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Sample records for torus experiment nstx

  1. National Spherical Torus Experiment Upgrade (NSTX-U) | Princeton Plasma

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

    Physics Lab National Spherical Torus Experiment Upgrade (NSTX-U) NSTX-U The National Spherical Torus Experiment Upgrade (NSTX-U) is an innovative magnetic fusion device that was constructed by the Princeton Plasma Physics Laboratory (PPPL) in collaboration with the Oak Ridge National Laboratory, Columbia University, and the University of Washington at Seattle. History First plasma was obtained on NSTX on Friday, February 12, 1999 at 6:06 p.m. NSTX-U is being used to study the physics

  2. National Spherical Torus Experiment (NSTX) Torus Design, Fabrication and Assembly

    SciTech Connect (OSTI)

    C. Neumeyer; G. Barnes; J.H. Chrzanowski; P. Heitzenroeder; et al

    1999-11-01

    The National Spherical Torus Experiment (NSTX) is a low aspect ratio spherical torus (ST) located at Princeton Plasma Physics Laboratory (PPPL). Fabrication, assembly, and initial power tests were completed in February of 1999. The majority of the design and construction efforts were constructed on the Torus system components. The Torus system includes the centerstack assembly, external Poloidal and Toroidal coil systems, vacuum vessel, torus support structure and plasma facing components (PFC's). NSTX's low aspect ratio required that the centerstack be made with the smallest radius possible. This, and the need to bake NSTXs carbon-carbon composite plasma facing components at 350 degrees C, was major drivers in the design of NSTX. The Centerstack Assembly consists of the inner legs of the Toroidal Field (TF) windings, the Ohmic Heating (OH) solenoid and its associated tension cylinder, three inner Poloidal Field (PF) coils, thermal insulation, diagnostics and an Inconel casing which forms the inner wall of the vacuum vessel boundary. It took approximately nine months to complete the assembly of the Centerstack. The tight radial clearances and the extreme length of the major components added complexity to the assembly of the Centerstack components. The vacuum vessel was constructed of 304-stainless steel and required approximately seven months to complete and deliver to the Test Cell. Several of the issues associated with the construction of the vacuum vessel were control of dimensional stability following welding and controlling the permeability of the welds. A great deal of time and effort was devoted to defining the correct weld process and material selection to meet our design requirements. The PFCs will be baked out at 350 degrees C while the vessel is maintained at 150 degrees C. This required care in designing the supports so they can accommodate the high electromagnetic loads resulting from plasma disruptions and the resulting relative thermal expansions

  3. National Spherical Torus Experiment (NSTX) | U.S. DOE Office...

    Office of Science (SC) Website

    It is one of the world's two largest embodiments of the spherical torus confinement concept. NSTX has a unique, nearly spherical plasma shape that provides a test of the theory of ...

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

    SciTech Connect (OSTI)

    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

    2009-01-05

    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

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

    SciTech Connect (OSTI)

    Gates, D. A.; 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.; Choe, W.; Crocker, N.; Darrow, D.; Delgado-Aparicio, L.; Diem, S.; DIppolito, 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.; 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, Jr., 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.; Rewo, 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.; Solomon, 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.; Welander, A.; Whaley, J.; White, R.; Wilgen, J.; Wilson, R.; Wong, K.; Wright, J.; Xia, Z.; Xu, X.; Youchison, D.; Yu, G.; Yuh, H.; Zakharov, L.; Zemlyanov, D.; Zweben, S.

    2009-03-24

    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 ? 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 are consistent with 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 current fraction, future ST designs envision running at very high elongation. Plasmas have been maintained on NSTX at very low internal inductance li ~0.4 with strong shaping (? ~ 2.7, ? ~ 0.8) with ?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 fNI ~71%. Instabilities driven by super-Alfvenic ions will be 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. The impact of n > 1 error fields on stability is a important result for ITER. RWM/RFA feedback combined with n=3 error field control was used on NSTX to maintain plasma rotation with ? above the no-wall limit. Other highlights are: results of

  6. Enhanced Conversion of Thermal Electron Bernstein Waves to the Extraordinary Electromagnetic Mode on the National Spherical Torus Experiment (NSTX)

    SciTech Connect (OSTI)

    G. Taylor; P.C. Efthimion; B. Jones; B.P. LeBlanc; J.R. Wilson; J.B. Wilgen; G.L. Bell; T.S. Bigelow; R. Maingi; D.A. Rasmussen; R.W. Harvey; A.P. Smirnov; F. Paoletti; S.A. Sabbagh

    2002-10-15

    A four-fold increase in the conversion of thermal electron-Bernstein waves (EBW) to the extraordinary mode (X-mode) was measured when the density scale length (L subscript ''n'') was progressively shortened by a local Boron nitride limiter in the scrape-off of an ohmically heated National Spherical Torus Experiment (NSTX) plasma [M. Ono, S. Kaye, M. Peng, et al., Proceedings 17th IAEA Fusion Energy Conference (IAEA, Vienna, Austria, 1999), Vol. 3, p. 1135]. The maximum conversion efficiency approached 50% when L subscript ''n'' was reduced to 0.7 cm, in agreement with theoretical predictions that used locally measured L subscript ''n''. Calculations indicate that it is possible to establish L subscript ''n'' < 0.3 cm with a local limiter, a value predicted to attain approximately 100% EBW conversion to the X-mode in support of proposed EBW heating and current drive scenarios.

  7. MHD-induced Energetic Ion Loss during H-mode Discharges in the National Spherical Torus Experiment (NSTX)

    SciTech Connect (OSTI)

    S.S. Medley; N.N. Gorelenkov; R. Andre; R.E. Bell; D.S. Darrow; E.D. Fredrickson; S.M. Kaye; B.P. LeBlanc; A.L. Roquemore; and the NSTX Team

    2004-03-15

    MHD-induced energetic ion loss in neutral-beam-heated H-mode [high-confinement mode] discharges in NSTX [National Spherical Torus Experiment] is discussed. A rich variety of energetic ion behavior resulting from magnetohydrodynamic (MHD) activity is observed in the NSTX using a horizontally scanning Neutral Particle Analyzer (NPA) whose sightline views across the three co-injected neutral beams. For example, onset of an n = 2 mode leads to relatively slow decay of the energetic ion population (E {approx} 10-100 keV) and consequently the neutron yield. The effect of reconnection events, sawteeth, and bounce fishbones differs from that observed for low-n, low-frequency, tearing-type MHD modes. In this case, prompt loss of the energetic ion population occurs on a time scale of less than or equal to 1 ms and a precipitous drop in the neutron yield occurs. This paper focuses on MHD-induced ion loss during H-mode operation in NSTX. After H-mode onset, the NPA charge-exchange spectrum usually exhibits a significant loss of energetic ions only for E > E(sub)b/2 where E(sub)b is the beam injection energy. The magnitude of the energetic ion loss was observed to decrease with increasing tangency radius, R(sub)tan, of the NPA sightline, increasing toroidal field, B(sub)T, and increasing neutral-beam injection energy, E(sub)b. TRANSP modeling suggests that MHD-induced ion loss is enhanced during H-mode operation due to an evolution of the q and beam deposition profiles that feeds both passing and trapped ions into the region of low-n MHD activity. ORBIT code analysis of particle interaction with a model magnetic perturbation supported the energy selectivity of the MHD-induced loss observed in the NPA measurements. Transport analysis with the TRANSP code using a fast-ion diffusion tool to emulate the observed MHD-induced energetic ion loss showed significant modifications of the neutral- beam heating as well as the power balance, thermal diffusivities, energy confinement times

  8. Status of the Control System on the National Spherical Torus Experiment (NSTX)

    SciTech Connect (OSTI)

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

    2005-08-05

    In 2003, the NSTX plasma control system was used for plasma shape control using real-time equilibrium reconstruction (using the rtEFIT code - J. Ferron, et al., Nucl. Fusion 38 1055 (1998)). rtEFIT is now in routine use for plasma boundary control [D. A. Gates, et al., submitted to Nuclear Fusion (2005)]. 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 real-time data acquisition system now acquires 352 channels of data at 5kHz for each NSTX plasma discharge. The latency for the data acquisition, which uses the FPDP (Front Panel Data Port) protocol, is measured to be {approx}8 microseconds. 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 [D. Mastrovito, Fusion Eng. And Design 71 65 (2004)] on the NSTX control system has been upgraded. The control computer is an eight processor (8x333MHz G4) built by Sky Computers (Helmsford, MA). 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. An important initial task in RWM feedback is to develop a reliable mode detection algorithm.

  9. Chosen Solutions to the Engineering Challenges of the National Spherical Torus Experiment (NSTX) Magnets

    SciTech Connect (OSTI)

    C. Neumeyer; H.M. Fan; J. Chrzanowski; P. Heitzenroeder; and the NSTX Team

    1999-10-01

    NSTX is one of the largest of a new class of magnetic plasma research devices known as spherical toroids (STs). The plasma in a ST is characterized by its almost spherical shape with a slender cylindrical region through its vertical axis. The so-called ''center stack'' is located in this region. It contains magnetic windings for confining the plasma, induce the plasma current, and shape the plasma. This paper will describe the engineering challenges of designing the center stack magnets to meet their operational requirements within this constrained space.

  10. Diagnostics for the biased electrode experiment on NSTX (Journal...

    Office of Scientific and Technical Information (OSTI)

    Diagnostics for the biased electrode experiment on NSTX Citation Details In-Document Search Title: Diagnostics for the biased electrode experiment on NSTX A linear array of four ...

  11. Characteristics of Energy Transport of Li-conditioned and non-Li-conditioned Plasmas in the National Spherical Torus Experiment (NSTX)

    SciTech Connect (OSTI)

    Ding, S.; Kaye, S. M.; Bell, R. E.; Kaita, R.; Kugel, H.; LeBlanc, B. P.; Paul, S.; Wan, B.

    2009-10-21

    The transport properties of NSTX plasmas obtained during the 2008 experimental cam- paign have been studied and are reported here. Transport trends and dependences have been isolated, and it is found that both electron and ion energy transport coefficients have strong dependences on local values of n?T, which in turn is strongly dependent on local current density profile. Without identifying this dependence, it is difficult to identify others, such as the dependence of transport coefficients on Bp (or q), Ip and Pheat. In addition, a comparison between discharges with and without Lithium wall conditioning has been made. While the trends in the two sets of data are similar, the thermal transport loss, especially in the electron channel, is found to strongly depend on the amount of Lithium deposited, decreasing by up to 50% of its no-Lithium value.

  12. Completed NSTX-U. After

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

    panel (15 tons) being inserted into the new neutral beam box. New neutral beam box (40 tons) being moved into the NSTX-U test cell. Center stack encased within the vacuum boundary and lowered into the NSTX-U. Completed center stack installed in the NSTX-U. Completed NSTX-U. After Original NSTX prior to the upgrade. Before Building the first quadrant of the center stack magnet. Winding the ohmic heating coil around the center stack. National Spherical Torus Experiment - Upgrade NSTX was a

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

    SciTech Connect (OSTI)

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

    2012-09-27

    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.

  14. Local Scrape-Off Layer Control Using Biased electrodes in NSTX...

    Office of Scientific and Technical Information (OSTI)

    Title: Local Scrape-Off Layer Control Using Biased electrodes in NSTX An experiment was ... near the outer midplane in the SOL of the National Spherical Torus Experiment (NSTX). ...

  15. Electron Bernstein Wave Research on the National Spherical Torus Experiment

    SciTech Connect (OSTI)

    G. Taylor; A. Bers; T.S. Bigelow; M.D. Carter; J.B. Caughman; J. Decker; S. Diem; P.C. Efthimion; N.M. Ershov; E. Fredd; R.W. Harvey; J. Hosea; F. Jaeger; J. Preinhaelter; A.K. Ram; D.A. Rasmussen; A.P. Smirnov; J.B. Wilgen; J.R. Wilson

    2005-04-21

    Off-axis electron Bernstein wave current drive (EBWCD) may be critical for sustaining noninductive high-beta National Spherical Torus Experiment (NSTX) plasmas. Numerical modeling results predict that the {approx}100 kA of off-axis current needed to stabilize a solenoid-free high-beta NSTX plasma could be generated via Ohkawa current drive with 3 MW of 28 GHz EBW power. In addition, synergy between EBWCD and bootstrap current may result in a 10% enhancement in current-drive efficiency with 4 MW of EBW power. Recent dual-polarization EBW radiometry measurements on NSTX confirm that efficient coupling to EBWs can be readily accomplished by launching elliptically polarized electromagnetic waves oblique to the confining magnetic field, in agreement with numerical modeling. Plans are being developed for implementing a 1 MW, 28 GHz proof-of-principle EBWCD system on NSTX to test the EBW coupling, heating and current-drive physics at high radio-frequency power densities.

  16. NSTX-U | Princeton Plasma Physics Lab

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

    NSTX-U Subscribe to RSS - NSTX-U The National Spherical Torus Experiment (NSTX), which is undergoing a $94 million upgrade that will make it the most powerful experimental fusion facility, or tokamak, of its type in the world when work is completed in 2015. Experiments will test the ability of the upgraded spherical facility to maintain a high-performance plasma under conditions of extreme heat and power. Results could strongly influence the design of future fusion reactors. PPPL intern creates

  17. Simulation of microtearing turbulence in national spherical torus experiment

    SciTech Connect (OSTI)

    Guttenfelder, W.; Kaye, S. M.; Bell, R. E.; Hammett, G. W.; LeBlanc, B. P.; Mikkelsen, D. R.; Ren, Y.; Candy, J.; Nevins, W. M.; Wang, E.; Zhang, J.; Crocker, N. A.; Yuh, H.

    2012-05-15

    Thermal energy confinement times in National Spherical Torus Experiment (NSTX) dimensionless parameter scans increase with decreasing collisionality. While ion thermal transport is neoclassical, the source of anomalous electron thermal transport in these discharges remains unclear, leading to considerable uncertainty when extrapolating to future spherical tokamak (ST) devices at much lower collisionality. Linear gyrokinetic simulations find microtearing modes to be unstable in high collisionality discharges. First non-linear gyrokinetic simulations of microtearing turbulence in NSTX show they can yield experimental levels of transport. Magnetic flutter is responsible for almost all the transport ({approx}98%), perturbed field line trajectories are globally stochastic, and a test particle stochastic transport model agrees to within 25% of the simulated transport. Most significantly, microtearing transport is predicted to increase with electron collisionality, consistent with the observed NSTX confinement scaling. While this suggests microtearing modes may be the source of electron thermal transport, the predictions are also very sensitive to electron temperature gradient, indicating the scaling of the instability threshold is important. In addition, microtearing turbulence is susceptible to suppression via sheared E Multiplication-Sign B flows as experimental values of E Multiplication-Sign B shear (comparable to the linear growth rates) dramatically reduce the transport below experimental values. Refinements in numerical resolution and physics model assumptions are expected to minimize the apparent discrepancy. In cases where the predicted transport is strong, calculations suggest that a proposed polarimetry diagnostic may be sensitive to the magnetic perturbations associated with the unique structure of microtearing turbulence.

  18. Modification Of The Electron Energy Distribution Function During Lithium Experiments On The National Spherical Torus Experiment

    SciTech Connect (OSTI)

    Jaworski, M A; Gray, T K; Kaita, R; Kallman, J; Kugel, H; LeBlanc, B; McLean, A; Sabbagh, S A; Soukanovskii, V; Stotler, D P

    2011-06-03

    The National Spherical Torus Experiment (NSTX) has recently studied the use of a liquid lithium divertor (LLD). Divertor Langmuir probes have also been installed for making measurements of the local plasma conditions. A non-local probe interpretation method is used to supplement the classical probe interpretation and obtain measurements of the electron energy distribution function (EEDF) which show the occurrence of a hot-electron component. Analysis is made of two discharges within a sequence that exhibited changes in plasma fueling efficiency. It is found that the local electron temperature increases and that this increase is most strongly correlated with the energy contained within the hot-electron population. Preliminary interpretative modeling indicates that kinetic effects are likely in the NSTX.

  19. New Capabilities and Results for the National Spherical Torus Experiment

    SciTech Connect (OSTI)

    M.G. Bell, R.E. Bell, D.A. Gates, S.M. Kaye, H. Kugel, B.P. LeBlanc, F.M. Levinton, R. Maingi, J.E. Menard, R. Raman, S.A. Sabbagh, D. Stutman and the NSTX Research Team

    2008-02-29

    The National Spherical Torus Experiment (NSTX) produces plasmas with toroidal aspect ratio as low as 1.25, which can be heated by up to 6 MW High-Harmonic Fast Waves and up to 7 MW of deuterium Neutral Beam Injection. Using new poloidal fields coils, plasmas with cross-section elongation up to 2.7, triangularity 0.8, plasma currents Ip up to 1.5 MA and normalized currents Ip/a?BT up to 7.5 MA/m?T have been achieved. A significant extension of the plasma pulse length, to 1.5 s at a plasma current of 0.7 MA, has been achieved by exploiting the bootstrap and NBI-driven currents to reduce the dissipation of poloidal flux. Inductive plasma startup has been supplemented by Coaxial Helicity Injection (CHI) and the production of persistent current on closed flux surfaces by CHI has now been demonstrated in NSTX. The plasma response to magnetic field perturbations with toroidal mode numbers n = 1 or 3 and the effects on the plasma rotation have been investigated using three pairs of coils outside the vacuum vessel. Recent studies of both MHD stability and of transport benefitted from improved diagnostics, including measurements of the internal poloidal field using the motional Stark effect (MSE). In plasmas with a region of reversed magnetic shear in the core, now confirmed by the MSE data, improved electron confinement has been observed.

  20. Hardwired Control Changes For NSTX DC Power Feeds

    SciTech Connect (OSTI)

    Ramakrishnan, S.

    2013-06-28

    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. The original TFTR Hardwired Control System (HCS) with electromechanical relays was used for NSTX DC Power loop control and protection during NSTX operations. As part of the NSTX Upgrade, the HCS is being changed to a PLC-based system with the same control logic. This paper gives a description of the changeover to the new PLC-based system __________________________________________________

  1. NSTX-U Digital Coil Protection System Software Detailed Design

    SciTech Connect (OSTI)

    2014-06-01

    The National Spherical Torus Experiment (NSTX) currently uses a collection of analog signal processing solutions for coil protection. Part of the NSTX Upgrade (NSTX-U) entails replacing these analog systems with a software solution running on a conventional computing platform. The new Digital Coil Protection System (DCPS) will replace the old systems entirely, while also providing an extensible framework that allows adding new functionality as desired.

  2. Progress in Understanding Error-field Physics in NSTX Spherical Torus Plasmas

    SciTech Connect (OSTI)

    E. Menard, R.E. Bell, D.A. Gates, S.P. Gerhardt, J.-K. Park, S.A. Sabbagh, J.W. Berkery, A. Egan, J. Kallman, S.M. Kaye, B. LeBlanc, Y.Q. Liu, A. Sontag, D. Swanson, H. Yuh, W. Zhu and the NSTX Research Team

    2010-05-19

    The low aspect ratio, low magnetic field, and wide range of plasma beta of NSTX plasmas provide new insight into the origins and effects of magnetic field errors. An extensive array of magnetic sensors has been used to analyze error fields, to measure error field amplification, and to detect resistive wall modes in real time. The measured normalized error-field threshold for the onset of locked modes shows a linear scaling with plasma density, a weak to inverse dependence on toroidal field, and a positive scaling with magnetic shear. These results extrapolate to a favorable error field threshold for ITER. For these low-beta locked-mode plasmas, perturbed equilibrium calculations find that the plasma response must be included to explain the empirically determined optimal correction of NSTX error fields. In high-beta NSTX plasmas exceeding the n=1 no-wall stability limit where the RWM is stabilized by plasma rotation, active suppression of n=1 amplified error fields and the correction of recently discovered intrinsic n=3 error fields have led to sustained high rotation and record durations free of low-frequency core MHD activity. For sustained rotational stabilization of the n=1 RWM, both the rotation threshold and magnitude of the amplification are important. At fixed normalized dissipation, kinetic damping models predict rotation thresholds for RWM stabilization to scale nearly linearly with particle orbit frequency. Studies for NSTX find that orbit frequencies computed in general geometry can deviate significantly from those computed in the high aspect ratio and circular plasma cross-section limit, and these differences can strongly influence the predicted RWM stability. The measured and predicted RWM stability is found to be very sensitive to the E B rotation profile near the plasma edge, and the measured critical rotation for the RWM is approximately a factor of two higher than predicted by the MARS-F code using the semi-kinetic damping model.

  3. Recent progress toward an advanced spherical torus operating point in NSTX

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

    S. P. Gerhardt; Gates, D. A.; Kaye, S.; Maingi, R.; Menard, J. E.; Sabbagh, S. A.; Soukhanovskii, V.; Bell, M. G.; Bell, R. E.; Canik, J. M.; et al

    2011-05-13

    Progress in the development of integrated advanced ST plasma scenarios in NSTX (Ono et al., 2000 Nucl. Fusion 40 557) is reported. Recent high-performance plasmas in NSTX following lithium coating of the plasma facing surfaces have achieved higher elongation and lower internal inductance than previously. Analysis of the thermal confinement in these lithiumized discharges shows a stronger plasma current and weaker toroidal field dependence than in previous ST confinement scaling studies; the ITER-98(y, 2) scaling expression describes these scenarios reasonably well. Analysis during periods free of MHD activity has shown that the reconstructed current profile can be understood as themore » sum of pressure driven, inductive and neutral beam driven currents, without requiring any anomalous fast-ion transport. Non-inductive fractions of 65–70%, and βP > 2, have been achieved at lower plasma current. Some of these low-inductance discharges have a significantly reduced no-wall βN limit, and often have βN at or near the with-wall limit. Coupled m/n = 1/1 + 2/1 kink/tearing modes can limit the sustained β values when rapidly growing ideal modes are avoided. A βN controller has been commissioned and utilized in sustaining high-performance plasmas. 'Snowflake' divertors compatible with high-performance plasmas have been developed. Scenarios with significantly larger aspect ratios have also been developed, in support of next-step ST devices. Furthermore, these NSTX plasmas have many characteristics required for next-step ST devices.« less

  4. Physics of forced magnetic reconnection in coaxial helicity injection experiments in National Spherical Torus Experiment

    SciTech Connect (OSTI)

    Ebrahimi, F.; Bhattacharjee, A.; Raman, R.; Hooper, E. B.; Sovinec, C. R.

    2014-05-15

    We numerically examine the physics of fast flux closure in transient coaxial helicity injection (CHI) experiments in National Spherical Torus Experiment (NSTX). By performing resistive Magnetohydrodynamics (MHD) simulations with poloidal injector coil currents held constant in time, we find that closed flux surfaces are formed through forced magnetic reconnection. Through a local Sweet-Parker type reconnection with an elongated current sheet in the injector region, closed flux surfaces expand in the NSTX global domain. Simulations demonstrate outflows approaching poloidally Alfvénic flows and reconnection times consistent with the Sweet-Parker model. Critical requirements for magnetic reconnection and flux closure are studied in detail. These primary effects, which are magnetic diffusivity, injector flux, injector flux footprint width, and rate of injector voltage reduction, are simulated for transient CHI experiments. The relevant time scales for effective reconnection are τ{sub V}<τ{sub rec}≈τ{sub A}√(S)(1+Pm){sup 1/4}<τ{sub R}, where τ{sub V} is the time for the injector voltage reduction, τ{sub A} is the poloidal Alfvén transit time, τ{sub R} is the global resistive diffusion time, and Pm and S are Prandtl and Lundquist numbers.

  5. The Impact Of Lithium Wall Coatings On NSTX Discharges And The Engineering Of The Lithium Tokamak eXperiment (LTX)

    SciTech Connect (OSTI)

    R. Majeski, H. Kugel and R. Kaita

    2010-03-18

    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 Land 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 oC 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.

  6. NSTX Electrical Power Systems

    SciTech Connect (OSTI)

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

    1999-12-16

    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.

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

    SciTech Connect (OSTI)

    Bitter, M.; Hill, K.W.; Roquemore, A.L.; Beiersdorfer, P.; Kahn, S.M.; Elliott, S.R.; Fraenkel, B.

    1999-01-01

    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.}

  8. Control System for the NSTX Lithium Pellet Injector

    SciTech Connect (OSTI)

    P. Sichta; J. Dong; R. Gernhardt; G. Gettelfinger; H. Kugel

    2003-10-27

    The Lithium Pellet Injector (LPI) is being developed for the National Spherical Torus Experiment (NSTX). The LPI will inject ''pellets'' of various composition into the plasma in order to study wall conditioning, edge impurity transport, liquid limiter simulations, and other areas of research. The control system for the NSTX LPI has incorporated widely used advanced technologies, such as LabVIEW and PCI bus I/O boards, to create a low-cost control system which is fully integrated into the NSTX computing environment. This paper will present the hardware and software design of the computer control system for the LPI.

  9. Electron Bernstein Wave Research on NSTX and CDX-U

    SciTech Connect (OSTI)

    G. Taylor; P.C. Efthimion; B. Jones; G.L. Bell; A. Bers; T.S. Bigelow; M.D. Carter; R.W. Harvey; A.K. Ram; D.A. Rasmussen; A.P. Smirnov; J.B. Wilgen; J.R. Wilson

    2003-06-10

    Studies of thermally emitted electron Bernstein waves (EBWs) on CDX-U and NSTX, via mode conversion (MC) to electromagnetic radiation, support the use of EBWs to measure the Te profile and provide local electron heating and current drive (CD) in overdense spherical torus plasmas. An X-mode antenna with radially adjustable limiters successfully controlled EBW MC on CDX-U and enhanced MC efficiency to {approx} 100%. So far the X-mode MC efficiency on NSTX has been increased by a similar technique to 40-50% and future experiments are focused on achieving * 80% MC. MC efficiencies on both machines agree well with theoretical predictions. Ray tracing and Fokker-Planck modeling for NSTX equilibria are being conducted to support the design of a 3 MW, 15 GHz EBW heating and CD system for NSTX to assist non-inductive plasma startup, current ramp up, and to provide local electron heating and CD in high beta NSTX plasmas.

  10. NSTX-U: Builders and Users | Princeton Plasma Physics Lab

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

    NSTX-U: Builders and Users Constructing the National Spherical Torus Experiment Upgrade took years of detailed planning and oversight. The team in charge brought decades of experience to the task, working together to make the $94 million upgrade a reality. Publication File: PDF icon Builders and Users Publication Type: Fact Sheets

  11. Using LGI experiments to achieve better understanding of pedestal-edge coupling in NSTX-U

    SciTech Connect (OSTI)

    Wang, Zhehui

    2015-02-23

    PowerPoint presentation. Latest advances in granule or dust injection technologies, fast and high-resolution imaging, together with micro-/nano-structured material fabrication, provide new opportunities to examine plasma-material interaction (PMI) in magnetic fusion environment. Some of our previous work in these areas is summarized. The upcoming LGI experiments in NSTX-U will shed new light on granular matter transport in the pedestal-edge region. In addition to particle control, these results can also be used for code validation and achieving better understanding of pedestal-edge coupling in fusion plasmas in both NSTX-U and others.

  12. Quasi-linear gyrokinetic predictions of the Coriolis momentum pinch in National Spherical Torus Experiment

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

    Guttenfelder, W.; Kaye, S. M.; Ren, Y.; Solomon, W.; Bell, R. E.; Candy, J.; Gerhardt, S. P.; LeBlanc, B. P.; Yuh, H.

    2016-05-11

    This paper presents quasi-linear gyrokinetic predictions of the Coriolis momentum pinch for low aspect-ratio National Spherical Torus Experiment (NSTX) H-modes where previous experimental measurements were focused. Local, linear calculations predict that in the region of interest (just outside the mid-radius) of these relatively high-beta plasmas, profiles are most unstable to microtearing modes that are only effective in transporting electron energy. However, sub-dominant electromagnetic and electrostaticballooning modes are also unstable, which are effective at transporting energy, particles, and momentum. The quasi-linear prediction of transport from these weaker ballooning modes, assuming they contribute transport in addition to that from microtearing modes inmore » a nonlinear turbulent state, leads to a very small or outward convection of momentum, inconsistent with the experimentally measured inward pinch, and opposite to predictions in conventional aspect ratio tokamaks. Additional predictions of a low beta L-mode plasma, unstable to more traditional electrostatic ion temperature gradient-trapped electron mode instability, show that the Coriolis pinch is inward but remains relatively weak and insensitive to many parameter variations. The weak or outward pinch predicted in NSTX plasmas appears to be at least partially correlated to changes in the parallel mode structure that occur at a finite beta and low aspect ratio, as discussed in previous theories. The only conditions identified where a stronger inward pinch is predicted occur either in the purely electrostatic limit or if the aspect ratio is increased. Lastly, as the Coriolis pinch cannot explain the measured momentum pinch, additional theoretical momentum transport mechanisms are discussed that may be potentially important.« less

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

    Office of Scientific and Technical Information (OSTI)

    (Technical Report) | SciTech Connect Comparison of Gas Puff Imaging Data in NSTX with the DEGAS 2 Simulation Citation Details In-Document Search Title: Comparison of Gas Puff Imaging Data in NSTX with the DEGAS 2 Simulation Gas-Pu -Imaging (GPI) is a two dimensional diagnostic which measures the edge Dα light emission from a neutral Dα gas puff near the outer mid- plane of the National Spherical Torus Experiment (NSTX). DEGAS 2 is a 3-D Monte Carlo code used to model neutral transport and

  14. A dual wavelength imaging system for plasma-surface interaction studies on the National Spherical Torus Experiment Upgrade

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

    Scotti, F.; Soukhanovskii, V. A.

    2015-12-09

    A two-channel spectral imaging system based on a charge injection device radiation-hardened intensified camera was built for studies of plasma-surface interactions on divertor plasma facing components in the National Spherical Torus Experiment Upgrade (NSTX-U) tokamak. By means of commercially available mechanically referenced optical components, the two-wavelength setup images the light from the plasma, relayed by a fiber optic bundle, at two different wavelengths side-by-side on the same detector. Remotely controlled filter wheels are used for narrow band pass and neutral density filters on each optical path allowing for simultaneous imaging of emission at wavelengths differing in brightness up to 3more » orders of magnitude. Applications on NSTX-U will include the measurement of impurity influxes in the lower divertor strike point region and the imaging of plasma-material interaction on the head of the surface analysis probe MAPP (Material Analysis and Particle Probe). Furthermore, the diagnostic setup and initial results from its application on the lithium tokamak experiment are presented.« less

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

    SciTech Connect (OSTI)

    Ali Asgarian, M. E-mail: maa@msu.edu; Parvazian, A.; Abbasi, M.; Verboncoeur, J. P.

    2014-09-15

    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.

  16. Analysis Efforts Supporting NSTX Upgrades

    SciTech Connect (OSTI)

    H.Zhang, P. Titus, P. Rogoff, A.Zolfaghari, D. Mangra, M. Smith

    2010-11-29

    The National Spherical Torus Experiment (NSTX) is a low aspect ratio, spherical torus (ST) configuration device which is located at Princeton Plasma Physics Laboratory (PPPL) This device is presently being updated to enhance its physics by doubling the TF field to 1 Tesla and increasing the plasma current to 2 Mega-amperes. The upgrades include a replacement of the centerstack and addition of a second neutral beam. The upgrade analyses have two missions. The first is to support design of new components, principally the centerstack, the second is to qualify existing NSTX components for higher loads, which will increase by a factor of four. Cost efficiency was a design goal for new equipment qualification, and reanalysis of the existing components. Showing that older components can sustain the increased loads has been a challenging effort in which designs had to be developed that would limit loading on weaker components, and would minimize the extent of modifications needed. Two areas representing this effort have been chosen to describe in more details: analysis of the current distribution in the new TF inner legs, and, second, analysis of the out-of-plane support of the existing TF outer legs.

  17. Visible imaging of edge turbulence in NSTX

    SciTech Connect (OSTI)

    S. Zweben; R. Maqueda; K. Hill; D. Johnson; et al

    2000-06-13

    Edge plasma turbulence in tokamaks and stellarators is believed to cause the radical heat and particle flux across the separatrix and into the scrape-off-layers of these devices. This paper describes initial measurements of 2-D space-time structure of the edge density turbulence made using a visible imaging diagnostic in the National Spherical Torus Experiment (NSTX). The structure of the edge turbulence is most clearly visible using a method of gas puff imaging to locally illuminate the edge density turbulence.

  18. Power Supply Changes for NSTX Resistive Wall Mode Coils

    SciTech Connect (OSTI)

    Ramakrishnan, S S.

    2013-06-28

    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.

  19. Associate Research Physicist (Post-doc) - NSTX-U | Princeton Plasma Physics

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

    Lab (Post-doc) - NSTX-U Department: Experimental Supervisor(s): Dr. Luis F. Delgado-Aparicio Staff: RM 1 Requisition Number: 1600451 The Princeton University Plasma Physics Laboratory (PPPL) seeks to fill a post-doctoral research physicist position at the National Spherical Torus Experiment Upgrade (NSTX-U) in Princeton, NJ. For tokamaks and future facilities to operate safely in a high-pressure long-pulse discharge, it is imperative to address key issues associated with impurity sources,

  20. NSTX Diagnostics for Fusion Plasma Science Studies

    SciTech Connect (OSTI)

    R. Kaita; D. Johnson; L. Roquemore; M. Bitter; F. Levinton; F. Paoletti; D. Stutman; and the NSTX Team

    2001-07-05

    This paper will discuss how plasma science issues are addressed by the diagnostics for the National Spherical Torus Experiment (NSTX), the newest large-scale machine in the magnetic confinement fusion (MCF) program. The development of new schemes for plasma confinement involves the interplay of experimental results and theoretical interpretations. A fundamental requirement, for example, is a determination of the equilibria for these configurations. For MCF, this is well established in the solutions of the Grad-Shafranov equation. While it is simple to state its basis in the balance between the kinetic and magnetic pressures, what they are as functions of space and time are often not easy to obtain. Quantities like the plasma pressure and current density are not directly measurable. They are derived from data that are themselves complex products of more basic parameters. The same difficulties apply to the understanding of plasma instabilities. Not only are the needs for spatial and temporal resolution more stringent, but the wave parameters which characterize the instabilities are difficult to resolve. We will show how solutions to the problems of diagnostic design on NSTX, and the physics insight the data analysis provides, benefits both NSTX and the broader scientific community.

  1. Lithium Pellet Injector Development for NSTX

    SciTech Connect (OSTI)

    G. Gettelfinger; J. Dong; R. Gernhardt; H. Kugel; P. Sichta; J. Timberlake

    2003-12-04

    A pellet injector suitable for the injection of lithium and other low-Z pellets of varying mass into plasmas at precise velocities from 5 to 500 m/s is being developed for use on NSTX (National Spherical Torus Experiment). The ability to inject low-Z impurities will significantly expand NSTX experimental capability for a broad range of diagnostic and operational applications. The architecture employs a pellet-carrying cartridge propelled through a guide tube by deuterium gas. Abrupt deceleration of the cartridge at the end of the guide tube results in the pellet continuing along its intended path, thereby giving controlled reproducible velocities for a variety of pellets materials and a reduced gas load to the torus. The planned injector assembly has four hundred guide tubes contained in a rotating magazine with eight tubes provided for injection into plasmas. A PC-based control system is being developed as well and will be described elsewhere in these Proceedings. The development path and mechanical performance of the injector will be described.

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

    SciTech Connect (OSTI)

    Berkery, J. W.; Sabbagh, S. A.; Balbaky, A.; Bell, R. E.; Diallo, A.; Gerhardt, S. P.; LeBlanc, B. P.; Manickam, J.; Menard, J. E.; Podest, M.; Betti, R.

    2014-05-15

    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.

  3. Electron Bernstein Wave Research on CDX-U and NSTX

    SciTech Connect (OSTI)

    Taylor, G.; Efthimion, P.C.; Jones, B.; Hosea, J.C.; Kaita, R.; LeBlanc, B.P.; Majeski, R.; Munsat, T.; Phillips, C.K.; Spaleta, J.; Wilson, J.R.; Rasmussen, D.; Bell, G.; Bigelow, T.S.; Carter, M.D.; Swain, D.W.; Wilgen, J.B.; Ram, A.K.; Bers, A.; Harvey, R.W.; and Forest, C.B.

    2001-05-18

    Mode-converted electron Bernstein waves (EBWs) potentially allow the measurement of local electron temperature (Te) and the implementation of local heating and current drive in spherical torus (ST) devices, which are not directly accessible to low harmonic electron cyclotron waves. This paper reports on the measurement of X-mode radiation mode-converted from EBWs observed normal to the magnetic field on the midplane of the Current Drive Experiment-Upgrade (CDX-U) and the National Spherical Torus Experiment (NSTX) spherical torus plasmas. The radiation temperature of the EBW emission was compared to Te measured by Thomson scattering and Langmuir probes. EBW mode-conversion efficiencies of over 20% were measured on both CDX-U and NSTX. Sudden increases of mode-conversion efficiency, of over a factor of three, were observed at high-confinement-mode transitions on NSTX, when the measured edge density profile steepened. The EBW mode-conversion efficiency was found to depend on the density gradient at the mode-conversion layer in the plasma scrape-off, consistent with theoretical predictions. The EBW emission source was determined by a perturbation technique to be localized at the electron cyclotron resonance layer and was successfully used for radial transport studies. Recently, a new in-vessel antenna and Langmuir probe array were installed on CDX-U to better characterize and enhance the EBW mode-conversion process. The probe incorporates a local adjustable limiter to control and maximize the mode-conversion efficiency in front of the antenna by modifying the density profile in the plasma scrape-off where fundamental EBW mode conversion occurs. Initial results show that the mode-conversion efficiency can be increased to {approximately}100% when the local limiter is inserted near the mode-conversion layer. Plans for future EBW research, including EBW heating and current-drive studies, are discussed.

  4. Progress Towards High Performance, Steady-state Spherical Torus

    SciTech Connect (OSTI)

    M. Ono; M.G. Bell; R.E. Bell; T. Bigelow; M. Bitter; W. Blanchard; J. Boedo; C. Bourdelle; C. Bush; W. Choe; J. Chrzanowski; D.S. Darrow; S.J. Diem; R. Doerner; P.C. Efthimion; J.R. Ferron; R.J. Fonck; E.D. Fredrickson; G.D. Garstka; D.A. Gates; T. Gray; L.R. Grisham; W. Heidbrink; K.W. Hill; D. Hoffman; T.R. Jarboe; D.W. Johnson; R. Kaita; S.M. Kaye; C. Kessel; J.H. Kim; M.W. Kissick; S. Kubota; H.W. Kugel; B.P. LeBlanc; K. Lee; S.G. Lee; B.T. Lewicki; S. Luckhardt; R. Maingi; R. Majeski; J. Manickam; R. Maqueda; T.K. Mau; E. Mazzucato; S.S. Medley; J. Menard; D. Mueller; B.A. Nelson; C. Neumeyer; N. Nishino; C.N. Ostrander; D. Pacella; F. Paoletti; H.K. Park; W. Park; S.F. Paul; Y.-K. M. Peng; C.K. Phillips; R. Pinsker; P.H. Probert; S. Ramakrishnan; R. Raman; M. Redi; A.L. Roquemore; A. Rosenberg; P.M. Ryan; S.A. Sabbagh; M. Schaffer; R.J. Schooff; R. Seraydarian; C.H. Skinner; A.C. Sontag; V. Soukhanovskii; J. Spaleta; T. Stevenson; D. Stutman; D.W. Swain; E. Synakowski; Y. Takase; X. Tang; G. Taylor; J. Timberlake; K.L. Tritz; E.A. Unterberg; A. Von Halle; J. Wilgen; M. Williams; J.R. Wilson; X. Xu; S.J. Zweben; R. Akers; R.E. Barry; P. Beiersdorfer; J.M. Bialek; B. Blagojevic; P.T. Bonoli; M.D. Carter; W. Davis; B. Deng; L. Dudek; J. Egedal; R. Ellis; M. Finkenthal; J. Foley; E. Fredd; A. Glasser; T. Gibney; M. Gilmore; R.J. Goldston; R.E. Hatcher; R.J. Hawryluk; W. Houlberg; R. Harvey; S.C. Jardin; J.C. Hosea; H. Ji; M. Kalish; J. Lowrance; L.L. Lao; F.M. Levinton; N.C. Luhmann; R. Marsala; D. Mastravito; M.M. Menon; O. Mitarai; M. Nagata; G. Oliaro; R. Parsells; T. Peebles; B. Peneflor; D. Piglowski; G.D. Porter; A.K. Ram; M. Rensink; G. Rewoldt; P. Roney; K. Shaing; S. Shiraiwa; P. Sichta; D. Stotler; B.C. Stratton; R. Vero; W.R. Wampler; G.A. Wurden

    2003-10-02

    Research on the Spherical Torus (or Spherical Tokamak) is being pursued to explore the scientific benefits of modifying the field line structure from that in more moderate aspect-ratio devices, such as the conventional tokamak. The Spherical Tours (ST) experiments are being conducted in various U.S. research facilities including the MA-class National Spherical Torus Experiment (NSTX) at Princeton, and three medium-size ST research facilities: Pegasus at University of Wisconsin, HIT-II at University of Washington, and CDX-U at Princeton. In the context of the fusion energy development path being formulated in the U.S., an ST-based Component Test Facility (CTF) and, ultimately a Demo device, are being discussed. For these, it is essential to develop high-performance, steady-state operational scenarios. The relevant scientific issues are energy confinement, MHD stability at high beta (B), noninductive sustainment, ohmic-solenoid-free start-up, and power and particle handling. In the confinement area, the NSTX experiments have shown that the confinement can be up to 50% better than the ITER-98-pby2 H-mode scaling, consistent with the requirements for an ST-based CTF and Demo. In NSTX, CTF-relevant average toroidal beta values bT of up to 35% with the near unity central betaT have been obtained. NSTX will be exploring advanced regimes where bT up to 40% can be sustained through active stabilization of resistive wall modes. To date, the most successful technique for noninductive sustainment in NSTX is the high beta-poloidal regime, where discharges with a high noninductive fraction ({approx}60% bootstrap current + neutral-beam-injected current drive) were sustained over the resistive skin time. Research on radio-frequency-based heating and current drive utilizing HHFW (High Harmonic Fast Wave) and EBW (Electron Bernstein Wave) is also pursued on NSTX, Pegasus, and CDX-U. For noninductive start-up, the Coaxial Helicity Injection (CHI), developed in HIT/HIT-II, has been

  5. Addressing the challenges of plasma-surface interactions in NSTX-U*

    SciTech Connect (OSTI)

    Kaita, Robert; Abrams, Tyler; Jaworski, Michael; Lucia, Matthew; Nichols, Jacob H.; Skinner, Charles H.; Stotler, Daren; Allain, Jean Paul; Bedoya, Felipe

    2015-04-01

    The importance of conditioning plasma-facing components (PFCs) has long been recognized as a critical element in obtaining high-performance plasmas in magnetic confinement devices. Lithium coatings, for example, have been used for decades for conditioning PFCs. Since the initial studies on the Tokamak Fusion Test Reactor, experiments on devices with different aspect ratios and magnetic geometries like the National Spherical Torus Experiment (NSTX) continue to show the relationship between lithium PFCs and good confinement and stability. While such results are promising, their empirical nature do not reflect the detailed relationship between PFCs and the dynamic conditions that occur in the tokamak environment. A first step developing an understanding such complexity will be taken in the upgrade to NSTX (NSTX-U) that is nearing completion. New measurement capabilities include the Materials Analysis and Particle Probe (MAPP) for in situ surface analysis of samples exposed to tokamak plasmas. The OEDGE suite of codes, for example, will provide a new way to model the underlying mechanisms for such material migration in NSTX-U. This will lead to a better understanding of how plasma-facing surfaces evolve during a shot, and how the composition of the plasma facing surface influences the discharge performance we observe. This paper will provide an overview of these capabilities, and highlight their importance for NSTX-U plans to transition from carbon to high-Z PFCs.

  6. Addressing the challenges of plasma-surface interactions in NSTX-U*

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

    Kaita, Robert; Abrams, Tyler; Jaworski, Michael; Lucia, Matthew; Nichols, Jacob H.; Skinner, Charles H.; Stotler, Daren; Allain, Jean Paul; Bedoya, Felipe

    2015-04-01

    The importance of conditioning plasma-facing components (PFCs) has long been recognized as a critical element in obtaining high-performance plasmas in magnetic confinement devices. Lithium coatings, for example, have been used for decades for conditioning PFCs. Since the initial studies on the Tokamak Fusion Test Reactor, experiments on devices with different aspect ratios and magnetic geometries like the National Spherical Torus Experiment (NSTX) continue to show the relationship between lithium PFCs and good confinement and stability. While such results are promising, their empirical nature do not reflect the detailed relationship between PFCs and the dynamic conditions that occur in the tokamakmore » environment. A first step developing an understanding such complexity will be taken in the upgrade to NSTX (NSTX-U) that is nearing completion. New measurement capabilities include the Materials Analysis and Particle Probe (MAPP) for in situ surface analysis of samples exposed to tokamak plasmas. The OEDGE suite of codes, for example, will provide a new way to model the underlying mechanisms for such material migration in NSTX-U. This will lead to a better understanding of how plasma-facing surfaces evolve during a shot, and how the composition of the plasma facing surface influences the discharge performance we observe. This paper will provide an overview of these capabilities, and highlight their importance for NSTX-U plans to transition from carbon to high-Z PFCs.« less

  7. Fast Camera Movies of NSTX Plasmas

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Maqueda, Ricky; Wurden, Glenn

    The National Spherical Torus Experiment (NSTX) is an innovative magnetic fusion device that is being used to study the physics principles of spherically shaped plasmas -- hot ionized gases in which nuclear fusion will occur under the appropriate conditions of temperature, density, and confinement in a magnetic field. Fusion is the energy source of the Sun and all the stars. Scientists believe it can provide an inexhaustible, safe, and environmentally attractive source. NSTX was constructed by the Princeton Plasma Physics Laboratory (PPPL) in conjunction with Oak Ridge National Laboratory, Columbia University, and the University of Washington Seattle. The original TIF images recorded by the KODAK digital camera (i.e., "raw data") are available, using the contact information given on the same web page that provides access to these fast camera movies. MPEG clips are organized under the following headings: • Gas Puff Imaging (GPI) diagnostic • GPI experiments • H-modes (longer) • H-modes (short) • Coaxial Helicity Injection experiments More than 100 MPEGS dating back to 1999 are available for public access.

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

    SciTech Connect (OSTI)

    2013-08-27

    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.

  9. The Role of Lithium Conditioning in Achieving High Performance, Long Pulse H-mode Discharges in the NSTX and EAST Devices

    SciTech Connect (OSTI)

    Maingi, Rajesh; Mansfield, D. K.; Gong, X. Z.; Sun, Z.; Bell, M. G.

    2014-10-01

    In this paper, the role of lithium wall conditioning on the achievement of high performance, long pulse discharges in the National Spherical Torus Experiment (NSTX) and the Experimental Advanced Superconducting Tokamak (EAST) is documented. Common observations include recycling reduction and elimination of ELMs. In NSTX, lithium conditioning typically resulted in ELM-free operation with impurity accumulation, which was ameliorated e.g. with pulsed 3D fields to trigger controlled ELMs. Active lithium conditioning in EAST discharges has overcome this problem, producing an ELM-free Hmode with controlled density and impurities.

  10. An overview of recent physics results from NSTX

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

    Kaye, S. M.; Abrams, T.; Ahn, J. -W.; Allain, J. P.; Andre, R.; Andruczyk, D.; Barchfeld, R.; Battaglia, D.; Bhattacharjee, A.; Bedoya, F.; et al

    2015-03-27

    Currently, the National Spherical Torus Experiment (NSTX) is being upgraded to operate at twice the toroidal field and plasma current (up to 1 T and 2 MA), with a second, more tangentially aimed neutral beam (NB) for current and rotation control, allowing for pulse lengths up to 5 s. Recent NSTX physics analyses have addressed topics that will allow NSTX-Upgrade to achieve the research goals critical to a Fusion Nuclear Science Facility. These include producing stable, 100% non-inductive operation in high-performance plasmas, assessing plasma-material interface (PMI) solutions to handle the high heat loads expected in the next-step devices and exploringmore » the unique spherical torus (ST) parameter regimes to advance predictive capability. Non-inductive operation and current profile control in NSTX-U will be facilitated by co-axial helicity injection (CHI) as well as radio frequency (RF) and NB heating. CHI studies using NIMROD indicate that the reconnection process is consistent with the 2D Sweet-Parker theory. Full-wave AORSA simulations show that RF power losses in the scrape-off layer (SOL) increase significantly for both NSTX and NSTX-U when the launched waves propagate in the SOL. Moreover, Toroidal Alfven eigenmode avalanches and higher frequency Alfven eigenmodes can affect NB-driven current through energy loss and redistribution of fast ions. The inclusion of rotation and kinetic resonances, which depend on collisionality, is necessary for predicting experimental stability thresholds of fast growing ideal wall and resistive wall modes. Neutral beams and neoclassical toroidal viscosity generated from applied 3D fields can be used as actuators to produce rotation profiles optimized for global stability. DEGAS-2 has been used to study the dependence of gas penetration on SOL temperatures and densities for the MGI system being implemented on the Upgrade for disruption mitigation. PMI studies have focused on the effect of ELMs and 3D fields on plasma

  11. NSTX: Facility/Research Highlights and Near Term Facility Plans

    SciTech Connect (OSTI)

    M. Ono

    2008-11-19

    The National Spherical Torus Experiment (NSTX) is a collaborative mega-ampere-class spherical torus research facility with high power heating and current drive systems and the state-of-the-art comprehensive diagnostics. For the 2008 experimental campaign, the high harmonic fast wave (HHFW) heating efficiency in deuterium improved significantly with lithium evaporation and produced a record central Te of 5 keV. The HHFW heating of NBI-heated discharges was also demonstrated for the first time with lithium application. The EBW emission in H-mode was also improved dramatically with lithium which was shown to be attributable to reduced edge collisional absorption. Newly installed FIDA energetic particle diagnostic measured significant transport of energetic ions associated with TAE avalanche as well as n=1 kink activities. A full 75 channel poloidal CHERS system is now operational yielding tantalizing initial results. In the near term, major upgrade activities include a liquid-lithium divertor target to achieve lower collisionality regime, the HHFW antenna upgrades to double its power handling capability in H-mode, and a beam-emission spectroscopy diagnostic to extend the localized turbulence measurements toward the ion gyro-radius scale from the present concentration on the electron gyro-radius scale. For the longer term, a new center stack to significantly expand the plasma operating parameters is planned along with a second NBI system to double the NBI heating and CD power and provide current profile control. These upgrades will enable NSTX to explore fully non-inductive operations over a much expanded plasma parameter space in terms of higher plasma temperature and lower collisionality, thereby significantly reducing the physics parameter gap between the present NSTX and the projected next-step ST experiments.

  12. Simulations towards the achievement of non-inductive current ramp-up and sustainment in the National Spherical Torus Experiment Upgrade

    SciTech Connect (OSTI)

    Poli, F. M.; Andre, R. G.; Bertelli, N.; Gerhardt, S. P.; Mueller, D.; Taylor, G.

    2015-10-30

    One of the goals of the National Spherical Torus Experiment Upgrade (NSTX-U) (Menard et al 2012 Nucl. Fusion 52 083015) is the demonstration of fully non-inductive start-up, current ramp-up and sustainment. This work discusses predictive simulations where the available heating and current drive systems are combined to maximize the non-inductive current and minimize the solenoidal contribution. Radio-frequency waves at harmonics higher than the ion cyclotron resonance (high-harmonic fast waves (HHFW)) and neutral beam injection are used to ramp the plasma current non-inductively starting from an initial Ohmic plasma. An interesting synergy is observed in the simulations between the HHFW and electron cyclotron (EC) wave heating. Furthermore, time-dependent simulations indicate that, depending on the phasing of the HHFW antenna, EC wave heating can significantly increase the effectiveness of the radio-frequency power, by heating the electrons and increasing the current drive efficiency, thus relaxing the requirements on the level of HHFW power that needs to be absorbed in the core plasma to drive the same amount of fast-wave current.

  13. Simulations towards the achievement of non-inductive current ramp-up and sustainment in the National Spherical Torus Experiment Upgrade

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

    Poli, F. M.; Andre, R. G.; Bertelli, N.; Gerhardt, S. P.; Mueller, D.; Taylor, G.

    2015-10-30

    One of the goals of the National Spherical Torus Experiment Upgrade (NSTX-U) (Menard et al 2012 Nucl. Fusion 52 083015) is the demonstration of fully non-inductive start-up, current ramp-up and sustainment. This work discusses predictive simulations where the available heating and current drive systems are combined to maximize the non-inductive current and minimize the solenoidal contribution. Radio-frequency waves at harmonics higher than the ion cyclotron resonance (high-harmonic fast waves (HHFW)) and neutral beam injection are used to ramp the plasma current non-inductively starting from an initial Ohmic plasma. An interesting synergy is observed in the simulations between the HHFW andmore » electron cyclotron (EC) wave heating. Furthermore, time-dependent simulations indicate that, depending on the phasing of the HHFW antenna, EC wave heating can significantly increase the effectiveness of the radio-frequency power, by heating the electrons and increasing the current drive efficiency, thus relaxing the requirements on the level of HHFW power that needs to be absorbed in the core plasma to drive the same amount of fast-wave current.« less

  14. The contribution of radio-frequency rectification to field-aligned losses of high-harmonic fast wave power to the divertor in the National Spherical Torus eXperiment

    SciTech Connect (OSTI)

    Perkins, R. J. Hosea, J. C.; Jaworski, M. A.; Diallo, A.; Bell, R. E.; Bertelli, N.; Gerhardt, S.; Kramer, G. J.; LeBlanc, B. P.; Phillips, C. K.; Podestà, M.; Roquemore, L.; Taylor, G.; Wilson, J. R.; Ahn, J.-W.; Gray, T. K.; McLean, A.; Sabbagh, S.

    2015-04-15

    The National Spherical Torus eXperiment (NSTX) can exhibit a major loss of high-harmonic fast wave (HHFW) power along scrape-off layer (SOL) field lines passing in front of the antenna, resulting in bright and hot spirals on both the upper and lower divertor regions. One possible mechanism for this loss is RF sheaths forming at the divertors. Here, we demonstrate that swept-voltage Langmuir probe characteristics for probes under the spiral are shifted relative to those not under the spiral in a manner consistent with RF rectification. We estimate both the magnitude of the RF voltage across the sheath and the sheath heat flux transmission coefficient in the presence of the RF field. Although precise comparison between the computed heat flux and infrared (IR) thermography cannot yet be made, the computed heat deposition compares favorably with the projections from IR camera measurements. The RF sheath losses are significant and contribute substantially to the total SOL losses of HHFW power to the divertor for the cases studied. This work will guide future experimentation on NSTX-U, where a wide-angle IR camera and a dedicated set of coaxial Langmuir probes for measuring the RF sheath voltage directly will quantify the contribution of RF sheath rectification to the heat deposition from the SOL to the divertor.

  15. Status and Plans for the National Spherical Torus Experimental Research Facility

    SciTech Connect (OSTI)

    M. Ono; M.G. Bell; R.E. Bell; J.M. Bialek; T. Bigelow; M. Bitter; plus 148 additional authors

    2005-07-27

    An overview of the research capabilities and the future plans on the MA-class National Spherical Torus Experiment (NSTX) at Princeton is presented. NSTX research is exploring the scientific benefits of modifying the field line structure from that in more conventional aspect ratio devices, such as the tokamak. The relevant scientific issues pursued on NSTX include energy confinement, MHD stability at high beta, non-inductive sustainment, solenoid-free start-up, and power and particle handling. In support of the NSTX research goal, research tools are being developed by the NSTX team. In the context of the fusion energy development path being formulated in the US, an ST-based Component Test Facility (CTF) and, ultimately a high beta Demo device based on the ST, are being considered. For these, it is essential to develop high performance (high beta and high confinement), steady-state (non-inductively driven) ST operational scenarios and an efficient solenoid-free start-up concept. We will also briefly describe the Next-Step-ST (NSST) device being designed to address these issues in fusion-relevant plasma conditions.

  16. PPPL intern creates software for snapshot of plasma in NSTX-U | Princeton

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

    Plasma Physics Lab PPPL intern creates software for snapshot of plasma in NSTX-U By Jeanne Jackson DeVoe September 2, 2016 Tweet Widget Google Plus One Share on Facebook Max Wallace, a Community College intern from Laney College in Oakland, California, shows fellow intern Priya Jaglal a poster on his research during a student poster session at PPPL on Aug. 10. Wallace developed software to allow scientists to get a quick snapshot of experiments on the National Spherical Torus

  17. Advanced ST Plasma Scenario Simulations for NSTX

    SciTech Connect (OSTI)

    C.E. Kessel; E.J. Synakowski; D.A. Gates; R.W. Harvey; S.M. Kaye; T.K. Mau; J. Menard; C.K. Phillips; G. Taylor; R. Wilson; the NSTX Research Team

    2004-10-28

    Integrated scenario simulations are done for NSTX [National Spherical Torus Experiment] that address four primary milestones for developing advanced ST configurations: high {beta} and high {beta}{sub N} inductive discharges to study all aspects of ST physics in the high-beta regime; non-inductively sustained discharges for flattop times greater than the skin time to study the various current-drive techniques; non-inductively sustained discharges at high {beta} for flattop times much greater than a skin time which provides the integrated advanced ST target for NSTX; and non-solenoidal start-up and plasma current ramp-up. The simulations done here use the Tokamak Simulation Code (TSC) and are based on a discharge 109070. TRANSP analysis of the discharge provided the thermal diffusivities for electrons and ions, the neutral-beam (NB) deposition profile, and other characteristics. CURRAY is used to calculate the High Harmonic Fast Wave (HHFW) heating depositions and current drive. GENRAY/CQL3D is used to establish the heating and CD [current drive] deposition profiles for electron Bernstein waves (EBW). Analysis of the ideal-MHD stability is done with JSOLVER, BALMSC, and PEST2. The simulations indicate that the integrated advanced ST plasma is reachable, obtaining stable plasmas with {beta} {approx} 40% at {beta}{sub N}'s of 7.7-9, I{sub P} = 1.0 MA, and B{sub T} = 0.35 T. The plasma is 100% non-inductive and has a flattop of 4 skin times. The resulting global energy confinement corresponds to a multiplier of H{sub 98(y,2)} = 1.5. The simulations have demonstrated the importance of HHFW heating and CD, EBW off-axis CD, strong plasma shaping, density control, and early heating/H-mode transition for producing and optimizing these plasma configurations.

  18. 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)

    Sechrest, Y.; Munsat, T.; D’Ippolito, D. A.; Maqueda, R. J.; Myra, J. R.; Russell, D.; Zweben, S. J.

    2011-01-01

    Fluctuations in the edge and scrape-off layer (SOL) of L-mode plasmas in the National Spherical Torus Experiment (NSTX) 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 Dα light contained in the SOL, which acts as a measure of turbulentmore » 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.« less

  19. Analysis of NSTX Upgrade OH Magnet and Center Stack

    SciTech Connect (OSTI)

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

    2010-11-30

    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.

  20. Solenoid-free Plasma Startup in NSTX using Coaxial Helicity Injection

    SciTech Connect (OSTI)

    Roger Raman; Thomas R. Jarboe; Michael G. Bell; Dennis Mueller; Brian A. Nelson; Benoit LeBlanc; Charles Bush; Masayoshi Nagata; Ted Biewer

    2005-01-03

    The favorable properties of the Spherical Torus (ST) arise from its very small aspect ratio. However, small aspect ratio devices have very restricted space for a substantial central solenoid. Thus methods for initiating the plasma current without relying on induction from a central solenoid are essential for the viability of the ST concept. Coaxial Helicity Injection (CHI) is a promising candidate for solenoid-free plasma startup in a ST. Recent experiments on the HIT-II ST at the University of Washington, have demonstrated the capability of a new method, referred to as transient CHI, to produce a high quality, closed-flux equilibrium that has then been coupled to induction, with a reduced requirement for transformer flux [R. Raman, T.R. Jarboe, B.A. Nelson, et al., Phys. Rev. Lett. 90 (February 2003) 075005-1]. An initial test of this method on the National Spherical Torus Experiment (NSTX) has produced about 140 kA of toroidal current. Modifications are now underway to improve capability for transient CHI in NSTX.

  1. Recent Progress on Spherical Torus Research

    SciTech Connect (OSTI)

    Ono, Masayuki; Kaita, Robert

    2014-01-01

    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 β (radio of plasma to magnetic pressure) stability limit increases rapidly, approximately as β ~ 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 κ, 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.

  2. Techniques for the measurement of disruption halo currents in the National Spherical Torus Experiment

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

    Gerhardt, S. P.; Fredrickson, E.; Guttadora, L.; Kaita, R.; Kugel, H.; Menard, J.; Takahashi, H.

    2011-10-06

    This paper describes techniques for measuring halo currents, and their associated toroidal peaking, in the National Spherical Torus Experiments. The measurements are based on three techniques: (i) measurement of the toroidal field created by the poloidal halo current, either with segmented Rogowski coils or discrete toroidal field sensors, (ii) the direct measurement of halo currents into specially instrument tiles, and (iii) small Rogowski coils placed on the mechanical supports of in-vessel components. For the segmented Rogowski coils and discrete toroidal field detectors, it is shown that the toroidal peaking factor inferred from the data is significantly less than the peakingmore » factor of the underlying halo current distribution, and a simple model is developed to relate the two. For the array of discrete toroidal field detectors and small Rogowski sensors, the compensation steps that are used to isolate the halo current signal are described. The electrical and mechanical design of compact under-tile resistive shunts and mini-Rogowski coils is described. Example data from the various systems is shown.« less

  3. Fast response of electron-scale turbulence to auxiliary heating cessation in National Spherical Torus Experiment

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

    Ren, Y.; Wang, W. X.; LeBlanc, B. P.; Guttenfelder, W.; Kaye, S. M.; Ethier, S.; Mazzucato, E.; Lee, K. C.; Domier, C. W.; Bell, R.; et al

    2015-11-03

    In this letter, we report the first observation of the fast response of electron-scale turbulence to auxiliary heating cessation in National Spherical Torus eXperiment [Ono et al., Nucl. Fusion 40, 557 (2000)]. The observation was made in a set of RF-heated L-mode plasmas with toroidal magnetic field of 0.55 T and plasma current of 300 kA. It is observed that electron-scale turbulence spectral power (measured with a high-k collective microwave scattering system) decreases significantly following fast cessation of RF heating that occurs in less than 200 μs. The large drop in the turbulence spectral power has a short time delaymore » of about 1–2 ms relative to the RF cessation and happens on a time scale of 0.5–1 ms, much smaller than the energy confinement time of about 10 ms. Power balance analysis shows a factor of about 2 decrease in electron thermal diffusivity after the sudden drop of turbulence spectral power. Measured small changes in equilibrium profiles across the RF cessation are unlikely able to explain this sudden reduction in the measured turbulence and decrease in electron thermal transport, supported by local linear stability analysis and both local and global nonlinear gyrokinetic simulations. Furthermore, the observations imply that nonlocal flux-driven mechanism may be important for the observed turbulence and electron thermal transport.« less

  4. Characterization of the plasma current quench during disruptions in the National Spherical Torus Experiment

    SciTech Connect (OSTI)

    Gerhardt, S.P., Menard, J.E., and the NSTX Research Team

    2008-12-17

    A detailed analysis of the plasma current quench in the National Spherical Torus Experiment [M.Ono, et al Nuclear Fusion 40, 557 (2000)] is presented. The fastest current quenches are fit better by a linear waveform than an exponential one. Area-normalized current quench times down to .4 msec/m2 have been observed, compared to the minimum of 1.7 msec/m2 recommendation based on conventional aspect ratio tokamaks; as noted in previous ITPA studies, the difference can be explained by the reduced self-inductance at low aspect ratio and high-elongation. The maximum instantaneous dIp/dt is often many times larger than the mean quench rate, and the plasma current before the disruption is often substantially less than the flat-top value. The poloidal field time-derivative during the disruption, which is directly responsible for driving eddy currents, has been recorded at various locations around the vessel. The Ip quench rate, plasma motion, and magnetic geometry all play important roles in determining the rate of poloidal field change.

  5. Snowflake divertor configuration studies for NSTX-Upgrade

    SciTech Connect (OSTI)

    Soukhanovskii, V A

    2011-11-12

    Snowflake divertor experiments in NSTX provide basis for PMI development toward NSTX-Upgrade. Snowflake configuration formation was followed by radiative detachment. Significant reduction of steady-state divertor heat flux observed in snowflake divertor. Impulsive heat loads due to Type I ELMs are partially mitigated in snowflake divertor. Magnetic control of snowflake divertor configuration is being developed. Plasma material interface development is critical for NSTX-U success. Four divertor coils should enable flexibility in boundary shaping and control in NSTX-U. Snowflake divertor experiments in NSTX provide good basis for PMI development in NSTX-Upgrade. FY 2009-2010 snowflake divertor experiments in NSTX: (1) Helped understand control of magnetic properties; (2) Core H-mode confinement unchanged; (3) Core and edge carbon concentration reduced; and (4) Divertor heat flux significantly reduced - (a) Steady-state reduction due to geometry and radiative detachment, (b) Encouraging results for transient heat flux handling, (c) Combined with impurity-seeded radiative divertor. Outlook for snowflake divertor in NSTX-Upgrade: (1) 2D fluid modeling of snowflake divertor properties scaling - (a) Edge and divertor transport, radiation, detachment threshold, (b) Compatibility with cryo-pump and lithium conditioning; (2) Magnetic control development; and (3) PFC development - PFC alignment and PFC material choice.

  6. Dependence of Recycling and Edge Profiles on Lithium Evaporation in High Triangularity, High Performance NSTX H-mode Discharges

    SciTech Connect (OSTI)

    Maingi, R; Osborne, T H; Bell, M G; Bell, R E; Boyle, D P; Canik, J M; Dialla, A; Kaita, R; Kaye, S M; Kugel, H W; LeBlanc, B P; Sabbagh, S A; Skinner, C H; Soukhanovskii, V A

    2014-04-01

    In this paper, the effects of a pre-discharge lithium evaporation scan on highly shaped discharges in the National Spherical Torus Experiment (NSTX) are documented. Lithium wall conditioning ('dose') was routinely applied onto graphite plasma facing components between discharges in NSTX, partly to reduce recycling. Reduced D[sub]α emission from the lower and upper divertor and center stack was observed, as well as reduced midplane neutral pressure; the magnitude of reduction increased with the pre-discharge lithium dose. Improved energy confinement, both raw τ[sub]E and H-factor normalized to scalings, with increasing lithium dose was also observed. At the highest doses, we also observed elimination of edge-localized modes. The midplane edge plasma profiles were dramatically altered, comparable to lithium dose scans at lower shaping, where the strike point was farther from the lithium deposition centroid. This indicates that the benefits of lithium conditioning should apply to the highly shaped plasmas planned in NSTX-U.

  7. Energy Secretary Moniz Launches the Nation's Newest Fusion Experiment at

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

    PPPL | Princeton Plasma Physics Lab Energy Secretary Moniz Launches the Nation's Newest Fusion Experiment at PPPL National Spherical Torus Experiment - Upgrade will help determine the course of fusion energy for years to come By Larry Bernard May 20, 2016 Tweet Widget Google Plus One Share on Facebook U.S. Energy Secretary Ernest Moniz, center, in the NSTX-U test cell. From left: PPPL physicist Stefan Gerhardt; Princeton University President Christopher L. Eisgruber; Princeton University

  8. Ion heating during magnetic relaxation in the helicity injected torus-II experiment

    SciTech Connect (OSTI)

    O'Neill, R.G.; Redd, A.J.; Hamp, W.T.; Smith, R.J.; Jarboe, T.R.

    2005-12-15

    Ion doppler spectroscopy (IDS) is applied to the helicity injected torus (HIT-II) spherical torus to measure impurity ion temperature and flows. [A. J. Redd et al., Phys. Plasmas 9, 2006 (2002)] The IDS instrument employs a 16-channel photomultiplier and can track temperature and velocity continuously through a discharge. Data for the coaxial helicity injection (CHI), transformer, and combined current drive configurations are presented. Ion temperatures for transformer-driven discharges are typically equal to or somewhat lower than electron temperatures measured by Thomson scattering. Internal reconnection events in transformer-driven discharges cause rapid ion heating. The CHI discharges exhibit anomalously high ion temperatures >250 eV, which are an order of magnitude higher than Thomson measurements, indicating ion heating through magnetic relaxation. The CHI discharges that exhibit current and poloidal flux buildup after bubble burst show sustained ion heating during current drive.

  9. NSTX-U Advances in Real-Time C++11 on Linux

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

    Erickson, Keith G.

    2015-08-14

    Programming languages like C and Ada combined with proprietary embedded operating systems have dominated the real-time application space for decades. The new C++11standard includes native, language-level support for concurrency, a required feature for any nontrivial event-oriented real-time software. Threads, Locks, and Atomics now exist to provide the necessary tools to build the structures that make up the foundation of a complex real-time system. The National Spherical Torus Experiment Upgrade (NSTX-U) at the Princeton Plasma Physics Laboratory (PPPL) is breaking new ground with the language as applied to the needs of fusion devices. A new Digital Coil Protection System (DCPS) willmore »serve as the main protection mechanism for the magnetic coils, and it is written entirely in C++11 running on Concurrent Computer Corporation's real-time operating system, RedHawk Linux. It runs over 600 algorithms in a 5 kHz control loop that determine whether or not to shut down operations before physical damage occurs. To accomplish this, NSTX-U engineers developed software tools that do not currently exist elsewhere, including real-time atomic synchronization, real-time containers, and a real-time logging framework. Together with a recent (and carefully configured) version of the GCC compiler, these tools enable data acquisition, processing, and output using a conventional operating system to meet a hard real-time deadline (that is, missing one periodic is a failure) of 200 microseconds.« less

  10. NSTX-U Advances in Real-Time C++11 on Linux

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

    Erickson, Keith G.

    2015-08-14

    Programming languages like C and Ada combined with proprietary embedded operating systems have dominated the real-time application space for decades. The new C++11standard includes native, language-level support for concurrency, a required feature for any nontrivial event-oriented real-time software. Threads, Locks, and Atomics now exist to provide the necessary tools to build the structures that make up the foundation of a complex real-time system. The National Spherical Torus Experiment Upgrade (NSTX-U) at the Princeton Plasma Physics Laboratory (PPPL) is breaking new ground with the language as applied to the needs of fusion devices. A new Digital Coil Protection System (DCPS) willmore » serve as the main protection mechanism for the magnetic coils, and it is written entirely in C++11 running on Concurrent Computer Corporation's real-time operating system, RedHawk Linux. It runs over 600 algorithms in a 5 kHz control loop that determine whether or not to shut down operations before physical damage occurs. To accomplish this, NSTX-U engineers developed software tools that do not currently exist elsewhere, including real-time atomic synchronization, real-time containers, and a real-time logging framework. Together with a recent (and carefully configured) version of the GCC compiler, these tools enable data acquisition, processing, and output using a conventional operating system to meet a hard real-time deadline (that is, missing one periodic is a failure) of 200 microseconds.« less

  11. NSTX-U Advances in Real-Time C++11 on Linux

    SciTech Connect (OSTI)

    Erickson, Keith G.

    2015-08-14

    Programming languages like C and Ada combined with proprietary embedded operating systems have dominated the real-time application space for decades. The new C++11standard includes native, language-level support for concurrency, a required feature for any nontrivial event-oriented real-time software. Threads, Locks, and Atomics now exist to provide the necessary tools to build the structures that make up the foundation of a complex real-time system. The National Spherical Torus Experiment Upgrade (NSTX-U) at the Princeton Plasma Physics Laboratory (PPPL) is breaking new ground with the language as applied to the needs of fusion devices. A new Digital Coil Protection System (DCPS) will serve as the main protection mechanism for the magnetic coils, and it is written entirely in C++11 running on Concurrent Computer Corporation's real-time operating system, RedHawk Linux. It runs over 600 algorithms in a 5 kHz control loop that determine whether or not to shut down operations before physical damage occurs. To accomplish this, NSTX-U engineers developed software tools that do not currently exist elsewhere, including real-time atomic synchronization, real-time containers, and a real-time logging framework. Together with a recent (and carefully configured) version of the GCC compiler, these tools enable data acquisition, processing, and output using a conventional operating system to meet a hard real-time deadline (that is, missing one periodic is a failure) of 200 microseconds.

  12. Local Effects of Biased Electrodes in the Divertor of NSTX

    Office of Scientific and Technical Information (OSTI)

    ... Evidence for convective cell formation induced by non-axisymmetric biased electrodes was previously obtained in JFT-2M 11, CASTOR 15, and MAST 18. A prior experiment on NSTX ...

  13. Electron Bernstein wave-bootstrap current synergy in the National Spherical Torus Experiment

    SciTech Connect (OSTI)

    Harvey, R.W.; Taylor, G.

    2005-05-15

    Current driven by electron Bernstein waves (EBW) and by the electron bootstrap effect are calculated separately and concurrently with a kinetic code to determine the degree of synergy between them. A target {beta}=40% NSTX [M. Ono, S. Kaye, M. Peng et al., Proceedings of the 17th IAEA Fusion Energy Conference, edited by M. Spak (IAEA, Vienna, Austria, 1999), Vol. 3, p. 1135] plasma is examined. A simple bootstrap model in the collisional-quasilinear CQL3D Fokker-Planck code (National Technical Information Service document No. DE93002962) is used in these studies: the transiting electron distributions are connected in velocity space at the trapped-passing boundary to trapped-electron distributions that are displaced radially by a half-banana-width outwards/inwards for the co-passing/counter-passing regions. This model agrees well with standard bootstrap current calculations over the outer 60% of the plasma radius. Relatively small synergy net bootstrap current is obtained for EBW power up to 4 MW. Locally, bootstrap current density increases in proportion to increased plasma pressure, and this effect can significantly affect the radial profile of driven current.

  14. NSTX power supply real time controller

    SciTech Connect (OSTI)

    Neumeyer, C.; Hatcher, R.; Marsala, R.; Ramakrishnan, S.

    2000-01-06

    The NSTX is a new national facility for the study of plasma confinement, heating, and current drive in a low aspect ratio, spherical torus (ST) configuration. The ST configuration is an alternate magnetic confinement concept which is characterized by high beta (ratio plasma pressure to magnetic field pressure) and low toroidal field compared to conventional tokamaks, and could provide a pathway to the realization of a practical fusion power source. The NSTX depends on a real time, high speed, synchronous, and deterministic control system acting on a system of thyristor rectifier power supplies to (1) establish the initial magnetic field configuration; (2) initiate plasma within the vacuum vessel; (3) inductively drive plasma current; and (4) control plasma position and shape. For the initial ``day 0'' 1st plasma operations (Feb. 1999), the system was limited to closed loop proportional-integral current control of the power supplies based on preprogrammed reference waveforms. For the ``day 1'' phase of operations beginning Sept. 1999 the loop has been closed on plasma current and position. This paper focuses on the Power Supply Real Time Controller (PSRTC).

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

    SciTech Connect (OSTI)

    Mardenfeld, Michael

    2013-07-01

    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.

  16. Evaluation of thermal helium beam and line-ratio fast diagnostic on the National Spherical Torus Experiment-Upgrade

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

    Munoz Burgos, Jorge M.; Agostini, Matteo; Scarin, Paolo; Stotler, Daren P.; Unterberg, Ezekial A.; Loch, Stuart D.; Schmitz, Oliver; Tritz, Kevin; Stutman, Dan

    2015-05-06

    A 1-D kinetic collisional radiative model (CRM) with state-of-the-art atomic data is developed and employed to simulate line emission to evaluate the Thermal Helium Beam (THB) diagnostic on NSTX-U. This diagnostic is currently in operation on RFX-mod, and it is proposed to be installed on NSTX-U. The THB system uses the intensity ratios of neutral helium lines 667.8, 706.5, and 728.1 nm to derive electron temperature (eV ) and density (cm–3) profiles. The purpose of the present analysis is to evaluate the applications of this diagnostic for determining fast (~4 μs) electron temperature and density radial profiles on the scrape-offmore » layer (SOL) and edge regions of NSTX-U that are needed in turbulence studies. The diagnostic is limited by the level of detection of the 728.1 nm line, which is the weakest of the three. In conclusion, this study will also aid in future design of a similar 2-D diagnostic systems on the divertor.« less

  17. NSTX-U Control System Upgrades

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

    Erickson, K. G.; Gates, D. A.; Gerhardt, S. P.; Lawson, J. E.; Mozulay, R.; Sichta, P.; Tchilinguirian, G. J.

    2014-06-01

    The National Spherical Tokamak Experiment (NSTX) is undergoing a wealth of upgrades (NSTX-U). These upgrades, especially including an elongated pulse length, require broad changes to the control system that has served NSTX well. A new fiber serial Front Panel Data Port input and output (I/O) stream will supersede the aging copper parallel version. Driver support for the new I/O and cyber security concerns require updating the operating system from Redhat Enterprise Linux (RHEL) v4 to RedHawk (based on RHEL) v6. While the basic control system continues to use the General Atomics Plasma Control System (GA PCS), the effort to forwardmore » port the entire software package to run under 64-bit Linux instead of 32-bit Linux included PCS modifications subsequently shared with GA and other PCS users. Software updates focused on three key areas: (1) code modernization through coding standards (C99/C11), (2) code portability and maintainability through use of the GA PCS code generator, and (3) support of 64-bit platforms. Central to the control system upgrade is the use of a complete real time (RT) Linux platform provided by Concurrent Computer Corporation, consisting of a computer (iHawk), an operating system and drivers (RedHawk), and RT tools (NightStar). Strong vendor support coupled with an extensive RT toolset influenced this decision. The new real-time Linux platform, I/O, and software engineering will foster enhanced capability and performance for NSTX-U plasma control.« less

  18. Progress in understanding the enhanced pedestal H-mode in NSTX

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

    Gerhardt, S. P.; Canik, J. M.; Maingi, R.; Battaglia, D.; Bell, R. E.; Guttenfelder, W.; LeBlanc, B. P.; Smith, D. R.; Yuh, H.; Sabbagh, S.

    2014-08-01

    The 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 themore » 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.« less

  19. Progress In Understanding The Enhanced Petestal H-mode In NSTX

    SciTech Connect (OSTI)

    Gerhardt, S. P.; Canik, J. M.; Maingi, R.; Battaglia, D.; Bell, R. E.; Guttenfelder, W.; LeBlanc, B. P.; Smith, D. R.; Yuh, H.; Sabbagh, S.

    2014-06-26

    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.

  20. Progress in understanding the enhanced pedestal H-mode in NSTX

    SciTech Connect (OSTI)

    Gerhardt, S. P.; Canik, J. M.; Maingi, R.; Battaglia, D.; Bell, R. E.; Guttenfelder, W.; LeBlanc, B. P.; Smith, D. R.; Yuh, H.; Sabbagh, S.

    2014-08-01

    The 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.

  1. Edge transport studies in the edge and scrape-off layer of the National Spherical Torus Experiment with Langmuir probes

    SciTech Connect (OSTI)

    Boedo, J. A. Rudakov, D. L.; Myra, J. R.; D'Ippolito, D. A.; Zweben, S.; Maingi, R.; Maqueda, R. J.; Bell, R.; Kugel, H.; Leblanc, B.; Roquemore, L. A.; Soukhanovskii, V. A.; Ahn, J. W.; Canik, J.; Crocker, N.

    2014-04-15

    Transport and turbulence profiles were directly evaluated using probes for the first time in the edge and scrape-off layer (SOL) of NSTX [Ono et al., Nucl. Fusion 40, 557 (2000)] in low (L) and high (H) confinement, low power (P{sub in}? 1.3?MW), beam-heated, lower single-null discharges. Radial turbulent particle fluxes peak near the last closed flux surface (LCFS) at ?410{sup 21}?s{sup ?1} in L-mode and are suppressed to ?0.210{sup 21}?s{sup ?1} in H mode (80%90% lower) mostly due to a reduction in density fluctuation amplitude and of the phase between density and radial velocity fluctuations. The radial particle fluxes are consistent with particle inventory based on SOLPS fluid modeling. A strong intermittent component is identified. Hot, dense plasma filaments 410?cm in diameter, appear first ?2?cm inside the LCFS at a rate of ?110{sup 21}?s{sup ?1} and leave that region with radial speeds of ?35?km/s, decaying as they travel through the SOL, while voids travel inward toward the core. Profiles of normalized fluctuations feature levels of 10% inside LCFS to ?150% at the LCFS and SOL. Once properly normalized, the intermittency in NSTX falls in similar electrostatic instability regimes as seen in other devices. The L-H transition causes a drop in the intermittent filaments velocity, amplitude and number in the SOL, resulting in reduced outward transport away from the edge and a less dense SOL.

  2. Mitigation of Alfvenic activity by 3D magnetic perturbations on NSTX

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

    Kramer, G. J.; Bortolon, A.; Ferraro, N. M.; Spong, D. A.; Crocker, N. A.; Darrow, D. S.; Fredrickson, E. D.; Kubota, S.; Park, J. -K.; Podesta, M.; et al

    2016-05-20

    Observations on the National Spherical Torus eXperiment (NSTX) indicate that externally applied non-axisymmetric magnetic perturbations (MP) can reduce the amplitude of Toroidal Alfv´en Eigenmodes (TAE) and Global Alf´ven Eigenmodes (GAE) in response to pulsed n=3 non-resonant fields. From full-orbit following Monte Carlo simulations with the 1- and 2-fluid resistive MHD plasma response to the magnetic perturbation included, it was found that in response to MP pulses the fast-ion losses increased and the fast-ion drive for the GAEs was reduced. The MP did not affect the fast-ion drive for the TAEs significantly but the Alfv´en continuum at the plasma edge wasmore » found to be altered due to the toroidal symmetry breaking which leads to coupling of different toroidal harmonics. The TAE gap was reduced at the edge creating enhanced continuum damping of the global TAEs, which is consistent with the observations. Furthermore, the results suggest that optimized non-axisymmetric MP might be exploited to control and mitigate Alfv´en instabilities by tailoring the fast-ion distribution function and/or continuum structure.« less

  3. Dependence of various SOL widths on plasma current and density in NSTX H-mode plasmas

    SciTech Connect (OSTI)

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

    2009-02-12

    The dependence of various SOL widths on the line-averaged density ({ovr n}{sub e}) and plasma current (l{sub p}) for the quiescent H-mode plasmas with Type-V ELMs in the National Spherical Torus Experiment (NSTX) was investigated. It is found that the heat flux SOL width ({lambda}{sub q}), measured by the IR camera, is virtually insensitive to {ovr n}{sub e} and has a strong negative dependence on l{sub p}. This insensitivity of {lambda}{sub q} to {ovr n}{sub e} is consistent with the scaling law from JET H-mode plasmas that shows a very weak dependence on the upstream density. The electron temperature, ion saturation current density, electron density, and electron pressure decay lengths ({lambda}{sub Te}, {lambda}{sub jsat}, {lambda}{sub ne}, and {lambda}{sub pe}, respectively) measured by the probe showed that {lambda}{sub Te} and {lambda}{sub jsat} have strong negative dependence on l{sub p}, whereas {lambda}{sub ne} and {lambda}{sub pe} revealed only a little or no dependence. The dependence of {lambda}{sub Te} on l{sub p} is consistent with the scaling law in the literature while {lambda}{sub ne} and {lambda}{sub pe} dependence shows a different trend.

  4. Development of a radio frequency ion source with multi-helicon plasma injectors for neutral beam injection system of Versatile Experiment Spherical Torus

    SciTech Connect (OSTI)

    Choe, Kyumin; Jung, Bongki; Chung, Kyoung-Jae; Hwang, Y. S.; Center for Advance Research in Fusion Reactor Engineering, Seoul National University, Seoul 151-744

    2014-02-15

    Despite of high plasma density, helicon plasma has not yet been applied to a large area ion source such as a driver for neutral beam injection (NBI) system due to intrinsically poor plasma uniformity in the discharge region. In this study, a radio-frequency (RF) ion source with multi-helicon plasma injectors for high plasma density with good uniformity has been designed and constructed for the NBI system of Versatile Experiment Spherical Torus at Seoul National University. The ion source consists of a rectangular plasma expansion chamber (120 120 120 mm{sup 3}), four helicon plasma injectors with annular permanent magnets and RF power system. Main feature of the source is downstream plasma confinement in the cusp magnetic field configuration which is generated by arranging polarities of permanent magnets in the helicon plasma injectors. In this paper, detailed design of the multi-helicon plasma injector and plasma characteristics of the ion source are presented.

  5. News | Princeton Plasma Physics Lab

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

    Torus Experiment-Upgrade. Technicians inspect the new center stack that forms the heart of the NSTX-U. The new neutral beam box arrives in the NSTX-U test cell. The NSTX-U...

  6. NSTX Plasma Response to Lithium Coated Divertor

    SciTech Connect (OSTI)

    H.W. Kugel, M.G. Bell, J.P. Allain, R.E. Bell, S. Ding, S.P. Gerhardt, M.A. Jaworski, R. Kaita, J. Kallman, S.M. Kaye, B.P. LeBlanc, R. Maingi, R. Majeski, R. Maqueda, D.K. Mansfield, D. Mueller, R. Nygren, S.F. Paul, R. Raman, A.L. Roquemore, S.A. Sabbagh, H. Schneider, C.H. Skinner, V.A. Soukhanovskii, C.N. Taylor, J.R. Timberlak, W.R. Wampler, L.E. Zakharov, S.J. Zweben, and the NSTX Research Team

    2011-01-21

    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 Zeff 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.

  7. NSTX-U Press Kit | Princeton Plasma Physics Lab

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

    Overview Experimental Fusion Research Theoretical Fusion Research Basic Plasma Science Plasma Astrophysics Other Physics and Engineering Research PPPL Technical Reports NSTX-U Education Organization Contact Us Overview Experimental Fusion Research Theoretical Fusion Research Basic Plasma Science Plasma Astrophysics Other Physics and Engineering Research PPPL Technical Reports NSTX-U NSTX-U Press Kit Upgraded NSTX center stack. (photo by Elle Starkman/ PPPL Office of Communications The NSTX-U

  8. Lithium Wall Conditioning And Surface Dust Detection On NSTX

    SciTech Connect (OSTI)

    Skinner, C H; Bell, M G; Friesen, F.Q.L.; Heim, B; Jaworski, M A; Kugel, H; Maingi, R; Rais, B

    2011-05-23

    Lithium evaporation onto NSTX plasma facing components (PFC) has resulted in improved energy confinement, and reductions in the number and amplitude of edge-localized modes (ELMs) up to the point of complete ELM suppression. The associated PFC surface chemistry has been investigated with a novel plasma material interface probe connected to an in-vacuo surface analysis station. Analysis has demonstrated that binding of D atoms to the polycrystalline graphite material of the PFCs is fundamentally changed by lithium - in particular deuterium atoms become weakly bonded near lithium atoms themselves bound to either oxygen or the carbon from the underlying material. Surface dust inside NSTX has been detected in real-time using a highly sensitive electrostatic dust detector. In a separate experiment, electrostatic removal of dust via three concentric spiral-shaped electrodes covered by a dielectric and driven by a high voltage 3-phase waveform was evaluated for potential application to fusion reactors

  9. Lithium Surface Coatings for Improved Plasma Performance in NSTX

    SciTech Connect (OSTI)

    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

    2008-02-19

    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.

  10. Design and Construction of the NSTX Bakeout, Cooling and Vacuum Systems

    SciTech Connect (OSTI)

    L.E. Dudek; M. Kalish; R. Gernhardt; R.F. Parsells; W. Blanchard

    1999-11-01

    This paper will describe the design, construction and initial operation of the NSTX bakeout, water cooling and vacuum systems. The bakeout system is designed for two modes of operation. The first mode allows heating of the first wall components to 350 degrees C while the external vessel is cooled to 150 degrees C. The second mode cools the first wall to 150 degrees C and the external vessel to 50 degrees C. The system uses a low viscosity heat transfer oil which is capable of high temperature low pressure operation. The NSTX Torus Vacuum Pumping System (TVPS) is designed to achieve a base pressure of approximately 1x10 (superscript -8) Torr and to evacuate the plasma fuel gas loads in less than 5 minutes between discharges. The vacuum pumping system is capable of a pumping speed of approximately 3400 l/s for deuterium. The hardware consists of two turbo molecular pumps (TMPs) and a mechanical pump set consisting of a mechanical and a Roots blower pump. A PLC is used as the control system to provide remote monitoring, control and software interlock capability. The NSTX cooling water provides chilled, de ionized water for heat removal in the TF, OH and PF, power supplies, bus bar systems, and various diagnostics. The system provides flow monitoring via a PLC to prevent damage due to loss of flow.

  11. Simulation of Diffusive Lithium Evaporation Onto the NSTX Vessel Walls

    SciTech Connect (OSTI)

    Stotler, D. P.; Skinner, C. H.; Blanchard, W. R.; Krstic, P. S.; Kugel, H. W.; Schneider, H.; Zakharov, L. E.

    2010-12-09

    A model for simulating the diffusive evaporation of lithium into a helium filled NSTX vacuum vessel is described and validated against an initial set of deposition experiments. The DEGAS 2 based model consists of a three-dimensional representation of the vacuum vessel, the elastic scattering process, and a kinetic description of the evaporated atoms. Additional assumptions are required to account for deuterium out-gassing during the validation experiments. The model agrees with the data over a range of pressures to within the estimated uncertainties. Suggestions are made for more discriminating experiments that will lead to an improved model.

  12. MPI Multicore Torus Communication Benchmark

    Energy Science and Technology Software Center (OSTI)

    2008-02-05

    The MPI Multicore Torus Communications Benchmark (TorusTest) measues the aggegate bandwidth across all six links from/to any multicore node in a logical torus. It can run in wo modi: using a static or a random mapping of tasks to torus locations. The former can be used to achieve optimal mappings and aggregate bandwidths that can be achieved with varying node mappings.

  13. Spherical torus fusion reactor

    DOE Patents [OSTI]

    Martin Peng, Y.K.M.

    1985-10-03

    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.

  14. Effect of Lithium PFC Coatings on NSTX Density Control (Journal...

    Office of Scientific and Technical Information (OSTI)

    Effect of Lithium PFC Coatings on NSTX Density Control Citation Details In-Document Search Title: Effect of Lithium PFC Coatings on NSTX Density Control Lithium coatings on the ...

  15. Effect of Lithium PFC Coatings on NSTX Density Control (Journal...

    Office of Scientific and Technical Information (OSTI)

    Effect of Lithium PFC Coatings on NSTX Density Control Citation Details In-Document Search Title: Effect of Lithium PFC Coatings on NSTX Density Control You are accessing a ...

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

    SciTech Connect (OSTI)

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

    2012-10-27

    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.

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

    SciTech Connect (OSTI)

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

    2012-11-08

    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. __________________________________________________

  18. Intermittency in the Scrape-off Layer of the National Spherical Torus Experiment During H-mode Confinement

    SciTech Connect (OSTI)

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

    2010-11-22

    A gas puff imaging diagnostic is used in the National Spherical Tokamak Experiment [M. Ono, et al., Nucl. Fusion 40, 557 (2000)] to study the edge turbulence and intermittency present during H-mode discharges. In the case of low power Ohmic H-modes the suppression of turbulence/blobs is maintained through the duration of the (short lived) H-modes. Similar quiescent edges are seen during the early stages of H-modes created with the use of neutral beam injection. Nevertheless, as time progresses following the L-H transition, turbulence and blobs reappear although at a lower level than that typically seen during L-mode confinement. It is also seen that the time-averaged SOL emission profile broadens, as the power loss across the separatrix increases. These broad profiles are characterized by a large level of fluctuations and intermittent events.

  19. Implementation of BN Control in the National Spherical Torus...

    Office of Scientific and Technical Information (OSTI)

    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...

  20. Spherical torus fusion reactor

    DOE Patents [OSTI]

    Peng, Yueng-Kay M.

    1989-04-04

    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.

  1. Spherical torus fusion reactor

    DOE Patents [OSTI]

    Peng, Yueng-Kay M.

    1989-01-01

    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.

  2. Microsoft Word - 9-Menard.doc

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

    March 2015 Scientific Opportunities and Challenges in the Upgraded National Spherical Torus Experiment* Dr. Jonathan Menard Program Director for the National Spherical Torus eXperiment - Upgrade (NSTX-U) Princeton Plasma Physics Laboratory Princeton, NJ ABSTRACT: Upon completion, the National Spherical Torus Experiment - Upgrade (NSTX-U) will be the most capable spherical torus (ST) facility in the world fusion program. A major mission of NSTX-U is to develop the physics and technology basis for

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

    SciTech Connect (OSTI)

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

    2012-09-19

    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.

  4. NSTX Report on FES Joint Facilities Research Milestone 2010

    SciTech Connect (OSTI)

    Maingi, R.; Ahn, J- W.; Gray, T. K.; McLean, A. G.; Soukhanovskii, V. A.

    2011-03-24

    Annual Target: Conduct experiments on major fusion facilities to improve understanding of the heat transport in the tokamak scrape-off layer (SOL) plasma, strengthening the basis for projecting divertor conditions in ITER. The divertor heat flux profiles and plasma characteristics in the tokamak scrape-off layer will be measured in multiple devices to investigate the underlying thermal transport processes. The unique characteristics of C-Mod, DIII-D, and NSTX will enable collection of data over a broad range of SOL and divertor parameters (e.g., collisionality ?*, beta ?, parallel heat flux q||, and divertor geometry). Coordinated experiments using common analysis methods will generate a data set that will be compared with theory and simulation.

  5. Detection of Disruptions in the High-β Spherical Torus NSTX...

    Office of Scientific and Technical Information (OSTI)

    Publisher: Nuclear Fusion (January 2013) Research Org: Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States) Sponsoring Org: USDOE Office of Science (SC) ...

  6. Detection of Disruptions in the High-β Spherical Torus NSTX

    Office of Scientific and Technical Information (OSTI)

    ... This actual point total is based on that associated with a 1.5% false positive rate; see discussion below for motivation on the connections between point totals and false positive ...

  7. Numerical optimization of three-dimensional coils for NSTX-U

    SciTech Connect (OSTI)

    Lazerson, S. A.; Park, J. -K.; Logan, N.; Boozer, A.

    2015-09-03

    A tool for the calculation of optimal three-dimensional (3D) perturbative magnetic fields in tokamaks has been developed. The IPECOPT code builds upon the stellarator optimization code STELLOPT to allow for optimization of linear ideal magnetohydrodynamic perturbed equilibrium (IPEC). This tool has been applied to NSTX-U equilibria, addressing which fields are the most effective at driving NTV torques. The NTV torque calculation is performed by the PENT code. Optimization of the normal field spectrum shows that fields with n = 1 character can drive a large core torque. It is also shown that fields with n = 3 features are capable of driving edge torque and some core torque. Coil current optimization (using the planned in-vessel and existing RWM coils) on NSTX-U suggest the planned coils set is adequate for core and edge torque control. In conclusion, comparison between error field correction experiments on DIII-D and the optimizer show good agreement.

  8. Kelsey Tresemer | Princeton Plasma Physics Lab

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

    Tresemer has been the primary design engineer and cost account manager for plasma-facing components for the National Spherical Torus Experiment (NSTX), and currently serves as...

  9. Research | U.S. DOE Office of Science (SC)

    Office of Science (SC) Website

    The primary goal of ITER is achieving and maintaining a burning plasma with a peak output ... Torus Experiment (NSTX) at Princeton Plasma Physics Laboratory (PPPL) in Princeton, ...

  10. Edge Turbulence Velocity Changes with Lithium Coating on NSTX

    SciTech Connect (OSTI)

    Cao, A.; Zweben, S. J.; Stotler, D. P.; Bell, M.; Diallo, A.; Kaye, S. M.; LeBlanc, B.

    2012-08-10

    Lithium coating improves energy confinement and eliminates edge localized modes in NSTX, but the mechanism of this improvement is not yet well understood. We used the gas-puff-imaging (GPI) diagnostic on NSTX to measure the changes in edge turbulence which occurred during a scan with variable lithium wall coating, in order to help understand the reason for the confinement improvement with lithium. There was a small increase in the edge turbulence poloidal velocity and a decrease in the poloidal velocity fluctuation level with increased lithium. The possible effect of varying edge neutral density on turbulence damping was evaluated for these cases in NSTX. __________________________________________________

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

    SciTech Connect (OSTI)

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

    2009-01-05

    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.

  12. Reduced model simulations of the scrape-off-layer heat-flux width and comparison with experiment

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

    Myra, J. R.; Russell, D. A.; D’Ippolito, D. A.; Ahn, J.-W.; Maingi, R.; Maqueda, R. J.; Lundberg, D. P.; Stotler, D. P.; Zweben, S. J.; Boedo, J.; et al

    2011-01-01

    Reduced model simulations of turbulence in the edge and scrape-off-layer (SOL) region of a spherical torus or tokamak plasma are employed to address the physics of the scrape-off-layer heat flux width. The simulation model is an electrostatic two-dimensional fluid turbulence model, applied in the plane perpendicular to the magnetic field at the outboard midplane of the torus. The model contains curvature-driven-interchange modes, sheath losses, and both perpendicular turbulent diffusive and convective (blob) transport. These transport processes compete with classical parallel transport to set the SOL width. Midplane SOL profiles of density, temperature and parallel heat flux are obtained from themore » simulation and compared with experimental results from the National Spherical Torus Experiment (NSTX) to study the scaling of the heat flux width with power and plasma current. It is concluded that midplane turbulence is the main contributor to the SOL heat flux width for the low power H-mode discharges studied, while additional physics is required to explain the plasma current scaling of the SOL heat flux width observed experimentally in higher power discharges. Intermittent separatrix spanning convective cells are found to be the main mechanism that sets the near-SOL width in the simulations. The roles of sheared flows and blob trapping vs. emission are discussed.« less

  13. Unusual emission lines of carbon in the 170-190 A region on NSTX...

    Office of Scientific and Technical Information (OSTI)

    Unusual emission lines of carbon in the 170-190 A region on NSTX Citation Details In-Document Search Title: Unusual emission lines of carbon in the 170-190 A region on NSTX You...

  14. Fast soft x-ray images of magnetohydrodynamic phenomena in NSTX...

    Office of Scientific and Technical Information (OSTI)

    Fast soft x-ray images of magnetohydrodynamic phenomena in NSTX Citation Details In-Document Search Title: Fast soft x-ray images of magnetohydrodynamic phenomena in NSTX A variety ...

  15. Unusual emission lines of carbon in the 170-190 A region on NSTX...

    Office of Scientific and Technical Information (OSTI)

    Unusual emission lines of carbon in the 170-190 A region on NSTX Citation Details In-Document Search Title: Unusual emission lines of carbon in the 170-190 A region on NSTX Authors: ...

  16. Developing the digital safeguard that protects the National Spherical Torus

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

    Experiment-Upgrade at PPPL | Princeton Plasma Physics Lab Developing the digital safeguard that protects the National Spherical Torus Experiment-Upgrade at PPPL By John Greenwald February 22, 2016 Tweet Widget Google Plus One Share on Facebook Members of the team that developed the DCPS, from left: Gretchen Zimmer, Kevin Lamb, Greg Tchillingarian, Paul Sichta, John Lawson, Tim Stevenson, Stefan Gerhardt and Roman Rozenblat. Not shown: Vince Mastrocola, John Dong, Gary Gibilisco. (Photo by

  17. Developing the digital safeguard that protects the National Spherical Torus

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

    Experiment-Upgrade at PPPL | Princeton Plasma Physics Lab Developing the digital safeguard that protects the National Spherical Torus Experiment-Upgrade at PPPL By John Greenwald February 22, 2016 Tweet Widget Google Plus One Share on Facebook Members of the team that developed the DCPS, from left: Gretchen Zimmer, Kevin Lamb, Greg Tchillingarian, Paul Sichta, John Lawson, Tim Stevenson, Stefan Gerhardt and Roman Rozenblat. Not shown: Vince Mastrocola, John Dong, Gary Gibilisco. (Photo by

  18. Dynamics of the Disruption Halo Current Toroidal Asymmetry in NSTX

    SciTech Connect (OSTI)

    S.P. Gerhardt

    2012-09-27

    This paper describes the dynamics of disruption halo current non-axisymmetries in the lower divertor of the National Spherical Torus Experiment [M. Ono, et al. Nuclear Fusion 40, 557 (2000)]. While. The halo currents typically have a strongly asymmetric structure where they enter the divertor floor, and this asymmetry has been observed to complete up to 7 toroidal revolutions over the duration of the halo current pulse. However, the rotation speed and toroidal extend of the asymmetry can vary significantly during the pulse. The rotation speed, halo current pulse duration, and total number of revolutions tend to be smaller in cases with large halo currents. The halo current pattern is observed to become toroidally symmetric at the end of the halo current pulse. It is proposed that this symmeterization is due to the loss of most or all of the closed field line geometry in the final phase of the vertical displacement event.

  19. Implications of NSTX Lithium Results for Magnetic Fusion Research

    SciTech Connect (OSTI)

    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

    2010-01-14

    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.

  20. CONSTRUCTING THE NATIONAL Spherical Torus Experiment Upgrade...

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

    ... 5 a.m. to check emails each day. He oversaw the progress of construction twice every morning and twice in the afternoon, seven days a week, then rechecked emails at 10 p.m. when ...

  1. Numerical optimization of three-dimensional coils for NSTX-U

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

    Lazerson, S. A.; Park, J. -K.; Logan, N.; Boozer, A.

    2015-09-03

    A tool for the calculation of optimal three-dimensional (3D) perturbative magnetic fields in tokamaks has been developed. The IPECOPT code builds upon the stellarator optimization code STELLOPT to allow for optimization of linear ideal magnetohydrodynamic perturbed equilibrium (IPEC). This tool has been applied to NSTX-U equilibria, addressing which fields are the most effective at driving NTV torques. The NTV torque calculation is performed by the PENT code. Optimization of the normal field spectrum shows that fields with n = 1 character can drive a large core torque. It is also shown that fields with n = 3 features are capablemore » of driving edge torque and some core torque. Coil current optimization (using the planned in-vessel and existing RWM coils) on NSTX-U suggest the planned coils set is adequate for core and edge torque control. In conclusion, comparison between error field correction experiments on DIII-D and the optimizer show good agreement.« less

  2. 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

  3. Jonathan E Menard | Princeton Plasma Physics Lab

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

    Jonathan E Menard Principal Research Physicst, Program Director for NSTX Jonathan Menard is program director for the National Spherical Torus Experiment-Upgrade (NSTX-U) and is responsible for guiding the scientific research program of NSTX-U working with an international research team. His research interests include the magnetohydrodynamic (MHD) equilibrium and stability properties of spherical torus (ST) and tokamak plasmas, advanced operating scenarios in the ST, and the development of next-

  4. HEATING AND CURRENT DRIVE IN NSTX WITH ELECTRON BERNSTEIN WAVES AND HIGH HARMONIC FAST WAVES

    SciTech Connect (OSTI)

    Ram, Abhay K

    2010-06-14

    A suitable theoretical and computational framework for studying heating and current drive by electron Bernstein waves in the National Spherical Torus Experiment has been developed. This framework can also be used to study heating and current drive by electron Bernstein waves in spherical tori and other magnetic confinement devices. It is also useful in studying the propagation and damping of electron cyclotron waves in the International Thermonuclear Experimental Reactor

  5. Upward-facing Lithium Flash Evaporator for NSTX-U

    SciTech Connect (OSTI)

    Roquemore, A. L.

    2013-07-09

    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.

  6. Masayuki Ono | Princeton Plasma Physics Lab

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

    Masayuki Ono Principal Research Physicist, Head, NSTX Department Masa Ono is project director of the National Spherical Torus Experiment-Upgrade (NSTX-U). Ono has led a number of PPPL research teams including those involved in the Advanced Concept Torus (ACT-1), the Current Drive Experiment (CDX), the Current Drive Experiment Upgrade (CDX-U) and the NSTX. He is a fellow of the American Physical Society and the author of more than 250 scientific papers. Interests Fusion energy NSTX-U Contact

  7. Results from the NSTX X-ray Crystal Spectrometer

    SciTech Connect (OSTI)

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

    2003-01-14

    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.

  8. Energy Secretary Moniz Launches the Nation's Newest Fusion Experiment...

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

    Energy Secretary Moniz Launches the Nation's Newest Fusion Experiment at PPPL National ... One Share on Facebook U.S. Energy Secretary Ernest Moniz, center, in the NSTX-U test cell. ...

  9. Raman Spectroscopy of Carbon Dust Samples from NSTX

    SciTech Connect (OSTI)

    Y. Raitses, C.H. Skinner, F. Jiang and T.S. Duffy

    2008-02-21

    The Raman spectrum of dust particles exposed to the NSTX plasma is different from the spectrum of unexposed particles scraped from an unused graphite tile. For the unexposed particles, the high energy G-mode peak (Raman shift ~1580 cm-1) is much stronger than the defect-induced D-mode peak (Raman shift ~ 1350 cm-1), a pattern that is consistent with Raman spectrum for commercial graphite materials. For dust particles exposed to the plasma, the ratio of G-mode to D-mode peaks is lower and becomes even less than 1. The Raman measurements indicate that the production of carbon dust particles in NSTX involves modifications of the physical and chemical structure of the original graphite material. These modifications are shown to be similar to those measured for carbon deposits from atmospheric pressure helium arc discharge with an ablating anode electrode made from a graphite tile material. We also demonstrate experimentally that heating to 2000-2700 K alone can not explain the observed structural modifications indicating that they must be due to higher temperatures needed for graphite vaporization, which is followed either by condensation or some plasma-induced processes leading to the formation of more disordered forms of carbon material than the original graphite.

  10. Lithium Coatings on NSTX Plasma Facing Components and Its Effects On Boundary Control, Core Plasma Performance, and Operation

    SciTech Connect (OSTI)

    H.W.Kugel, M.G.Bell, H.Schneider, J.P.Allain, R.E.Bell, R Kaita, J.Kallman, S. Kaye, B.P. LeBlanc, D. Mansfield, R.E. Nygen, R. Maingi, J. Menard, D. Mueller, M. Ono, S. Paul, S.Gerhardt, R.Raman, S.Sabbagh, C.H.Skinner, V.Soukhanovskii, J.Timberlake, L.E.Zakharov, and the NSTX Research Team

    2010-01-25

    NSTX high-power divertor plasma experiments have used in succession lithium pellet injection (LPI), evaporated lithium, and injected lithium powder to apply lithium coatings to graphite plasma facing components. In 2005, following wall conditioning and LPI, discharges exhibited edge density reduction and performance improvements. Since 2006, first one, and now two lithium evaporators have been used routinely to evaporate lithium onto the lower divertor region at total rates of 10-70 mg/min for periods 5-10 min between discharges. Prior to each discharge, the evaporators are withdrawn behind shutters. Significant improvements in the performance of NBI heated divertor discharges resulting from these lithium depositions were observed. These evaporators are now used for more than 80% of NSTX discharges. Initial work with injecting fine lithium powder into the edge of NBI heated deuterium discharges yielded comparable changes in performance. Several operational issues encountered with lithium wall conditions, and the special procedures needed for vessel entry are discussed. The next step in this work is installation of a Liquid Lithium Divertor surface on the outer part of the lower divertor.

  11. Lithium coatings on NSTX plasma facing components and its effects on boundary control, core plasma performance, and operation

    SciTech Connect (OSTI)

    Kugel, H. W.; Bell, M. G.; Maingi, R.

    2010-01-01

    NSTX high power divertor plasma experiments have used in succession lithium pellet injection (LPI), evaporated lithium, and injected lithium powder to apply lithium coatings to graphite plasma facing components. In 2005, following the wall conditioning and LPI, discharges exhibited edge density reduction and performance improvements. Since 2006, first one, and now two lithium evaporators have been used routinely to evaporate lithium onto the lower divertor region at total rates of 10-70 mg/min for periods 5-10 min between discharges. Prior to each discharge, the evaporators are withdrawn behind shutters. Significant improvements in the performance of NBI heated divertor discharges resulting from these lithium depositions were observed. These evaporators are now used for more than 80% of NSTX discharges. Initial work with injecting fine lithium powder into the edge of NBI heated deuterium discharges yielded comparable changes in performance. Several operational issues encountered with lithium wall conditions, and the special procedures needed for vessel entry are discussed. The next step in this work is installation of a liquid lithium divertor surface on the outer part of the lower divertor.

  12. Central safety factor and β N control on NSTX-U via beam power...

    Office of Scientific and Technical Information (OSTI)

    Central safety factor and N control on NSTX-U via beam power and plasma boundary shape ... Citation Details In-Document Search Title: Central safety factor and N control on ...

  13. Local Scrape-Off Layer Control Using Biased electrodes in NSTX...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Local Scrape-Off Layer Control Using Biased electrodes in NSTX Citation Details In-Document Search Title: Local Scrape-Off Layer Control Using Biased electrodes in ...

  14. NSTX-U Advances in Real-time C++11 on Linux | Princeton Plasma...

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

    NSTX-U Advances in Real-time C++11 on Linux Programming languages like C and Ada combined ... The new C++11 standard includes native, language-level support for concurrency, a ...

  15. Panel ensures safe operation of the $94 million NSTX Upgrade | Princeton

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

    Plasma Physics Lab Panel ensures safe operation of the $94 million NSTX Upgrade By John Greenwald January 15, 2015 Tweet Widget Google Plus One Share on Facebook Members inspect the chief operating engineer's station in the NSTX-U control room. Seated from left, John Lacenere, Larry Dudek. Standing from left, Anthony Indelicato, Tracy Estes, Stefan Gerhardt, Tim Stevenson, Al von Halle, Jerry Levine, Charles Gentile. (Photo by Elle Starkman/PPPL Office of Communications) Members inspect the

  16. Overview of innovative PMI research on NSTX-U and associated PMI facilities at PPPL

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

    M. Ono; Jaworski, M.; Kaita, R.; Skinner, C. N.; Allain, J. P.; Maingi, R.; Scotti, F.; Soukhanovskii, V. A.

    2013-05-01

    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 NSTX-U, the PMI research has received a strong emphasis. Moreover, 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.

  17. Frelinghuysen, Holt visit PPPL to report on bipartisan efforts...

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

    U.S. Rep. Rush Holt (D-NJ-12), Plainsboro Mayor Peter Cantu, and PPPL Director Stewart Prager next to the National Spherical Torus Experiment (NSTX) during a June 13 visit...

  18. DOE Policy for Digital Research Data Management: Resources at...

    Energy Savers [EERE]

    Facility Host Institution Data Management Resources DIII-D General Atomics Link National Spherical Torus Experiment (NSTX) PPPL Link Alcator C-Mod MIT Link High Energy Physics (HEP...

  19. Arithmetic functions in torus and tree networks

    DOE Patents [OSTI]

    Bhanot, Gyan; Blumrich, Matthias A.; Chen, Dong; Gara, Alan G.; Giampapa, Mark E.; Heidelberger, Philip; Steinmacher-Burow, Burkhard D.; Vranas, Pavlos M.

    2007-12-25

    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.

  20. NSTX-U IS ONE OF AN ELITE GROUP

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

    U IS ONE OF AN ELITE GROUP of magnetic fusion facilities scattered across the globe. These powerful and complex machines are advancing mankind's quest to harness fusion as a safe, clean and abundant source of energy for producing electricity. Here is a selection of major facilities. Joint European Torus (JET) Location: Culham Centre for Fusion Energy in the United Kingdom Start Date: 1984 Major Radius: 2.96 meters Magnetic Field Strength: 3.45 teslas JET is the largest tokamak now in operation.

  1. NSTX Protection And Interlock Systems For Coil And Powers Supply Systems

    SciTech Connect (OSTI)

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

    2009-09-24

    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.

  2. Mechanical Design of the NSTX Liquid Lithium Divertor

    SciTech Connect (OSTI)

    R. Ellis, R. Kaita, H. Kugel, G. Paluzzi, M. Viola and R. Nygren

    2009-02-19

    The Liquid Lithium Divertor (LLD) on NSTX will be the first test of a fully-toroidal liquid lithium divertor in a high-power magnetic confinement device. It will replace part of the lower outboard divertor between a specified inside and outside radius, and ultimately provide a lithium surface exposed to the plasma with enough depth to absorb a significant particle flux. There are numerous technical challenges involved in the design. The lithium layer must be as thin as possible, and maintained at a temperature between 200 and 400 degrees Celsius to minimize lithium evaporation. This requirement leads to the use of a thick copper substrate, with a thin stainless steel layer bonded to the plasma-facing surface. A porous molybdenum layer is then plasma-sprayed onto the stainless steel, to provide a coating that facilitates full wetting of the surface by the liquid lithium. Other challenges include the design of a robust, vacuumcompatible heating and cooling system for the LLD. Replacement graphite tiles that provided the proper interface between the existing outer divertor and the LLD also had to be designed, as well as accommodation for special LLD diagnostics. This paper describes the mechanical design of the LLD, and presents analyses showing the performance limits of the LLD.

  3. Divertor Heat Flux Mitigation in the National Spherical Torus...

    Office of Scientific and Technical Information (OSTI)

    for both ITER and spherical torus-based devices with compact high power density divertors. ... Fusion 40, 557 2000 using high magnetic flux expansion at the divertor strike point and ...

  4. Torus through Integrated Data Analysis Mark Nornberg Matthew...

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

    Z eff in the Madison Symmetric Torus through Integrated Data Analysis Mark Nornberg Matthew Galante (Nova Photonics) L.M. Reusch, D.J. Den Hartog, J.R. Johnson, M.B. McGarry H. D. ...

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

    SciTech Connect (OSTI)

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

    2014-06-01

    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.

  6. Nonlinear coupling of tearing fluctuations in the Madison Symmetric Torus

    SciTech Connect (OSTI)

    Sarff, J.S.; Almagri, A.F.; Cekic, M.; Den Hartog, D.J.; Fiksel, G.; Hokin, S.A.; Ji, H.; Prager, S.C.; Shen, W.; Stoneking, M.R.; Assadi, S.; Sidikman, K.L.

    1992-11-01

    Three-wave, nonlinear, tearing mode coupling has been measured in the Madison Symmetric Torus (MST) reversed-field pinch (RFP) [Fusion Technol. 19, 131 (1991)] using bispectral analysis of edge magnetic fluctuations resolved in ``k-space. The strength of nonlinear three-wave interactions satisfying the sum rules m{sub 1} + m{sub 2} = m{sub 3} and n{sub 1} + n{sub 2} = n{sub 3} is measured by the bicoherency. In the RFP, m=l, n{approximately}2R/a (6 for MST) internally resonant modes are linearly unstable and grow to large amplitude. Large values of bicoherency occur for two m=l modes coupled to an m=2 mode and the coupling of intermediate toroidal modes, e.g., n=6 and 7 coupled to n=13. These experimental bispectral features agree with predicted bispectral features derived from MHD computation. However, in the experiment, enhanced coupling occurs in the ``crash`` phase of a sawtooth oscillation concomitant with a broadened mode spectrum suggesting the onset of a nonlinear cascade.

  7. Nonlinear coupling of tearing fluctuations in the Madison Symmetric Torus

    SciTech Connect (OSTI)

    Sarff, J.S.; Almagri, A.F.; Cekic, M.; Den Hartog, D.J.; Fiksel, G.; Hokin, S.A.; Ji, H.; Prager, S.C.; Shen, W.; Stoneking, M.R. ); Assadi, S. ); Sidikman, K.L. )

    1992-11-01

    Three-wave, nonlinear, tearing mode coupling has been measured in the Madison Symmetric Torus (MST) reversed-field pinch (RFP) [Fusion Technol. 19, 131 (1991)] using bispectral analysis of edge magnetic fluctuations resolved in k-space. The strength of nonlinear three-wave interactions satisfying the sum rules m[sub 1] + m[sub 2] = m[sub 3] and n[sub 1] + n[sub 2] = n[sub 3] is measured by the bicoherency. In the RFP, m=l, n[approximately]2R/a (6 for MST) internally resonant modes are linearly unstable and grow to large amplitude. Large values of bicoherency occur for two m=l modes coupled to an m=2 mode and the coupling of intermediate toroidal modes, e.g., n=6 and 7 coupled to n=13. These experimental bispectral features agree with predicted bispectral features derived from MHD computation. However, in the experiment, enhanced coupling occurs in the crash'' phase of a sawtooth oscillation concomitant with a broadened mode spectrum suggesting the onset of a nonlinear cascade.

  8. Reversed-field pinch studies in the Madison Symmetric Torus

    SciTech Connect (OSTI)

    Hokin, S.; Almagri, A.; Cekic, M.; Chapman, B.; Crocker, N.; Den Hartog, D.J.; Fiksel, G.; Henry, J.; Ji, H.; Prager, S.; Sarff, J.; Scime, E.; Shen, W.; Stoneking, M.; Watts, C.

    1993-04-03

    Studies of large-size (R = 1.5 m, a = 0.5 m), moderate current (I < 750 kA) reversed-field pinch (RFP) plasmas are carried out in the Madison Symmetric Torus in order to evaluate and improve RFP confinement, study general toroidal plasma MHD issues, determine the mechanism of the RFP dynamo, and measure fluctuation-induced transport and anomalous ion heating. MST confinement has been improved by reduction of magnetic field errors with correction coils in the primary circuit and reduction of impurities using boronization; high densities have been achieved with hydrogen pellet injection. MHD tearing modes with poloidal mode number m = 1 and toroidal mode numbers n = 5--7 are prevalent and nonlinearly couple to produce sudden relaxations akin to tokamak sawteeth. Edge fluctuation-induced transport has been measured with a variety of insertable probes. Ions exhibit anomalous heating, with increases of ion temperature occuring during strong MHD relaxation. The RFP dynamo has been studied with attention to various possible mechanisms, including motion-EMF drive, the Hall effect, and superthermal electrons. Initial profile control experiments have begun using insertable biased probes and plasma guns. The toroidal field capacity of MST will be upgraded during Summer, 1993 to allow low-current tokamak operation as well as improved RFP operation.

  9. The CLAS12 Torus Detector Magnet at Jefferson Laboratory

    SciTech Connect (OSTI)

    Luongo, Cesar; Ballard, Joshua; Biallas, George; Elouadrhiri, Latifa; Fair, Ruben; Ghoshal, Probir; Kashy, Dave; Legg, Robert; Pastor, Orlando; Rajput-Ghoshal, Renuka; Rode, Claus; Wiseman, Mark; Young, Glenn; Elementi, Luciano; Krave, Steven; Makarov, Alexander; Nobrega, Fred; Velev, George

    2015-12-17

    The CLAS12 Torus is a toroidal superconducting magnet, which is part of the detector for the 12-GeV accelerator upgrade at Jefferson Laboratory (JLab). The coils were wound/fabricated by Fermilab, with JLab responsible for all other parts of the project scope, including design, integration, cryostating the individual coils, installation, cryogenics, I&C, etc. This paper provides an overview of the CLAS12 Torus magnet features and serves as a status report of its installation in the experimental hall. Completion and commissioning of the magnet is expected in 2016.

  10. Maass Cusp Forms on Singly Punctured Two-Torus

    SciTech Connect (OSTI)

    Siddig, Abubaker Ahmed Mohamed [Laboratory of Computational Sciences and Informatics, Institute for Mathematical Research Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Shah, Nurisya Mohd [Theoretical Physics Group, Department of Physics, Faculty of Science Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Zainuddin, Hishamuddin [Laboratory of Computational Sciences and Informatics, Institute for Mathematical Research Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Theoretical Physics Group, Department of Physics, Faculty of Science Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia)

    2009-07-07

    Quantum mechanical systems on punctured surfaces modeled by hyperbolic spaces can play an interesting role in exploring quantum chaos and in studying behaviour of future quantum nano-devices. The case of singly-punctured two-torus, for example, has been well-studied in the literature particularly for its scattering states. However, the bound states on the punctured torus given by Maass cusp forms are lesser known. In this note, we report on the algorithm of numerically computing these functions and we present ten lower-lying eigenvalues for each odd and even Maass cusp forms.

  11. The CLAS12 torus detector magnet at Jefferson Laboratory

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

    Luongo, Cesar; Wiseman, Mark A.; Kashy, David H.; Pastor, Orlando; Ghoshal, Probir K.; Fair, Ruben J.; Ballard, Joshua T.; Legg, Robert A.; Rajput-Ghoshal, Renuka; Biallas, George H.; et al

    2015-12-17

    The CLAS12 Torus is a toroidal superconducting magnet, part of the detector for the 12GeV accelerator upgrade at Jefferson Lab. The coils were wound/fabricated by Fermi Lab, with Jlab responsible for all other parts of the project scope, including design, integration, cryostating the individual coils, installation, cryogenics, I&C, etc. The study provides an overview of the CLAS12 Torus magnet features, and serves as a status report of its installation in the experimental hall. Completion and commissioning of the magnet is expected in 2016.

  12. Hole in one: Technicians smoothly install the center stack in the NSTX-U

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

    vacuum vessel | Princeton Plasma Physics Lab Hole in one: Technicians smoothly install the center stack in the NSTX-U vacuum vessel By John Greenwald November 10, 2014 Tweet Widget Google Plus One Share on Facebook Closeup of the center stack being lowered into position by an overhead crane. (Photo by Elle Starkman/PPPL Office of Communications) Closeup of the center stack being lowered into position by an overhead crane. Gallery: Technicians guide the unit into place. (Photo by Elle

  13. Fivefold confinement time increase in the Madison Symmetric Torus using inductive poloidal current drive

    SciTech Connect (OSTI)

    Stoneking, M.R.; Lanier, N.E.; Prager, S.C.; Sarff, J.S.; Sinitsyn, D.

    1996-12-01

    Current profile control is employed in the Madison Symmetric Torus reversed field pinch to reduce the magnetic fluctuations responsible for anomalous transport. An inductive poloidal electric field pulse is applied in the sense to flatten the parallel current profile, reducing the dynamo fluctuation amplitude required to sustain the equilibrium. This technique demonstrates a substantial reduction in fluctuation amplitude (as much as 50%), and improvement in energy confinement (from 1 ms to 5 ms); a record low fluctuation (0.8%) and record high temperature (615 eV) for this device were observed simultaneously during current drive experiments. Plasma beta increases by 50% and the Ohmic input power is three times lower. Particle confinement improves and plasma impurity contamination is reduced. The results of the transient current drive experiments provide motivation for continuing development of steady-state current profile control strategies for the reversed field pinch.

  14. Stefan Gerhardt | Princeton Plasma Physics Lab

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

    Stefan Gerhardt Principal Research Physicist Stefan Gerhardt is head of Experimental Research Operations for the National Spherical Torus Experiment- Upgrade (NSTX-U). He operates numerous diagnostics on NSTX-U, along with designing plasma control schemes and running physics experiments. He has previously worked on a wide variety of fusion machines, including spherical tokamaks, stellarators, and field reversed configurations. Interests Fusion energy Plasma diagnostics Plasma physics

  15. T

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

    wo major new components power the National Spherical Torus Experiment-Upgrade: A widened center stack that doubles the magnetic field strength and plasma current and quintuples the length of fusion experiments, and a second neutral beam injector that doubles the tokamak's heating power. Taken together, the new parts boost the NSTX-U operating conditions closer to those that will be found in a commercial fusion power plant. "This project was more complex than building the NSTX in the first

  16. Laboratory Director Stewart Prager heralds start of new era with NSTX-U and

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

    looks to future projects in "State of the Laboratory" address | Princeton Plasma Physics Lab Laboratory Director Stewart Prager heralds start of new era with NSTX-U and looks to future projects in "State of the Laboratory" address By Jeanne Jackson DeVoe October 13, 2015 Tweet Widget Google Plus One Share on Facebook PPPL Director Stewart Prager (Photo by Elle Starkman/PPPL Office of Communications) PPPL Director Stewart Prager The completion of the $94 million National

  17. Laboratory Director Stewart Prager heralds start of new era with NSTX-U and

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

    looks to future projects in "State of the Laboratory" address | Princeton Plasma Physics Lab Laboratory Director Stewart Prager heralds start of new era with NSTX-U and looks to future projects in "State of the Laboratory" address By Jeanne Jackson DeVoe October 28, 2015 Tweet Widget Google Plus One Share on Facebook PPPL Director Stewart Prager (Photo by Elle Starkman/PPPL Office of Communications) PPPL Director Stewart Prager The completion of the $94 million National

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

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

    Director Stewart Prager says | Princeton Plasma Physics Lab "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 Lab Director Stewart Prager gave a "tour" of PPPL's accomplishments during his annual State of the Lab address on April 29. (Photo by Russ DeSantis/PPPL Office of Communications ) Lab Director Stewart Prager gave a "tour" of

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

    SciTech Connect (OSTI)

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

    2012-08-27

    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

  20. Blob structure and motion in the edge and SOL of NSTX

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

    Zweben, S. J.; Myra, J. R.; Davis, W. M.; D’Ippolito, D. A.; Gray, T. K.; Kaye, S. M.; LeBlanc, B. P.; Maqueda, R. J.; Russell, D. A.; Stotler, D. P.

    2016-01-28

    Here, the structure and motion of discrete plasma blobs (a.k.a. filaments) in the edge and scrape-off layer of NSTX is studied for representative Ohmic and H-mode discharges. Individual blobs were tracked in the 2D radial versus poloidal plane using data from the gas puff imaging diagnostic taken at 400 000 frames s-1. A database of blob amplitude, size, ellipticity, tilt, and velocity was obtained for ~45 000 individual blobs. Empirical relationships between various properties are described, e.g. blob speed versus amplitude and blob tilt versus ellipticity. The blob velocities are also compared with analytic models.

  1. Torus Network on a BG/Q System | Argonne Leadership Computing...

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

    Blue GeneQ Versus Blue GeneP BGQ Drivers Status Machine Overview Machine Partitions Torus Network Data Storage & File Systems Compiling & Linking Queueing & Running Jobs Data...

  2. High-resolution Tangential AXUV Arrays for Radiated Power Density Measurements on NSTX-U

    SciTech Connect (OSTI)

    Delgado-Aparicio, L; Bell, R E; Faust, I; Tritz, K; Diallo, A; Gerhardt, S P; Kozub, T A; LeBlanc, B P; Stratton, B C

    2014-07-01

    Precise measurements of the local radiated power density and total radiated power are a matter of the uttermost importance for understanding the onset of impurity-induced instabilities and the study of particle and heat transport. Accounting of power balance is also needed for the understanding the physics of various divertor con#12;gurations for present and future high-power fusion devices. Poloidal asymmetries in the impurity density can result from high Mach numbers and can impact the assessment of their flux-surface-average and hence vary the estimates of P[sub]rad (r, t) and (Z[sub]eff); the latter is used in the calculation of the neoclassical conductivity and the interpretation of non-inductive and inductive current fractions. To this end, the bolometric diagnostic in NSTX-U will be upgraded, enhancing the midplane coverage and radial resolution with two tangential views, and adding a new set of poloidally-viewing arrays to measure the 2D radiation distribution. These systems are designed to contribute to the near- and long-term highest priority research goals for NSTX-U which will integrate non-inductive operation at reduced collisionality, with high-pressure, long energy-confinement-times and a divertor solution with metal walls.

  3. A New Era Begins | Princeton Plasma Physics Lab

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

    A New Era Begins Welcome to the first major addition to the U.S. fusion program of the 21st century. The U.S. Department of Energy's Princeton Plasma Physics Laboratory's (PPPL) new $94 million National Spherical Torus Experiment-Upgrade (NSTX-U) is the most powerful fusion facility of its kind on Earth and a device poised to bring the world closer to a bold new energy age. Publication File: PDF icon NSTX-U_presskit_print_NewEra

  4. W

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

    a new era in fusion research at the U.S. Department of Energy's Princeton Plasma Physics Laboratory. Today we unveil the National Spherical Torus Experiment- Upgrade (NSTX-U), the most powerful spherical tokamak in the world and the first major addition to the U.S. fusion program in the 21st century. The NSTX-U represents a $94 million, nearly three-year upgrade of the original National Spherical Torus Experiment that ran from 1999 to 2011 in the Laboratory, which Princeton University manages

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

    SciTech Connect (OSTI)

    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.; Ahn, J-W.; Gray, T. K.; Green, D. L.; McLean, A.; and others

    2014-02-12

    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

  6. Observation of Non-Maxwellian Electron Distributions in th e NSTX Divertor

    SciTech Connect (OSTI)

    M.A. Jaworski, et. al.

    2013-03-07

    The scrape-off layer plasma at the tokamak region is characterized by open field lines and often contains large variations in plasma properties along these field-lines. Proper characterization of local plasma conditions is critical to assessing plasma-material interaction processes occuring at the target. Langmuir probes are frequently employed in tokamak divertors but are challenging to interpretation. A kinetic interpretation for Langmuir probes in NSTX has yielded non-Maxwellian electron distributions in the divertor characterized by cool bulk populations and energetic tail populations with temperatures of 2-4 times the bulk. Spectroscopic analysis and modeling confirms the bulk plasma temperature and density which can only be obtained with the kinetic interpretation

  7. Ahmed Diallo | Princeton Plasma Physics Lab

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

    Ahmed Diallo Staff Research Physicist Ahmed Diallo is leader of the pedestal structure and control topical science group of the National Spherical Torus Experiment-Upgrade (NSTX-U) and is a recipient of a DOE Early Career award. He is developing a fast burst laser system to investigate the dynamics of the pedestal as well as to control it. He has contributed to the upgrade of the Thomson scattering diagnostic system in preparation for the NSTX-U, and has participated in the operation of the NSTX

  8. Major Milestone: PPPL completes first quadrant of the heart of the National

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

    Spherical Torus Experiment Upgrade | Princeton Plasma Physics Lab Major Milestone: PPPL completes first quadrant of the heart of the National Spherical Torus Experiment Upgrade By John Greenwald March 18, 2013 Tweet Widget Google Plus One Share on Facebook Mission accomplished: The completed first section of the NSTX-U center stack capped months of demanding preparations and close teamwork. (Photo by Elle Starkman, PPPL Office of Communications) Mission accomplished: The completed first

  9. Construction completed, PPPL is set to resume world-class fusion research |

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

    Princeton Plasma Physics Lab Construction completed, PPPL is set to resume world-class fusion research By John Greenwald September 25, 2015 Tweet Widget Google Plus One Share on Facebook Staffers who worked on the National Spherical Torus Experiment-Upgrade. (Photo by Elle Starkman/Office of Communications) Staffers who worked on the National Spherical Torus Experiment-Upgrade. Gallery: Technicians inspect the new center stack that forms the heart of the NSTX-U. (Photo by PPPL) Technicians

  10. Builders and Users | Princeton Plasma Physics Lab

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

    Builders and Users Constructing the National Spherical Torus Experiment Upgrade took years of detailed planning and oversight. The team in charge brought decades of experience to the task, working together to make the $94 million upgrade a reality. Publication File: PDF icon NSTX-U_presskit_print_Builders-Users

  11. NSTX presentation

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

    ... particles away from boundaries For a 5 Tesla magnetic field, 100 million C plasma 1-2 ... particles away from boundaries For a 5 Tesla magnetic field, 100 million C plasma 1-2 ...

  12. Numerical simulation of torus breakdown to chaos in an atmospheric-pressure dielectric barrier discharge

    SciTech Connect (OSTI)

    Zhang, J.; Wang, Y. H.; Wang, D. Z. [Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)] [Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams, School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

    2013-08-15

    Understanding the routes to chaos occurring in atmospheric-pressure dielectric barrier discharge systems by changing controlling parameters is very important to predict and control the dynamical behaviors. In this paper, a route of a quasiperiodic torus to chaos via the strange nonchaotic attractor is observed in an atmospheric-pressure dielectric barrier discharge driven by triangle-wave voltage. By increasing the driving frequency, the discharge system first bifurcates to a quasiperiodic torus from a stable single periodic state, and then torus and phase-locking periodic state appear and disappear alternately. In the meantime, the torus becomes increasingly wrinkling and stretching, and gradually approaches a fractal structure with the nonpositive largest Lyapunov exponent, i.e., a strange nonchaotic attractor. After that, the discharge system enters into chaotic state. If the driving frequency is further increased, another well known route of period-doubling bifurcation to chaos is also observed.

  13. Time-dependent analysis of visible helium line-ratios for electron temperature and density diagnostic using synthetic simulations on NSTX-U

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

    Muñoz Burgos, J. M.; Barbui, T.; Schmitz, O.; Stutman, D.; Tritz, K.

    2016-07-11

    Helium line-ratios for electron temperature (Te) and density (ne) plasma diagnostic in the Scrape-Off-Layer (SOL) and Edge regions of tokamaks are widely used. Due to their intensities and proximity of wavelengths, the singlet 667.8 and 728.1 nm, and triplet 706.5 nm visible lines have been typically preferred. Time-dependency of the triplet line (706.5 nm) has been previously analyzed in detail by including transient effects on line-ratios during gas-puff diagnostic applications. In this work, several line-ratio combinations within each of the two spin systems are analyzed with the purpose of eliminating transient effects to extend the application of this powerful diagnosticmore » to high temporal resolution characterization of plasmas. The analysis is done using synthetic emission modeling and diagnostic for low electron density NSTX SOL plasma conditions by several visible lines. Quasi-static equilibrium, and time-dependent models are employed to evaluate transient effects of the atomic population levels that may affect the derived electron temperatures and densities as the helium gas-puff penetrates the plasma. Ultimately, the analysis of a wider range of spectral lines will help to extend this powerful diagnostic to experiments where the wavelength range of the measured spectra may be constrained either by limitations of the spectrometer, or by other conflicting lines from different ions.« less

  14. An In-situ materials analysis particle probe (MAPP) diagnostic to study particle density control and hydrogenic fuel retention in NSTX

    SciTech Connect (OSTI)

    Allain, Jean-Paul

    2014-09-05

    A new materials analysis particle probe (MAPP) was designed, constructed and tested to develop understanding of particle control and hydrogenic fuel retention in lithium-based plasma-facing surfaces in NSTX. The novel feature of MAPP is an in-situ tool to probe the divertor NSTX floor during LLD and lithium-coating shots with subsequent transport to a post-exposure in-vacuo surface analysis chamber to measure D retention. In addition, the implications of a lithiated graphite-dominated plasma-surface environment in NSTX on LLD performance, operation and ultimately hydrogenic pumping and particle control capability are investigated in this proposal. MAPP will be an invaluable tool for erosion/redeposition simulation code validation.

  15. Low energy ion distribution measurements in Madison Symmetric Torus plasmas

    SciTech Connect (OSTI)

    Titus, J. B. Mezonlin, E. D.; Johnson, J. A.

    2014-06-15

    Charge-exchange neutrals contain information about the contents of a plasma and can be detected as they escape confinement. The Florida A and M University compact neutral particle analyzer (CNPA), used to measure the contents of neutral particle flux, has been reconfigured, calibrated, and installed on the Madison Symmetric Torus (MST) for high temperature deuterium plasmas. The energy range of the CNPA has been extended to cover 0.34–5.2 keV through an upgrade of the 25 detection channels. The CNPA has been used on all types of MST plasmas at a rate of 20 kHz throughout the entire discharge (∼70 ms). Plasma parameter scans show that the ion distribution is most dependent on the plasma current. Magnetic reconnection events throughout these scans produce stronger poloidal electric fields, stronger global magnetic modes, and larger changes in magnetic energy all of which heavily influence the non-Maxwellian part of the ion distribution (the fast ion tail)

  16. Ideal magnetohydrodynamic equilibrium in a non-symmetric topological torus

    SciTech Connect (OSTI)

    Weitzner, Harold

    2014-02-15

    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.

  17. Implementation of the 3D edge plasma code EMC3-EIRENE on NSTX

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

    Lore, J. D.; Canik, J. M.; Feng, Y.; Ahn, J. -W.; Maingi, R.; Soukhanovskii, V.

    2012-05-09

    The 3D edge transport code EMC3-EIRENE has been applied for the first time to the NSTX spherical tokamak. A new disconnected double null grid has been developed to allow the simulation of plasma where the radial separation of the inner and outer separatrix is less than characteristic widths (e.g. heat flux width) at the midplane. Modelling results are presented for both an axisymmetric case and a case where 3D magnetic field is applied in an n = 3 configuration. In the vacuum approximation, the perturbed field consists of a wide region of destroyed flux surfaces and helical lobes which aremore » a mixture of long and short connection length field lines formed by the separatrix manifolds. This structure is reflected in coupled 3D plasma fluid (EMC3) and kinetic neutral particle (EIRENE) simulations. The helical lobes extending inside of the unperturbed separatrix are filled in by hot plasma from the core. The intersection of the lobes with the divertor results in a striated flux footprint pattern on the target plates. As a result, profiles of divertor heat and particle fluxes are compared with experimental data, and possible sources of discrepancy are discussed.« less

  18. Turbulent transport in the Madison Symmetric Torus reversed-field pinch

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

    transport in the Madison Symmetric Torus reversed-field pinch* T. D. Rempel,+ A. F. Almagri, S. Assadi, D. J. Den Hartog, S. A. Hokin, S. C. Prager, J. S. Sarff, W. Shen, K. L. Sidikman, C. W. Spragins, J. C. Sprott, M. R. Stoneking, and E. J. Zita University of Wisconsin, Madison, Wisconsin 53 706 (Received 22 November 1991; accepted 20 February 1992) Measurements of edge turbulence and the associated transport are ongoing in the Madison Symmetric Torus (MST) reversed-field pinch [Fusion

  19. FMEA on the superconducting torus for the Jefferson Lab 12 GeV accelerator upgrade

    SciTech Connect (OSTI)

    Ghoshal, Probir K.; Biallas, George H.; Fair, Ruben J.; Rajput-Ghoshal, Renuka; Schneider, William J.; Legg, Robert A.; Kashy, David H.; Hogan, John P.; Wiseman, Mark A.; Luongo, Cesar; Ballard, Joshua T.; Young, Glenn R.; Elouadrhiri, Latifa; Rode, Claus H.

    2015-01-16

    As part of the Jefferson Lab 12GeV accelerator upgrade project, Hall B requires two conduction cooled superconducting magnets. One is a magnet system consisting of six superconducting trapezoidal racetrack-type coils assembled in a toroidal configuration and the second is an actively shielded solenoidal magnet system consisting of 5 coils. Both magnets are to be wound with Superconducting Super Collider-36 NbTi strand Rutherford cable soldered into a copper channel. This paper describes the various failure modes in torus magnet along with the failure modes that could be experienced by the torus and its interaction with the solenoid which is located in close proximity.

  20. Predictions of VRF on a Langmuir Probe under the RF Heating Spiral on the Divertor Floor on NSTX-U

    SciTech Connect (OSTI)

    Hosea, J C; Perkins, R J; Jaworski, M A; Kramer, G J; Ahn, J-W

    2014-07-01

    RF heating deposition spirals are observed on the divertor plates on NSTX as shown in for a NB plus RF heating case. It has been shown that the RF spiral is tracked quite well by the spiral mapping of the strike points on the divertor plate of magnetic field lines passing in front of the high harmonic fast wave (HHFW) antenna on NSTX. Indeed, both current instrumented tiles and Langmuir probes respond to the spiral when it is positioned over them. In particular, a positive increment in tile current (collection of electrons) is obtained when the spiral is over the tile. This current can be due to RF rectification and/or RF heating of the scrape off layer (SOL) plasma along the magnetic field lines passing in front of the the HHFW antenna. It is important to determine quantitatively the relative contributions of these processes. Here we explore the properties of the characteristics of probes on the lower divertor plate to determine the likelyhood that the primary cause of the RF heat deposition is RF rectification.

  1. Magnetohydrodynamic modes analysis and control of Fusion Advanced Studies Torus high-current scenarios

    SciTech Connect (OSTI)

    Villone, F.; Mastrostefano, S.; Calabrò, G.; Vlad, G.; Crisanti, F.; Fusco, V.; Marchiori, G.; Bolzonella, T.; Marrelli, L.; Martin, P.; Liu, Y. Q.

    2014-08-15

    One of the main FAST (Fusion Advanced Studies Torus) goals is to have a flexible experiment capable to test tools and scenarios for safe and reliable tokamak operation, in order to support ITER and help the final DEMO design. In particular, in this paper, we focus on operation close to a possible border of stability related to low-q operation. To this purpose, a new FAST scenario has then been designed at I{sub p} = 10 MA, B{sub T} = 8.5 T, q{sub 95} ≈ 2.3. Transport simulations, carried out by using the code JETTO and the first principle transport model GLF23, indicate that, under these conditions, FAST could achieve an equivalent Q ≈ 3.5. FAST will be equipped with a set of internal active coils for feedback control, which will produce magnetic perturbation with toroidal number n = 1 or n = 2. Magnetohydrodynamic (MHD) mode analysis and feedback control simulations performed with the codes MARS, MARS-F, CarMa (both assuming the presence of a perfect conductive wall and using the exact 3D resistive wall structure) show the possibility of the FAST conductive structures to stabilize n = 1 ideal modes. This leaves therefore room for active mitigation of the resistive mode (down to a characteristic time of 1 ms) for safety purposes, i.e., to avoid dangerous MHD-driven plasma disruption, when working close to the machine limits and magnetic and kinetic energy density not far from reactor values.

  2. Experiments

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

    Experiments - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Energy Defense Waste Management Programs Advanced Nuclear Energy

  3. Understanding ion cyclotron harmonic fast wave heating losses in the scrape off layer of tokamak plasmas

    SciTech Connect (OSTI)

    Bertelli, N; Jaeger, E F; Hosea, J C; Phillips, C K; Berry, L; Bonoli, P T; Gerhardt, S P; Green, D; LeBlanc, B; Perkins, R J; Ryan, P M; Taylor, G; Valeo, E J; Wilso, J R; Wright, J C

    2014-07-01

    Fast waves at harmonics of the ion cyclotron frequency, which have been used successfully on National Spherical Torus Experiment (NSTX), will also play an important role in ITER and are a promising candidate for the Fusion Nuclear Science Facility (FNSF) designs based on spherical torus (ST). Experimental studies of high harmonic fast waves (HHFW) heating on the NSTX have demonstrated that substantial HHFW power loss occurs along the open field lines in the scrape-off layer (SOL), but the mechanism behind the loss is not yet understood. The full wave RF code AORSA, in which the edge plasma beyond the last closed flux surface (LCFS) is included in the solution domain, is applied to specific NSTX discharges in order to predict the effects and possible causes of this power loss. In the studies discussed here, a collisional damping parameter has been implemented in AORSA as a proxy to represent the real, and most likely nonlinear, damping processes. A prediction for the NSTX Upgrade (NSTX-U) experiment, that will begin operation next year, is also presented, indicating a favorable condition for the experiment due to a wider evanescent region in edge density.*Research supported by the U.S. DOE under Contract No. DE-AC02-09CH11466 with Princeton University.

  4. Experiment

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

    MiniBooNE Experiment September, 2002 SeptemMyungkee Sung (LSU/MiniBooNE) 4th International Workshop on the Identification of Dark Matter Cosmologically Interesting Region; Hot Dark Matter? LSND Signal at High ∆m 2 KARMEN II narrowed the signal region MiniBooNE will fully address this signal. Neutrino Osillation at High ∆m 2 LSND: Searching for ν µ →ν e ν µ - From µ + decay at rest with endpoint energy 53 MeV L = 30m, L/E ~ 1m/MeV, 167 tons of Mineral Oil Look for ν e Appearance: ν

  5. News | Princeton Plasma Physics Lab

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

    News RSS Feed September 2, 2016 PPPL intern creates software for snapshot of plasma in NSTX-U By Jeanne Jackson DeVoe Max Wallace, a Community College intern from Laney College in Oakland, California, shows fellow intern Priya Jaglal a poster on his research during a student poster session at PPPL on Aug. 10. Wallace developed software to allow scientists to get a quick snapshot of experiments on the National Spherical Torus Experiment-Upgrade (NSTX-U). When most of today's college interns were

  6. Reduced model prediction of electron temperature profiles in...

    Office of Scientific and Technical Information (OSTI)

    FUSION TECHNOLOGY Confinement; H-mode Plasma Confinement; Spherical Torus; Spherical Tokamak; Stability, Microinstability; Tokamaks, NSTX; Transport Phenomena Word Cloud More...

  7. 3D Torus Routing Engine Module for OFA OpenSM v. 1.0

    Energy Science and Technology Software Center (OSTI)

    2009-11-12

    This OpenFabrics Alliance (OFA) OpenSM routing engine module provides credit-loop-free routing while supporting two quality of service (QoS) levels for an InfiniBand fabric with a 3D torus topology. In addition it is able to route around multiple failed fabric links or a single failed fabric switch without introducing credit loops, and without changing path Service Level (SL) values granted before the failure.This OFA OpenSM routing engine module improves the operational characteristics of a parallel computermore » built using an InfiniBand fabric with a 3D torus topology. By providing two QoS levels, it allows system administrators to prevent application interprocess communication and file system communication from impacting each other. By providing the capability to route traffic around failed fabric components, it enables repair of failed components without impacting jobs running on the computer system.« less

  8. Numerical study of the Columbia high-beta device: Torus-II

    SciTech Connect (OSTI)

    Izzo, R.

    1981-01-01

    The ionization, heating and subsequent long-time-scale behavior of the helium plasma in the Columbia fusion device, Torus-II, is studied. The purpose of this work is to perform numerical simulations while maintaining a high level of interaction with experimentalists. The device is operated as a toroidal z-pinch to prepare the gas for heating. This ionization of helium is studied using a zero-dimensional, two-fluid code. It is essentially an energy balance calculation that follows the development of the various charge states of the helium and any impurities (primarily silicon and oxygen) that are present. The code is an atomic physics model of Torus-II. In addition to ionization, we include three-body and radiative recombination processes.

  9. FMEA on the superconducting torus for the Jefferson Lab 12 GeV accelerator upgrade

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

    Ghoshal, Probir K.; Biallas, George H.; Fair, Ruben J.; Rajput-Ghoshal, Renuka; Schneider, William J.; Legg, Robert A.; Kashy, David H.; Hogan, John P.; Wiseman, Mark A.; Luongo, Cesar; et al

    2015-01-16

    As part of the Jefferson Lab 12GeV accelerator upgrade project, Hall B requires two conduction cooled superconducting magnets. One is a magnet system consisting of six superconducting trapezoidal racetrack-type coils assembled in a toroidal configuration and the second is an actively shielded solenoidal magnet system consisting of 5 coils. Both magnets are to be wound with Superconducting Super Collider-36 NbTi strand Rutherford cable soldered into a copper channel. This paper describes the various failure modes in torus magnet along with the failure modes that could be experienced by the torus and its interaction with the solenoid which is located inmore » close proximity.« less

  10. Summary of TFTR (Tokamak Fusion Test Reactor) diagnostics, including JET (Joint European Torus) and JT-60

    SciTech Connect (OSTI)

    Hill, K.W.; Young, K.M.; Johnson, L.C.

    1990-05-01

    The diagnostic instrumentation on TFTR (Tokamak Fusion Test Reactor) and the specific properties of each diagnostic, i.e., number of channels, time resolution, wavelength range, etc., are summarized in tables, grouped according to the plasma parameter measured. For comparison, the equivalent diagnostic capabilities of JET (Joint European Torus) and the Japanese large tokamak, JT-60, as of late 1987 are also listed in the tables. Extensive references are given to publications on each instrument.

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

    SciTech Connect (OSTI)

    Giacomelli, L.; Department of Physics, Universit degli Studi di Milano-Bicocca, Milano ; Conroy, S.; Department of Physics and Astronomy, Uppsala University, Uppsala ; Gorini, G.; Horton, L.; Murari, A.; Popovichev, S.; Syme, D. B.

    2014-02-15

    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.

  12. A Star on Earth

    ScienceCinema (OSTI)

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

    2014-06-06

    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.

  13. A Star on Earth

    SciTech Connect (OSTI)

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

    2014-03-05

    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.

  14. Identification of new turbulence contributions to plasma transport and confinement in spherical tokamak regime

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

    Wang, W. X.; Ethier, S.; Ren, Y.; Kaye, S.; Chen, J.; Startsev, E.; Lu, Z.; Li, Z. Q.

    2015-10-15

    Highly distinct features of spherical tokamaks (ST), such as National Spherical Torus eXperiment (NSTX) and NSTX-U, result in a different fusion plasma regime with unique physics properties compared to conventional tokamaks. Nonlinear global gyrokinetic simulations critical for addressing turbulence and transport physics in the ST regime have led to new insights. The drift wave Kelvin-Helmholtz (KH) instability characterized by intrinsic mode asymmetry is identified in strongly rotating NSTX L-mode plasmas. While the strong E x B shear associated with the rotation leads to a reduction in KH/ion temperature gradient turbulence, the remaining fluctuations can produce a significant ion thermal transportmore » that is comparable to the experimental level in the outer core region (with no "transport shortfall"). The other new, important turbulence source identified in NSTX is the dissipative trapped electron mode (DTEM), which is believed to play little role in conventional tokamak regime. Due to the high fraction of trapped electrons, long wavelength DTEMs peaking around kθρs ~ 0.1 are destabilized in NSTX collisionality regime by electron density and temperature gradients achieved there. Surprisingly, the E x B shear stabilization effect on DTEM is remarkably weak, which makes it a major turbulence source in the ST regime dominant over collisionless TEM (CTEM). The latter, on the other hand, is subject to strong collisional and E x B shear suppression in NSTX. DTEM is shown to produce significant particle, energy and toroidal momentum transport, in agreement with experimental levels in NSTX H-modes. Furthermore, DTEM-driven transport in NSTX parametric regime is found to increase with electron collision frequency, providing one possible source for the scaling of confinement time observed in NSTX H-modes. Most interestingly, the existence of a turbulence-free regime in the collision-induced CTEM to DTEM transition, corresponding to a minimum plasma transport in

  15. Observations of Improved Stability and Confinement in a High-{beta} Self-Organized Spherical-Torus-Like Field-Reversed Configuration

    SciTech Connect (OSTI)

    Guo, H.Y.; Hoffman, A.L.; Steinhauer, L.C.; Miller, K.E.

    2005-10-21

    An extremely high-{beta} (over 85%) self-organized field-reversed configuration (FRC) with a spherical-torus- (ST-)like core is produced in the translation, confinement, and sustainment experiment by highly super-Alfvenic translation of a spheromaklike plasmoid. Substantial flux conversion from toroidal into poloidal occurs during the capture process, resulting in the ST-like core. This plasma state exhibits a remarkable stabilizing property for the ubiquitous n=2 centrifugally driven interchange modes present in {theta}-pinch formed FRCs. This is explained, for the first time, by a simple model taking into account magnetic shear and centrifugal effects. The FRC-ST configuration has up to 4 times improvement in flux confinement times over the scaling of conventional {theta}-pinch formed FRCs and, thus, a significant improvement in the resistivity and transport.

  16. TORUS AND ACTIVE GALACTIC NUCLEUS PROPERTIES OF NEARBY SEYFERT GALAXIES: RESULTS FROM FITTING INFRARED SPECTRAL ENERGY DISTRIBUTIONS AND SPECTROSCOPY

    SciTech Connect (OSTI)

    Alonso-Herrero, Almudena; Ramos Almeida, Cristina; Mason, Rachel; Asensio Ramos, Andres; Rodriguez Espinosa, Jose Miguel; Perez-Garcia, Ana M.; Roche, Patrick F.; Levenson, Nancy A.; Elitzur, Moshe; Packham, Christopher; Young, Stuart; Diaz-Santos, Tanio

    2011-08-01

    We used the CLUMPY torus models and a Bayesian approach to fit the infrared spectral energy distributions and ground-based high angular resolution mid-infrared spectroscopy of 13 nearby Seyfert galaxies. This allowed us to put tight constraints on torus model parameters such as the viewing angle i, the radial thickness of the torus Y, the angular size of the cloud distribution {sigma}{sub torus}, and the average number of clouds along radial equatorial rays N{sub 0}. We found that the viewing angle i is not the only parameter controlling the classification of a galaxy into type 1 or type 2. In principle, type 2s could be viewed at any viewing angle i as long as there is one cloud along the line of sight. A more relevant quantity for clumpy media is the probability for an active galactic nucleus (AGN) photon to escape unabsorbed. In our sample, type 1s have relatively high escape probabilities, P{sub esc} {approx} 12%-44%, while type 2s, as expected, tend to have very low escape probabilities. Our fits also confirmed that the tori of Seyfert galaxies are compact with torus model radii in the range 1-6 pc. The scaling of the models to the data also provided the AGN bolometric luminosities L{sub bol}(AGN), which were found to be in good agreement with estimates from the literature. When we combined our sample of Seyfert galaxies with a sample of PG quasars from the literature to span a range of L{sub bol}(AGN) {approx} 10{sup 43}-10{sup 47} erg s{sup -1}, we found plausible evidence of the receding torus. That is, there is a tendency for the torus geometrical covering factor to be lower (f{sub 2} {approx} 0.1-0.3) at high AGN luminosities than at low AGN luminosities (f{sub 2} {approx} 0.9-1 at {approx}10{sup 43}-10{sup 44} erg s{sup -1}). This is because at low AGN luminosities the tori appear to have wider angular sizes (larger {sigma}{sub torus}) and more clouds along radial equatorial rays. We cannot, however, rule out the possibility that this is due to

  17. News Archive | Princeton Plasma Physics Lab

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

    Archive Subscribe to Princeton Plasma Physics Laboratory News September 2, 2016 PPPL intern creates software for snapshot of plasma in NSTX-U By Jeanne Jackson DeVoe Max Wallace, a Community College intern from Laney College in Oakland, California, shows fellow intern Priya Jaglal a poster on his research during a student poster session at PPPL on Aug. 10. Wallace developed software to allow scientists to get a quick snapshot of experiments on the National Spherical Torus Experiment-Upgrade

  18. Experimental Fusion Research | Princeton Plasma Physics Lab

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

    Experimental Fusion Research PPPL fusion research centers on the National Spherical Torus Experiment (NSTX), which is undergoing a $94 million upgrade that will make it the most powerful experimental fusion facility, or tokamak, of its type in the world when work is completed in 2014. Experiments will test the ability of the upgraded spherical facility to maintain a high-performance plasma under conditions of extreme heat and power. Results could strongly influence the design of future fusion

  19. Magnetic reconstruction of nonaxisymmetric quasi-single-helicity configurations in the Madison Symmetric Torus

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

    reconstruction of nonaxisymmetric quasi-single-helicity configurations in the Madison Symmetric Torus This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2011 Plasma Phys. Control. Fusion 53 105006 (http://iopscience.iop.org/0741-3335/53/10/105006) Download details: IP Address: 128.104.166.218 The article was downloaded on 15/04/2013 at 17:18 Please note that terms and conditions apply. View the table of contents for this issue, or go to the journal

  20. Nonlinear coupling of tearing fluctuations in the Madison Symmetric Torus<atother>@f|</atother>

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

    coupling of tearing fluctuations in the Madison Symmetric Torus* J. S. Sarff,? S. Assadi,a) A. F. Almagri, M. Cekic, D. J. Den Hat-tog, G. Fiksel, S. A. Hokin, H. Ji, S. C. Prager, W. Shen, K. L. Sidikman,b) and M. R. Stoneking University of Wisconsin, Madison, Wisconsin 53 706 (Received 9 December 1992; accepted 21 December 1992) Three-wave, nonlinear, tearing mode coupling has been measured in the Madison Symmetric Torus (MST) reversed-field pinch (RFP) [Fusion Technol. 19, 131 ( 1991)] using

  1. TORUS: Theory of Reactions for Unstable iSotopes - Year 1 Continuation and Progress Report

    SciTech Connect (OSTI)

    Arbanas, G; Elster, C; Escher, J; Mukhamedzhanov, A; Nunes, F; Thompson, I J

    2011-02-24

    The TORUS collaboration derives its name from the research it focuses on, namely the Theory of Reactions for Unstable iSotopes. It is a Topical Collaboration in Nuclear Theory, and funded by the Nuclear Theory Division of the Office of Nuclear Physics in the Office of Science of the Department of Energy. The funding started on June 1, 2010, it will have been running for nine months by the date of submission of this Annual Continuation and Progress Report on March 1, 2011. The extent of funding was reduced from the original application, and now supports one postdoctoral researcher for the years 1 through 3. The collaboration brings together as Principal Investigators a large fraction of the nuclear reaction theorists currently active within the USA. The mission of the TORUS Topical Collaboration is to develop new methods that will advance nuclear reaction theory for unstable isotopes by using three-body techniques to improve direct-reaction calculations, and, by using a new partial-fusion theory, to integrate descriptions of direct and compound-nucleus reactions. This multi-institution collaborative effort is directly relevant to three areas of interest: the properties of nuclei far from stability; microscopic studies of nuclear input parameters for astrophysics, and microscopic nuclear reaction theory.

  2. News | Princeton Plasma Physics Lab

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

    Major next steps for fusion energy based on the spherical tokamak design Click on an image below to view the high resolution image. Then right click on the image and select "Save Image" or "Save Image As..." Test cell of the National Spherical Torus Experiment-Upgrade with tokamak in the center. Physicist Jonathan Menard. Center stack of the NSTX-U. Mega Ampere Spherical Tokamak. Photo courtesy of Culham Centre for Fusion Energy.

  3. Creating a Star on Earth | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    a Star on Earth Creating a Star on Earth March 5, 2014 - 11:45am Addthis In the video above, learn how scientists at the Princeton Plasma Physics Lab are creating a star on Earth in the National Spherical Torus Experiment (NSTX), a magnetic fusion device that is used to study the physics principles of spherically shaped plasmas. | Video by Matty Greene, Energy Department. Ben Dotson Ben Dotson Former Project Coordinator for Digital Reform, Office of Public Affairs Matty Greene Matty Greene

  4. Cummins Corporate Energy Management | Department of Energy

    Energy Savers [EERE]

    Creating a Star on Earth Creating a Star on Earth March 5, 2014 - 11:45am Addthis In the video above, learn how scientists at the Princeton Plasma Physics Lab are creating a star on Earth in the National Spherical Torus Experiment (NSTX), a magnetic fusion device that is used to study the physics principles of spherically shaped plasmas. | Video by Matty Greene, Energy Department. Ben Dotson Ben Dotson Former Project Coordinator for Digital Reform, Office of Public Affairs Matty Greene Matty

  5. DIII-D National Fusion Facility (DIII-D) | U.S. DOE Office of Science (SC)

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

    DIII-D National Fusion Facility (DIII-D) Fusion Energy Sciences (FES) FES Home About Research Facilities User Facilities DIII-D National Fusion Facility (DIII-D) National Spherical Torus Experiment (NSTX) Alcator C-Mod ITER External link Science Highlights Benefits of FES Funding Opportunities Fusion Energy Sciences Advisory Committee (FESAC) Community Resources Contact Information Fusion Energy Sciences U.S. Department of Energy SC-24/Germantown Building 1000 Independence Ave., SW Washington,

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

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

    Facilities Fusion Energy Sciences (FES) FES Home About Research Facilities User Facilities DIII-D National Fusion Facility (DIII-D) National Spherical Torus Experiment (NSTX) Alcator C-Mod ITER External link Science Highlights Benefits of FES Funding Opportunities Fusion Energy Sciences Advisory Committee (FESAC) Community 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:

  7. Alcator C-Mod | U.S. DOE Office of Science (SC)

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

    Alcator C-Mod Fusion Energy Sciences (FES) FES Home About Research Facilities User Facilities DIII-D National Fusion Facility (DIII-D) National Spherical Torus Experiment (NSTX) Alcator C-Mod ITER External link Science Highlights Benefits of FES Funding Opportunities Fusion Energy Sciences Advisory Committee (FESAC) Community 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

  8. Quest Magazine Summer 2016 | Princeton Plasma Physics Lab

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

    Quest Magazine Summer 2016 It is my pleasure to welcome readers to the fourth annual edition of Quest, the Laboratory's research magazine. Research has begun full bore on the National Spherical Torus Experiment-Upgrade (NSTX-U), our flagship fusion facility, whose construction was completed in 2015 after nearly four years of building and a cost of $94 million. Image: Quest 2016 Publication File: PDF icon Quest Magazine Summer 2016 Publication Type: Quest

  9. Electromagnetic Transport From Microtearing Mode Turbulence

    SciTech Connect (OSTI)

    Guttenfelder, W; Kaye, S M; Nevins, W M; Wang, E; Bell, R E; Hammett, G W; LeBlanc, B P; Mikkelsen, D R

    2011-03-23

    This Letter presents non-linear gyrokinetic simulations of microtearing mode turbulence. The simulations include collisional and electromagnetic effects and use experimental parameters from a high beta discharge in the National Spherical Torus Experiment (NSTX). The predicted electron thermal transport is comparable to that given by experimental analysis, and it is dominated by the electromagnetic contribution of electrons free streaming along the resulting stochastic magnetic field line trajectories. Experimental values of flow shear can significantly reduce the predicted transport.

  10. 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)

    Perkins, Roy

    2013-06-21

    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.

  11. Reverberation measurements of the inner radius of the dust torus in 17 Seyfert galaxies

    SciTech Connect (OSTI)

    Koshida, Shintaro; Minezaki, Takeo; Yoshii, Yuzuru; Sakata, Yu; Sugawara, Shota; Kobayashi, Yukiyasu; Suganuma, Masahiro; Enya, Keigo; Tomita, Hiroyuki; Aoki, Tsutomu; Peterson, Bruce A. E-mail: minezaki@ioa.s.u-tokyo.ac.jp

    2014-06-20

    We present the results of a dust reverberation survey for 17 nearby Seyfert 1 galaxies, which provides the largest homogeneous data collection for the radius of the innermost dust torus. A delayed response of the K-band light curve after the V-band light curve was found for all targets, and 49 measurements of lag times between the flux variation of the dust emission in the K band and that of the optical continuum emission in the V band were obtained by the cross-correlation function analysis and also by an alternative method for estimating the maximum likelihood lag. The lag times strongly correlated with the optical luminosity in the luminosity range of M{sub V} = –16 to –22 mag, and the regression analysis was performed to obtain the correlation log Δt (days) = –2.11 – 0.2 M{sub V} assuming Δt∝L {sup 0.5}, which was theoretically expected. We discuss the possible origins of the intrinsic scatter of the dust lag-luminosity correlation, which was estimated to be approximately 0.13 dex, and we find that the difference of internal extinction and delayed response of changes in lag times to the flux variations could have partly contributed to intrinsic scatter. However, we could not detect any systematic change of the correlation with the subclass of the Seyfert type or the Eddington ratio. Finally, we compare the dust reverberation radius with the near-infrared interferometric radius of the dust torus and the reverberation radius of broad Balmer emission lines. The interferometric radius in the K band was found to be systematically larger than the dust reverberation radius in the same band by the about a factor of two, which could be interpreted by the difference between the flux-weighted radius and response-weighted radius of the innermost dust torus. The reverberation radius of the broad Balmer emission lines was found to be systematically smaller than the dust reverberation radius by about a factor of four to five, which strongly supports the unified

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

    SciTech Connect (OSTI)

    Zuccarello, F. P.; Poedts, S.; Seaton, D. B.; Mierla, M.; Rachmeler, L. A.; Romano, P.; Zuccarello, F. E-mail: Stefaan.Poedts@wis.kuleuven.be E-mail: marilena@oma.be E-mail: Paolo.Romano@oact.inaf.it

    2014-04-20

    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 dayseven weekswhich 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 the Solar Dynamics Observatory (SDO) and the Solar TErrestrial RElations Observatory to reconstruct the three-dimensional shape of the filament, to follow its morphological evolution, and to determine its height just before eruption. The magnetograms acquired by SDO/Helioseismic and Magnetic Imager are used to infer the topology of the ambient field and to derive the critical height for the onset of the torus instability. Our analysis shows that the torus instability is the trigger of the eruption. We also find that some pre-eruptive processes, such as magnetic reconnection during the observed flares and flux cancellation at the neutral line, facilitated the eruption by bringing the filament to a region where the magnetic field was more vulnerable to the torus instability.

  13. Resonant-like behaviour during edge-localised mode cycles in the Joint European Torus

    SciTech Connect (OSTI)

    Webster, A. J.; Morris, J.; Todd, T. N.; Coad, P.; Brezinsek, S.; Likonen, J.; Rubel, M.; Collaboration: JET-EFDA Contributors

    2015-08-15

    A unique sequence of 120 almost identical plasmas in the Joint European Torus (JET) recently provided two orders of magnitude more statistically equivalent data than ever previously available. The purpose was to study movement of eroded plasma-facing material from JET's new Beryllium wall, but it has allowed the statistical detection of otherwise unobservable phenomenon. This includes a sequence of resonant-like waiting times between edge-localised plasma instabilities (ELMs), instabilities that must be mitigated or avoided in large magnetically confined plasmas such as those planned for ITER. Here, we investigate the cause of this phenomenon, using the unprecedented quantity of data to produce a detailed picture of the plasma's behaviour. After combining the data, oscillations are clearly observable in the plasma's vertical position, in edge losses of ions, and in Beryllium II (527 nm) light emissions. The oscillations are unexpected, are not obvious in data from a single pulse alone, and are all clearly correlated with each other. They are likely to be caused by a small vertical oscillation that the plasma control system is not reacting to prevent, but a more complex explanation is possible. The clearly observable but unexpected link between small changes in the plasma's position and changes to edge-plasma transport and stability suggest that these characteristics cannot always be studied in isolation. It also suggests new opportunities for ELM mitigation and control that may exist.

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

    SciTech Connect (OSTI)

    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)

    2013-07-15

    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.

  15. Elmo Bumpy Torus proof of principle, Phase II: Title 1 report. Volume V. Vacuum-pumping system. Preliminary design report

    SciTech Connect (OSTI)

    Not Available

    1982-02-26

    This report summarizes Title I Preliminary Design of the EBT-P Vacuum Pumping System. The Vacuum Pumping System has been designed by the McDonnell Douglas Astronautics Co. - St. Louis (MDAC). It includes the necessary vacuum pumps and vacuum valves to evacuate the torus, the Mirror Coil Dewars (MC Dewars), and the Gyrotron Magnet Dewars. The pumping ducts, manifolds, and microwave protection system are also included. A summary of the function of each subsystem and a description of its principle components is provided below. The analyses performed during the system design are also identified.

  16. Identification and mitigation of stray laser light in the Thomson scattering system on the Madison Symmetric Torus (MST)

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

    and mitigation of stray laser light in the Thomson scattering system on the Madison Symmetric Torus (MST) C. M. Jacobson, M. T. Borchardt, D. J. Den Hartog, A. F. Falkowski, L. A. Morton, and M. A. Thomas Citation: Review of Scientific Instruments 87, 11E511 (2016); doi: 10.1063/1.4960063 View online: http://dx.doi.org/10.1063/1.4960063 View Table of Contents: http://scitation.aip.org/content/aip/journal/rsi/87/11?ver=pdfcov Published by the AIP Publishing Articles you may be interested in A

  17. Embedding global barrier and collective in torus network with each node combining input from receivers according to class map for output to senders

    DOE Patents [OSTI]

    Chen, Dong; Coteus, Paul W; Eisley, Noel A; Gara, Alan; Heidelberger, Philip; Senger, Robert M; Salapura, Valentina; Steinmacher-Burow, Burkhard; Sugawara, Yutaka; Takken, Todd E

    2013-08-27

    Embodiments of the invention provide a method, system and computer program product for embedding a global barrier and global interrupt network in a parallel computer system organized as a torus network. The computer system includes a multitude of nodes. In one embodiment, the method comprises taking inputs from a set of receivers of the nodes, dividing the inputs from the receivers into a plurality of classes, combining the inputs of each of the classes to obtain a result, and sending said result to a set of senders of the nodes. Embodiments of the invention provide a method, system and computer program product for embedding a collective network in a parallel computer system organized as a torus network. In one embodiment, the method comprises adding to a torus network a central collective logic to route messages among at least a group of nodes in a tree structure.

  18. Electromagnetic and Mechanical Analysis of the Coil Structure for the CLAS12 Torus for 12 GeV Upgrade

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

    Ghoshal, P. K.; Pastor, O.; Kashy, D.; Schneider, W.; Wiseman, M.; Zarecky, M.; Young, G.; Rode, C.; Elouadrhiri, L.; Burkert, V.

    2014-12-18

    The torus magnet for the CLAS12 spectrometer is a 3.6 T superconducting magnet being designed and built as part of the Jefferson Lab 12 GeV Upgrade. The magnet consists of six coil case assemblies mounted to a cold central hub. The coil case assembly consists of an aluminum case and cover enclosing an epoxy vacuum impregnated coil pack. The coil pack consists of a 117 turn double-pancake winding wrapped with 2 layers of 0.635 mm thick copper cooling sheets. The coil case assembly is cooled by supercritical helium at 4.6 K. This report details the structural analysis of the coilmore » case assembly and the assessment of the coil pack stresses. For the normal operation of the torus magnet, the coil case assembly was analyzed for cool down to 4.6 K and the Lorentz forces at normal operating current. In addition to the normal operating configuration, the coil case assembly was analyzed for Lorentz forces arising from coil misalignment and current imbalances. The allowable stress criteria for the magnet followed the approach of the ASME codes. Primary stresses were limited to the lesser of 2/3 times the yield strength or 1/3 times the ultimate tensile strength. Primary plus secondary stresses were limited to 3 times the primary stress allowable. The analysis was performed using ANSYS Maxwell to calculate the magneto-static loads and ANSYS Mechanical to calculate the stresses.« less

  19. Electromagnetic and Mechanical Analysis of the Coil Structure for the CLAS12 Torus for 12 GeV Upgrade

    SciTech Connect (OSTI)

    Ghoshal, P. K.; Pastor, O.; Kashy, D.; Schneider, W.; Wiseman, M.; Zarecky, M.; Young, G.; Rode, C.; Elouadrhiri, L.; Burkert, V.

    2014-12-18

    The torus magnet for the CLAS12 spectrometer is a 3.6 T superconducting magnet being designed and built as part of the Jefferson Lab 12 GeV Upgrade. The magnet consists of six coil case assemblies mounted to a cold central hub. The coil case assembly consists of an aluminum case and cover enclosing an epoxy vacuum impregnated coil pack. The coil pack consists of a 117 turn double-pancake winding wrapped with 2 layers of 0.635 mm thick copper cooling sheets. The coil case assembly is cooled by supercritical helium at 4.6 K. This report details the structural analysis of the coil case assembly and the assessment of the coil pack stresses. For the normal operation of the torus magnet, the coil case assembly was analyzed for cool down to 4.6 K and the Lorentz forces at normal operating current. In addition to the normal operating configuration, the coil case assembly was analyzed for Lorentz forces arising from coil misalignment and current imbalances. The allowable stress criteria for the magnet followed the approach of the ASME codes. Primary stresses were limited to the lesser of 2/3 times the yield strength or 1/3 times the ultimate tensile strength. Primary plus secondary stresses were limited to 3 times the primary stress allowable. The analysis was performed using ANSYS Maxwell to calculate the magneto-static loads and ANSYS Mechanical to calculate the stresses.

  20. Design and Manufacture of the Conduction Cooled Torus Coils for the Jefferson Lab 12GeV Upgrade

    SciTech Connect (OSTI)

    Wiseman, M; Elouadhiri, L; Ghoshal, P K; Kashy, D; Elementi, L; Gabrielli, G; Gardner, T J; Kiemschies, O; Krave, S; Makarov, A; Robotham, B; Szal, J; Velev, G

    2015-06-01

    The design of the 12-GeV torus required the construction of six superconducting coils with a unique geometry required for the experimental needs of Jefferson Laboratory Hall B. Each of these coils consists of 234 turns of copper-stabilized superconducting cable conduction cooled by 4.6 K helium gas. The finished coils are each roughly 2 × 4 × 0.05 m and supported in an aluminum coil case. Because of its geometry, new tooling and manufacturing methods had to be developed for each stage of construction. The tooling was designed and developed while producing a practice coil at Fermi National Laboratory. This paper describes the tooling and manufacturing techniques required to produce the six production coils and two spare coils required by the project. Project status and future plans are also presented.

  1. Design and Manufacture of the Conduction Cooled Torus Coils for The Jefferson Laboratory 12-GeV Upgrade

    SciTech Connect (OSTI)

    Wiseman, M.; Elementi, L.; Elouadhiri, L.; Gabrielli, G.; Gardner, T. J.; Ghoshal, P. K.; Kashy, D.; Kiemschies, O.; Krave, S.; Makarov, A.; Robotham, B.; Szal, J.; Velev, G.

    2015-01-01

    The design of the 12-GeV torus required the construction of six superconducting coils with a unique geometry required for the experimental needs of Jefferson Laboratory Hall B. Each of these coils consists of 234 turns of copper-stabilized superconducting cable conduction cooled by 4.6 K helium gas. The finished coils are each roughly 2 × 4 × 0.05 m and supported in an aluminum coil case. Because of its geometry, new tooling and manufacturing methods had to be developed for each stage of construction. The tooling was designed and developed while producing a practice coil at Fermi National Laboratory. This paper describes the tooling and manufacturing techniques required to produce the six production coils and two spare coils required by the project. Project status and future plans are also presented.

  2. Overview of torus magnet coil production at Fermilab for the Jefferson Lab 12-GeV Hall B upgrade

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

    Krave, S.; Velev, G.; Makarov, A.; Nobrega, F.; Kiemschies, O.; Robotham, B.; Elementi, L.; Elouadrhiri, Latifa; Luongo, Cesar; Kashy, David H.; et al

    2016-02-29

    Fermi National Accelerator Laboratory (Fermilab) fabricated the torus magnet coils for the 12 GeV Hall B upgrade at Jefferson Laboratory (JLab). The production consisted of 6 large superconducting coils for the magnet and 2 spare coils. The toroidal field coils are approximately 2 m x 4 m x 5 cm thick. Each of these coils consists of two layers, each of which has 117 turns of copper-stabilized superconducting cable which will be conduction cooled by helium gas. Due to the size of the coils and their unique geometry, Fermilab designed and fabricated specialized tooling and, together with JLab, developed uniquemore » manufacturing techniques for each stage of the coil construction. In conclusion, this paper describes the tooling and manufacturing techniques required to produce the six production coils and two spare coils needed by the project.« less

  3. PPPL to launch major upgrade of key fusion energy test facility | Princeton

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

    Plasma Physics Lab to launch major upgrade of key fusion energy test facility NSTX project will produce most powerful spherical torus in the world By John Greenwald January 9, 2012 Tweet Widget Google Plus One Share on Facebook NSTX-U cross section. NSTX-U cross section. Gallery: (Photo by Elle Starkman, PPPL Office of Communications) (Photo by Elle Starkman, PPPL Office of Communications) (Photo by Elle Starkman, PPPL Office of Communications) (Photo by Elle Starkman, PPPL Office of

  4. Radio Frequency Current Drive Considerations for Small Aspect Ratio Tori

    SciTech Connect (OSTI)

    Carter, M.D.

    1998-01-01

    Noninductive current drive is required during plasma initiation and for current sustainment in the National Spherical Torus Experiment (NSTX). In this paper, the physics of high harmonic fast waves (HHFW) and the design of an antenna system for NSTX are considered using numerical models. For high current discharges in NSTX, the static magnetic field component in the poloidal direction varies widely during the discharge and can become comparable to the toroidal component in NSTX. Therefore, they calculate the plasma loading for a broad range of antenna and plasma geometries in a three-dimensional model, so that the results can be used to influence the antenna design. Two-dimensional calculations of the wave propagation and absorption in the core plasma indicate that the theoretical current drive efficiency for HHFW can be high, and a general survey of parameters gives a good target for the antenna design. The current drive efficiency calculation is sensitive to the equilibrium model because finite beta effects can substantially alter the calculation of the trapped particle fraction. Traditional methods of toroidally phasing an antenna array as well as poloidal phasing are studied to optimize the current drive efficiency for a range of equilibria. Non-zero poloidal model excitation is also found to affect the antenna performance and flexibility. Performance expectations for a preliminary antenna design are given.

  5. Radio frequency current drive considerations for small aspect ratio tori

    SciTech Connect (OSTI)

    Carter, M.D.; Jaeger, E.F.; Strickler, D.J.; Ryan, P.M.; Swain, D.W.; Batchelor, D.B.

    1998-07-01

    Noninductive current drive is required during plasma initiation and for current sustainment in the National Spherical Torus Experiment (NSTX). In this paper, the physics of high harmonic fast waves (HHFW) and the design of an antenna system for NSTX are considered using numerical models. For high current discharges in NSTX, the static magnetic field component in the poloidal direction varies widely during the discharge and can become comparable to the toroidal component in NSTX. Therefore, they calculate the plasma loading for a broad range of antenna and plasma geometries in a three-dimensional model, so that the results can be used to influence the antenna design. Two-dimensional calculations of the wave propagation and absorption in the core plasma indicate that the theoretical current drive efficiency for HHFW can be high, and a general survey of parameters gives a good target for the antenna design. The current drive efficiency calculation is sensitive to the equilibrium model because finite beta effects can substantially alter the calculation of the trapped particle fraction. Traditional methods of toroidally phasing an antenna array as well as poloidal phasing are studied to optimize the current drive efficiency for a range of equilibria. Non-zero poloidal mode excitation is also found to affect the antenna performance and flexibility. Performance expectations for a preliminary antenna design are given.

  6. TORUS: Theory of Reactions for Unstable iSotopes.Topical Collaboration for Nuclear Theory Project. Period: June 1, 2010 - May 31, 2015

    SciTech Connect (OSTI)

    Arbanas, Goran; Elster, Charlotte; Escher, Jutta; Nunes, Filomena; Thompson, Ian

    2015-08-28

    The work of this collaboration during its existence is summarized. The mission of the TORUS Topical Collaboration was to develop new methods that advance nuclear reaction theory for unstable isotopes by using three-body techniques to improve direct reaction calculations. This multi-institution collaborative effort was and remains directly relevant to three areas of interest: the properties of nuclei far from stability, microscopic studies of nuclear input parameters for astrophysics, and microscopic nuclear reaction theory. The TORUS project focused on understanding the details of (d,p) reactions for neutron transfer to heavier nuclei. The bulk of the work fell into three areas: coupled channel theory, modeling (d,p) reactions with a Faddeev-AGS approach, and capture reactions.

  7. Suppression of energetic particle driven instabilities with HHFW heating

    SciTech Connect (OSTI)

    Fredrickson, E. D.; Taylor, G.; Bertelli, N.; Darrow, D. S.; Gorelenkov, N.; Kramer, G.; Liu, D.; Crocker, N. A.; Kubota, S.; White, R.

    2015-01-01

    In plasmas in the National Spherical Torus Experiment (NSTX) [Ono et al., Nucl. Fusion 40 (2000) 557] heated with neutral beams, the beam ions typically excite Energetic Particle Modes (EPMs or fishbones), and Toroidal, Global or Compressional Alfvén Eigenmodes (TAE, GAE, CAE). These modes can redistribute the energetic beam ions, altering the beam driven current profile and the plasma heating profile, or they may affect electron thermal transport or cause losses of the beam ions. In this paper we present experimental results where these instabilities, driven by the super-thermal beam ions, are suppressed with the application of High Harmonic Fast Wave heating.

  8. Suppression of energetic particle driven instabilities with HHFW heating

    SciTech Connect (OSTI)

    Fredrickson, E. D.; Taylor, G.; Bertelli, N.; Darrow, D. S.; Gorelenkov, N.; Kramer, G.; Liu, D.; Crocker, N. A.; Kubota, S.; White, R.

    2015-01-01

    In plasmas in the National Spherical Torus Experiment (NSTX) [Ono et al., Nucl. Fusion 40 (2000) 557] heated with neutral beams, the beam ions typically excite Energetic Particle Modes (EPMs or fishbones), and Toroidal, Global or Compressional Alfvn Eigenmodes (TAE, GAE, CAE). These modes can redistribute the energetic beam ions, altering the beam driven current profile and the plasma heating profile, or they may affect electron thermal transport or cause losses of the beam ions. In this paper we present experimental results where these instabilities, driven by the super-thermal beam ions, are suppressed with the application of High Harmonic Fast Wave heating.

  9. W

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

    the first major addition to the U.S. fusion program of the 21st century. Today the U.S. Department of Energy's Princeton Plasma Physics Laboratory (PPPL) unveils the new $94 million National Spherical Torus Experiment- Upgrade (NSTX-U), the most powerful fusion facility of its kind on Earth and a device poised to bring the world closer to a bold new energy age. This upgrade doubles the heating power and magnetic field strength of the original facility and enhances the worldwide quest for fusion

  10. Anomalous Electron Transport Due to Multiple High Frequency Beam Ion Driven Alfven Eigenmode

    SciTech Connect (OSTI)

    Gorelenkov, N. N.; Stutman, D.; Tritz, K.; Boozer, A.; Delgardo-Aparicio, L.; Fredrickson, E.; Kaye, S.; White, R.

    2010-07-13

    We report on the simulations of recently observed correlations of the core electron transport with the sub-thermal ion cyclotron frequency instabilities in low aspect ratio plasmas of the National Spherical Torus Experiment (NSTX). In order to model the electron transport of the guiding center code ORBIT is employed. A spectrum of test functions of multiple core localized Global shear Alfven Eigenmode (GAE) instabilities based on a previously developed theory and experimental observations is used to examine the electron transport properties. The simulations exhibit thermal electron transport induced by electron drift orbit stochasticity in the presence of multiple core localized GAE.

  11. Phillips-Tikhonov regularization with a priori information for neutron emission tomographic reconstruction on Joint European Torus

    SciTech Connect (OSTI)

    Bielecki, J.; Scholz, M.; Drozdowicz, K.; Giacomelli, L.; Kiptily, V.; Kempenaars, M.; Conroy, S.; Craciunescu, T.; Collaboration: EUROfusion Consortium, JET, Culham Science Centre, Abingdon OX14 3DB

    2015-09-15

    A method of tomographic reconstruction of the neutron emissivity in the poloidal cross section of the Joint European Torus (JET, Culham, UK) tokamak was developed. Due to very limited data set (two projection angles, 19 lines of sight only) provided by the neutron emission profile monitor (KN3 neutron camera), the reconstruction is an ill-posed inverse problem. The aim of this work consists in making a contribution to the development of reliable plasma tomography reconstruction methods that could be routinely used at JET tokamak. The proposed method is based on Phillips-Tikhonov regularization and incorporates a priori knowledge of the shape of normalized neutron emissivity profile. For the purpose of the optimal selection of the regularization parameters, the shape of normalized neutron emissivity profile is approximated by the shape of normalized electron density profile measured by LIDAR or high resolution Thomson scattering JET diagnostics. In contrast with some previously developed methods of ill-posed plasma tomography reconstruction problem, the developed algorithms do not include any post-processing of the obtained solution and the physical constrains on the solution are imposed during the regularization process. The accuracy of the method is at first evaluated by several tests with synthetic data based on various plasma neutron emissivity models (phantoms). Then, the method is applied to the neutron emissivity reconstruction for JET D plasma discharge #85100. It is demonstrated that this method shows good performance and reliability and it can be routinely used for plasma neutron emissivity reconstruction on JET.

  12. Processes and properties of edge-localised instabilities in 2T 2MA plasmas in the Joint European Torus

    SciTech Connect (OSTI)

    Webster, A. J. Webster, S. J.

    2014-11-15

    During July 2012, 150 almost identical H-mode plasmas were consecutively created in the Joint European Torus, providing a combined total of approximately 8 minutes of steady-state plasma with 15?000 Edge Localised Modes (ELMs). In principle, each of those 15?000 ELMs are statistically equivalent. Here, the changes in edge density and plasma energy associated with those ELMs are explored, using the spikes in Beryllium II (527?nm) radiation as an indicator for the onset of an ELM. Clearly different timescales are observed during the ELM process. Edge temperature falls over a 2?ms timescale, edge density and pressure fall over a 5?ms timescale, and there is an additional 10?ms timescale that is consistent with a resistive relaxation of the plasma's edge. The statistical properties of the energy and density losses due to the ELMs are explored. For these plasmas the ELM energy (?E) is found to be approximately independent of the time between ELMs, despite the average ELM energy (??E?) and average ELM frequency (f) being consistent with the scaling of ??E??1/f. Instead, beyond the first 0.02 s of waiting time between ELMs, the energy losses due to individual ELMs are found to be statistically the same. Surprisingly no correlation is found between the energies of consecutive ELMs either. A weak link is found between the density drop and the ELM waiting time. Consequences of these results for ELM control and modelling are discussed.

  13. Observation of dust torus with poloidal rotation in direct current glow discharge plasma

    SciTech Connect (OSTI)

    Kaur, Manjit Bose, Sayak; Chattopadhyay, P. K. Sharma, Devendra; Ghosh, J.; Saxena, Y. C.

    2015-03-15

    Observation of dust cloud rotation in parallel-plate DC glow discharge plasma is reported here. The experiments are carried out at high pressures (∼130 Pa) with a metallic ring placed on the lower electrode (cathode). The dust cloud rotates poloidally in the vertical plane near the cathode surface. This structure is continuous toroidally. Absence of magnetic field rules out the possibility of E × B induced ion flow as the cause of dust rotation. The dust rotational structures exist even with water cooled cathode. Therefore, temperature gradient driven mechanisms, such as thermophoretic force, thermal creep flow, and free convection cannot be causing the observed dust rotation. Langmuir probe measurement reveals the existence of a sharp density gradient near the location of the rotating dust cloud. The gradient in the density, giving rise to a gradient in the ion drag force, has been identified as the principal cause behind the rotation of dust particles.

  14. Distinct turbulence sources and confinement features in the spherical tokamak plasma regime

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

    Wang, W. X.; Ethier, S.; Ren, Y.; Kaye, S.; Chen, J.; Startsev, E.; Lu, Z.

    2015-10-30

    New turbulence contributions to plasma transport and confinement in the spherical tokamak (ST) regime are identified through nonlinear gyrokinetic simulations. The drift wave Kelvin-Helmholtz (KH) mode characterized by intrinsic mode asymmetry is shown to drive significant ion thermal transport in strongly rotating national spherical torus experiment (NSTX) L-modes. The long wavelength, quasi-coherent dissipative trapped electron mode (TEM) is destabilized in NSTX H-modes despite the presence of strong E x B shear, providing a robust turbulence source dominant over collisionless TEM. Dissipative trapped electron mode (DTEM)-driven transport in the NSTX parametric regime is shown to increase with electron collision frequency, offeringmore » one possible source for the confinement scaling observed in experiments. There exists a turbulence-free regime in the collision-induced collisionless trapped electron mode to DTEM transition for ST plasmas. In conclusion, this predicts a natural access to a minimum transport state in the low collisionality regime that future advanced STs may cover.« less

  15. Full wave simulations of fast wave efficiency and power losses in the scrape-off layer of tokamak plasmas in mid/high harmonic and minority heating regimes

    SciTech Connect (OSTI)

    Bertelli, N.; Jaeger, E. F.; Hosea, J. C.; Phillips, C. K.; Berry, L.; Bonoli, P. T.; Gerhardt, S. P.; Green, D.; LeBlanc, B.; Perkins, R. J.; Qin, C. M.; Pinsker, R. I.; Prater, R.; Ryan, P. M.; Taylor, G.; Valeo, E. J.; Wilson, J. R.; Wright, J. C.; Zhang, X. J.

    2015-12-17

    Here, several experiments on different machines and in different fast wave (FW) heating regimes, such as hydrogen minority heating and high harmonic fast waves (HHFW), have found strong interaction between radio-frequency (RF) waves and the scrape-off layer (SOL) region. This paper examines the propagation and the power loss in the SOL by using the full wave code AORSA, in which the edge plasma beyond the last closed flux surface (LCFS) is included in the solution domain and a collisional damping parameter is used as a proxy to represent the real, and most likely nonlinear, damping processes. 2D and 3D AORSA results for the National Spherical Torus eXperiment (NSTX) have shown a strong transition to higher SOL power losses (driven by the RF field) when the FW cut-off is removed from in front of the antenna by increasing the edge density. Here, full wave simulations have been extended for 'conventional' tokamaks with higher aspect ratios, such as the DIII-D, Alcator C-Mod, and EAST devices. DIII-D results in HHFW regime show similar behavior found in NSTX and NSTX-U, consistent with previous DIII-D experimental observations. In contrast, a different behavior has been found for C-Mod and EAST, which operate in the minority heating regime.

  16. Full wave simulations of fast wave efficiency and power losses in the scrape-off layer of tokamak plasmas in mid/high harmonic and minority heating regimes

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

    Bertelli, N.; Jaeger, E. F.; Hosea, J. C.; Phillips, C. K.; Berry, L.; Bonoli, P. T.; Gerhardt, S. P.; Green, D.; LeBlanc, B.; Perkins, R. J.; et al

    2015-12-17

    Here, several experiments on different machines and in different fast wave (FW) heating regimes, such as hydrogen minority heating and high harmonic fast waves (HHFW), have found strong interaction between radio-frequency (RF) waves and the scrape-off layer (SOL) region. This paper examines the propagation and the power loss in the SOL by using the full wave code AORSA, in which the edge plasma beyond the last closed flux surface (LCFS) is included in the solution domain and a collisional damping parameter is used as a proxy to represent the real, and most likely nonlinear, damping processes. 2D and 3D AORSAmore » results for the National Spherical Torus eXperiment (NSTX) have shown a strong transition to higher SOL power losses (driven by the RF field) when the FW cut-off is removed from in front of the antenna by increasing the edge density. Here, full wave simulations have been extended for 'conventional' tokamaks with higher aspect ratios, such as the DIII-D, Alcator C-Mod, and EAST devices. DIII-D results in HHFW regime show similar behavior found in NSTX and NSTX-U, consistent with previous DIII-D experimental observations. In contrast, a different behavior has been found for C-Mod and EAST, which operate in the minority heating regime.« less

  17. Integrated simulations of saturated neoclassical tearing modes in DIII-D, Joint European Torus, and ITER plasmas

    SciTech Connect (OSTI)

    Halpern, Federico D.; Bateman, Glenn; Kritz, Arnold H.

    2006-06-15

    A revised version of the ISLAND module [C. N. Nguyen et al., Phys. Plasmas 11, 3604 (2004)] is used in the BALDUR code [C. E. Singer et al., Comput. Phys. Commun. 49, 275 (1988)] to carry out integrated modeling simulations of DIII-D [J. Luxon, Nucl. Fusion 42, 614 (2002)], Joint European Torus (JET) [P. H. Rebut et al., Nucl. Fusion 25, 1011 (1985)], and ITER [R. Aymar et al., Plasma Phys. Control. Fusion 44, 519 (2002)] tokamak discharges in order to investigate the adverse effects of multiple saturated magnetic islands driven by neoclassical tearing modes (NTMs). Simulations are carried out with a predictive model for the temperature and density pedestal at the edge of the high confinement mode (H-mode) plasma and with core transport described using the Multi-Mode model. The ISLAND module, which is used to compute magnetic island widths, includes the effects of an arbitrary aspect ratio and plasma cross sectional shape, the effect of the neoclassical bootstrap current, and the effect of the distortion in the shape of each magnetic island caused by the radial variation of the perturbed magnetic field. Radial transport is enhanced across the width of each magnetic island within the BALDUR integrated modeling simulations in order to produce a self-consistent local flattening of the plasma profiles. It is found that the main consequence of the NTM magnetic islands is a decrease in the central plasma temperature and total energy. For the DIII-D and JET discharges, it is found that inclusion of the NTMs typically results in a decrease in total energy of the order of 15%. In simulations of ITER, it is found that the saturated magnetic island widths normalized by the plasma minor radius, for the lowest order individual tearing modes, are approximately 24% for the 2/1 mode and 12% for the 3/2 mode. As a result, the ratio of ITER fusion power to heating power (fusion Q) is reduced from Q=10.6 in simulations with no NTM islands to Q=2.6 in simulations with fully saturated

  18. Resonance in fast-wave amplitude in the periphery of cylindrical plasmas and application to edge losses of wave heating power in tokamaks

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

    Perkins, R. J.; Hosea, J. C.; Bertelli, N.; Taylor, G.; Wilson, J. R.

    2016-07-01

    Heating magnetically confined plasmas using waves in the ion-cyclotron range of frequencies typically requires coupling these waves over a steep density gradient. Furthermore, this process has produced an unexpected and deleterious phenomenon on the National Spherical Torus eXperiment (NSTX): a prompt loss of wave power along magnetic field lines in front of the antenna to the divertor. Understanding this loss may be key to achieving effective heating and expanding the operational space of NSTX-Upgrade. Here, we propose that a new type of mode, which conducts a significant fraction of the total wave power in the low-density peripheral plasma, is drivingmore » these losses. We demonstrate the existence of such modes, which are distinct from surface modes and coaxial modes, in a cylindrical cold-plasma model when a half wavelength structure fits into the region outside the core plasma. The latter condition generalizes the previous hypothesis regarding the occurence of the edge losses and may explain why full-wave simulations predict these losses in some cases but not others. If valid, this condition implies that outer gap control is a potential strategy for mitigating the losses in NSTX-Upgrade in addition to raising the magnetic field or influencing the edge density.« less

  19. 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)

    Choi, Myunghee; Chan, Vincent S.

    2014-02-28

    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.

  20. Effect of the scrape-off layer in AORSA full wave simulations of fast wave minority, mid/high harmonic, and helicon heating regimes

    SciTech Connect (OSTI)

    Bertelli, N. Gerhardt, S.; Hosea, J. C.; LeBlanc, B.; Perkins, R. J.; Phillips, C. K.; Taylor, G.; Valeo, E. J.; Wilson, J. R.; Jaeger, E. F.; Lau, C.; Blazevski, D.; Green, D. L.; Berry, L.; Ryan, P. M.; Bonoli, P. T.; Wright, J. C.; Pinsker, R. I.; Prater, R.; Qin, C. M.; and others

    2015-12-10

    Several experiments on different machines and in different fast wave (FW) heating regimes, such as hydrogen minority heating and high harmonic fast waves, have found strong interactions between radio-frequency (RF) waves and the scrape-off layer (SOL) region. This paper examines the propagation and the power loss in the SOL by using the full wave code AORSA, in which the edge plasma beyond the last closed flux surface (LCFS) is included in the solution domain and a collisional damping parameter is used as a proxy to represent the real, and most likely nonlinear, damping processes. 3D AORSA results for the National Spherical Torus eXperiment (NSTX), where a full antenna spectrum is reconstructed, are shown, confirming the same behavior found for a single toroidal mode results in Bertelli et al, Nucl. Fusion, 54 083004, 2014, namely, a strong transition to higher SOL power losses (driven by the RF field) when the FW cut-off is moved away from in front of the antenna by increasing the edge density. Additionally, full wave simulations have been extended to “conventional” tokamaks with higher aspect ratios, such as the DIII-D, Alcator C-Mod, and EAST devices. DIII-D results show similar behavior found in NSTX and NSTX-U, consistent with previous DIII-D experimental observations. In contrast, a different behavior has been found for Alcator C-Mod and EAST, which operate in the minority heating regime unlike NSTX/NSTX-U and DIII-D, which operate in the mid/high harmonic regime. A substantial discussion of some of the main aspects, such as (i) the pitch angle of the magnetic field; (ii) minority heating vs. mid/high harmonic regimes is presented showing the different behavior of the RF field in the SOL region for NSTX-U scenarios with different plasma current. Finally, the preliminary results of the impact of the SOL region on the evaluation of the helicon current drive efficiency in DIII-D is presented for the first time and briefly compared with the different regimes

  1. 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)

    Tazaki, Fumie; Ueda, Yoshihiro; Terashima, Yuichi; Mushotzky, Richard F.; Tombesi, Francesco

    2013-07-20

    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.

  2. New Benchmarks from Tokamak Experiments for Theoretical Calculations of the Dielectronic Satellite Spectra of Helium-like Ions

    SciTech Connect (OSTI)

    M. Bitter; M.F. Gu; L.A. Vainshtein; P. Beiersdorfer; G. Bertschinger; O. Marchuk; R. Bell; B. LeBlanc; K.W. Hill; D. Johnson; L. Roquemore

    2003-08-29

    Dielectronic satellite spectra of helium-like argon, recorded with a high-resolution X-ray crystal spectrometer at the National Spherical Torus Experiment, were found to be inconsistent with existing predictions resulting in unacceptable values for the power balance and suggesting the unlikely existence of non-Maxwellian electron energy distributions. These problems were resolved with calculations from a new atomic code. It is now possible to perform reliable electron temperature measurements and to eliminate the uncertainties associated with determinations of non-Maxwellian distributions.

  3. Modeling the effect of lithium-induced pedestal profiles on scrape-off-layer turbulence and the heat flux width

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

    Russell, David A.; D'Ippolito, Daniel A.; Myra, James R.; Canik, John M.; Gray, Travis K.; Zweben, Stewart J.

    2015-09-01

    The effect of lithium (Li) wall coatings on scrape-off-layer (SOL) turbulence in the National Spherical Torus Experiment (NSTX) is modeled with the Lodestar SOLT (“SOL Turbulence”) code. Specifically, the implications for the SOL heat flux width of experimentally observed, Li-induced changes in the pedestal profiles are considered. The SOLT code used in the modeling has been expanded recently to include ion temperature evolution and ion diamagnetic drift effects. This work focuses on two NSTX discharges occurring pre- and with-Li deposition. The simulation density and temperature profiles are constrained, inside the last closed flux surface only, to match those measured inmore » the two experiments, and the resulting drift-interchange-driven turbulence is explored. The effect of Li enters the simulation only through the pedestal profile constraint: Li modifies the experimental density and temperature profiles in the pedestal, and these profiles affect the simulated SOL turbulence. The power entering the SOL measured in the experiments is matched in the simulations by adjusting “free” dissipation parameters (e.g., diffusion coefficients) that are not measured directly in the experiments. With power-matching, (a) the heat flux SOL width is smaller, as observed experimentally by infra-red thermography, and (b) the simulated density fluctuation amplitudes are reduced with Li, as inferred for the experiments as well from reflectometry analysis. The instabilities and saturation mechanisms that underlie the SOLT model equilibria are also discussed.« less

  4. Modeling the effect of lithium-induced pedestal profiles on scrape-off-layer turbulence and the heat flux width

    SciTech Connect (OSTI)

    Russell, David A.; D'Ippolito, Daniel A.; Myra, James R.; Canik, John M.; Gray, Travis K.; Zweben, Stewart J.

    2015-09-01

    The effect of lithium (Li) wall coatings on scrape-off-layer (SOL) turbulence in the National Spherical Torus Experiment (NSTX) is modeled with the Lodestar SOLT (“SOL Turbulence”) code. Specifically, the implications for the SOL heat flux width of experimentally observed, Li-induced changes in the pedestal profiles are considered. The SOLT code used in the modeling has been expanded recently to include ion temperature evolution and ion diamagnetic drift effects. This work focuses on two NSTX discharges occurring pre- and with-Li deposition. The simulation density and temperature profiles are constrained, inside the last closed flux surface only, to match those measured in the two experiments, and the resulting drift-interchange-driven turbulence is explored. The effect of Li enters the simulation only through the pedestal profile constraint: Li modifies the experimental density and temperature profiles in the pedestal, and these profiles affect the simulated SOL turbulence. The power entering the SOL measured in the experiments is matched in the simulations by adjusting “free” dissipation parameters (e.g., diffusion coefficients) that are not measured directly in the experiments. With power-matching, (a) the heat flux SOL width is smaller, as observed experimentally by infra-red thermography, and (b) the simulated density fluctuation amplitudes are reduced with Li, as inferred for the experiments as well from reflectometry analysis. The instabilities and saturation mechanisms that underlie the SOLT model equilibria are also discussed.

  5. Design of solid state neutral particle analyzer array for National...

    Office of Scientific and Technical Information (OSTI)

    Torus Experiment-Upgrade Citation Details In-Document Search Title: Design of solid state neutral particle analyzer array for National Spherical Torus Experiment-Upgrade A ...

  6. Chaos in plasma simulation and experiment

    SciTech Connect (OSTI)

    Watts, C.; Newman, D.E.; Sprott, J.C.

    1993-09-01

    We investigate the possibility that chaos and simple determinism are governing the dynamics of reversed field pinch (RFP) plasmas using data from both numerical simulations and experiment. A large repertoire of nonlinear analysis techniques is used to identify low dimensional chaos. These tools include phase portraits and Poincard sections, correlation dimension, the spectrum of Lyapunov exponents and short term predictability. In addition, nonlinear noise reduction techniques are applied to the experimental data in an attempt to extract any underlying deterministic dynamics. Two model systems are used to simulate the plasma dynamics. These are -the DEBS code, which models global RFP dynamics, and the dissipative trapped electron mode (DTEM) model, which models drift wave turbulence. Data from both simulations show strong indications of low,dimensional chaos and simple determinism. Experimental data were obtained from the Madison Symmetric Torus RFP and consist of a wide array of both global and local diagnostic signals. None of the signals shows any indication of low dimensional chaos or other simple determinism. Moreover, most of the analysis tools indicate the experimental system is very high dimensional with properties similar to noise. Nonlinear noise reduction is unsuccessful at extracting an underlying deterministic system.

  7. Mechanisms of Stochastic Diffusion of Energetic Ions in Spherical Tori

    SciTech Connect (OSTI)

    Ya.I. Kolesnichenko; R.B. White; Yu.V. Yakovenko

    2001-01-18

    Stochastic diffusion of the energetic ions in spherical tori is considered. The following issues are addressed: (I) Goldston-White-Boozer diffusion in a rippled field; (ii) cyclotron-resonance-induced diffusion caused by the ripple; (iii) effects of non-conservation of the magnetic moment in an axisymmetric field. It is found that the stochastic diffusion in spherical tori with a weak magnetic field has a number of peculiarities in comparison with conventional tokamaks; in particular, it is characterized by an increased role of mechanisms associated with non-conservation of the particle magnetic moment. It is concluded that in current experiments on National Spherical Torus eXperiment (NSTX) the stochastic diffusion does not have a considerable influence on the confinement of energetic ions.

  8. Ignition Experiments

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

    ignition experiments 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 more energy than the energy required to initiate the fusion reaction-an event called ignition. In moving closer to achieving ignition, NIF researchers are fulfilling the vision of early laser pioneers who conceived of using the x rays generated by a powerful, brief laser pulse to fuse

  9. Mixture Experiments

    SciTech Connect (OSTI)

    Piepel, Gregory F.

    2007-12-01

    A mixture experiment involves combining two or more components in various proportions or amounts and then measuring one or more responses for the resulting end products. Other factors that affect the response(s), such as process variables and/or the total amount of the mixture, may also be studied in the experiment. A mixture experiment design specifies the combinations of mixture components and other experimental factors (if any) to be studied and the response variable(s) to be measured. Mixture experiment data analyses are then used to achieve the desired goals, which may include (i) understanding the effects of components and other factors on the response(s), (ii) identifying components and other factors with significant and nonsignificant effects on the response(s), (iii) developing models for predicting the response(s) as functions of the mixture components and any other factors, and (iv) developing end-products with desired values and uncertainties of the response(s). Given a mixture experiment problem, a practitioner must consider the possible approaches for designing the experiment and analyzing the data, and then select the approach best suited to the problem. Eight possible approaches include 1) component proportions, 2) mathematically independent variables, 3) slack variable, 4) mixture amount, 5) component amounts, 6) mixture process variable, 7) mixture of mixtures, and 8) multi-factor mixture. The article provides an overview of the mixture experiment designs, models, and data analyses for these approaches.

  10. On The Anomalous Fast Ion Energy Diffusion in Toroidal Plasmas Due to Cavity Modes

    SciTech Connect (OSTI)

    N.N. Gorelenkov, N.J. Fisch and E. Fredrickson

    2010-03-09

    An enormous wave-particle diffusion coefficient along paths suitable for alpha channeling had been deduced in mode converted ion Bernstein wave experiments on Tokamak Fusion Test Reactor (TFTR) the only plausible explanation advanced for such a large diffusion coefficient was the excitation of internal cavity modes which induce particle diffusion along identical diffusion paths, but at much higher rates. Although such a mode was conjectured, it was never observed. However, recent detailed observations of high frequency compressional Alfven eigenmodes (CAEs) on the National Spherical torus Experiment (NSTX) indirectly support the existence of the related conjectured modes on TFTR. The eigenmodes responsible for the high frequency magnetic activity can be identified as CAEs through the polarization of the observed magnetic field oscillations in NSTX and through a comparison with the theoretically derived freuency dispersion relation. Here, we show how these recent observations of high frequency CAEs lend support to this explanation of the long-standing puzzle of anomalous fast ion energy diffusion on TFTR. The support of the conjecure that these internal modes could have caused the remarkable ion energy diffusion on TFTR carries significant and favorable implications for the possibilities in achieving the alpha channeling effect with small injected power in a tokamak reactor.

  11. He Puff System For Dust Detector Upgrade

    SciTech Connect (OSTI)

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

    2010-10-01

    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. __________________________________________________

  12. Suppression of energetic particle driven instabilities with HHFW heating

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

    Fredrickson, E. D.; Taylor, G.; Bertelli, N.; Darrow, D. S.; Gorelenkov, N.; Kramer, G.; Liu, D.; Crocker, N. A.; Kubota, S.; White, R.

    2015-01-01

    In plasmas in the National Spherical Torus Experiment (NSTX) [Ono et al., Nucl. Fusion 40 (2000) 557] heated with neutral beams, the beam ions typically excite Energetic Particle Modes (EPMs or fishbones), and Toroidal, Global or Compressional Alfvén Eigenmodes (TAE, GAE, CAE). These modes can redistribute the energetic beam ions, altering the beam driven current profile and the plasma heating profile, or they may affect electron thermal transport or cause losses of the beam ions. In this paper we present experimental results where these instabilities, driven by the super-thermal beam ions, are suppressed with the application of High Harmonic Fastmore » Wave heating.« less

  13. NSTX-U Control System Upgrades

    Office of Scientific and Technical Information (OSTI)

    Fusion Engineering and Design j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m l o c a t e f u s e n g d e s F u sio n E n g in e e rin g s - - - - a n d D e sig ...

  14. Princeton Plasma Physics Lab - NSTX-U

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

    "field-label">Byline:

    John Greenwald
  15. Current Schedule of Experiments

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

    current schedule of experiments Current Schedule of Experiments Current Schedule of Experiments - Updated 4/2016

  16. Comment on Magnetic geometry and physics of advanced divertors: The X-divertor and the snowflake [Phys. Plasmas 20, 102507 (2013)

    SciTech Connect (OSTI)

    Ryutov, D. D. Cohen, R. H.; Rognlien, T. D.; Soukhanovskii, V. A.; Umansky, M. V.

    2014-05-15

    In the recently published paper Magnetic geometry and physics of advanced divertors: The X-divertor and the snowflake [Phys. Plasmas 20, 102507 (2013)], the authors raise interesting and important issues concerning divertor physics and design. However, the paper contains significant errors: (a) The conceptual framework used in it for the evaluation of divertor quality is reduced to the assessment of the magnetic field structure in the outer Scrape-Off Layer. This framework is incorrect because processes affecting the pedestal, the private flux region and all of the divertor legs (four, in the case of a snowflake) are an inseparable part of divertor operation. (b) The concept of the divertor index focuses on only one feature of the magnetic field structure and can be quite misleading when applied to divertor design. (c) The suggestion to rename the divertor configurations experimentally realized on NSTX (National Spherical Torus Experiment) and DIII-D (Doublet III-D) from snowflakes to X-divertors is not justified: it is not based on comparison of these configurations with the prototypical X-divertor, and it ignores the fact that the NSTX and DIII-D poloidal magnetic field geometries fit very well into the snowflake two-null prescription.

  17. Multiwell experiment

    SciTech Connect (OSTI)

    Sattler, A.R.; Warpinski, N.R.; Lorenz, J.C.; Hart, C.M.; Branagan, P.T.

    1985-01-01

    The Multiwell Experiment is a research-oriented field laboratory. Its overall objectives are to characterize lenticular, low-permeability gas reservoirs and to develop technology for their production. This field laboratory has been established at a site in the east-central Piceance basin, Colorado. Here the Mesaverde formation lies at a depth of 4000 to 8250 ft. This interval contains different, distinct reservoir types depending upon their depositional environments. These different zones serve as the focus of the various testing and stimulation programs. Field work began in late 1981 and is scheduled through mid-1988. One key to the Multiwell Experiment is three closely spaced wells. Core, log, well testing, and well-to-well seismic data are providing a far better definition of the geological setting than has been available previously. The closely spaced wells also allow interference and tracer tests to obtain in situ reservoir parameters. The vertical variation of in situ stress throughout the intervals of interest is being measured. A series of stimulation experiments is being conducted in one well and the other two wells are being used as observation wells for improved fracture diagnostics and well testing. Another key to achieving the Multiwell Experiment objectives is the synergism resulting from a broad spectrum of activities: geophysical surveys, sedimentological studies, core and log analyses, well testing, in situ stress determination, stimulation, fracture diagnostics, and reservoir analyses. The results from the various activities will define the reservoir and the hydraulic fracture. These, in turn, define the net pay stimulated: the intersection of a hydraulic fracture of known geometry with a reservoir of known morphology and properties. Accomplishments of the past year are listed. 4 refs.

  18. SANE experiment

    SciTech Connect (OSTI)

    H. Baghdasaryan, SANE Collaboration

    2012-04-01

    The Spin Asymmetries of the Nucleon Experiment (SANE) is a measurement of parallel and near-perpendicular double spin asymmetries in an inclusive electron scattering. The main goal of the experiment was to measure A{sub {parallel}} and A{sub 80} and extract the spin asymmetries of the proton A{sub 1}{sup p}, A{sub 2}{sup p} and spin structure functions g{sub 1}{sup p} and g{sub 2}{sup p}. Using the Thomas Jefferson National Accelerator Facility's polarized electron beam and the University of Virginia's polarized frozen ammonia ({sup 14}NH{sub 3}) target in Hall C, the experiment ran in 2009, collecting data in a Q{sup 2} region from 2.5 to 6.5 GeV{sup 2} and between Bjorken x of 0.3 to 0.8. Particle detection was accomplished using the Big Electron Telescope Array (BETA), a novel non-magnetic detector. This talk will address the progress of the analysis designed to extract the proton spin asymmetries and structure functions. Preliminary results will be presented.

  19. Approved Experiments

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

    Cycle 31OCT97 Exp# Spokesperson Experiment Title Days 666 Clark Magnetic Rotation in 104Sn 5 667 Janssens Unsafe COULEX of the 240Pu Nucleus 3 670 Smith Exotic Structures in very Neutron-Deficient 55 < Z < 59, A ~ 120 Nuclei 6 671LI Butler The Feasibility of Studying Octupole Correlations in 224,226U using Gammasphere and the FMA 1 672 Svensson Superdeformation in 3060Zn30 and Proton-Decay from Excited States in 3366As33 5 677 Woods Structure of Deformed Ho Isotopes Beyond the Proton

  20. Lower hybrid system design for the Tokamak physics experiment

    SciTech Connect (OSTI)

    Goranson, P.L.; Conner, D.L.; Swain, D.W.; Yugo, J.J.; Bernabei, S.; Greenough, N.

    1995-12-31

    The lower hybrid (LH) launcher configuration has been redesigned to integrate the functions of the vertical four-way power splitter and the front waveguide array (front array). This permits 256 waveguide channels to be fed by only 64 waveguides at the vacuum window interface. The resulting configuration is a more compact coupler, which incorporates the simplicity of a multijunction coupler while preserving the spectral flexibility of a conventional lower hybrid launcher. Other spin-offs of the redesign are reduction in thermal incompatibility between the front array and vacuum windows, improved maintainability, in situ vacuum window replacement, a reduced number of radio frequency (rf) connections, and a weight reduction of 7300 kg. There should be a significant cost reduction as well. Issues associated with the launcher design and fabrication have been addressed by a research and development program that includes brazing of the front array and testing of the power splitter configuration to confirm that phase errors due to reflections in the shorted splitter legs will not significantly impact the rf spectrum. The Conceptual Design Review requires that radiation levels at the torus radial port mounting flange and outer surface of the toroidal field coils should be sufficiently low to permit hands-on maintenance. Low activation materials and neutron shielding are incorporated in the launcher design to meet these requirements. The launcher is configured to couple 3 MW of steady state LH heating/LH current drive power at 3.7 GHz to the Tokamak Physics Experiment plasma.

  1. Princeton Plasma Physics Laboratory Annual Site Environmental Report for Calendar Year 2000

    SciTech Connect (OSTI)

    Virginia L. Finley

    2002-04-22

    The results of the 2000 environmental surveillance and monitoring program for the Princeton Plasma Physics Laboratory (PPPL) are presented and discussed. The purpose of this report is to provide the U.S. Department of Energy and the public with information on the level of radioactive and nonradioactive pollutants (if any) that are added to the environment as a result of PPPL's operations. The report also summarizes environmental initiatives, assessments, and programs that were undertaken in 2000. The Princeton Plasma Physics Laboratory has engaged in fusion energy research since 1951. The long-range goal of the U.S. Magnetic Fusion Energy Research Program is to create innovations to make fusion power a practical reality -- an alternative energy source. The year 2000 marked the second year of National Spherical Torus Experiment (NSTX) operations and Tokamak Fusion Test Reactor (TFTR) dismantlement and deconstruction activities. A collaboration among fourteen national laboratories, universities, and research institutions, the NSTX is a major element in the U.S. Fusion Energy Sciences Program. It has been designed to test the physics principles of spherical torus (ST) plasmas. The ST concept could play an important role in the development of smaller, more economical fusion power plants. With its completion within budget and ahead of its target schedule, NSTX first plasma occurred on February 12, 1999. In 2000, PPPL's radiological environmental monitoring program measured tritium in the air at on-site and off-site sampling stations. PPPL is capable of detecting small changes in the ambient levels of tritium by using highly sensitive monitors. The operation of an in-stack monitor located on D-site is a requirement of the National Emission Standard for Hazardous Air Pollutants (NESHAPs) regulations with limits set by the Environmental Protection Agency (EPA). Also included in PPPL's radiological environmental monitoring program, are precipitation, surface, ground, a nd

  2. Science and Technology of the 10-MA Spherical Tori

    SciTech Connect (OSTI)

    Peng, Y-K.M.

    1999-11-14

    The Spherical Torus (ST) configuration has recently emerged as an example of confinement concept innovation that enables attractive steps in the development of fusion energy. The scientific potential for the ST has been indicated by recent encouraging results from START,2 CDX-U, and HIT. The scientific principles for the D-fueled ST will soon be tested by NSTX (National Spherical Torus Experiment3) in the U.S. and MAST (Mega-Amp Spherical Tokamak4) in the U.K. at the level of l-2 MA in plasma current. More recently, interest has grown in the U.S. in the possibility of near-term ST fusion burn devices at the level of 10 MA in plasma current. The missions for these devices would be to test burning plasma performance in a small, pulsed D-T-fueled ST (i.e., DTST) and to develop fusion energy technologies in a small steady state ST-based Volume Neutron Source (VNS). This paper reports the results of analysis of the key science and technology issues for these devices.

  3. Fueling Requirements for Steady State high butane current fraction discharges

    SciTech Connect (OSTI)

    R.Raman

    2003-10-08

    The CT injector originally used for injecting CTs into 1T toroidal field discharges in the TdeV tokamak was shipped PPPL from the Affiliated Customs Brokers storage facility in Montreal during November 2002. All components were transported safely, without damage, and are currently in storage at PPPL, waiting for further funding in order to begin advanced fueling experiments on NSTX. The components are currently insured through the University of Washington. Several technical presentations were made to investigate the feasibility of the CT injector installation on NSTX. These technical presentations, attached to this document, were: (1) Motivation for Compact Toroida Injection in NSTX; (2) Assessment of the Engineering Feasibility of Installing CTF-II on NSTX; (3) Assessment of the Cost for CT Installation on NSTX--A Peer Review; and (4) CT Fueling for NSTX FY 04-08 steady-state operation needs.

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

    SciTech Connect (OSTI)

    Gorelenkov, Nikolai N

    2013-06-01

    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).

  5. Three-dimensional magnetohydrodynamics simulations of counter-helicity spheromak merging in the Swarthmore Spheromak Experiment

    SciTech Connect (OSTI)

    Myers, C. E.; Belova, E. V.; Brown, M. R.; Gray, T.; Cothran, C. D.; Schaffer, M. J.

    2011-11-15

    Recent counter-helicity spheromak merging experiments in the Swarthmore Spheromak Experiment (SSX) have produced a novel compact torus (CT) with unusual features. These include a persistent antisymmetric toroidal magnetic field profile and a slow, nonlinear emergence of the n = 1 tilt mode. Experimental measurements are inconclusive as to whether this unique CT is a fully merged field-reversed configuration (FRC) with strong toroidal field or a partially merged ''doublet CT'' configuration with both spheromak- and FRC-like characteristics. In this paper, the SSX merging process is studied in detail using three-dimensional resistive MHD simulations from the Hybrid Magnetohydrodynamics (HYM) code. These simulations show that merging plasmas in the SSX parameter regime only partially reconnect, leaving behind a doublet CT rather than an FRC. Through direct comparisons, we show that the magnetic structure in the simulations is highly consistent with the SSX experimental observations. We also find that the n = 1 tilt mode begins as a fast growing linear mode that evolves into a slower-growing nonlinear mode before being detected experimentally. A simulation parameter scan over resistivity, viscosity, and line-tying shows that these parameters can strongly affect the behavior of both the merging process and the tilt mode. In fact, merging in certain parameter regimes is found to produce a toroidal-field-free FRC rather than a doublet CT.

  6. Study of Thermonuclear Alfven Instabilities in Next Step Burning Plasma Experiments

    SciTech Connect (OSTI)

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

    2002-07-02

    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

  7. Fast ion energy distribution from third harmonic radio frequency heating measured with a single crystal diamond detector at the Joint European Torus

    SciTech Connect (OSTI)

    Nocente, M.; Rebai, M.; Gorini, G.; Cazzaniga, C.; Tardocchi, M.; Giacomelli, L.; Muraro, A.; Binda, F.; Eriksson, J.; Sharapov, S.; Collaboration:

    2015-10-15

    Neutron spectroscopy measurements with a single crystal diamond detector have been carried out at JET, for the first time in an experiment aimed at accelerating deuterons to MeV energies with radio frequency heating at the third harmonic. Data are interpreted by means of the expected response function of the detector and are used to extract parameters of the highly non-Maxwellian distribution function generated in this scenario. A comparison with observations using a time of flight and liquid scintillator neutron spectrometers is also presented. The results demonstrate the capability of diamond detectors to contribute to fast ion physics studies at JET and are of more general relevance in view of the application of such detectors for spectroscopy measurements in the neutron camera of next step tokamak devices.

  8. ORISE: Research Experiences

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

    Research Experiences Research Experiences The Oak Ridge Institute for Science and Education (ORISE) administers more than 150 science education programs on behalf of the U.S....

  9. Tritium Plasma Experiment and

    Office of Environmental Management (EM)

    Plasma Experiment and its role in PHENIX program Masashi Shimada, Chase Taylor Fusion ... ID Outline: 1. Motivation 2. Tritium Plasma Experiment 3. INLSTAR's role on US-Japan ...

  10. Water Vapor Experiment Concludes

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

    3 Water Vapor Experiment Concludes The AIRS (atmospheric infrared sounder) Water Vapor Experiment - Ground (AWEX-G) intensive operations period (IOP) at the SGP central facility ...

  11. Operating Experience Committee Charter

    Broader source: Energy.gov [DOE]

    The Operating Experience Committe Charter explains the purpose of the Department of Energy (DOE) Operating Experience Committee (OEC), which is to support line management within DOE and the DOE community in developing and sustaining effective oeprating experience programs so that lessons from inernal and external operating experience lead to improvement in future operational and safety performance.

  12. Safety assessment document (SAD) for the Princeton Beta Experiment Modification (PBX-M)

    SciTech Connect (OSTI)

    Stencel, J.R.; Parsells, R.F.

    1988-04-01

    The Princeton Beta Experiment-Modification (PBX-M) is an experimental device of the tokamak type. A tokamak is characterized by a strong toroidal magnetic field composed of an externally driven component parallel to the torus centerline modified by the field produced by a transformer-driven current (OH) in the confined plasma. A second magnetic field parallel to the major toroidal axis is added to provide radial equilibrium for the plasma. As an advanced tokamak, PBX-M will have additional magnetic fields to reshape the plasma cross section from a circle into a kidney bean shape; it will also be equipped with 6MW or more of auxiliary heating power provided by four neutral beam injectors, with RF systems, and with an extensive set of diagnostics. Potential hazards associated with PBX-M, which are analyzed in this report, result from energy stored in the magnetic fields, high voltages necessary for the operation of some of the equipment and diagnostics, neutron radiation when the neutral beams are run with deuterium and x-rays, especially those emitted as a result of plasma-wall interaction. This report satisfies the requirements set forth in the PPPL Health and Safety Directives, specifically HSD-5003, and in DOE Order 5481.1B and its Chicago operations supplement (DOE86, DOE82).

  13. Operating Experience Committee Charter

    Broader source: Energy.gov [DOE]

    The Operating Experience Committee (OEC) charter provides a description of the OEC's purpose, background, membership, functions, and operations.

  14. Coupled-channel scattering on a torus

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

    Guo, Peng; Dudek, Jozef Jon; Edwards, Robert G.; Szczepaniak, Adam Pawel

    2013-07-01

    Based on the Hamiltonian formalism approach, a generalized Luscher's formula for two particle scattering in both the elastic and coupled-channel cases in moving frames is derived from a relativistic Lippmann-Schwinger equation. Some strategies for extracting scattering amplitudes for a coupled-channel system from the discrete finite-volume spectrum are discussed and illustrated with a toy model of two-channel resonant scattering. This formalism will, in the near future, be used to extract information about hadron scattering from lattice QCD computations.

  15. Zone routing in a torus network

    DOE Patents [OSTI]

    Chen, Dong; Heidelberger, Philip; Kumar, Sameer

    2013-01-29

    A system for routing data in a network comprising a network logic device at a sending node for determining a path between the sending node and a receiving node, wherein the network logic device sets one or more selection bits and one or more hint bits within the data packet, a control register for storing one or more masks, wherein the network logic device uses the one or more selection bits to select a mask from the control register and the network logic device applies the selected mask to the hint bits to restrict routing of the data packet to one or more routing directions for the data packet within the network and selects one of the restricted routing directions from the one or more routing directions and sends the data packet along a link in the selected routing direction toward the receiving node.

  16. Double Beta Decay Experiments

    SciTech Connect (OSTI)

    Nanal, Vandana [Dept. of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Mumbai 400 005 (India)

    2011-11-23

    At present, neutrinoless double beta decay is perhaps the only experiment that can tell us whether the neutrino is a Dirac or a Majorana particle. Given the significance of the 0{nu}{beta}{beta}, there is a widespread interest for these rare event studies employing a variety of novel techniques. This paper describes the current status of DBD experiments. The Indian effort for an underground NDBD experiment at the upcoming INO laboratory is also presented.

  17. Experiment Safety Requirements

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

    Experiment Safety Experiment Safety Requirements Print Safety at the ALS The mission of the ALS is to "Support users in doing outstanding science in a safe environment." How Do I...? Complete an Experiment Safety Sheet? (Do this upon receiving beam time.) Complete Safety Training? Bring and Use Electrical Equipment at the ALS? Determine what Personal Protective Equipment (PPE) to Wear? Get Authorization to Work with Lasers at the ALS? Ship Radioactive Materials to LBNL for Use at the

  18. Future reactor experiments

    SciTech Connect (OSTI)

    Wen, Liangjian

    2015-07-15

    The non-zero neutrino mixing angle θ{sub 13} has been discovered and precisely measured by the current generation short-baseline reactor neutrino experiments. It opens the gate of measuring the leptonic CP-violating phase and enables the neutrino mass ordering. The JUNO and RENO-50 proposals aim at resolving the neutrino mass ordering using reactors. The experiment design, physics sensitivity, technical challenges as well as the progresses of those two proposed experiments are reviewed in this paper.

  19. ORISE: Faculty Research Experiences

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

    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...

  20. Nuclear Physics: Experiment Research

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

    Colloquium Experiment Research UserResearcher Information print version Research Highlights Public Interest Nuclear Physics Accelerator Free Electron Laser (FEL) Medical Imaging ...

  1. Nuclear Physics: Experiment Research

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

    Accelerator and Experimental Schedule Beam Time Request Form Experiment Scheduling and General Information Radiation Budget Form (pdf) Interactive beam request form (for contact...

  2. Operating Experience Summaries

    Broader source: Energy.gov [DOE]

    The Office of Environment, Health, Safety and Security (AU) Office of Analysis publishes the Operating Experience Summary to exchange lessons-learned information between DOE facilities.

  3. ORISE: Research Team Experiences

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

    Research Team Experiences The Oak Ridge Institute for Science and Education (ORISE) brings together mentors and research teams to serve as a bridge between the classroom and the...

  4. Nuclear Physics: Experiment Research

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

    Free Electron Laser (FEL) Medical Imaging Physics Topics Campaigns Meetings Recent Talks Archived Talks Additional Information Computing at JLab Operations Logbook Experiment ...

  5. Princeton Plasma Physics Laboratory Annual Site Environmental Report for Calendar Year 2001

    SciTech Connect (OSTI)

    Virginia L. Finley

    2004-04-07

    The purpose of this report is to provide the U.S. Department of Energy (DOE) and the public with information on the level of radioactive and nonradioactive pollutants (if any) that are added to the environment as a result of the Princeton Plasma Physics Laboratory's (PPPL) operations. The results of the 2001 environmental surveillance and monitoring program for PPPL are presented and discussed. The report also summarizes environmental initiatives, assessments, and programs that were undertaken in 2001. PPPL has engaged in fusion energy research since 1951. The vision of the Laboratory is to create innovations to make fusion power a practical reality--a clean, alternative energy source. The Year 2001 marked the third year of National Spherical Torus Experiment (NSTX) operations and Tokamak Fusion Test Reactor (TFTR) dismantlement and deconstruction activities. A collaboration among fourteen national laboratories, universities, and research institutions, the NSTX is a major element in the U.S. Fusion Energy Sciences Program. It has been designed to test the physics principles of spherical torus (ST) plasmas. The ST concept could play an important role in the development of smaller, more economical fusion reactors. In 2001, PPPL's radiological environmental monitoring program measured tritium in the air at on- and off-site sampling stations. PPPL is capable of detecting small changes in the ambient levels of tritium by using highly sensitive monitors. The operation of an in-stack monitor located on D-site is a requirement of the National Emission Standard for Hazardous Air Pollutants (NESHAPs) regulations; also included in PPPL's radiological environmental monitoring program, are water monitoring--precipitation, ground-, surface-, and waste-waters. PPPL's radiological monitoring program characterized the ambient, background levels of tritium in the environment and from the D-site stack; the data are presented in this report. Groundwater monitoring continue d under a

  6. BooNE Experiment

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

    Experiment Goals of BooNE BooNE in a Nutshell Making Neutrinos Detecting Neutrinos schematic of BooNE experiment A sample event (3M animated PDF file) A cosmic ray event as displayed by the MiniBooNE detector.

  7. Franklin: User Experiences

    SciTech Connect (OSTI)

    National Energy Research Supercomputing Center; He, Yun; Kramer, William T.C.; Carter, Jonathan; Cardo, Nicholas

    2008-05-07

    The newest workhorse of the National Energy Research Scientific Computing Center is a Cray XT4 with 9,736 dual core nodes. This paper summarizes Franklin user experiences from friendly early user period to production period. Selected successful user stories along with top issues affecting user experiences are presented.

  8. NSTX-U Digital Coil Protection System Software Detailed Design...

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

    a protection system for anything that can be modeled as a system of equations that must stay within limits. Currently, DCPS calculates 1200 equations every 200 microseconds, but...

  9. Electronics Engineer (NSTX-U) | Princeton Plasma Physics Lab

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

    C and C++. To excel in our diverse engineering culture the candidate must possess the ability to effectively communicate in a multidisciplinary team and travel occasionally...

  10. Edge Physics Studies on the NSTX Spherical Tokamak

    SciTech Connect (OSTI)

    Boedo, J.

    2013-01-29

    In this funding period, activities were focused on processing data for publication, writing code to facilitate processing of data in the future as programmatic needs arise, and closing down grant activities.

  11. NSTX-U Control System Upgrades | Princeton Plasma Physics Lab

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

    Control System Upgrades This system can serve as a control system for any fusion device, including ITER. Currently, the PCS calculates many complicated and disjoint algorithms...

  12. Improvement in Plasma Performance with Lithium Coatings in NSTX...

    Office of Scientific and Technical Information (OSTI)

    Authors: 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...

  13. Improvement in Plasma Performance with Lithium Coatings in NSTX...

    Office of Scientific and Technical Information (OSTI)

    Authors: 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 ; ...

  14. Associate Research Physicist (Integrated Tokamak Modeling, NSTX-U) REVISED

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

    Power Act Authority | Department of Energy Assistant Secretary Hoffman Speaks to House Subcommittee on DOE's Federal Power Act Authority Assistant Secretary Hoffman Speaks to House Subcommittee on DOE's Federal Power Act Authority May 9, 2012 - 4:13pm Addthis Assistant Secretary Patricia Hoffman appeared before the U.S. House of Representatives Energy and Commerce Subcommittee on Energy and Power on May 9, 2012 to speak about the Department of Energy's emergency authority under section

  15. Electron Bernstein Wave Emission and Mode Conversion Physics on NSTX

    Office of Scientific and Technical Information (OSTI)

    50 PPPL- 4750 Layout And Results From The Initial Opeeration Of The High-resolution X-ray Imaging Crystal Spectrometer On The Large Helical Device April, 2012 N.A. Pablant, M. Bitter, L. Delgado-Apricio, M. Goto, K.W. Hill, S. Lazerson, S. Morita, A.L. Roquemore, D. Gates, D. Monticello, H. Neilson, A. Reiman, M. Reinke, J.E. Rice and H. Yamada Princeton Plasma Physics Laboratory Report Disclaimers Full Legal Disclaimer This report was prepared as an account of work sponsored by an agency of the

  16. Components of the NSTX-U | Princeton Plasma Physics Lab

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

    Compliance and Special Report Orders Compliance and Special Report Orders Compliance Orders July 12, 2007 Compliance Order, Los Alamos National Security, LLC - July 12, 2007 Issued to Los Alamos National Security, LLC related to the Unauthorized Reproduction and Removal of Classified Matter from the Los Alamos National Laboratory May 26, 1999 Preliminary Notice of Violation and Compliance Order, EA-1999-04 Issued to Fluor Daniel Hanford, Inc., relating to events at the Spent Nuclear Fuels

  17. Booster Neutrino Experiment - Introduction

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

    close The MiniBooNE Experiment next The Oscillating Neutrino The first phase of the Booster Neutrino Experiment (BooNE) at the Fermi National Accelerator Laboratory is a smaller version of the final planned experiment, and has been dubbed "MiniBooNE." The physicists working on MiniBooNE are trying to find out more about the fundamental properties of neutrinos. But, what exactly is a neutrino? To answer that question, we need to look at what's called the Standard Model of particles and

  18. PLASMA JETS AND ERUPTIONS IN SOLAR CORONAL HOLES: A THREE-DIMENSIONAL FLUX EMERGENCE EXPERIMENT

    SciTech Connect (OSTI)

    Moreno-Insertis, F.

    2013-07-01

    A three-dimensional (3D) numerical experiment of the launching of a hot and fast coronal jet followed by several violent eruptions is analyzed in detail. These events are initiated through the emergence of a magnetic flux rope from the solar interior into a coronal hole. We explore the evolution of the emerging magnetically dominated plasma dome surmounted by a current sheet and the ensuing pattern of reconnection. A hot and fast coronal jet with inverted-Y shape is produced that shows properties comparable to those frequently observed with EUV and X-ray detectors. We analyze its 3D shape, its inhomogeneous internal structure, and its rise and decay phases, lasting for some 15-20 minutes each. Particular attention is devoted to the field line connectivities and the reconnection pattern. We also study the cool and high-density volume that appears to encircle the emerged dome. The decay of the jet is followed by a violent phase with a total of five eruptions. The first of them seems to follow the general pattern of tether-cutting reconnection in a sheared arcade, although modified by the field topology created by the preceding reconnection evolution. The two following eruptions take place near and above the strong-field concentrations at the surface. They show a twisted, {Omega}-loop-like rope expanding in height, with twist being turned into writhe, thus hinting at a kink instability (perhaps combined with a torus instability) as the cause of the eruption. The succession of a main jet ejection and a number of violent eruptions that resemble mini-CMEs and their physical properties suggest that this experiment may provide a model for the blowout jets recently proposed in the literature.

  19. Experiment Safety Requirements

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

    Experiment Safety Requirements Print Safety at the ALS The mission of the ALS is to "Support users in doing outstanding science in a safe environment." How Do I...? Complete an...

  20. ATLAS APPROVED EXPERIMENTS

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

    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...

  1. Experiment Scheduling Committee

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

    Experiment Scheduling Committee Title Name Phome Email Deputy Director for Research Bob McKeown (757) 269-6481 bmck@jlab.org Physics Division AD (co-chair) Rolf Ent (757) 269-7373...

  2. 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.

  3. Experiment Safety Requirements

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

    Experiment Safety Requirements Print Safety at the ALS The mission of the ALS is to "Support users in doing outstanding science in a safe environment." How Do I...? Complete an Experiment Safety Sheet? (Do this upon receiving beam time.) Complete Safety Training? Bring and Use Electrical Equipment at the ALS? Determine what Personal Protective Equipment (PPE) to Wear? Get Authorization to Work with Lasers at the ALS? Ship Radioactive Materials to LBNL for Use at the ALS? Ship Samples

  4. Experiment Safety Requirements

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

    Experiment Safety Requirements Print Safety at the ALS The mission of the ALS is to "Support users in doing outstanding science in a safe environment." How Do I...? Complete an Experiment Safety Sheet? (Do this upon receiving beam time.) Complete Safety Training? Bring and Use Electrical Equipment at the ALS? Determine what Personal Protective Equipment (PPE) to Wear? Get Authorization to Work with Lasers at the ALS? Ship Radioactive Materials to LBNL for Use at the ALS? Ship Samples

  5. Fermilab | Tevatron | Experiments

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

    Experiments In this Section: Tevatron Experiments CDF DZero Energy Frontier Tevatron Before shutting down on Sept. 29, 2011, the Tevatron was the world's largest proton-antiproton collider. Residing at Fermilab, the Tevatron accelerated and stored beams of protons and antiprotons traveling in opposite directions around an underground ring four miles in circumference at almost the speed of light before colliding them at the center of two detectors. The detectors, called CDF, for Collider Detector

  6. The MAJORANA Experiment

    SciTech Connect (OSTI)

    Aguayo Navarrete, Estanislao; Avignone, F. T.; Back, Henning O.; Barabash, Alexander S.; Bergevin, M.; Bertrand, F.; Boswell, M.; Brudanin, V.; Busch, Matthew; Chan, Yuen-Dat; Christofferson, Cabot-Ann; Collar, J. I.; Combs, Dustin C.; Cooper, R. J.; Detwiler, Jason A.; Doe, Peter J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, Steven R.; Esterline, James H.; Fast, James E.; Fields, N.; Finnerty, P.; Fraenkle, Florian; Gehman, Victor M.; Giovanetti, G. K.; Green, Matthew P.; Guiseppe, Vincente; Gusey, K.; Hallin, A. L.; Hazama, R.; Henning, R.; Hime, Andrew; Hoppe, Eric W.; Horton, Mark; Howard, Stanley; Howe, M. A.; Johnson, R. A.; Keeter, K.; Keillor, Martin E.; Keller, C.; Kephart, Jeremy D.; Kidd, Mary; Knecht, A.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; LaFerriere, Brian D.; LaRoque, B. H.; Leon, Jonathan D.; Leviner, L.; Loach, J. C.; MacMullin, S.; Marino, Michael G.; Martin, R. D.; Mei, Dong-Ming; Merriman, Jason H.; Miller, M. L.; Mizouni, Leila; Nomachi, Masaharu; Orrell, John L.; Overman, Nicole R.; Phillips, D.; Poon, Alan; Perumpilly, Gopakumar; Prior, Gersende; Radford, D. C.; Rielage, Keith; Robertson, R. G. H.; Ronquest, M. C.; Schubert, Alexis G.; Shima, T.; Shirchenko, M.; Snavely, Kyle J.; Sobolev, V.; Steele, David; Strain, J.; Thomas, K.; Timkin, V.; Tornow, W.; Vanyushin, I.; Varner, R. L.; Vetter, Kai; Vorren, Kris R.; Wilkerson, John; Wolfe, B. A.; Yakushev, E.; Young, A.; Yu, Chang-Hong; Yumatov, Vladimir; Zhang, C.

    2011-10-01

    The Majorana collaboration is actively pursuing research and development aimed at a tonne-scale {sup 76}Ge neutrinoless double-beta decay ({beta}{beta}(0{nu})-decay) experiment. The current, primary focus is the construction of the Majorana Demonstrator experiment, an R and D effort that will field approximately 40 kg of germanium detectors with mixed enrichment levels. This article provides a status update on the construction of the Demonstrator.

  7. Experiment Safety Requirements

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

    Experiment Safety Requirements Print Safety at the ALS The mission of the ALS is to "Support users in doing outstanding science in a safe environment." How Do I...? Complete an Experiment Safety Sheet? (Do this upon receiving beam time.) Complete Safety Training? Bring and Use Electrical Equipment at the ALS? Determine what Personal Protective Equipment (PPE) to Wear? Get Authorization to Work with Lasers at the ALS? Ship Radioactive Materials to LBNL for Use at the ALS? Ship Samples

  8. Experiment Safety Requirements

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

    Experiment Safety Requirements Print Safety at the ALS The mission of the ALS is to "Support users in doing outstanding science in a safe environment." How Do I...? Complete an Experiment Safety Sheet? (Do this upon receiving beam time.) Complete Safety Training? Bring and Use Electrical Equipment at the ALS? Determine what Personal Protective Equipment (PPE) to Wear? Get Authorization to Work with Lasers at the ALS? Ship Radioactive Materials to LBNL for Use at the ALS? Ship Samples

  9. Experiment Safety Requirements

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

    Experiment Safety Requirements Print Safety at the ALS The mission of the ALS is to "Support users in doing outstanding science in a safe environment." How Do I...? Complete an Experiment Safety Sheet? (Do this upon receiving beam time.) Complete Safety Training? Bring and Use Electrical Equipment at the ALS? Determine what Personal Protective Equipment (PPE) to Wear? Get Authorization to Work with Lasers at the ALS? Ship Radioactive Materials to LBNL for Use at the ALS? Ship Samples

  10. The Majorana Experiment

    SciTech Connect (OSTI)

    Aguayo, E.; Fast, J. E.; Hoppe, E. W.; Keillor, M. E.; Kephart, J. D.; Kouzes, R. T.; LaFerriere, B. D.; Merriman, J. H.; Orrell, J. L.; Overman, N. R. [Pacific Northwest National Laboratory, Richland, WA (United States); Avignone, F. T. III [Department of Physics and Astronomy, University of South Carolina, Columbia, SC (United States); Oak Ridge National Laboratory, Oak Ridge, TN (United States); Back, H. O. [Department of Physics, North Carolina State University, Raleigh, NC (United States); Triangle Universities Nuclear Laboratory, Durham, NC (United States); Barabash, A. S.; Konovalov, S. I.; Vanyushin, I.; Yumatov, V. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Bergevin, M.; Chan, Y.-D.; Detwiler, J. A.; Loach, J. C. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); and others

    2011-12-16

    The Majorana collaboration is actively pursuing research and development aimed at a tonne-scale {sup 76}Ge neutrinoless double-beta decay ({beta}{beta}(0{nu})-decay) experiment. The current, primary focus is the construction of the Majorana Demonstrator experiment, an R and D effort that will field approximately 40 kg of germanium detectors with mixed enrichment levels. This article provides a status update on the construction of the Demonstrator.

  11. Experiment Research | Jefferson Lab

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

    Experiment Research Jefferson Lab has an ongoing and ambitious experimental program. Most experiments carried out with the Continuous Electron Beam Accelerator Facility (CEBAF) are in the field of nuclear physics and can be described in terms of the following. Structure of the Nucleus Here at Jefferson Lab, we study the structure of nuclear matter: how protons and neutrons (called nucleons) combine to make the nucleus and what forces bind nucleons together. We also peer deep inside nucleons to

  12. Experiment Safety Requirements

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

    Experiment Safety Requirements Print Safety at the ALS The mission of the ALS is to "Support users in doing outstanding science in a safe environment." How Do I...? Complete an Experiment Safety Sheet? (Do this upon receiving beam time.) Complete Safety Training? Bring and Use Electrical Equipment at the ALS? Determine what Personal Protective Equipment (PPE) to Wear? Get Authorization to Work with Lasers at the ALS? Ship Radioactive Materials to LBNL for Use at the ALS? Ship Samples

  13. Tritium Plasma Experiment and

    Office of Environmental Management (EM)

    Plasma Experiment and its role in PHENIX program Masashi Shimada, Chase Taylor Fusion Safety Program Idaho National Laboratory Rob Kolasinski Sandia National Laboratories, Livermore Tritium Focus Group meeting September 23-25, 2014 at Idaho National Laboratory, Idaho Falls, ID Outline: 1. Motivation 2. Tritium Plasma Experiment 3. INL/STAR's role on US-Japan collaboration 4. Role of TPE in PHENIX project 5. TPE modification and development of plasma-driven permeation M.Shimada | Tritium Focus

  14. The GLUEX Experiment

    SciTech Connect (OSTI)

    M.R. Shepherd

    2009-12-01

    The GLUEX experiment, to be constructed in the new Hall D at Jefferson Lab as part of the 12 GeV upgrade, will utilize a linearly polarized 9 GeV photon beam, produced via coherent bremsstrahlung radiation off of a diamond wafer, incident on a proton target to conduct a search for exotic hybrid mesons. A summary of the physics motivation for the experiment and the key factors that drive the design of the detector and beam line is presented.

  15. Sharing Smart Grid Experiences

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

    Sharing Smart Grid Experiences through Performance Feedback March 31, 2011 DOE/NETL- DE-FE0004001 U.S. Department of Energy Office of Electricity Delivery and Energy Reliability Prepared by: National Energy Technology Laboratory Sharing Smart Grid Experiences through Performance Feedback v1.0 Page ii Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their

  16. PPPL Celebrates Earth Day with Reduction in Greenhouse Gas Emissions...

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

    NSTX is one of the largest fusion experiments in the nation. We looked at the systems and equipment valve by valve, fitting by fitting, to find chronic, low-level leaks," Stevenson ...

  17. PPPL engineers design and build state-of-the-art controller for...

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

    engineers design and build state-of-the-art controller for AC to DC converter that manages ... able to perform experiments on NSTX-U to advance the design of a working fusion reactor. ...

  18. Construction completed, PPPL is set to resume world-class fusion...

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

    Experiment-Upgrade. Gallery: Technicians inspect the new center stack that forms the heart of the NSTX-U. (Photo by PPPL) Technicians inspect the new center stack that forms the...

  19. Gyroharmonic conversion experiments

    SciTech Connect (OSTI)

    Hirshfield, J.L.; LaPointe, M.A.; Ganguly, A.K. [Omega-P, Inc., New Haven, Connecticut 06520 (United States); LaPointe, M.A. [Yale University, New Haven, Connecticut 06511 (United States)

    1999-05-01

    Generation of high power microwaves has been observed in experiments where a 250{endash}350 kV, 20{endash}30 A electron beam accelerated in a cyclotron autoresonance accelerator (CARA) passes through a cavity tuned gyroharmonic) and at 8.6 GHz (3rd harmonic) will be described. Theory indicates that high conversion efficiency can be obtained for a high quality beam injected into CARA, and when mode competition can be controlled. Comparisons will be made between the experiments and theory. Planned 7th harmonic experiments will also be described, in which phase matching between the TE-72 mode at 20 GHz, and the TE-11 mode at 2.86 GHz, allows efficient 20 GHz co-generation within the CARA waveguide itself. {copyright} {ital 1999 American Institute of Physics.}

  20. Gyroharmonic conversion experiments

    SciTech Connect (OSTI)

    Hirshfield, J. L.; LaPointe, M. A. [Omega-P, Inc., New Haven, Connecticut 06520 (United States); Yale University, New Haven, Connecticut 06511 (United States); Ganguly, A. K. [Omega-P, Inc., New Haven, Connecticut 06520 (United States)

    1999-05-07

    Generation of high power microwaves has been observed in experiments where a 250-350 kV, 20-30 A electron beam accelerated in a cyclotron autoresonance accelerator (CARA) passes through a cavity tuned gyroharmonic) and at 8.6 GHz (3rd harmonic) will be described. Theory indicates that high conversion efficiency can be obtained for a high quality beam injected into CARA, and when mode competition can be controlled. Comparisons will be made between the experiments and theory. Planned 7th harmonic experiments will also be described, in which phase matching between the TE-72 mode at 20 GHz, and the TE-11 mode at 2.86 GHz, allows efficient 20 GHz co-generation within the CARA waveguide itself.

  1. Princeton Plasma Physics Laboratory achieves milestone, completing first

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

    part of heart of fusion experiment | Princeton Plasma Physics Lab Princeton Plasma Physics Laboratory achieves milestone, completing first part of heart of fusion experiment By John Greenwald March 22, 2013 Tweet Widget Google Plus One Share on Facebook The completed first section of the NSTX-U center stack. (Photo by Elle Starkman, PPPL Office of Communications) The completed first section of the NSTX-U center stack. Gallery: Related Images: Engineers and technicians at the U.S. Department

  2. Complete Experiment Safety Documentation

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

    Complete Experiment Safety Documentation Print User Safety Overview Upon receiving beam time: 1. Log in to ALSHub to complete an Experiment Safety Sheet (ESS). The ALS This e-mail address is being protected from spambots. You need JavaScript enabled to view it is available to support you through this process. Please contact This e-mail address is being protected from spambots. You need JavaScript enabled to view it at the email link or at (510) 486-7222 at if you have questions or need more

  3. Complete Experiment Safety Documentation

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

    Complete Experiment Safety Documentation Print User Safety Overview Upon receiving beam time: 1. Log in to ALSHub to complete an Experiment Safety Sheet (ESS). The ALS This e-mail address is being protected from spambots. You need JavaScript enabled to view it is available to support you through this process. Please contact This e-mail address is being protected from spambots. You need JavaScript enabled to view it at the email link or at (510) 486-7222 at if you have questions or need more

  4. Complete Experiment Safety Documentation

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

    Complete Experiment Safety Documentation Print User Safety Overview Upon receiving beam time: 1. Log in to ALSHub to complete an Experiment Safety Sheet (ESS). The ALS This e-mail address is being protected from spambots. You need JavaScript enabled to view it is available to support you through this process. Please contact This e-mail address is being protected from spambots. You need JavaScript enabled to view it at the email link or at (510) 486-7222 at if you have questions or need more

  5. Complete Experiment Safety Documentation

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

    Complete Experiment Safety Documentation Print User Safety Overview Upon receiving beam time: 1. Log in to ALSHub to complete an Experiment Safety Sheet (ESS). The ALS This e-mail address is being protected from spambots. You need JavaScript enabled to view it is available to support you through this process. Please contact This e-mail address is being protected from spambots. You need JavaScript enabled to view it at the email link or at (510) 486-7222 at if you have questions or need more

  6. The Majorana Experiment

    SciTech Connect (OSTI)

    Aalseth, Craig E.; Aguayo Navarrete, Estanislao; Amman, M.; Avignone, F. T.; Back, Henning O.; Bai, Xinhua; Barabash, Alexander S.; Barbeau, P. S.; Bergevin, M.; Bertrand, F.; Boswell, M.; Brudanin, V.; Bugg, William; Burritt, Tom H.; Busch, Matthew; Capps, Greg L.; Chan, Yuen-Dat; Collar, J. I.; Cooper, R. J.; Creswick, R.; Detwiler, Jason A.; Diaz, J.; Doe, Peter J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, S. R.; Ely, James H.; Esterline, James H.; Farach, H. A.; Fast, James E.; Fields, N.; Finnerty, P.; Fraenkle, Florian; Gehman, Victor M.; Giovanetti, G. K.; Green, M.; Guiseppe, Vincente; Gusey, K.; Hallin, A. L.; Harper, Gregory; Hazama, R.; Henning, Reyco; Hime, Andrew; Hong, H.; Hoppe, Eric W.; Hossbach, Todd W.; Howard, Stanley; Howe, M. A.; Johnson, R. A.; Keeter, K.; Keillor, Martin E.; Keller, C.; Kephart, Jeremy D.; Kidd, M. F.; Knecht, A.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; LaRoque, B. H.; Leviner, L.; Loach, J. C.; Luke, P.; MacMullin, S.; Marino, Michael G.; Martin, R. D.; Medlin, D.; Mei, Dong-Ming; Miley, Harry S.; Miller, M. L.; Mizouni, Leila; Myers, Allan W.; Nomachi, Masaharu; Orrell, John L.; Peterson, David; Phillips, D.; Poon, Alan; Perevozchikov, O.; Perumpilly, Gopakumar; Prior, Gersende; Radford, D. C.; Reid, Douglas J.; Rielage, Keith; Robertson, R. G. H.; Rodriguez, Larry; Ronquest, M. C.; Salazar, Harold; Schubert, Alexis G.; Shima, T.; Shirchenko, M.; Sobolev, V.; Steele, David; Strain, J.; Swift, Gary; Thomas, K.; Timkin, V.; Tornow, W.; Van Wechel, T. D.; Vanyushin, I.; Varner, R. L.; Vetter, Kai; Vorren, Kris R.; Wilkerson, J. F.; Wolfe, B. A.; Xiang, W.; Yakushev, E.; Yaver, Harold; Young, A.; Yu, Chang-Hong; Yumatov, V.; Zhang, C.

    2011-08-01

    The Majorana Collaboration is assembling an array of HPGe detectors to search for neutrinoless double-beta decay in 76Ge. 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.

  7. The MAJORANA Experiment

    SciTech Connect (OSTI)

    Guiseppe, V.E.; Keller, C.; Mei, D-M; Perevozchikov, O.; Perumpilly, G.; Thomas, K.; Xiang, W.; Zhang, C.; Aalseth, C.E.; Aguayo, E.; Ely, J.; Fast, J.E.; Hoppe, E.W.; Hossbach, T.W.; Keillor, M.; Kephart, J.D.; Kouzes, R.; Miley, H.S.; Mizouni, L.; Myers, A.W.; Reid, D.; Amman, M.; Bergevin, M.; Chan, Y-D; Detwiler, J.A.; Loach, J.C.; Luke, P.N.; Martin, R.D.; Poon, A.W.P.; Prior, G.; Vetter, K.; Yaver, H.; Avignone, F.T. III; Creswick, R.; Farach, H.; Mizouni, L.; Avignone, Frank Titus; Bertrand Jr, Fred E; Capps, Gregory L; Cooper, Reynold J; Radford, David C; Varner Jr, Robert L; Wilkerson, John F; Yu, Chang-Hong; Back, H.O.; Leviner, L.; Young, A.R.; Back , H.O.; Bai, X.; Hong, H.; Howard, S.; Medlin, D.; Sobolev, V.; Barabash, A.S.; Konovalov, S.I.; Vanyushin, I.; Yumatov, V.; Barbeau, P.S.; Collar, J.I.; Fields, N.; Boswell , M.; Brudanin, V.; Egorov, V.; Gusey, K.; Kochetov, O.; Shirchenko, M.; Timkin, V.; Yakushev, E.; Bugg, W.; Efremenko, M.; Burritt , T.H.; Burritt , T.H.; Busch, M.; Esterline, J.; Swift, G.; Tornow, W.; Hazama, R.; Nomachi, M.; Shima, T.; Finnerty , P.; et al.

    2011-01-01

    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.

  8. Stirling machine operating experience

    SciTech Connect (OSTI)

    Ross, B.; Dudenhoefer, J.E.

    1991-01-01

    Numerous Stirling machines have been built and operated, but the operating experience of these machines is not well known. It is important to examine this operating experience in detail, because it largely substantiates the claim that Stirling machines are capable of reliable and lengthy lives. The amount of data that exists is impressive, considering that many of the machines that have been built are developmental machines intended to show proof of concept, and were not expected to operate for any lengthy period of time. Some Stirling machines (typically free-piston machines) achieve long life through non-contact bearings, while other Stirling machines (typically kinematic) have achieved long operating lives through regular seal and bearing replacements. In addition to engine and system testing, life testing of critical components is also considered.

  9. Ganges Valley Aerosol Experiment

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

    Ganges Valley Aerosol Experiment In northeastern India, the fertile land around the Ganges River supports several hundred million people. This river, the largest in India, is fed by monsoon rains and runoff from the nearby Himalayan Mountains. Through an intergovernmental agreement with India, the U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility deployed its portable laboratory, the ARM Mobile Facility (AMF), to Nainital, India, in June 2011. During

  10. Wake Steering Experiment

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

    Steering Experiment - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Energy Defense Waste Management Programs Advanced Nuclear

  11. Booster Neutrino Experiment - Introduction

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

    back The MiniBooNE Experiment next The Oscillating Neutrino Normal matter is made of atoms. Atoms are also composite objects, made up in turn of protons and neutrons (in the nucleus) and the lightweight and familiar electrons. Electrons belong to a class of particles called leptons, the same family to which neutrinos belong. Neutrinos are the very lightweight (originally thought massless) neutral partners of the electrically charged electron and its more exotic cousins the muon and the tau.

  12. 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, Westinghouse Electric Company LLC Advanced Modeling Applications 28 March 2014 CASL-U-2014-0036-000 Consortium for Advanced Simulation of LWRs ii CASL-U-2014-0036-000 REVISION LOG Revision Date Affected Pages Revision Description 0 3/28/2014 All Original Report Document pages that are: Export Controlled

  13. The LUX experiment

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

    Akerib, D. S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Bernard, E.; Bernstein, A.; Bradley, A.; Byram, D.; Cahn, S. B.; et al

    2015-03-24

    We present the status and prospects of the LUX experiment, which employs approximately 300 kg of two-phase xenon to search for WIMP dark matter interactions. The LUX detector was commissioned at the surface laboratory of the Sanford Underground Research Facility in Lead, SD, between December 2011 and February 2012 and the detector has been operating underground since January, 2013. These proceedings review the results of the commissioning run as well as the status of underground data-taking.

  14. A Snowflake-Shaped Magnetic Field Holds Promise for Taming Harsh...

    Office of Science (SC) Website

    Recent experiments have confirmed the great potential of a novel plasma-material interface ... The National Spherical Torus Experiment Device at Princeton Plasma Physics Laboratory ...

  15. 2169 steel waveform experiments.

    SciTech Connect (OSTI)

    Furnish, Michael David; Alexander, C. Scott; Reinhart, William Dodd; Brown, Justin L.

    2012-11-01

    In support of LLNL efforts to develop multiscale models of a variety of materials, we have performed a set of eight gas gun impact experiments on 2169 steel (21% Cr, 6% Ni, 9% Mn, balance predominantly Fe). These experiments provided carefully controlled shock, reshock and release velocimetry data, with initial shock stresses ranging from 10 to 50 GPa (particle velocities from 0.25 to 1.05 km/s). Both windowed and free-surface measurements were included in this experiment set to increase the utility of the data set, as were samples ranging in thickness from 1 to 5 mm. Target physical phenomena included the elastic/plastic transition (Hugoniot elastic limit), the Hugoniot, any phase transition phenomena, and the release path (windowed and free-surface). The Hugoniot was found to be nearly linear, with no indications of the Fe - phase transition. Releases were non-hysteretic, and relatively consistent between 3- and 5-mm-thick samples (the 3 mm samples giving slightly lower wavespeeds on release). Reshock tests with explosively welded impactors produced clean results; those with glue bonds showed transient releases prior to the arrival of the reshock, reducing their usefulness for deriving strength information. The free-surface samples, which were steps on a single piece of steel, showed lower wavespeeds for thin (1 mm) samples than for thicker (2 or 4 mm) samples. A configuration used for the last three shots allows release information to be determined from these free surface samples. The sample strength appears to increase with stress from ~1 GPa to ~ 3 GPa over this range, consistent with other recent work but about 40% above the Steinberg model.

  16. Fundamental experiments in velocimetry

    SciTech Connect (OSTI)

    Briggs, Matthew Ellsworth; Hull, Larry; Shinas, Michael

    2009-01-01

    One can understand what velocimetry does and does not measure by understanding a few fundamental experiments. Photon Doppler Velocimetry (PDV) is an interferometer that will produce fringe shifts when the length of one of the legs changes, so we might expect the fringes to change whenever the distance from the probe to the target changes. However, by making PDV measurements of tilted moving surfaces, we have shown that fringe shifts from diffuse surfaces are actually measured only from the changes caused by the component of velocity along the beam. This is an important simplification in the interpretation of PDV results, arising because surface roughness randomizes the scattered phases.

  17. Lower Hybrid Experiments

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

    Lower Hybrid Experiments on MST M.C. Kaufman, J.A. Goetz, M.A. Thomas, D.R. Burke and D.J. Clayton Department of Physics, University of Wisconsin, Madision, WI 53706 Abstract. Current drive using RF waves has been proposed as a means to reduce the tearing fluctuations responsible for anomalous energy transport in the RFP. A traveling wave antenna op- erating at 800 MHz is being used to launch lower hybrid waves into MST to assess the feasibility of this approach. Parameter studies show that edge

  18. Stirling machine operating experience

    SciTech Connect (OSTI)

    Ross, B.; Dudenhoefer, J.E.

    1994-09-01

    Numerous Stirling machines have been built and operated, but the operating experience of these machines is not well known. It is important to examine this operating experience in detail, because it largely substantiates the claim that stirling machines are capable of reliable and lengthy operating lives. The amount of data that exists is impressive, considering that many of the machines that have been built are developmental machines intended to show proof of concept, and are not expected to operate for lengthy periods of time. Some Stirling machines (typically free-piston machines) achieve long life through non-contact bearings, while other Stirling machines (typically kinematic) have achieved long operating lives through regular seal and bearing replacements. In addition to engine and system testing, life testing of critical components is also considered. The record in this paper is not complete, due to the reluctance of some organizations to release operational data and because several organizations were not contacted. The authors intend to repeat this assessment in three years, hoping for even greater participation.

  19. The PANTHER User Experience

    SciTech Connect (OSTI)

    Coram, Jamie L.; Morrow, James D.; Perkins, David Nikolaus

    2015-09-01

    This document describes the PANTHER R&D Application, a proof-of-concept user interface application developed under the PANTHER Grand Challenge LDRD. The purpose of the application is to explore interaction models for graph analytics, drive algorithmic improvements from an end-user point of view, and support demonstration of PANTHER technologies to potential customers. The R&D Application implements a graph-centric interaction model that exposes analysts to the algorithms contained within the GeoGraphy graph analytics library. Users define geospatial-temporal semantic graph queries by constructing search templates based on nodes, edges, and the constraints among them. Users then analyze the results of the queries using both geo-spatial and temporal visualizations. Development of this application has made user experience an explicit driver for project and algorithmic level decisions that will affect how analysts one day make use of PANTHER technologies.

  20. HPCToolsExperiences.pptx

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

    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

  1. Programs for Assembling SBH Experiments

    Energy Science and Technology Software Center (OSTI)

    1995-11-28

    DB EXP ASSEMBLY is a suite of programs that enable selection of bundles of data, which are referred to as experiments, from the DB SBH archival database. In other words, an experiment is a bundle of data which is analyzed as a unit. Program DBJ creates raw experiments based on initial specification. Program DBK then tests the experiments for a number of consistemcy and completeness criteria, reports bugs in the experiment and recommends solutions, andmore » performs the desired corrections. An experiment that has passed the final DBK test is ready for analysis by the DB DISCOVERY programs.« less

  2. The polarized SRF gun experiment

    SciTech Connect (OSTI)

    Kewisch,J.; Ben-Zvi, I.; Rao, T.; Burrill, A.; Pate, D.; Todd, R.; Wang, E.; Bluem, H.; Holmes, D.; Shultheiss, T.

    2008-10-01

    An experiment is under way to prove the feasibility of a super-conducting RF gun for the production of polarized electrons. We report on the progress of the experiment and on simulations predicting the possibility of success.

  3. 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)

    Ii, Toru; Gi, Keii; Umezawa, Toshiyuki; Inomoto, Michiaki; Ono, Yasushi; Asai, Tomohiko

    2012-08-15

    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.

  4. Subterranean stress engineering experiments

    SciTech Connect (OSTI)

    Campbell, J.R.; Colgate, S.A.; Wheat, B.M.

    1980-01-01

    The state of stress in a subterranean rock mass has classically been assumed to be constant at best. In soil with a high clay content, preconsolidation and drainage methods can lead to more stable foundation material, but methods for engineering the stresses in large masses of rock are not well known. This paper shows the results from an experiment designed to alter the in situ rock stress field in an oil shale mine. This was done by hydrofracturing the rock by use of a packed-well injection system and then propping the crack open with a thixotropic gel, which slowly hardened to the consistency of cement. Successive hydrofracture and high-pressure grouting resulted in an overstressed region. Well-head injection pressures, surface tilts, injection rates, and subterranean strains were measured and recorded on floppy disk by a Z-80 microprocessor. The results were then transmitted to the large computer system at the Los Alamos Scientific Laboratory (LASL). To put the data in a more useful form, computer-generated movies of the tilts and strains were made by use of computer graphics developed at LASL. The purpose of this paper is to present results from the Single Large Instrumented Test conducted in the Colony Oil Shale Mine near Rifle, Colorado. 13 figures.

  5. Evaluation of the DHCE Experiment

    SciTech Connect (OSTI)

    Greenwood, Lawrence R.; Baldwin, David L.; Hollenberg, Glenn W.; Kurtz, Richard J.

    2002-03-31

    The Dynamic Helium Charging Experiment (DHCE) experiment was conducted in the Fast Flux Test Facility (FFTF) during cycle 12, which was completed in 1992. The purpose of the experiment was to enhance helium generation in vanadium alloys to simulate fusion reactor helium-to-dpa ratios with a target goal of 4-5 appm He/dpa. The Fusion Materials Science Program is considering mounting another experiment in hopes of gathering additional data on the effect of helium on the mechanical and physical properties of vanadium structural materials. Pacific Northwest National Laboratory was assigned the task of evaluating the feasibility of conducting another DHCE experiment by carefully evaluating the results obtained of the first DHCE experiment. This report summarizes the results of our evaluation and presents recommendations for consideration by the Materials Science Coordinators Organization.

  6. Scientific Opportunities and Challenges in the Upgraded National Spherical

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

    Torus Experiment | Princeton Plasma Physics Lab March 14, 2015, 9:30am to 11:00am Science On Saturday MBG Auditorium Scientific Opportunities and Challenges in the Upgraded National Spherical Torus Experiment Dr. Jonathan Menard, Principal Research Physicist PPPL Abstract: PDF icon Menard.pdf Science On Saturday, March 14, 2015, "Scientific Opportunities & Challenges in the Upgraded National Spherical Torus Experiment", Dr. Jonathan Menard, PPPL Contact Information Website:

  7. 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' expertise beyond the traditional university setting. Some graduate students come to ORISE looking for the right setting to conduct their thesis research; some are master's students preparing to pursue their doctorates; some are looking for a program to help fund their education; others seek or a short-term experience, like a

  8. Results from Neutrino Oscillations Experiments

    SciTech Connect (OSTI)

    Aguilar-Arevalo, Alexis

    2010-09-10

    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.

  9. ARM West Antarctic Radiation Experiment

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

    West Antarctic Radiation Experiment of the most advanced atmospheric research ... From the fall of 2015 to early 2017, the Atmospheric Radiation Measurement (ARM) West ...

  10. AMIE (ACRF MJO Investigation Experiment)

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

    AMIE (ACRF MJO Investigation Experiment) Planning Meeting AMIE Science Steering Committee Chuck Long, Tony DelGenio, Bill Gustafson, Bob Houze, Mike Jensen, Steve Klein, Ruby...

  11. Booster Neutrino Experiment - About Neutrinos

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

    from major neutrino experiments and important results in neutrino physics. Includes java applets. Janet's Neutrino Oscillation Page More extensive material about neutrino...

  12. UNIRIB Participant Experiences: Ron Goans

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

    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...

  13. Daya Bay Reactor Neutrino Experiment

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

    Ao Nuclear Power Plant reactors. The experiment is being built by blasting three kilometers of tunnel through the granite rock under the mountains where the power plants are...

  14. APS Experiment Safety Review System

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

    that present minimal hazards common to all beamlines should be submitted at least seven (7) days prior to the scheduled start of the experiment. Additional time is required...

  15. Audit on Subcritical Experiment Activities

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

    of nuclear weapon materials, such as plutonium, with the use of complex, high-speed diagnostic instruments. The experiments are subcritical because no critical mass is formed and...

  16. LANSCE | User Resources | Experiment Reports

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

    Experiment Reports For experiment report guidance, examples or a blank form, select one of the following .pdf files: Instructions.pdf Experiment Report Form.pdf Send reports to the LANSCE User Office. Reports are due three months after you receive beam time. If you didn't complete a User Survey during your visit, please do so when you complete your Experiment Report. The responses to the survey are used by LANSCE to identify and address issues and are also reported to the agencies providing

  17. The Physics of Tokamak Start-up (Technical Report) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    In some cases inductive startup is assisted with auxiliary power from electron cyclotron radio frequency heating. ITER, the National Spherical Torus eXperiment Upgrade and JT60, ...

  18. Full toroidal imaging of non-axisymmetric plasma material interaction...

    Office of Scientific and Technical Information (OSTI)

    plasma material interaction in the National Spherical Torus eXperiment divertor Citation Details In-Document Search Title: Full toroidal imaging of non-axisymmetric plasma ...

  19. The ATLAS Positron Experiment -- APEX

    SciTech Connect (OSTI)

    Ahmad, I.; Back, B.B.; Betts, R.R.; Dunford, R.; Kutschera, W.; Rhein, M.D.; Schiffer, J.P.; Wilt, P.; Wuosmaa, A.; Austin, S.M.; Kashy, E.; Winfield, J.S.; Yurkon, J.E.; Bazin, D.; Calaprice, F.P.; Young, A.; Chan, K.C.; Chisti, A.; Chowhury, P.; Greenberg, J.S.; Kaloskamis, N.; Lister, C.J.; Fox, J.D.; Roa, E.; Freedman, S.; Maier, M.R.; Freer, M.; Gazes, S.; Hallin, A.L.; Liu, M.; Happ, T.; Perera, A.; Wolfs, F.L.H.; Trainor, T.; Wolanski, M. |

    1994-03-01

    APEX -- the ATLAS Positron Experiment -- is designed to measure electrons and positrons emitted in heavy-ion collisions. Its scientific goal is to gain insight into the puzzling positron-line phenomena observed at the GSI Darmstadt. It is in operation at the ATLAS accelerator at Argonne National Lab. The assembly of the apparatus is finished and beginning 1993 the first positrons produced in heavy-ion collisions were observed. The first full scale experiment was carried out in December 1993, and the data are currently being analyzed. In this paper, the principles of operation are explained and a status report on the experiment is given.

  20. Laser driven hydrodynamic instability experiments

    SciTech Connect (OSTI)

    Remington, B.A.; Weber, S.V.; Haan, S.W.; Kilkenny, J.D.; Glendinning, S.G.; Wallace, R.J.; Goldstein, W.H.; Wilson, B.G.; Nash, J.K.

    1992-12-07

    We have conducted an extensive series of experiments on the Nova laser to measure hydrodynamic instabilities in planar foils accelerated by x-ray ablation. Single mode experiments allow a measurement of the fundamental growth rates from the linear well into the nonlinear regime; multimode foils allow an assessment of the degree of mode coupling; and surface-finish experiments allow a measurement of the evolution of a broad spectrum of random initial modes. Experimental results and comparisons with theory and simulations are presented.

  1. Fellowships, Appointments and the Postdoctoral Experience | Argonne...

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

    Experience Fellowships, Appointments and the Postdoctoral Experience Early career STEM professionals may join Argonne as Distinguished Fellows or Divisional Postdoctoral...

  2. User Experience Research and Statistics

    Broader source: Energy.gov [DOE]

    To improve your website or application, especially for new projects, EERE strongly recommends, but does not require, conducting user experience (UX) research. We only require that you get the...

  3. Status of the MINOS Experiment

    SciTech Connect (OSTI)

    Elizabeth Buckley-Geer

    2003-03-17

    We report on the status of the MINOS long baseline neutrino experiment presently under construction at the Fermi National Accelerator Laboratory and the Soudan mine. There is growing evidence that the solar neutrino and atmospheric neutrino anomalies [1] are the result of neutrino oscillations. The MINOS experiment is a long baseline neutrino oscillation experiment designed to study the region of parameter space indicated by the SuperKamiokande atmospheric neutrino results [2]. The experiment consists of two detectors, one with a mass of 980 tons located at Fermilab (the near detector) and the other of mass 5400 tons located 731 km away in the Soudan mine in northern Minnesota (the far detector). The third component is the neutrino beam which is currently under construction at Fermilab.

  4. User Experience Research Online Tools

    Broader source: Energy.gov [DOE]

    The Office of Energy Efficiency and Renewable Energy (EERE) has a variety of online tools to help you conduct user experience (UX) research. The following tools are free for use by staff and contractors who work on the EERE website.

  5. ARM Cloud Aerosol Precipitation Experiment

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

    Experiment a NOAA ship in the Pacific Ocean and on a DOE- sponsored plane over land and sea. These researchers will study: (1) water sources, evolution and structure of...

  6. DOE Corporate Operating Experience Program

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

    2011-04-08

    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. Supersedes DOE O 210.2.

  7. Learning Experiences | Argonne National Laboratory

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

    Contact education@anl.gov Learning Experiences "Science is a way of thinking much more than it is a body of knowledge." - Carl Sagan, Astrophysicist Argonne Education provides a variety of learning opportunities to enhance middle and high school math, science and comptuer science curriculum. We offer programs that strengthen youth scientific inquiry and develop a research based mindset. We have programs that provide schools with: an intense inquiry-based learning experience in our

  8. The MINERvA Experiment

    SciTech Connect (OSTI)

    Harris, Deborah A.; Kopp, Sacha; /Fermilab

    2011-03-18

    The MINERvA experiment is a dedicated cross-section experiment whose aim is to measure neutrino cross sections for inclusive and exclusive final states on several nuclei. The detector is fully commissioned and began running in March 2010. As a dedicated cross-section experiment, MINERvA has a particular need to know the incident neutrino flux: both the absolute level and the energy dependence. In these proceedings we describe the MINERvA detector, give an update on the experimental status, and discuss the means to determine the neutrino flux. The MINERvA experiment is now running and has completed 25% of its full Low Energy run. There are various techniques planned for understanding the flux, including taking neutrino data at several different beam configurations. The experiment has gotten a first glimpse of two of the six configurations, and completed four horn current scans. Because of its exclusive final state reconstruction capabilities MINERvA can provide the much needed input for current and future oscillation experiments. The inclusive final state measurements and comparisons of nuclear effects across as many states as possible will provide new insights into neutrino-nucleus scattering.

  9. Experiences

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

    ... timesteps, into distinct regions inmemory. 4.5 Optimizations On the 16 sending ... We used a 100Gbps link connecting National Energy Research Scientific Computing Center ...

  10. Optimizing New Dark Energy Experiments

    SciTech Connect (OSTI)

    Tyson, J. Anthony

    2013-08-26

    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.

  11. Solar neutrino experiments: An update

    SciTech Connect (OSTI)

    Hahn, R.L.

    1993-12-31

    The situation in solar neutrino physics has changed drastically in the past few years, so that now there are four neutrino experiments in operation, using different methods to look at different regions of the solar neutrino energy spectrum. These experiments are the radiochemical {sup 37}Cl Homestake detector, the realtime Kamiokande detector, and the different forms of radiochemical {sup 71}Ga detectors used in the GALLEX and SAGE projects. It is noteworthy that all of these experiments report a deficit of observed neutrinos relative to the predictions of standard solar models (although in the case of the gallium detectors, the statistical errors are still relatively large). This paper reviews the basic principles of operation of these neutrino detectors, reports their latest results and discusses some theoretical interpretations. The progress of three realtime neutrino detectors that are currently under construction, SuperKamiok, SNO and Borexino, is also discussed.

  12. DOE Corporate Operating Experience Program

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

    2006-06-12

    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.

  13. Soliton molecules: Experiments and optimization

    SciTech Connect (OSTI)

    Mitschke, Fedor

    2014-10-06

    Stable compound states of several fiber-optic solitons have recently been demonstrated. In the first experiment their shape was approximated, for want of a better description, by a sum of Gaussians. Here we discuss an optimization strategy which helps to find preferable shapes so that the generation of radiative background is reduced.

  14. Soudan 2 nucleon decay experiment

    SciTech Connect (OSTI)

    Thron, J.L.

    1986-01-01

    The Soudan 2 nucleon decay experiment consists of a 1.1 Kton fine grained iron tracking calorimeter. It has a very isotropic detection structure which along with its flexible trigger will allow detection of multiparticle and neutrino proton decay modes. The detector has now entered its construction stage.

  15. Two LANL laboratory astrophysics experiments

    SciTech Connect (OSTI)

    Intrator, Thomas P.

    2014-01-24

    Two laboratory experiments are described that have been built at Los Alamos (LANL) to gain access to a wide range of fundamental plasma physics issues germane to astro, space, and fusion plasmas. The overarching theme is magnetized plasma dynamics which includes significant currents, MHD forces and instabilities, magnetic field creation and annihilation, sheared flows and shocks. The Relaxation Scaling Experiment (RSX) creates current sheets and flux ropes that exhibit fully 3D dynamics, and can kink, bounce, merge and reconnect, shred, and reform in complicated ways. Recent movies from a large data set describe the 3D magnetic structure of a driven and dissipative single flux rope that spontaneously self-saturates a kink instability. Examples of a coherent shear flow dynamo driven by colliding flux ropes will also be shown. The Magnetized Shock Experiment (MSX) uses Field reversed configuration (FRC) experimental hardware that forms and ejects FRCs at 150km/sec. This is sufficient to drive a collision less magnetized shock when stagnated into a mirror stopping field region with Alfven Mach number MA=3 so that super critical shocks can be studied. We are building a plasmoid accelerator to drive Mach numbers MA >> 3 to access solar wind and more exotic astrophysical regimes. Unique features of this experiment include access to parallel, oblique and perpendicular shocks, shock region much larger than ion gyro radii and ion inertial length, room for turbulence, and large magnetic and fluid Reynolds numbers.

  16. Operational experience of the OC-OTEC experiments at NELH

    SciTech Connect (OSTI)

    Link, H.

    1989-02-01

    The Solar Energy Research Institute, under funding and program direction from the US Department of Energy, has been operating a small-scale test apparatus to investigate key components of open- cycle ocean thermal energy conversion (OC-OTEC). The apparatus started operations in October 1987 and continues to provide valuable information on heat-and mass-transfer processes in evaporators and condensers, gas sorption processes as seawater is depressurized and repressurized, and control and instrumentation characteristics of open-cycle systems. Although other test facilities have been used to study some of these interactions, this is the largest apparatus of its kind to use seawater since Georges Claude's efforts in 1926. The information obtained from experiments conducted in this apparatus is being used to design a larger scale experiment in which a positive net power production is expected to be demonstrated for the first time with OC-OTEC. This paper describes the apparatus, the major tests conducted during its first 18 months of operation, and the experience gained in OC-OTEC system operation. 13 refs., 8 figs.

  17. Operational experience of the OC-OTEC experiments at NELH

    SciTech Connect (OSTI)

    Link, H.

    1989-02-01

    The Solar Energy Research Institute, under funding and program direction from the US Department of Energy, has been operating a small-scale test apparatus to investigate key components of open- cycle ocean thermal energy conversion (OC-OTEC). The apparatus started operations in October 1987 and continues to provide valuable information on heat-and mass-transfer processes in evaporators and condensers, gas sorption processes as seawater is depressurized and repressurized, and control and instrumentation characteristics of open-cycle systems. Although other test facilities have been used to study some of these interactions, this is the largest apparatus of its kind to use seawater since Georges Claude`s efforts in 1926. The information obtained from experiments conducted in this apparatus is being used to design a larger scale experiment in which a positive net power production is expected to be demonstrated for the first time with OC-OTEC. This paper describes the apparatus, the major tests conducted during its first 18 months of operation, and the experience gained in OC-OTEC system operation. 13 refs., 8 figs.

  18. International Collaborations on Engineered Barrier Systems: Experiment...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    and clay barrier performance; 2) EBS Experiment -thermo-hydro-mechanical-chemical ... DR-A (diffusion and retention) borehole experiment in Opalinus Clay, and cement-clay ...

  19. Southern Great Plains Ice Nuclei Characterization Experiment...

    Office of Scientific and Technical Information (OSTI)

    Characterization Experiment Final Campaign Summary Citation Details In-Document Search Title: Southern Great Plains Ice Nuclei Characterization Experiment Final Campaign ...

  20. Emergency First Responders' Experience with Colorimetric Detection...

    Office of Scientific and Technical Information (OSTI)

    Emergency First Responders' Experience with Colorimetric Detection Methods Citation Details In-Document Search Title: Emergency First Responders' Experience with Colorimetric ...

  1. Operating Experience Committee Charter | Department of Energy

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

    Experience Committee (OEC), which is to support line management within DOE and the DOE community in developing and sustaining effective oeprating experience programs so that...

  2. Hydrogen Embrittlement Fundamentals, Modeling, and Experiment...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Fundamentals, Modeling, and Experiment Hydrogen Embrittlement Fundamentals, Modeling, and Experiment Embrittlement, under static load could be a result of the synergistic action of ...

  3. Shock Desensitization Experiments and Reactive Flow Modeling...

    Office of Scientific and Technical Information (OSTI)

    Shock Desensitization Experiments and Reactive Flow Modeling on Self-Sustaining LX-17 Detonation Waves Citation Details In-Document Search Title: Shock Desensitization Experiments ...

  4. Former Workers Medical Facilities with Experience Evaluating...

    Energy Savers [EERE]

    Former Workers Medical Facilities with Experience Evaluating Chronic Beryllium Disease Former Workers Medical Facilities with Experience Evaluating Chronic Beryllium Disease April...

  5. Benchmarking kinetic calculations of resistive wall mode stability

    SciTech Connect (OSTI)

    Berkery, J. W.; Sabbagh, S. A.; Liu, Y. Q.; Betti, R.

    2014-05-15

    Validating the calculations of kinetic resistive wall mode (RWM) stability is important for confidently predicting RWM stable operating regions in ITER and other high performance tokamaks for disruption avoidance. Benchmarking the calculations of the Magnetohydrodynamic Resistive SpectrumKinetic (MARS-K) [Y. Liu et al., Phys. Plasmas 15, 112503 (2008)], Modification to Ideal Stability by Kinetic effects (MISK) [B. Hu et al., Phys. Plasmas 12, 057301 (2005)], and Perturbed Equilibrium Nonambipolar Transport (PENT) [N. Logan et al., Phys. Plasmas 20, 122507 (2013)] codes for two Solov'ev analytical equilibria and a projected ITER equilibrium has demonstrated good agreement between the codes. The important particle frequencies, the frequency resonance energy integral in which they are used, the marginally stable eigenfunctions, perturbed Lagrangians, and fluid growth rates are all generally consistent between the codes. The most important kinetic effect at low rotation is the resonance between the mode rotation and the trapped thermal particle's precession drift, and MARS-K, MISK, and PENT show good agreement in this term. The different ways the rational surface contribution was treated historically in the codes is identified as a source of disagreement in the bounce and transit resonance terms at higher plasma rotation. Calculations from all of the codes support the present understanding that RWM stability can be increased by kinetic effects at low rotation through precession drift resonance and at high rotation by bounce and transit resonances, while intermediate rotation can remain susceptible to instability. The applicability of benchmarked kinetic stability calculations to experimental results is demonstrated by the prediction of MISK calculations of near marginal growth rates for experimental marginal stability points from the National Spherical Torus Experiment (NSTX) [M. Ono et al., Nucl. Fusion 40, 557 (2000)].

  6. Jitter debugging two laser experiments

    SciTech Connect (OSTI)

    Rayner, D.M.; Hackett, P.A.; Willis, C.

    1982-03-01

    A method to overcome the problem of timing jitter in two laser experiments is described. The technique involves the use of a time-to-pulse height converter to measure the interpulse separation and a data acquisition system capable of recording this and other experimental parameters on a shot-to-shot basis. The method is estimated to be useful in measurement systems with resolution down to 10 ps.

  7. Solar neutrinos: theory vs experiment

    SciTech Connect (OSTI)

    Haxton, W.C.

    1991-01-01

    I review the standard solar model, the disparities between its predictions and the solar neutrino flux measurements of the Homestake and Kamioka II collaborations, and possible particle physics resolutions of this puzzle. The effects of matter, including density fluctuations and turbulence, on solar neutrino oscillations are reviewed, including possibilities for generating time variations in the solar neutrino flux. Finally, I consider possible outcomes and implications of the SAGE/GALLEX gallium experiments.

  8. Summer of Applied Geophysical Experience

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

    Summer of Applied Geophysical Experience (SAGE) 2016 - Our 34 rd Year! SAGE is a 3-4 week research and education program in exploration geophysics for graduate, undergraduate students, and working professionals based in Santa Fe, NM, U.S.A. Application deadline March 27, 2016, 5:00pm MDT SAGE students, faculty, teaching assistants, and visiting scientists acquire, process and interpret reflection/refraction seismic, magnetotelluric (MT)/electromagnetic (EM), ground penetrating radar (GPR),

  9. Mapping applications with collectives over sub-communicators on torus

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

    Mapping a Course to Improved Community Resilience Mapping a Course to Improved Community Resilience June 4, 2015 - 2:16pm Addthis OE interns Jeremy Call and Henry Puppe at last month's first-ever mapathon hosted by the White House OE interns Jeremy Call and Henry Puppe at last month's first-ever mapathon hosted by the White House Denice Ross Denice Ross Last month's first-ever mapathon hosted by the White House brought people together from across the public and private sectors to celebrate and

  10. Divertor Heat Flux Mitigation in the National Spherical Torus...

    Office of Scientific and Technical Information (OSTI)

    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 ...

  11. ELECTRON THERMAL TRANSPORT IN THE MADISON SYMMETRIC TORUS

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

    ... While the ruby is Q-switched, this can make an audible metallic "snap," and is visible as heat damage to the stainless steel baffles. The laser beam should be aligned to pass ...

  12. Nonmaximality of known extremal metrics on torus and Klein bottle

    SciTech Connect (OSTI)

    Karpukhin, M A

    2013-12-31

    The El Soufi-Ilias theorem establishes a connection between minimal submanifolds of spheres and extremal metrics for eigenvalues of the Laplace-Beltrami operator. Recently, this connection was used to provide several explicit examples of extremal metrics. We investigate the properties of these metrics and prove that none of them is maximal. Bibliography: 24 titles.

  13. Critical Configurations of Hard Disks on the Torus

    SciTech Connect (OSTI)

    Mason, J.

    2013-04-16

    CCHDT constructs and classifies various arrangements of hard disks of a single radius places on the unit square with periodic boundary conditions. Specifially, a given configuration is evolved to the nearest critical point on a smoothed hard disk energy fuction, and is classified by the adjacency matrix of the canonically labelled contact graph.

  14. Filamentary current structures in the Madison Symmetric Torus

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

    Association, Corso Stati Uniti 4, 35127 Padova, Italy 2 Department of Physics, University of Padova, Italy 3 NSF Center for Magnetic Self-Organization in Laboratory and ...

  15. Small-Scale Experiments.10-gallon drum experiment summary

    SciTech Connect (OSTI)

    Rosenberg, David M.

    2015-02-05

    A series of sub-scale (10-gallon) drum experiments were conducted to characterize the reactivity, heat generation, and gas generation of mixtures of chemicals believed to be present in the drum (68660) known to have breached in association with the radiation release event at the Waste Isolation Pilot Plant (WIPP) on February 14, 2014, at a scale expected to be large enough to replicate the environment in that drum but small enough to be practical, safe, and cost effective. These tests were not intended to replicate all the properties of drum 68660 or the event that led to its breach, or to validate a particular hypothesis of the release event. They were intended to observe, in a controlled environment and with suitable diagnostics, the behavior of simple mixtures of chemicals in order to determine if they could support reactivity that could result in ignition or if some other ingredient or event would be necessary. There is a significant amount of uncertainty into the exact composition of the barrel; a limited sub-set of known components was identified, reviewed with Technical Assessment Team (TAT) members, and used in these tests. This set of experiments was intended to provide a framework to postulate realistic, data-supported hypotheses for processes that occur in a “68660-like” configuration, not definitively prove what actually occurred in 68660.

  16. Schedule and status of irradiation experiments

    SciTech Connect (OSTI)

    Rowcliffe, A.F.; Grossbeck, M.L.; Robertson, J.P.

    1998-09-01

    The current status of reactor irradiation experiments is presented in tables summarizing the experimental objectives, conditions, and schedule. Currently, the program has one irradiation experiment in reactor and five experiments in the design or construction stages. Postirradiation examination and testing is in progress on ten experiments.

  17. Coherent electron cooling demonstration experiment

    SciTech Connect (OSTI)

    Litvinenko, V.N.; Belomestnykh, S.; Ben-Zvi, I.; Brutus, J.C.; Fedotov, A.; Hao, Y.; Kayran, D.; Mahler, G.; Marusic, A.; Meng, W.; McIntyre, G.; Minty, M.; Ptitsyn, V.; Pinayev, I.; Rao, T.; Roser, T.; Sheehy, B.; Tepikian, S.; Than, R.; Trbojevic, D.; Tuozzolo, J.; Wang, G.; Yakimenko, V.; Hutton, A.; Krafft, G.; Poelker, M.; Rimmer, R.; Bruhwiler, D.; Abell, D.T.; Nieter, C.; Ranjbar, V.; Schwartz, B.; Kholopov M.; Shevchenko, O.; McIntosh, P.; Wheelhouse, A.

    2011-09-04

    Coherent electron cooling (CEC) has a potential to significantly boost luminosity of high-energy, high-intensity hadron-hadron and electron-hadron colliders. In a CEC system, a hadron beam interacts with a cooling electron beam. A perturbation of the electron density caused by ions is amplified and fed back to the ions to reduce the energy spread and the emittance of the ion beam. To demonstrate the feasibility of CEC we propose a proof-of-principle experiment at RHIC using SRF linac. In this paper, we describe the setup for CeC installed into one of RHIC's interaction regions. We present results of analytical estimates and results of initial simulations of cooling a gold-ion beam at 40 GeV/u energy via CeC. We plan to complete the program in five years. During first two years we will build coherent electron cooler in IP2 of RHIC. In parallel we will develop complete package of computer simulation tools for the start-to-end simulation predicting exact performance of a CeC. The later activity will be the core of Tech X involvement into the project. We will use these tools to predict the performance of our CeC device. The experimental demonstration of the CeC will be undertaken in years three to five of the project. The goal of this experiment is to demonstrate the cooling of ion beam and to compare its measured performance with predictions made by us prior to the experiments.

  18. INCIDENT REPORTING: LEARNING FROM EXPERIENCE

    SciTech Connect (OSTI)

    Weiner, Steven C.; Kinzey, Bruce R.; Dean, Jesse D.; Davis, Patrick B.; Ruiz, Antonio

    2007-09-12

    Experience makes a superior teacher. Sharing the details surrounding safety events is one of the best ways to help prevent their recurrence elsewhere. This approach requires an open, non-punitive environment to achieve broad benefits. The Hydrogen Incident Reporting Tool (www.h2incidents.org) is intended to facilitate the sharing of lessons learned and other relevant information gained from actual experiences using and working with hydrogen and hydrogen systems. Its intended audience includes those involved in virtually any aspect of hydrogen technology, systems and use, with an emphasis towards energy and transportation applications. The database contains records of safety events both publicly available and/or voluntarily submitted. Typical records contain a general description of the occurrence, contributing factors, equipment involved, and some detailing of consequences and changes that have been subsequently implemented to prevent recurrence of similar events in the future. The voluntary and confidential nature and other characteristics surrounding the database mean that any analysis of apparent trends in its contents cannot be considered statistically valid for a universal population. A large portion of reported incidents have occurred in a laboratory setting due to the typical background of the reporting projects, for example. Yet some interesting trends are becoming apparent even at this early stage of the database’s existence and general lessons can already be taken away from these experiences. This paper discusses the database and a few trends that have already become apparent for the reported incidents. Anticipated future uses of this information are also described. This paper is intended to encourage wider participation and usage of the incidents reporting database and to promote the safety benefits offered by its contents.

  19. Attosecond Double-Slit Experiment

    SciTech Connect (OSTI)

    Lindner, F.; Schaetzel, M.G.; Baltuska, A.; Goulielmakis, E.; Walther, H.; Krausz, F.; Milosevic, D.B.; Bauer, D.; Becker, W.; Paulus, G.G.

    2005-07-22

    A new scheme for a double-slit experiment in the time domain is presented. Phase-stabilized few-cycle laser pulses open one to two windows (slits) of attosecond duration for photoionization. Fringes in the angle-resolved energy spectrum of varying visibility depending on the degree of which-way information are measured. A situation in which one and the same electron encounters a single and a double slit at the same time is observed. The investigation of the fringes makes possible interferometry on the attosecond time scale. From the number of visible fringes, for example, one derives that the slits are extended over about 500 as.

  20. Experience with pump gas seals

    SciTech Connect (OSTI)

    Nosowicz, J.; Schoepplein, W.

    1997-01-01

    The gas seal technology used in gas compressors has been successfully applied for emission-free sealing of liquid pumps in the past few years. The seals with pressurized gas supply systems are used as single or dual (tandem) seals. Gas seals, mainly as single seals, are frequently used as safety seals as well. Applying this non-contacting sealing system will result in reduced investment and operating cost. The paper discusses the sealing concept, operating performance, operating limits, gas-lubricated safety seals, field experience, and advantages.

  1. Shifting Standards: Experiments in Particle

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

    Shifting Standards: Experiments in Particle Physics in the Twentieth Century Allan Franklin University of Colorado July 15, 2015 4:00 p.m. (coffee @ 3:30) In this paper I will discuss changes in the presentation of experimental results from the early 20 th century to the present and their implications. In particular I will look at the history of high-energy physics from the 1960s to the present to see the evolution of the five-standards deviation discovery criterion. This history will

  2. Booster Neutrino Experiment - Virtual Tour

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

    Virtual Tour This series of pages about MiniBooNE will help you understand more about the what, why, and how of our experiment. When you begin the tour, a new window will open and you can use the next and back buttons to navigate. You may exit at any time by clicking on the "X" button in the upper right hand corner of the window. Start the tour here... This tour was created by Jessica Falco in 2000 and updated by Kelly O'Hear in 2002. Jessica and Kelly were high school students who

  3. RF breakdown experiments at SLAC

    SciTech Connect (OSTI)

    Laurent, L. [University of California Davis, Davis, California 95616 (United States); Vlieks, A.; Pearson, C.; Caryotakis, G.; Luhmann, N.C. [Stanford Linear Accelerator Center, Menlo Park, California 94025 (United States)

    1999-05-01

    RF breakdown is a critical issue in the conditioning of klystrons, accelerator sections, and rf components for the next linear collider (NLC), as well as other high gradient accelerators and high power microwave sources. SLAC is conducting a series of experiments using an X-band traveling wave ring to characterize the processes and trigger mechanisms associated with rf breakdown. The goal of the research is to identify materials, processes, and manufacturing methods that will increase the breakdown threshold and minimize the time required for conditioning. {copyright} {ital 1999 American Institute of Physics.}

  4. PPPL wins R&amp;D 100 Award | Princeton Plasma Physics Lab

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

    PPPL wins R&D 100 Award By Kitta MacPherson June 21, 2012 Tweet Widget Google Plus One Share on Facebook Award winners: (left to 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: (left to right) Jon Menard, the NSTX program director, and Vlad Soukhanovskii, who designed and led the experiments. Gallery: Egemen Kolemen Egemen Kolemen Joon-Wook Ahn Joon-Wook Ahn A

  5. ISOTHERMAL AIR INGRESS VALIDATION EXPERIMENTS

    SciTech Connect (OSTI)

    Chang H Oh; Eung S Kim

    2011-09-01

    Idaho National Laboratory carried out air ingress experiments as part of validating computational fluid dynamics (CFD) calculations. An isothermal test loop was designed and set to understand the stratified-flow phenomenon, which is important as the initial air flow into the lower plenum of the very high temperature gas cooled reactor (VHTR) when a large break loss-of-coolant accident occurs. The unique flow characteristics were focused on the VHTR air-ingress accident, in particular, the flow visualization of the stratified flow in the inlet pipe to the vessel lower plenum of the General Atomic’s Gas Turbine-Modular Helium Reactor (GT-MHR). Brine and sucrose were used as heavy fluids, and water was used to represent a light fluid, which mimics a counter current flow due to the density difference between the stimulant fluids. The density ratios were changed between 0.87 and 0.98. This experiment clearly showed that a stratified flow between simulant fluids was established even for very small density differences. The CFD calculations were compared with experimental data. A grid sensitivity study on CFD models was also performed using the Richardson extrapolation and the grid convergence index method for the numerical accuracy of CFD calculations . As a result, the calculated current speed showed very good agreement with the experimental data, indicating that the current CFD methods are suitable for predicting density gradient stratified flow phenomena in the air-ingress accident.

  6. The polarized SRF gun experiment.

    SciTech Connect (OSTI)

    Kewisch,J.; Ben-Zvi, I.; Rao, T.; Burrill, A.; Pate, D.; Grover, R.; Todd, R.; Bluem, H.; Holmes, D.; Schultheiss, T.

    2007-09-10

    RF electron guns are capable of producing electron bunches with high brightness, which outperform DC electron guns and may even be able to provide electron beams for the ILC without the need for a damping ring. However, all successful existing guns for polarized electrons are DC guns because the environment inside an RF gun is hostile to the GaAs cathode material necessary for polarization. While the typical vacuum pressure in a DC gun is better than 10{sup -11} torr the vacuum in an RF gun is in the order of 10{sup -9} torr. Experiments at BINP Novosibirsk show that this leads to strong ion back-bombardment and generation of dark currents, which destroy the GaAs cathode in a short time. The situation might be much more favorable in a (super-conducting) SRF gun. The cryogenic pumping of the gun cavity walls may make it possible to maintain a vacuum close to 10{sup -12} torr, solving the problem of ion bombardment and dark currents. Of concern would be contamination of the gun cavity by evaporating cathode material. This report describes an experiment that Brookhaven National Laboratory (BNL) in collaboration with Advanced Energy Systems (AES) is conducting to answer these questions.

  7. Stack Monitor Operating Experience Review

    SciTech Connect (OSTI)

    L. C. Cadwallader; S. A. Bruyere

    2009-05-01

    Stack monitors are used to sense radioactive particulates and gases in effluent air being vented from rooms of nuclear facilities. These monitors record the levels and types of effluents to the environment. This paper presents the results of a stack monitor operating experience review of the U.S. Department of Energy (DOE) Occurrence Reporting and Processing System (ORPS) database records from the past 18 years. Regulations regarding these monitors are briefly described. Operating experiences reported by the U.S. DOE and in engineering literature sources were reviewed to determine the strengths and weaknesses of these monitors. Electrical faults, radiation instrumentation faults, and human errors are the three leading causes of failures. A representative “all modes” failure rate is 1E-04/hr. Repair time estimates vary from an average repair time of 17.5 hours (with spare parts on hand) to 160 hours (without spare parts on hand). These data should support the use of stack monitors in any nuclear facility, including the National Ignition Facility and the international ITER project.

  8. Sasol's Fischer-Tropsch experience

    SciTech Connect (OSTI)

    Dry, M.E.

    1982-08-01

    Product slate from Fischer-Tropsch processing can be selectively varied over a wide range. Depending on the type reactor chosen and conditions of operation, either gasoline or diesel components can amount to as much as 75% of the hydrocarbons produced. Based on over 26 years of commercial experience in Fischer-Tropsch operations, Sasol has identified factors for controlling the product slate with respect to fraction produced and yields. Experience with two reactor types demonstrates their advantages and limitations while manipulation of the operating conditions has established control techniques for yields. Reactors of the low temperature fixed bed type produce products that are paraffinic and largely wax while yields from operation of higher temperature fluidized catalyst are a product that is highly olefinic and falls in the gasoline boiling range. After work up using normal refinery processing, the final products meet specifications applicable for motor fuels that are entirely compatible with crude oil products. In fact, the diesel product is superior because it has a cetane number higher than normal and a lower ring compound content.

  9. Flatback airfoil wind tunnel experiment.

    SciTech Connect (OSTI)

    Mayda, Edward A.; van Dam, C.P.; Chao, David D.; Berg, Dale E.

    2008-04-01

    A computational fluid dynamics study of thick wind turbine section shapes in the test section of the UC Davis wind tunnel at a chord Reynolds number of one million is presented. The goals of this study are to validate standard wind tunnel wall corrections for high solid blockage conditions and to reaffirm the favorable effect of a blunt trailing edge or flatback on the performance characteristics of a representative thick airfoil shape prior to building the wind tunnel models and conducting the experiment. The numerical simulations prove the standard wind tunnel corrections to be largely valid for the proposed test of 40% maximum thickness to chord ratio airfoils at a solid blockage ratio of 10%. Comparison of the computed lift characteristics of a sharp trailing edge baseline airfoil and derived flatback airfoils reaffirms the earlier observed trend of reduced sensitivity to surface contamination with increasing trailing edge thickness.

  10. Fermilab SRF cryomodule operational experience

    SciTech Connect (OSTI)

    Martinez, A.; Klebaner, A.L.; Theilacker, J.C.; DeGraff, B.D.; White, M.; Johnson, G.S.; /Fermilab

    2011-06-01

    Fermi National Accelerator Laboratory is constructing an Advanced Accelerator Research and Development facility at New Muon Lab. The cryogenic infrastructure in support of the initial phase of the facility consists of two Tevatron style standalone refrigerators, cryogenic distribution system as well as an ambient temperature pumping system to achieve 2K operations with supporting purification systems. During this phase of the project a single Type III plus 1.3 GHz cryomodule was installed, cooled and tested. Design constraints of the cryomodule required that the cryomodule individual circuits be cooled at predetermined rates. These constraints required special design solutions to achieve. This paper describes the initial cooldown and operational experience of a 1.3 GHz cryomodule using the New Muon Lab cryogenic system.

  11. Lessons Learned from Decontamination Experiences

    SciTech Connect (OSTI)

    Sorensen, JH

    2000-11-16

    This interim report describes a DOE project currently underway to establish what is known about decontamination of buildings and people and the procedures and protocols used to determine when and how people or buildings are considered ''clean'' following decontamination. To fulfill this objective, the study systematically examined reported decontamination experiences to determine what procedures and protocols are currently employed for decontamination, the timeframe involved to initiate and complete the decontamination process, how the contaminants were identified, the problems encountered during the decontamination process, how response efforts of agencies were coordinated, and the perceived social psychological effects on people who were decontaminated or who participated in the decontamination process. Findings and recommendations from the study are intended to aid decision-making and to improve the basis for determining appropriate decontamination protocols for recovery planners and policy makers for responding to chemical and biological events.

  12. Experiment Design and Analysis Guide - Neutronics & Physics

    SciTech Connect (OSTI)

    Misti A Lillo

    2014-06-01

    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.

  13. SOURCE PHENOMENOLOGY EXPERIMENTS IN ARIZONA

    SciTech Connect (OSTI)

    Jessie L. Bonner; Brian Stump; Mark Leidig; Heather Hooper; Xiaoning Yang; Rongmao Zhou; Tae Sung Kim; William R. Walter; Aaron Velasco; Chris Hayward; Diane Baker; C. L. Edwards; Steven Harder; Travis Glenn; Cleat Zeiler; James Britton; James F. Lewkowicz

    2005-09-30

    The Arizona Source Phenomenology Experiments (SPE) have resulted in an important dataset for the nuclear monitoring community. The 19 dedicated single-fired explosions and multiple delay-fired mining explosions were recorded by one of the most densely instrumented accelerometer and seismometer arrays ever fielded, and the data have already proven useful in quantifying confinement and excitation effects for the sources. It is very interesting to note that we have observed differences in the phenomenology of these two series of explosions resulting from the differences between the relatively slow (limestone) and fast (granodiorite) media. We observed differences at the two SPE sites in the way the rock failed during the explosions, how the S-waves were generated, and the amplitude behavior as a function of confinement. Our consortium's goal is to use the synergy of the multiple datasets collected during this experiment to unravel the phenomenological differences between the two emplacement media. The data suggest that the main difference between single-fired chemical and delay-fired mining explosion seismograms at regional distances is the increased surface wave energy for the latter source type. The effect of the delay-firing is to decrease the high-frequency P-wave amplitudes while increasing the surface wave energy because of the longer source duration and spall components. The results suggest that the single-fired explosions are surrogates for nuclear explosions in higher frequency bands (e.g., 6-8 Hz Pg/Lg discriminants). We have shown that the SPE shots, together with the mining explosions, are efficient sources of S-wave energy, and our next research stage is to postulate the possible sources contributing to the shear-wave energy.

  14. 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.

  15. Status of the MAJORANA DEMONSTRATOR experiment

    SciTech Connect (OSTI)

    Martin, R. D.; Abgrall, N.; Aguayo, Estanislao; Avignone, F. T.; Barabash, Alexander S.; Bertrand, F.; Boswell, M.; Brudanin, V.; Busch, Matthew; Caldwell, A. S.; Chan, Yuen-Dat; Christofferson, Cabot-Ann; Combs, Dustin C.; Detwiler, Jason A.; Doe, P. J.; Efremenko, Yuri; Egorov, Viatcheslav; Ejiri, H.; Elliott, S.; Esterline, James H.; Fast, James E.; Finnerty, P.; Fraenkle, Florian; Galindo-Uribarri, A.; Giovanetti, G. K.; Goett, J.; Green, M.; Gruszko, J.; Guiseppe, Vincente; Gusev, K.; Hallin, A. L.; Hazama, R.; Hegai, A.; Henning, R.; Hoppe, Eric W.; Howard, Stanley; Howe, M. A.; Keeter, K.; Kidd, M. F.; Kochetov, Oleg; Konovalov, S.; Kouzes, Richard T.; LaFerriere, Brian D.; Leon, Jonathan D.; Leviner, L.; Loach, J. C.; MacMullin, J.; MacMullin, S.; Mertens, S.; Mizouni, Leila; Nomachi, Masaharu; Orrell, John L.; O'Shaughnessy, Mark D.; Overman, Nicole R.; Phillips, David; Poon, Alan; Pushkin, K.; Radford, D. C.; Rielage, Keith; Robertson, R. G. H.; Romero-Romero, E.; Ronquest, M. C.; Schubert, Alexis G.; Shanks, B.; Shima, T.; Shirchenko, M.; Snavely, Kyle J.; Snyder, N.; Soin, Aleksandr; Suriano, Anne-Marie; Thompson, J.; Timkin, V.; Tornow, W.; Varner, R. L.; Vasilyev, Sergey; Vetter, Kai; Vorren, Kris R.; White, Brandon R.; Wilkerson, J. F.; Xu, W.; Yakushev, E.; Young, A.; Yu, Chang-Hong; Yumatov, Vladimir

    2014-07-08

    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.

  16. Status of the MAJORANA DEMONSTRATOR experiment

    SciTech Connect (OSTI)

    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

    2014-06-24

    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.

  17. Students gain work experience at WIPP

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

    Students Gain Work Experience at WIPP CARLSBAD, N.M., January 10, 2000 -- Students from two Eddy County high schools are gaining valuable experience by spending time with employees...

  18. Fermilab | Science at Fermilab | Experiments & Projects | Cosmic...

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

    How it works Questions for the Universe Scientific results Experiments CDMS COUPP GammeV Pierre Auger SDSS Dark Energy Survey Proposed Projects and Experiments photo-cosmic Cosmic ...

  19. CRAD, Operating Experience- February 11, 2009

    Broader source: Energy.gov [DOE]

    Operating Experience Inspection Criteria and Approach, DNFSB 2004-1 IP, Commitment 20 (HSS CRAD 64-41, Rev. 0)

  20. Current experiments in elementary particle physics. Revision

    SciTech Connect (OSTI)

    Galic, H.; Armstrong, F.E.; von Przewoski, B.

    1994-08-01

    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.

  1. NOvA Experiment - The Local Community

    ScienceCinema (OSTI)

    Deb Wieber

    2010-01-08

    Local proprietors Steve and Deb Wieber discuss the impact of the NOvA experiment on their community.

  2. Experiments on eta-meson production

    SciTech Connect (OSTI)

    Peng, J.C.

    1985-01-01

    Following a review of some highlights of eta-meson characteristics, the status of eta-meson production experiments is reviewed. The physics motivations and first results of two LAMPF experiments on (..pi..,eta) reactions are discussed. Possible future experiments are also discussed. 42 refs., 12 figs., 4 tabs.

  3. Central Equatorial Pacific Experiment (CEPEX)

    SciTech Connect (OSTI)

    Not Available

    1993-01-01

    The Earth's climate has varied significantly in the past, yet climate records reveal that in the tropics, sea surface temperatures seem to have been remarkably stable, varying by less than a few degrees Celsius over geologic time. Today, the large warm pool of the western Pacific shows similar characteristics. Its surface temperature always exceeds 27[degree]C, but never 31[degree]C. Heightened interest in this observation has been stimulated by questions of global climate change and the exploration of stabilizing climate feedback processes. Efforts to understand the observed weak sensitivity of tropical sea surface temperatures to climate forcing has led to a number of competing ideas about the nature of this apparent thermostat. Although there remains disagreement on the processes that regulate tropical sea surface temperature, most agree that further progress in resolving these differences requires comprehensive field observations of three-dimensional water vapor concentrations, solar and infrared radiative fluxes, surface fluxes of heat and water vapor, and cloud microphysical properties. This document describes the Central Equatorial Pacific Experiment (CEPEX) plan to collect such observations over the central equatorial Pacific Ocean during March of 1993.

  4. Deuterium accelerator experiments for APT.

    SciTech Connect (OSTI)

    Causey, Rion A. (Sandia National Laboratories, Livermore, CA); Hertz, Kristin L. (Sandia National Laboratories, Livermore, CA); Cowgill, Donald F. (Sandia National Laboratories, Livermore, CA)

    2005-08-01

    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.

  5. Spent Fuel Criticality Benchmark Experiments

    SciTech Connect (OSTI)

    J.M. Scaglione

    2001-07-23

    Characteristics between commercial spent fuel waste packages (WP), Laboratory Critical Experiments (LCEs), and commercial reactor critical (CRC) evaluations are compared in this work. Emphasis is placed upon comparisons of CRC benchmark results and the relative neutron flux spectra in each system. Benchmark evaluations were performed for four different pressurized water reactors using four different sets of isotopes. As expected, as the number of fission products used to represent the burned fuel inventory approached reality, the closer to unity k{sub eff} became. Examination of material and geometry characteristics indicate several fundamental similarities between the WP and CRC systems. In addition, spectral evaluations were performed on a representative pressurized water reactor CRC, a 21-assembly area of the core modeled in a potential WP configuration, and three LCEs considered applicable benchmarks for storage packages. Fission and absorption reaction spectra as well as relative neutron flux spectra are generated and compared for each system. The energy dependent reaction rates are the product of the neutron flux spectrum and the energy dependent total macroscopic cross section. With constant source distribution functions, and the total macroscopic cross sections for the fuel region in the CRCs and WP being composed of nearly the same isotopics, the resulting relative flux spectra in the CRCs and WP are very nearly the same. Differences in the relative neutron flux spectra between WPs and CRCs are evident in the thermal energy range as expected. However, the relative energy distribution of the absorption, fission, and scattering reaction rates in both the CRCs and the WP are essentially the same.

  6. The BigBoss Experiment

    SciTech Connect (OSTI)

    Schelgel, D.; Abdalla, F.; Abraham, T.; Ahn, C.; Allende Prieto, C.; Annis, J.; Aubourg, E.; Azzaro, M.; Bailey, S.; Baltay, C.; Baugh, C.; Bebek, C.; Becerril, S.; Blanton, M.; Bolton, A.; Bromley, B.; Cahn, R.; Carton, P.-H.; Cervanted-Cota, J.L.; Chu, Y.; Cortes, M.; /APC, Paris /Brookhaven /IRFU, Saclay /Marseille, CPPM /Marseille, CPT /Durham U. / /IEU, Seoul /Fermilab /IAA, Granada /IAC, La Laguna / /IAC, Mexico / / /Madrid, IFT /Marseille, Lab. Astrophys. / / /New York U. /Valencia U.

    2012-06-07

    BigBOSS is a Stage IV ground-based dark energy experiment to study baryon acoustic oscillations (BAO) and the growth of structure with a wide-area galaxy and quasar redshift survey over 14,000 square degrees. It has been conditionally accepted by NOAO in response to a call for major new instrumentation and a high-impact science program for the 4-m Mayall telescope at Kitt Peak. The BigBOSS instrument is a robotically-actuated, fiber-fed spectrograph capable of taking 5000 simultaneous spectra over a wavelength range from 340 nm to 1060 nm, with a resolution R = {lambda}/{Delta}{lambda} = 3000-4800. Using data from imaging surveys that are already underway, spectroscopic targets are selected that trace the underlying dark matter distribution. In particular, targets include luminous red galaxies (LRGs) up to z = 1.0, extending the BOSS LRG survey in both redshift and survey area. To probe the universe out to even higher redshift, BigBOSS will target bright [OII] emission line galaxies (ELGs) up to z = 1.7. In total, 20 million galaxy redshifts are obtained to measure the BAO feature, trace the matter power spectrum at smaller scales, and detect redshift space distortions. BigBOSS will provide additional constraints on early dark energy and on the curvature of the universe by measuring the Ly-alpha forest in the spectra of over 600,000 2.2 < z < 3.5 quasars. BigBOSS galaxy BAO measurements combined with an analysis of the broadband power, including the Ly-alpha forest in BigBOSS quasar spectra, achieves a FOM of 395 with Planck plus Stage III priors. This FOM is based on conservative assumptions for the analysis of broad band power (k{sub max} = 0.15), and could grow to over 600 if current work allows us to push the analysis to higher wave numbers (k{sub max} = 0.3). BigBOSS will also place constraints on theories of modified gravity and inflation, and will measure the sum of neutrino masses to 0.024 eV accuracy.

  7. Central Safety Factor and N Control on NSTX-U via Beam Power...

    Office of Scientific and Technical Information (OSTI)

    ... of Plasm as 4 (1997) 4179. 50 STAEBLER, G., COLYER, G., KAYE, S., KINSEY, J., and WALTZ, R., Testing the Trapped Gyro-Landau Fluid Transport Model with D ata from Tokamaks and ...

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

    Office of Scientific and Technical Information (OSTI)

    ... Transfer, 13, 333 (1973). 18 J. C. WEISHEIT, "Recombination in dense plasmas," J. Phys. B, 8, 2556 (1975). 19 R. K. JANEV and J. J. SMITH, "Cross sections for collision ...

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

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

    letters. He noted that three Office of Communications staff members: Science Writer John Greenwald, Photographer Elle Starkman, and Webmaster Chris Cane, received awards from...

  10. Panel ensures safe operation of the $94 million NSTX Upgrade | Princeton

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

    of Energy Panel Celebrates EM Achievements, Prepares for More Milestones Panel Celebrates EM Achievements, Prepares for More Milestones October 5, 2015 - 12:20pm Addthis EM Richland Operations Office Manager Stacy Charboneau kicked off the first panel at the National Cleanup Workshop. EM Richland Operations Office Manager Stacy Charboneau kicked off the first panel at the National Cleanup Workshop. EM Richland Operations Office Manager Stacy Charboneau kicked off the first panel at the

  11. Divertor Heat Flux Amelioration in Highly-Shaped Plasma in NSTX...

    Office of Scientific and Technical Information (OSTI)

    edge andor scrape-off layer (SOL) power and momentum loss, such as the radiative ... region have achieved the outer strike point (OSP) peak heat flux reduction from 4-6 ...

  12. NSTX-U Control System Upgrades (Journal Article) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    OSTI Identifier: 1172638 Report Number(s): PPPL--5045 Journal ID: ISSN 0920-3796; TRN: US1500484 GrantContract Number: AC02-09CH11466 Type: Accepted Manuscript Journal Name: ...

  13. Progress towards steady state on NSTX (Journal Article) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Number(s): UCRL-JRNL-221039 DOE Contract Number: W-7405-ENG-48 Resource Type: Journal Article Resource Relation: Journal Name: Nuclear Fusion, vol. 46, na, May 3, 2006, S22-S28...

  14. Upward-facing Lithium Flash Evaporator for NSTX-U (Conference...

    Office of Scientific and Technical Information (OSTI)

    Research Org: Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States) Sponsoring Org: USDOE Office of Science (SC) Country of Publication: United States Language: ...

  15. Analyses of Divertor Regimes in NSTX (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Authors: Soukhanovskii, V ; Maingi, R ; Bush, C ; Paul, S ; Boedo, J ; Kaita, R ; Kugel, H ; LeBlanc, B ; Porter, G ; Roquemore, A ; Wolf, N Publication Date: 2004-06-04 OSTI ...

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

    Office of Scientific and Technical Information (OSTI)

    code used to model neutral transport and plasma-neutral interactions in fusion plasmas. ... Resource Type: Technical Report Publisher: Fusion Science and Technology (November 2012) ...

  17. Local Effects of Biased Electrodes in the Divertor of NSTX (Technical...

    Office of Scientific and Technical Information (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 ...

  18. Local scrape-off layer control using biased electrodes in NSTX...

    Office of Scientific and Technical Information (OSTI)

    Volts, and the radial profile of the plasma between them was measured by an array of Langmuir probes. The biasing caused large changes in the local SOL profiles at least...

  19. Divertor Heat Flux Amelioration in Highly-Shaped Plasma in NSTX...

    Office of Scientific and Technical Information (OSTI)

    Authors: Soukhanovskii, V ; Maingi, R ; Gates, D ; Menard, J ; Raman, R ; Bell, R ; Bush, C ; Kaita, R ; Kugel, H ; LeBlanc, B ; Paul, S ; Roquemore, A Publication Date: 2007-07-02 ...

  20. Analyses of Divertor Regimes in NSTX (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    heating suggest that the inner divertor is detached at bar n sub e < 2-3x10sub 19 msup -3 whereas the outer divertor is attached, operating in the high recycling regime. ...

  1. NSTX-U Advances in Real-Time C++11 on Linux (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    (PPPL) is breaking new ground with the language as applied to the needs of fusion devices. ... GCC compiler, these tools enable data acquisition, processing, and output using a ...

  2. Co-counter asymmetry in fast wave heating and current drive and profile control in NSTX

    SciTech Connect (OSTI)

    Jaeger, E.F.; Carter, M.D.; Berry, L.A.; Batchelor, D.B.; Ryan, P.M.; Forest, C.B.; Weitzner, H.; Majeski, R.

    1997-08-01

    In this paper, full-wave ICRF coupling models are applied to understand the difference in plasma response when antenna arrays are phased to drive currents co and counter to the plasma current. The source of this difference lies in the natural up-down asymmetry of the antenna`s radiated power spectrum caused by Hall currents. When a poloidal field is applied, this up-down asymmetry acquires a toroidal component. The result is that plasma absorption (i.e., antenna loading) is shifted or skewed toward the co-current drive direction, independent of the direction of the magnetic field. When waves are launched to drive current counter to the plasma current, electron heating and current profiles are more peaked on axis, and this peaking becomes more pronounced at lower toroidal magnetic fields.

  3. Local scrape-off layer control using biased electrodes in NSTX...

    Office of Scientific and Technical Information (OSTI)

    to test the theory that biased electrodes can affect the local scrape-off layer (SOL) width by creating a strong radial ExB drift Cohen, R.H. and Ryutov, D.D, Nucl. Fusion...

  4. Current Experiments in Particle Physics (September 1996)

    SciTech Connect (OSTI)

    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.

    1996-09-01

    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.

  5. Student Career Experience Program | National Nuclear Security

    National Nuclear Security Administration (NNSA)

    Administration | (NNSA) Student Career Experience Program The Student Career Experience Program (SCEP) is a great way to start your NNSA career while pursuing your studies in college or graduate school. This program gives you the opportunity to combine your academic studies with on-the-job training and experience directly related to your academic program. You will have the opportunity to work on exciting NNSA projects, earn money while serving your nation and take advantage of an excellent

  6. The XENON100 Dark Matter Experiment

    SciTech Connect (OSTI)

    Tziaferi, E.

    2010-06-23

    The XENON100 experiment is searching for WIMPs, which are particles that may consist dark matter. It is located in the underground laboratory of Gran Sasso (LNGS) in Italy at a depth of {approx}3600 m.w.e.. The experiment description, its performance and the expected background based on Monte Carlo simulations and material screening along with the projected sensitivities of the experiment are presented. In addition, a brief description of the upgrade XENON100 detector is given.

  7. Magnet operating experience review for fusion applications

    SciTech Connect (OSTI)

    Cadwallader, L.C.

    1991-11-01

    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.

  8. JLab Completes 100th Experiment | Jefferson Lab

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

    Completes 100th Experiment JLab Completes 100th Experiment The experiment, titled "Quark Propagation through Cold QCD Matter," began its run in December 2003 and wrapped up in early March. It probed Quantum Chromodynamics (QCD), a fundamental theory of particle physics that describes the interactions of quarks and gluons - the basic building blocks of matter. A property of QCD, called confinement, states that no quark can ever be found alone. Instead, quarks combine in pairs or

  9. Summer of Applied Geophysical Experience Reading List

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

    Geophysical Experience Reading List Summer of Applied Geophysical Experience Reading List A National Science Foundation Research Experiences for Undergraduates program Contacts Institute Director Reinhard Friedel-Los Alamos SAGE Co-Director W. Scott Baldridge-Los Alamos SAGE Co-Director Larry Braile-Purdue University Professional Staff Assistant Georgia Sanchez (505) 665-0855 Keller, R., Khan, M. A., Morgan, P., et al., 1991, A Comparative Study of the Rio Grande and Kenya rifts, Tectonophys.,

  10. Laser-driven hydrodynamic instability experiments

    SciTech Connect (OSTI)

    Remington, B.A.; Weber, S.V.; Haan, S.W.; Kilkenny, J.D.; Glendinning, S.G.; Wallace, R.J.; Goldstein, W.H.; Wilson, B.G.; Nash, J.K. )

    1993-07-01

    An extensive series of experiments has been conducted on the Nova laser to measure hydrodynamic instabilities in planar foils accelerated by x-ray ablation. Single-mode experiments allow a measurement of the fundamental growth rates from the linear well into the nonlinear regime. Two-mode foils give a first direct observation of mode coupling. Surface-finish experiments allow a measurement of the evolution of a broad spectrum of random initial modes.

  11. Laser driven hydrodynamic instability experiments. Revision 1

    SciTech Connect (OSTI)

    Remington, B.A.; Weber, S.V.; Haan, S.W.; Kilkenny, J.D.; Glendinning, S.G.; Wallace, R.J.; Goldstein, W.H.; Wilson, B.G.; Nash, J.K.

    1993-02-17

    An extensive series of experiments has been conducted on the Nova laser to measure hydrodynamic instabilities in planar foils accelerated by x-ray ablation. Single mode experiments allow a measurement of the fundamental growth rates from the linear well into the nonlinear regime. Two-mode foils allow a first direct observation of mode coupling. Surface-finish experiments allow a measurement of the evolution of a broad spectrum of random initial modes.

  12. Systematic errors in long baseline oscillation experiments

    SciTech Connect (OSTI)

    Harris, Deborah A.; /Fermilab

    2006-02-01

    This article gives a brief overview of long baseline neutrino experiments and their goals, and then describes the different kinds of systematic errors that are encountered in these experiments. Particular attention is paid to the uncertainties that come about because of imperfect knowledge of neutrino cross sections and more generally how neutrinos interact in nuclei. Near detectors are planned for most of these experiments, and the extent to which certain uncertainties can be reduced by the presence of near detectors is also discussed.

  13. : The Resumption of Criticality Experiments Facility Operations...

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

    nuclear criticality experiments and hands-on training in nuclear safeguards, criticality safety and emergency response in support of the National Criticality Safety Program. ...

  14. BooNE: Booster Neutrino Experiment

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

    from major neutrino experiments and important results in neutrino physics. Includes java applets. Janet's Neutrino Oscillation Page More extensive material about neutrino...

  15. Conference Proceedings Available - The Smart Grid Experience...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Conference Proceedings Available - The Smart Grid Experience: Applying Results, Reaching Beyond March 23, 2015 - 10:55am Addthis In October 2014, the Electric Power Research ...

  16. ORISE: Undergraduates Research Experiences - Shaun Galvan

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

    Galvan was introduced to Raman spectroscopy during a previous research experience at the University of Wollongong in Australia. This technique involves firing a monochromatic laser ...

  17. Current experiments in elementary particle physics

    SciTech Connect (OSTI)

    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.

    1987-03-01

    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.

  18. Capturing Pioneer Plant Experience: Implications for Synfuels...

    Office of Environmental Management (EM)

    plants, the first set of synfuel technology projects will generate experience and information that will be valuable to firms contemplating investments in subsequent plants ...

  19. ARM - ARM MJO Investigation Experiment (AMIE)

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

    ARM MJO Investigation Experiment (AMIE) ARM field campaigns on Gan Island, Maldives, and Manus Island, Papua New Guinea, will contribute significantly to concurrent national and ...

  20. Operating Experience Summaries | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    June 19, 2014 Operating Experience Summary - 2014-03 - June 19, 2014 Inside this issue: Wilson Construction Company Crew Foreman Receives Fatal Shock during Transmission Line ...

  1. User Experience Testing | GE Global Research

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

    understandable, and actionable software experiences for GE customers, partners ... The fact that this work takes place within the Software CoE means that designers and ...

  2. Design Calculations for NIF Convergent Ablator Experiments. ...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Design Calculations for NIF Convergent Ablator Experiments. Citation ... DOE Contract Number: DE-AC04-94AL85000 Resource Type: Journal Article Resource Relation: ...

  3. Nocturnal Avian Migration Experiment Final Campaign Report

    Office of Scientific and Technical Information (OSTI)

    One solution is the incorporation of collocated acoustic monitoring that can provide ... The Nocturnal Avian Migration Experiment (NAME) took place at the Atmospheric Radiation ...

  4. Operating Experience Level 3: Radiologically Contaminated Respirators...

    Energy Savers [EERE]

    Experience Level 3 provides information on a safety concern related to radiological contamination of launderedreconditioned respirators and parts that have been certified as...

  5. Current experiments in elementary particle physics

    SciTech Connect (OSTI)

    Wohl, C.G.; Armstrong, F.E.; Trippe, T.G.; Yost, G.P. ); Oyanagi, Y. ); Dodder, D.C. ); Ryabov, Yu.G.; Slabospitsky, S.R. . Inst. Fiziki Vysokikh Ehnergij); Frosch, R. (Swiss Inst. for Nuclear Research, Villigen (Switzerla

    1989-09-01

    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.

  6. Presentations - Madison Dynamo Experiment - Cary Forest Group...

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

    Conferences APS DPP 2009 Meeting, Atlanta, GA, November 2-6, 2009 Zane Taylor, Strategies for Observing Self-excitation in the Madison Dynamo Experiment Elliot Kaplan, Perturbative ...

  7. Operating Experience Summary, 2015-01

    Energy Savers [EERE]

    1 September 16, 2015 Inside This Issue * Explosion at the Nonproliferation Test and Evaluation Complex ... 1 Page 1 of 8 Operating Experience Summary Office of Environment,...

  8. ATLAS APPROVED IN-BEAM EXPERIMENTS

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

    7 785 Baktash Band Termination, Superdeformation and Complex Clusters in 32S 5 TOTAL 82 ATLAS APPROVED SOURCE EXPERIMENTS (Depending on Gammasphere Availability) Exp Spokesperson...

  9. Current experiments in elementary particle physics. Revised

    SciTech Connect (OSTI)

    Galic, H.; Wohl, C.G.; Armstrong, B.; Dodder, D.C.; Klyukhin, V.I.; Ryabov, Yu.G.; Illarionova, N.S.; Lehar, F.; Oyanagi, Y.; Olin, A.; Frosch, R.

    1992-06-01

    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.

  10. NNSA releases Stockpile Stewardship Program quarterly experiments...

    National Nuclear Security Administration (NNSA)

    National Ignition Facility at Lawrence Livermore National Laboratory, and the Z machine at Sandia National Laboratories. The summary also provides the number of experiments...

  11. First experience of vectorizing electromagnetic physics models...

    Office of Scientific and Technical Information (OSTI)

    electromagnetic physics models for detector simulation Citation Details In-Document Search Title: First experience of vectorizing electromagnetic physics models for detector ...

  12. DEP Learning Experiences | Argonne National Laboratory

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

    Learning Experiences "Science is a way of thinking much more than it is a body of knowledge." - Carl Sagan, Astrophysicist Argonne Education provides a variety of...

  13. Renewables-Friendly Grid Development Strategies: Experience...

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

    penetrations of variable renewable electricity. China is actively contributing to this body of experience given the rapid growth in renewable electricity deployment there, while...

  14. Early Childhood Experiences Conference on October 30

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

    First Born Program presents "Understanding Early Childhood Experiences as a Primary Public Health Concern." October 1, 2012 dummy image Read our archives Contacts Editor...

  15. BooNE: Booster Neutrino Experiment

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

    Booster Neutrino Experiment (BooNE) Goals of BooNE BooNE in a Nutshell Making Neutrinos Detecting Neutrinos

  16. Data Quality of Quality Measurement Experiments

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

    Data Quality of Quality Measurement Experiments S. Bottone and S. Moore Mission Research ... assessment of the quality of incoming data based on internal consistency checks, ...

  17. Full toroidal imaging of non-axisymmetric plasma material interaction...

    Office of Scientific and Technical Information (OSTI)

    eXperiment divertor Citation Details In-Document Search Title: Full toroidal imaging of non-axisymmetric plasma material interaction in the National Spherical Torus eXperiment ...

  18. Overview of Field Experience - Degradation Rates & Lifetimes

    SciTech Connect (OSTI)

    Jordan, Dirk; Kurtz, Sarah

    2015-09-14

    The way a PV module fails may depend not only on its design and the materials used in its construction, but also on the weather it experiences, the way it is mounted, and the quality control during its manufacture. This presentation gives an overview of Field Experience - what degradation rates and what lifetimes are being observed in various regions.

  19. BooNE: Booster Neutrino Experiment

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

    Experiment Details This page provides information on the MiniBooNE experiment. Images are linked in their own page with captions. Additional resources are the Talks, Slides and Posters page, Publications page, and Data Release page Beamline Flux Detector Cross sections Light Propagation (Optical Model) Calibration Particle Identification BooNE photo montage

  20. Fast critical experiment data for space reactors

    SciTech Connect (OSTI)

    Collins, P.J.; McFarlane, H.F.; Olsen, D.N.; Atkinson, C.A.; Ross, J.R.

    1987-01-01

    Data from a number of previous critical experiments exist that are relevant to the design concepts being considered for SP-100 and MMW space reactors. Although substantial improvements in experiment techniques have since made some of the measured quantities somewhat suspect, the basic criticality data are still useful in most cases. However, the old experiments require recalculation with modern computational methods and nuclear cross section data before they can be applied to today's designs. Recently, we have calculated about 20 fast benchmark critical experiments with the latest ENDF/B data and modern transport codes. These calculations were undertaken as a part of the planning process for a new series of benchmark experiments aimed at supporting preliminary designs of SP-100 and MMW space reactors.

  1. MCNP simulations of material exposure experiments (u) (Technical...

    Office of Scientific and Technical Information (OSTI)

    MCNP simulations of material exposure experiments (u) Simulations of proposed material exposure experiments were performed using MCNP6. The experiments will expose ampules...

  2. First Subcritical Experiment Conducted at Nevada Test Site |...

    National Nuclear Security Administration (NNSA)

    Subcritical Experiment Conducted at Nevada Test Site First Subcritical Experiment Conducted at Nevada Test Site Nevada Test Site, NV The first "subcritical" physics experiment at ...

  3. Property:Past Pertinent Test Experience | Open Energy Information

    Open Energy Info (EERE)

    Past Pertinent Test Experience Jump to: navigation, search Property Name Past Pertinent Test Experience Property Type Text Pages using the property "Past Pertinent Test Experience"...

  4. Research Experience in Carbon Sequestration 2016 Now Accepting...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Experience in Carbon Sequestration 2016 Now Accepting Applications Research Experience in ... professionals can gain hands-on field research experience in areas related to carbon ...

  5. A second-generation cosmic axion experiment

    SciTech Connect (OSTI)

    Hagmann, C.; Stoeffl, W.; van Bibber, K.

    1995-05-01

    An experiment is described to detect dark matter axions trapped in the halo of our galaxy. Galactic axions are converted into microwave photons via the Primakoff effect in a static background field provided by a superconducting magnet. The photons are collected in a high Q microwave cavity and detected by a low noise receiver. The axion mass range accessible by this experiment is 1.3 {minus} 13 {mu}eV. The expected sensitivity will be roughly 50 times greater than achieved by previous experiments in this mass range. The assembly of the detector is well under any at LLNL and data taking will start in mid-1995.

  6. Accelerator/Experiment Operations - FY 2015

    SciTech Connect (OSTI)

    Czarapata, P.

    2015-10-01

    This Technical Memorandum summarizes the Fermilab accelerator and experiment operations for FY 2015. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2015 NOvA, MINOS+ and MINERvA experiments using the Main Injector Neutrino Beam (NuMI), the activities in the SciBooNE Hall using the Booster Neutrino Beam (BNB), and the SeaQuest experiment and Meson Test Beam (MTest) activities in the 120 GeV external Switchyard beam (SY120).

  7. Fuel Cell Power Plant Experience Naval Applications

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    clean Fuel Cell Power Plant Experience Naval Applications US Department of Energy/ Office of Naval Research Shipboard Fuel Cell Workshop Washington, DC March 29, 2011 FuelCell Energy, the FuelCell Energy logo, Direct FuelCell and "DFC" are all registered trademarks (®) of FuelCell Energy, Inc. *FuelCell Energy, Inc. *Renewable and Liquid Fuels Experience *HTPEM Fuel Cell Stack for Shipboard APU *Solid Oxide Experience and Applications DOE-ONR Workshop FuelCell Energy, the FuelCell

  8. COMPILATION OF CURRENT HIGH ENERGY PHYSICS EXPERIMENTS

    SciTech Connect (OSTI)

    Wohl, C.G.; Kelly, R.L.; Armstrong, F.E.; Horne, C.P.; Hutchinson, M.S.; Rittenberg, A.; Trippe, T.G.; Yost, G.P.; Addis, L.; Ward, C.E.W.; Baggett, N.; Goldschmidt-Clermong, Y.; Joos, P.; Gelfand, N.; Oyanagi, Y.; Grudtsin, S.N.; Ryabov, Yu.G.

    1981-05-01

    This is the fourth edition of our compilation of current high energy physics experiments. It is a collaborative effort of the Berkeley Particle Data Group, the SLAC library, and nine participating laboratories: Argonne (ANL), Brookhaven (BNL), CERN, DESY, Fermilab (FNAL), the Institute for Nuclear Study, Tokyo (INS), KEK, Serpukhov (SERP), and SLAC. The compilation includes summaries of all high energy physics experiments at the above laboratories that (1) were approved (and not subsequently withdrawn) before about April 1981, and (2) had not completed taking of data by 1 January 1977. We emphasize that only approved experiments are included.

  9. BooNE: Booster Neutrino Experiment

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

    (505) 695 8364 BooNE Experiment: contact-boone@fnal.gov Current Shifter: (505) 500 5511 Detector Enclosure: (630) 840 6881 or 6081 BooNE Collaborators and Associates:...

  10. BooNE: Booster Neutrino Experiment

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

    Goals of BooNE BooNE's primary goal is to investigate the neutrino oscillation signal reported by the Los Alamos Liquid Scintillator Neutrino Detector (LSND) experiment. In 1995,...

  11. Range gated imaging experiments using gated intensifiers

    SciTech Connect (OSTI)

    McDonald, T.E. Jr.; Yates, G.J.; Cverna, F.H.; Gallegos, R.A.; Jaramillo, S.A.; Numkena, D.M.; Payton, J.; Pena-Abeyta, C.R.

    1999-03-01

    A variety of range gated imaging experiments using high-speed gated/shuttered proximity focused microchannel plate image intensifiers (MCPII) are reported. Range gated imaging experiments were conducted in water for detection of submerged mines in controlled turbidity tank test and in sea water for the Naval Coastal Sea Command/US Marine Corps. Field experiments have been conducted consisting of kilometer range imaging of resolution targets and military vehicles in atmosphere at Eglin Air Force Base for the US Air Force, and similar imaging experiments, but in smoke environment, at Redstone Arsenal for the US Army Aviation and Missile Command (AMCOM). Wavelength of the illuminating laser was 532 nm with pulse width ranging from 6 to 12 ns and comparable gate widths. These tests have shown depth resolution in the tens of centimeters range from time phasing reflected LADAR images with MCPII shutter opening.

  12. Beta calutrons and Y-12 experiments

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

    calutrons and Y-12 experiments Among the most enjoyable parts of writing about Y-12's history is the feedback I get from those who actually lived the history I'm trying to capture...

  13. Operating Experience Level 3, Ladder Safety

    Office of Energy Efficiency and Renewable Energy (EERE)

    OE-3 2016-04: This Operating Experience Level 3 (OE-3) document provides information about a safety concern related to workers who use ladders during work at Department of Energy (DOE) facilities.

  14. BooNE: Booster Neutrino Experiment

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

    (numbers, plots, details) of the MiniBooNE experiment and analysis pieces. Images are linked in their own page with captions. Additional resources are the Talks, Slides and...

  15. Long term experiences with HDD SCR Catalysts

    Broader source: Energy.gov [DOE]

    Test bench results and on-road experiences of more than 1 million km offer comparisons of fresh and used catalyst activity and NOx conversion capability using appropriate methods of catalyst analysis.

  16. Operating Experience Level 3, Atmospheric Dispersion Parameter...

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

    5 OE-3 2015-02: Atmospheric Dispersion Parameter (xQ) for Calculation of Co-located Worker Dose This Operating Experience Level 3 (OE-3) document informs the complex of the...

  17. Operating Experience Level 3, Electrical Safety: Shocks

    Broader source: Energy.gov [DOE]

    OE-3: 2015-03 This Operating Experience Level 3 (OE-3) document provides information about a safety concern related to electrical shocks workers have received while performing work at Department of Energy (DOE) facilities.

  18. A Microscopic Double-Slit Experiment

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

    Microscopic Double-Slit Experiment Print Two centuries ago, Thomas Young performed the classic demonstration of the wave nature of light. He placed a screen with two tiny slits in...

  19. A Microscopic Double-Slit Experiment

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

    A Microscopic Double-Slit Experiment Print Two centuries ago, Thomas Young performed the classic demonstration of the wave nature of light. He placed a screen with two tiny slits...

  20. BooNE: Booster Neutrino Experiment

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

    by the Los Alamos LSND experiment. MiniBooNE represents the first phase for the BooNE collaboration and consists of a 1 GeV neutrino beam and a single, 800-ton mineral oil...