments at Brookhaven, CERN, CESR, DESY, Fermilab, Moscow Institute of Theoretical and Experimental Physics, Tokyo Institute of Nuclear Studies, KEK, LAMPF, Leningrad Nuclear Physics Institute, Saclay, Serpukhov, SIN, SLAC, and TRIUMF, and also experiments on proton decay. Instructions are given for searching online the computer database (maintained under the SLAC/SPIRES system) that contains the summaries. Properties of the fixed-target beams at most of the laboratories are summarized.

Wohl, C.G.; Armstrong, F.E., Oyanagi, Y.; Dodder, D.C.; Ryabov, Yu.G.; Frosch, R.; Olin, A.; Lehar, F.; Moskalev, A.N.; Barkov, B.P.

1987-03-01T23:59:59.000Z

454

Current experiments in elementary particle physics  

SciTech Connect (OSTI)

This report contains summaries of 736 current and recent experiments in elementary particle physics (experiments that finished taking data before 1982 are excluded). Included are experiments at Brookhaven, CERN, CESR, DESY, Fermilab, Tokyo Institute of Nuclear Studies, Moscow Institute of Theoretical and Experimental Physics, Joint Institute for Nuclear Research (Dubna), KEK, LAMPF, Novosibirsk, PSI/SIN, Saclay, Serpukhov, SLAC, and TRIUMF, and also several underground experiments. Also given are instructions for searching online the computer database (maintained under the SLAC/SPIRES system) that contains the summaries. Properties of the fixed-target beams at most of the laboratories are summarized.

Wohl, C.G.; Armstrong, F.E.; Trippe, T.G.; Yost, G.P. (Lawrence Berkeley Lab., CA (USA)); Oyanagi, Y. (Tsukuba Univ., Ibaraki (Japan)); Dodder, D.C. (Los Alamos National Lab., NM (USA)); Ryabov, Yu.G.; Slabospitsky, S.R. (Gosudarstvennyj Komitet po Ispol'zovaniyu Atomnoj Ehnergii SSSR, Serpukhov (USSR). Inst. Fiziki Vysokikh Ehnergij); Frosch, R. (Swiss Inst. for Nuclear Research, Villigen (Switzerla

1989-09-01T23:59:59.000Z

455

Current experiments in elementary particle physics. Revised  

SciTech Connect (OSTI)

This report contains summaries of 584 current and recent experiments in elementary particle physics. Experiments that finished taking data before 1986 are excluded. Included are experiments at Brookhaven, CERN, CESR, DESY, Fermilab, Tokyo Institute of Nuclear Studies, Moscow Institute of Theoretical and Experimental Physics, KEK, LAMPF, Novosibirsk, Paul Scherrer Institut (PSI), Saclay, Serpukhov, SLAC, SSCL, and TRIUMF, and also several underground and underwater experiments. Instructions are given for remote searching of the computer database (maintained under the SLAC/SPIRES system) that contains the summaries.

Galic, H. [Stanford Univ., CA (United States). Stanford Linear Accelerator Center; Wohl, C.G.; Armstrong, B. [Lawrence Berkeley Lab., CA (United States); Dodder, D.C. [Los Alamos National Lab., NM (United States); Klyukhin, V.I.; Ryabov, Yu.G. [Inst. for High Energy Physics, Serpukhov (Russian Federation); Illarionova, N.S. [Inst. of Theoretical and Experimental Physics, Moscow (Russian Federation); Lehar, F. [CEN Saclay, Gif-sur-Yvette (France); Oyanagi, Y. [Univ. of Tokyo (Japan). Faculty of Sciences; Olin, A. [TRIUMF, Vancouver, BC (Canada); Frosch, R. [Paul Scherrer Inst., Villigen (Switzerland)

1992-06-01T23:59:59.000Z

456

Peer Reviewed: Experimenting with Hydroelectric Reservoirs  

Science Journals Connector (OSTI)

Peer Reviewed: Experimenting with Hydroelectric Reservoirs ... Researchers created reservoirs in Canada to explore the impacts of hydroelectric developments on greenhouse gas and methylmercury production. ...

R. A. Bodaly; Kenneth G. Beaty; Len H. Hendzel; Andrew R. Majewski; Michael J. Paterson; Kristofer R. Rolfhus; Alan F. Penn; Vincent L. St. Louis; Britt D. Hall; Cory J. D. Matthews; Katharine A. Cherewyk; Mariah Mailman; James P. Hurley; Sherry L. Schiff; Jason J. Venkiteswaran

2004-09-15T23:59:59.000Z

457

Early Childhood Experiences Conference on October 30  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Early Childhood Experiences Conference Community Connections: Your link to news and opportunities from Los Alamos National Laboratory Latest Issue: Dec. 2014 - Jan. 2015 All Issues...

458

Operating Experience Summary, 2013-03  

Broader source: Energy.gov (indexed) [DOE]

Investigation: Contamination at Los Alamos Neutron Science Center Due to Deficiencies in Conduct of Operations ...5 Page 1 Page 5 Page 1 of 12 Operating Experience Summary...

459

Operating Experience Summaries | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

Contamination at Los Alamos Neutron Science Center Due to Deficiencies in Conduct of Operations - Page 5 August 14, 2013 Operating Experience Summary - 2013-02 - August 14,...

460

Review of double beta decay experiments  

E-Print Network [OSTI]

The brief review of current experiments on search and studying of double beta decay processes is done. Best present limits on $\\langle m_{\

A. S. Barabash

2014-03-12T23:59:59.000Z

Note: This page contains sample records for the topic "torus experiment nstx" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Playing games with EPR-type experiments  

E-Print Network [OSTI]

An approach towards quantum games is proposed that uses the unusual probabilities involved in EPR-type experiments directly in two-player games.

Azhar Iqbal

2005-07-17T23:59:59.000Z

462

Review of double beta decay experiments  

E-Print Network [OSTI]

The brief review of current experiments on search and studying of double beta decay processes is done. Best present limits on $\\langle m_{\

Barabash, A S

2014-01-01T23:59:59.000Z

463

International Collaborations on Engineered Barrier Systems: Experiment...  

Energy Savers [EERE]

modeling of field experiments at the Mont Terri URL, Switzerland, and the Horonobe URL, Japan. Modeling of coupled THM processes in the EBS is part of the international...

464

Effects of Density Control on Internal Plasma Dynamics and Current Drive in HIT-SI.  

E-Print Network [OSTI]

??The Helicity Injected Torus with Steady Inductive Helicity Injection (HIT-SI) experiment investigates a method of current drive and spheromak formation through constant inductive helicity injection… (more)

Victor, Brian Scott

2012-01-01T23:59:59.000Z

465

INTERPRETATION OF A HYDRAULIC FRACTURING EXPERIMENT, MONTICELLO, SOUTH CAROLINA  

E-Print Network [OSTI]

Letters INTERPRETATION OF A HYDRAULIC FRACTURING EXPERIMENT,12091 INTERPRETATION OF A HYDRAULIC FRACTURING EXPERIMENT,transient data from a hydraulic fracturing experiment have

Narasimhan, T.N.

2014-01-01T23:59:59.000Z

466

MARITIME BIODIVERSITY A VIRTUE-RACK EXPERIMENT.  

E-Print Network [OSTI]

MARITIME BIODIVERSITY A VIRTUE-RACK EXPERIMENT. How Water Condition Affects Organisms in Saline to different aquatic environments, an experiment consisting of two VIRTUE-racks was carried out. The VIRTUE-racks were placed at two different aquatic environments. One rack was exposed to waves, placed at the inflow

Harding, Karin

467

Presenting Data from Experiments in Algorithmics  

E-Print Network [OSTI]

Presenting Data from Experiments in Algorithmics Peter Sanders 1? Max�Planck�Institut f�ur Informatik Saarbr�ucken, Germany sanders@mpi�sb.mpg.de Abstract. Algorithmic experiments yield large amounts tools such as gnuplot 1 . 1 Introduction A paper in experimental algorithmics will often start

Sanders, Peter

468

Status of the MINERnuA Experiment  

SciTech Connect (OSTI)

MINERnuA is a dedicated neutrino cross section experiment at Fermilab that will study the axial current through neutrino-nucleon interactions and measure a variety of cross sections in support of long baseline neutrino oscillation experiments. A dataset of neutrino events was taken with a portion of MINERnuA, called the Tracking Prototype, installed in the NuMI beamline.

Eberly, B. [Department of Physics, University of Pittsburgh, Pittsburgh, PA (United States)

2010-03-30T23:59:59.000Z

469

Informational experiments with microparticles and atoms  

E-Print Network [OSTI]

Accepting information as a physical category and ascribing to inanimate matter some spirit (consciousness, intelligence) allows to explain quantum-mechanical phenomena, including delayed-choice and EPR-Bohm-Bell experiments, as well as irreversibility of time, remaining on the basis of local realism, and suggest essentially new experiments with microparticles and atoms in which information plays the principal role.

Raoul Nakhmanson

2005-09-07T23:59:59.000Z

470

The Immigration Experience in Saskatchewan's Labour Market  

E-Print Network [OSTI]

The Immigration Experience in Saskatchewan's Labour Market Douglas Durst Faculty of Social Work.durst@uregina.ca The Immigration Experience in Saskatchewan's Labour Market EDITORIAL AND DISTRIBUTION OFFICE Social Policy Research Unit (SPR) Faculty of Social Work University of Regina Regina, Saskatchewan, Canada S4S 0A2 Phone

Argerami, Martin

471

Accelerator/Experiment operations - FY 2004  

SciTech Connect (OSTI)

This Technical Memorandum (TM) summarizes the accelerator and experiment operations for FY 2004. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2004 Run II at the Tevatron Collider, the MiniBooNE neutrino experiment, and SY 120 activities.

Bromberg, C.; Conrad, J.; Denisov, D.; Holmes, S.; Louis, W.; Meyer, A.; Moore, Craig D.; Raja, R.; Ramberg, E.; Roser, R.; /Fermilab

2004-12-01T23:59:59.000Z

472

Capturing experience: a matter of contextualising events  

Science Journals Connector (OSTI)

This paper explores the notion of experience in the context of dynamic and interactive environments, such as web-based musea, where neither the individual user requirements nor the requested material can be predicted in advance. A definition of experiences ... Keywords: context, emotions, experiential systems, representation of events

Frank Nack

2003-11-01T23:59:59.000Z

473

ECRH in the Levitated Dipole Experiment1  

E-Print Network [OSTI]

experiment. ELECTRON CYCLOTRON HEATING ON LDX LDX has been designed to be a low cost experiment able, we have chosen to use multiple frequency electron cyclotron heating (MFECH) which will allow greater a reduction in plasma turbulence and increased heating efficiency. The pressure profile will be controlled

474

Ramp Compression Experiments - a Sensitivity Study  

SciTech Connect (OSTI)

We present the first sensitivity study of the material isentropes extracted from ramp compression experiments. We perform hydrodynamic simulations of representative experimental geometries associated with ramp compression experiments and discuss the major factors determining the accuracy of the equation of state information extracted from such data. In conclusion, we analyzed both qualitatively and quantitatively the major experimental factors that determine the accuracy of equations of state extracted from ramp compression experiments. Since in actual experiments essentially all the effects discussed here will compound, factoring out individual signatures and magnitudes, as done in the present work, is especially important. This study should provide some guidance for the effective design and analysis of ramp compression experiments, as well as for further improvements of ramp generators performance.

Bastea, M; Reisman, D

2007-02-26T23:59:59.000Z

475

The bridge of iconicity: from a world of experience to the experience of language  

Science Journals Connector (OSTI)

...Theme Issue Brain circuitry outside the synaptic cleft compiled and edited by Dmitri A. Rusakov and Alexander E. Dityatev The bridge of iconicity: from a world of experience to the experience of language Pamela Perniss Gabriella Vigliocco Phil. Trans. R...

2014-01-01T23:59:59.000Z

476

Electrical Transport Experiments at High Pressure  

SciTech Connect (OSTI)

High-pressure electrical measurements have a long history of use in the study of materials under ultra-high pressures. In recent years, electrical transport experiments have played a key role in the study of many interesting high pressure phenomena including pressure-induced superconductivity, insulator-to-metal transitions, and quantum critical behavior. High-pressure electrical transport experiments also play an important function in geophysics and the study of the Earth's interior. Besides electrical conductivity measurements, electrical transport experiments also encompass techniques for the study of the optoelectronic and thermoelectric properties of materials under high pressures. In addition, electrical transport techniques, i.e., the ability to extend electrically conductive wires from outside instrumentation into the high pressure sample chamber have been utilized to perform other types of experiments as well, such as high-pressure magnetic susceptibility and de Haas-van Alphen Fermi surface experiments. Finally, electrical transport techniques have also been utilized for delivering significant amounts of electrical power to high pressure samples, for the purpose of performing high-pressure and -temperature experiments. Thus, not only do high-pressure electrical transport experiments provide much interesting and valuable data on the physical properties of materials extreme compression, but the underlying high-pressure electrical transport techniques can be used in a number of ways to develop additional diagnostic techniques and to advance high pressure capabilities.

Weir, S

2009-02-11T23:59:59.000Z

477

Digestion Experiments With Texas Feeding Stuffs.  

E-Print Network [OSTI]

477-514-15m TEXAS AGRICULTURAL EXPERIMENT STATION BULLETIN NO. 166. MAK, 1914 DIVISION OF CHEMISTRY Digestion Experiments With Texas Feeding Stuffs Digeisston oExxprp gmWmhETa FdWSEu oEfTm1a ep2Wu VON BOECKMANN-JONES CO., PRINTERS, AUSTIN... EXPERIMENTS WITH TEXAS FEEDING STUFFS B Y Gr. S. PRAPS., P H . D., Chemist. This bulletin contains the results of digestion tests with the ordi? nary fodder groups of certain feeding stuffs. Other results have been published in Bulletin 149...

Fraps, G. S.

1914-01-01T23:59:59.000Z

478

The first cryogenic dark matter experiment  

SciTech Connect (OSTI)

An experimental search for dark matter particle candidates using cryogenic detectors requires a low radioactive background environment. The authors discuss the status of a cryogenic dark matter experiment to be performed in the Stanford Underground Facility. The detectors will be cooled in a specially designed cryostat connected to a modified side access Oxford 400 dilution refrigerator. Details of the cryostat design and its operating performance are presented. The effectiveness of the multi-level shield surrounding the cryostat, as well as the background levels expected to be achieved in the pilot experiment are discussed. Finally, the limits which can be set on dark matter candidates with such an experiment are discussed.

Barnes, P.D.; Aubourg, E.; Akerib, D.S.; Cummings, A.; Lange, A.E.; Margulies, S.; Sadoulet, B.; Shutt, T.; Stockwell, W.; White, S.; Young, B.A. (Univ. of California, Berkeley, CA (United States)); Da Silva, A. (Univ. of British Columbia, BC (Canada)); Bauer, D.; Borden, D.; Caldwell, D.O.; Gray, M.; Hale, D.; Lu, A.; Witherell, M.; Yellin, S. (Univ. of California, Santa Barbara, CA (United States)); Cabrera, B.; Chugg, B.; Dougherty, B.L.; Irwin, K.D.; Penn, M.J. (Stanford Univ., Stanford, CA (United States))