13 results on '"P. C. Efthimion"'
Search Results
2. Measurement of the magnetic field in a spherical torus plasma via electron Bernstein wave emission harmonic overlap
- Author
-
Tobin Munsat, P. C. Efthimion, B. Jones, and G. Taylor
- Subjects
Physics ,Electron density ,Harmonics ,Harmonic ,Torus ,Electron ,Atomic physics ,Condensed Matter Physics ,Plasma oscillation ,Electromagnetic radiation ,Magnetic field - Abstract
Measurement of the magnetic field in a spherical torus by observation of harmonic overlap frequencies in the electron Bernstein wave (EBW) spectrum has been previously suggested [V. F. Shevchenko, Plasma Phys. Rep. 26, 1000 (2000)]. EBW mode conversion to X-mode radiation has been studied in the Current Drive Experiment-Upgrade spherical torus (T. Jones, Ph.D. thesis, Princeton University, 1995) with emission measured at blackbody levels [B. Jones et al., Phys. Rev. Lett. 90, 165001 (2003)]. Sharp transitions in the thermally emitted EBW spectrum have been observed for the first two harmonic overlaps. These transition frequencies are determined by the magnetic field and electron density at the mode conversion layer in accordance with hot-plasma wave theory. Prospects of extending this measurement to higher harmonics, necessary in order to determine the magnetic field profile, and high-β equilibria are discussed for this proposed magnetic field diagnostic.
- Published
- 2004
3. Enhanced conversion of thermal electron Bernstein waves to the extraordinary electromagnetic mode on the National Spherical Torus Experiment
- Author
-
B.P. LeBlanc, G. L. Bell, F. Paoletti, B. Jones, T.S. Bigelow, G. Taylor, Alexander Smirnov, Rajesh Maingi, James R. Wilson, P. C. Efthimion, John B Wilgen, R. W. Harvey, David A Rasmussen, and S.A. Sabbagh
- Subjects
Physics ,law ,Energy conversion efficiency ,Limiter ,Particle accelerator ,Electron ,Cyclotron radiation ,Plasma ,Atomic physics ,Fusion power ,Condensed Matter Physics ,Electromagnetic radiation ,law.invention - Abstract
A fourfold increase in the conversion of thermal electron Bernstein waves (EBW) to the extraordinary mode (X mode) was measured when the density scale length (Ln) was progressively shortened by a local boron nitride limiter in the scrape-off of an Ohmically heated National Spherical Torus Experiment plasma [M. Ono, S. Kaye, M. Peng et al., Proceedings of the 17th IAEA Fusion Energy Conference (IAEA, Vienna, 1999), Vol. 3, p. 1135]. The maximum conversion efficiency approached 50% when Ln was reduced to 0.7 cm, in agreement with theoretical predictions that used locally measured Ln. Calculations indicate that it is possible to establish Ln
- Published
- 2003
4. Transient transport experiments in the current-drive experiment upgrade spherical torus
- Author
-
G. Taylor, Richard Majeski, Dan Stutman, Tobin Munsat, P. C. Efthimion, B. Jones, and R. Kaita
- Subjects
Physics ,Core (optical fiber) ,Interferometry ,Modulation ,Plasma diagnostics ,Torus ,Radius ,Sawtooth wave ,Atomic physics ,Condensed Matter Physics ,Order of magnitude - Abstract
Electron transport has been measured in the Current-Drive Experiment Upgrade (CDX-U) (T. Jones, Ph.D. thesis, Princeton University, 1995) using two separate perturbative techniques. Sawteeth at the q=1 radius (r/a∼0.15) induced outward-propagating heat pulses, providing time-of-flight information leading to a determination of χe as a function of radius. Gas modulation at the plasma edge introduced inward-propagating cold pulses, providing a complementary time-of-flight based χe profile measurement. This work represents the first localized measurement of χe in a spherical torus. Core (r/a
- Published
- 2002
5. Enhancement of mode-converted electron Bernstein wave emission during National Spherical Torus Experiment H-mode plasmas
- Author
-
B. Jones, P. C. Efthimion, R. Maingi, B.P. LeBlanc, and G. Taylor
- Subjects
Physics ,Physics::Plasma Physics ,Energy conversion efficiency ,Mode (statistics) ,Particle ,Plasma ,Electron ,Atomic physics ,Fusion power ,Condensed Matter Physics ,Electromagnetic radiation ,Magnetic field - Abstract
A sudden, threefold increase in emission from fundamental electrostatic electron Bernstein waves (EBW) which mode convert and tunnel to the electromagnetic X-mode has been observed during high energy and particle confinement (H-mode) transitions in the National Spherical Torus Experiment (NSTX) plasma [M. Ono, S. Kaye, M. Peng et al., in Proceedings of the 17th IAEA Fusion Energy Conference (IAEA, Vienna, Austria, 1999), Vol. 3, p. 1135]. The mode-converted EBW emission viewed normal to the magnetic field on the plasma midplane increases when the density profile steepens in the vicinity of the mode conversion layer, which is located in the plasma scrape off. The measured conversion efficiency during the H-mode is consistent with the calculated EBW to X-mode conversion efficiency derived using edge density data. Calculations indicate that there may also be a small residual contribution to the measured X-mode electromagnetic radiation from polarization-scrambled, O-mode emission, converted from EBWs.
- Published
- 2002
6. Initial physics results from the National Spherical Torus Experiment
- Author
-
Thomas Jarboe, J. R. Wilson, Neville C. Luhmann, P. C. Efthimion, Calvin Domier, Nobuhiro Nishino, M. Bitter, D.W. Swain, E. Synakowski, Lei Zeng, D. Gates, Thomas Rognlien, M. G. Bell, R. Raman, F. Paoletti, Yuichi Takase, S. J. Zweben, Xueqiao Xu, J. Manickam, S. Medley, D. Darrow, Y-K.M. Peng, G.D. Porter, R. Kaita, K. C. Lee, E. Mazzucato, B.-J. LeBlanc, Dan Stutman, S. Kubota, C. K. Phillips, E. D. Fredrickson, Stephen Jardin, T. Peebles, T. K. Mau, B. A. Nelson, John B Wilgen, D. Stotler, William R. Wampler, Abraham Bers, P.M. Ryan, Abhay K. Ram, G. A. Wurden, S. Paul, J.M. Bialek, L.L. Lao, H. Park, Ricardo Maqueda, B. Deng, Mark D. Carter, S.A. Sabbagh, J.R. Ferron, R. I. Pinsker, K. Hill, P.T. Bonoli, R. E. Bell, J. Menard, S. M. Kaye, G. Taylor, R. Majeski, T.S. Bigelow, D. Mueller, M.J. Schaffer, Rajesh Maingi, M. Rensink, M. Ono, Hantao Ji, B. Stratton, J. Hosea, C. H. Skinner, H. Kugel, D. Johnson, L. Grisham, E. J. Doyle, W. Zhu, and Michael Finkenthal
- Subjects
Physics ,Toroid ,chemistry.chemical_element ,Torus ,Plasma ,Collisionality ,Condensed Matter Physics ,Helicity ,Neutral beam injection ,Computational physics ,chemistry ,Atomic physics ,Helium ,Beam (structure) - Abstract
The mission of the National Spherical Torus Experiment (NSTX) is to extend the understanding of toroidal physics to low aspect ratio (R/a approximately equal to 1.25) in low collisionality regimes. NSTX is designed to operate with up to 6 MW of High Harmonic Fast Wave (HHFW) heating and current drive, 5 MW of Neutral Beam Injection (NBI) and Co-Axial Helicity Injection (CHI) for non-inductive startup. Initial experiments focused on establishing conditions that will allow NSTX to achieve its aims of simultaneous high-bt and high-bootstrap current fraction, and to develop methods for non-inductive operation, which will be necessary for Spherical Torus power plants. Ohmic discharges with plasma currents up to 1 MA and with a range of shapes and configurations were produced. Density limits in deuterium and helium reached 80% and 120% of the Greenwald limit respectively. Significant electron heating was observed with up to 2.3 MW of HHFW. Up to 270 kA of toroidal current for up to 200 msec was produced noninductively using CHI. Initial NBI experiments were carried out with up to two beam sources (3.2 MW). Plasmas with stored energies of up to 140 kJ and bt =21% were produced.
- Published
- 2001
7. Local transport barrier formation and relaxation in reverse-shear plasmas on the Tokamak Fusion Test Reactor
- Author
-
P. C. Efthimion, G. L. Schmidt, E. J. Synakowski, S. H. Batha, F. M. Levinton, A. T. Ramsey, Gregory W. Hammett, R. E. Bell, Robert Budny, E. Mazzucato, G. Taylor, G. Rewoldt, Michael A. Beer, T.S. Hahm, B.P. LeBlanc, C. E. Bush, Hyeon K. Park, M. C. Zarnstorff, M.G. Bell, and S. D. Scott
- Subjects
Shearing (physics) ,Physics ,Physics::Plasma Physics ,Turbulence ,Magnetic confinement fusion ,Mechanics ,Plasma ,Atomic physics ,Condensed Matter Physics ,Tokamak Fusion Test Reactor ,Critical value ,Instability ,Pressure gradient - Abstract
The roles of turbulence stabilization by sheared E×B flow and Shafranov shift gradients are examined for Tokamak Fusion Test Reactor [D. J. Grove and D. M. Meade, Nucl. Fusion 25, 1167 (1985)] enhanced reverse-shear (ERS) plasmas. Both effects in combination provide the basis of a positive-feedback model that predicts reinforced turbulence suppression with increasing pressure gradient. Local fluctuation behavior at the onset of ERS confinement is consistent with this framework. The power required for transitions into the ERS regime are lower when high power neutral beams are applied earlier in the current profile evolution, consistent with the suggestion that both effects play a role. Separation of the roles of E×B and Shafranov shift effects was performed by varying the E×B shear through changes in the toroidal velocity with nearly steady-state pressure profiles. Transport and fluctuation levels increase only when E×B shearing rates are driven below a critical value that is comparable to the fastest line...
- Published
- 1997
8. Deuterium–tritium plasmas in novel regimes in the Tokamak Fusion Test Reactor
- Author
-
J. Mcchesney, E. J. Strait, S. H. Batha, R. E. Bell, Harold P. Furth, D.K. Owens, V. Yavorski, H. H. Duong, I. Semenov, A. Kumar, J. S. Kim, Michael A. Beer, Stanley Kaye, Leonid E. Zakharov, Masaaki Yamada, E.D. Fredrickson, K. L. Wong, A. von Halle, D.C. McCune, M.G. Bell, Larry R. Grisham, A. V. Krasilnikov, E. Ruskov, W. Stodiek, R. O. Dendy, J. C. Hosea, P. C. Efthimion, Guoyong Fu, M. Hughes, G. A. Navratil, A. Belov, N. T. Lam, Robert Budny, B.P. LeBlanc, Hyeon K. Park, J. Manickam, T. Stevenson, G. L. Schmidt, W. Park, James R. Wilson, G. Mckee, J. Machuzak, Richard Majeski, Manfred Bitter, H. W. Herrmann, M. Sasao, D. R. Ernst, J. Callen, Chio-Zong Cheng, R. K. Fisher, Yoshio Nagayama, S. A. Sabbagh, S. D. Scott, S. von Goeler, F. M. Levinton, Nikolai Gorelenkov, K. W. Hill, G. Rewoldt, D. R. Mikkelsen, R. T. Walters, William Tang, R.J. Hawryluk, G. Schilling, S. F. Paul, E. J. Synakowski, S. S. Medley, Nathaniel J. Fisch, M. Williams, B. Rice, K. M. McGuire, Roscoe White, A. T. Ramsey, J. D. Strachan, T. Senko, G. Taylor, B. Breizman, H. Takahashi, S. Bernabei, R. Kaita, G. A. Wurden, W. A. Houlberg, D. Mueller, B. C. Stratton, Michael E. Mauel, Michael W Kissick, A. L. Roquemore, C.H. Skinner, P. Phillips, V.Ya. Goloborod'ko, S. Cauffman, M. C. Zarnstorff, William Dorland, J. Hogan, E. Mazzucato, D. L. Jassby, S. V. Mirnov, F. C. Jobes, M. H. Redi, M. Okabayashi, J. Kesner, Kenneth M. Young, W. W. Heidbrink, Dale Meade, J. H. Rogers, M. E. Thompson, S.N. Reznik, M. Phillips, Gregory W. Hammett, H. Berk, C. E. Bush, R. J. Fonck, H. Evenson, N. L. Bretz, Z. Chang, D.K. Mansfield, Raffi Nazikian, R. Wieland, Stewart Zweben, B. Hooper, H.W. Kugel, David Johnson, M. P. Petrov, D. S. Darrow, M. C. Herrmann, C. Ludescher, Choong-Seock Chang, P. H. LaMarche, C. K. Phillips, Shoujun Wang, B. Grek, and M. Osakabe
- Subjects
Physics ,Tokamak ,Magnetic confinement fusion ,Plasma ,Fusion power ,Condensed Matter Physics ,Instability ,law.invention ,Ion ,Physics::Plasma Physics ,law ,Electric current ,Atomic physics ,Tokamak Fusion Test Reactor - Abstract
Experiments in the Tokamak Fusion Test Reactor (TFTR) have explored several novel regimes of improved tokamak confinement in deuterium-tritium (D-T) plasmas, including plasmas with reduced or reversed magnetic shear in the core and high-current plasmas with increased shear in the outer region (high-l{sub i}). New techniques have also been developed to enhance the confinement in these regimes by modifying the plasma-limiter interaction through in-situ deposition of lithium. In reversed-shear plasmas, transitions to enhanced confinement have been observed at plasma currents up to 2.2 MA (q{sub a} {approx} 4.3), accompanied by the formation of internal transport barriers, where large radial gradients develop in the temperature and density profiles. Experiments have been performed to elucidate the mechanism of the barrier formation and its relationship with the magnetic configuration and with the heating characteristics. The increased stability of high-current, high-l{sub i} plasmas produced by rapid expansion of the minor cross-section, coupled with improvement in the confinement by lithium deposition has enabled the achievement of high fusion power, up to 8.7 MW, with D-T neutral beam heating. The physics of fusion alpha-particle confinement has been investigated in these regimes, including the interactions of the alphas with endogenous plasma instabilities and externally applied waves in the ion cyclotron range of frequencies. In D-T plasmas with q{sub 0} > 1 and weak magnetic shear in the central region, a toroidal Alfven eigenmode instability driven purely by the alpha particles has been observed for the first time. The interactions of energetic ions with ion Bernstein waves produced by mode-conversion from fast waves in mixed-species plasmas have been studied as a possible mechanism for transferring the energy of the alphas to fuel ions.
- Published
- 1997
9. Radially localized measurements of superthermal electrons using oblique electron cyclotron emission
- Author
-
S. Preische, P. C. Efthimion, and S. M. Kaye
- Subjects
Physics ,Electron density ,Tokamak ,law ,Beta (plasma physics) ,Cyclotron ,Cyclotron resonance ,Plasma diagnostics ,Electron ,Atomic physics ,Condensed Matter Physics ,Electron cyclotron resonance ,law.invention - Abstract
It is shown that radial localization of optically thin electron cyclotron emission from superthermal electrons can be imposed by observation of emission upshifted from the thermal cyclotron resonance in the horizontal midplane of a tokamak. A new and unique diagnostic has been proposed and operated to make radially localized measurements of superthermal electrons during lower hybrid current drive on the Princeton Beta Experiment‐Modified (PBX‐M) tokamak [Bernabei, et al., Phys. Fluids B 5, 2562 (1993)]. The superthermal electron density profile as well as moments of the electron energy distribution as a function of radius are measured during lower hybrid current drive. The time evolution of these measurements after the lower hybrid power is turned off are given and the observed behavior reflects the collisional isotropization of the energy distribution and radial diffusion of the spatial profile.
- Published
- 1996
10. Deuterium–tritium high confinement (H‐mode) studies in the Tokamak Fusion Test Reactor
- Author
-
Raffi Nazikian, Manfred Bitter, D.C. McCune, G. Taylor, Jay Kesner, D. S. Darrow, J.F. Schivell, S. D. Scott, C.E. Bush, C. K. Phillips, D.K. Mansfield, Michael E. Mauel, S. H. Batha, M. H. Redi, S.A. Sabbagh, L. C. Johnson, E. Mazzucato, D.R. Ernst, E.D. Fredrickson, Masakatsu Murakami, Fred Levinton, Hyeon K. Park, M. G. Bell, H. H. Towner, P. C. Efthimion, R.E. Bell, B.P. LeBlanc, C.H. Skinner, Z. Chang, John B Wilgen, Stewart Zweben, S.F. Paul, R.V. Budny, M. C. Zarnstorff, G.A. Navratil, N. L. Bretz, G. R. Hanson, and E. J. Synakowski
- Subjects
Nuclear physics ,Physics ,Deuterium ,Beta (plasma physics) ,Limiter ,Tritium ,Plasma ,Atomic physics ,Condensed Matter Physics ,Tokamak Fusion Test Reactor ,Neutral beam injection ,Beam (structure) - Abstract
High or enhanced confinement (H‐mode) plasmas have been obtained for the first time with nearly equal concentrations of deuterium and tritium in high‐temperature, high poloidal beta plasmas in the Tokamak Fusion Test Reactor (TFTR) [McGuire, Phys. Plasmas 2, 2176 (1995)]. Tritium fueling was provided mainly through high‐power neutral beam injection (NBI) with powers up to 31 MW and beam energies of 90–110 keV. A transition to a circular limiter H‐mode configuration has been obtained, following a programmed rapid decrease of the plasma current. Isotope effects, due to the presence of tritium, led to different behavior for deuterium–deuterium (DD) and deuterium–tritium (DT) H‐modes relative to confinement, edge localized magnetohydrodynamic modes (ELMs), and ELM effects on fusion products. However, the threshold power for the H‐mode transition was the same in DD and DT. Some of the highest values of the global energy confinement time, τE, have been achieved on TFTR during the ELM‐free phase of DT H‐mode plasmas. Enhancements of τE greater than four times the L‐mode have been attained.
- Published
- 1995
11. Review of deuterium–tritium results from the Tokamak Fusion Test Reactor
- Author
-
V. Garzotto, A. Nagy, V. Arunasalam, D. S. Darrow, P. C. Efthimion, A. Janos, V. Zavereev, M.G. Bell, Guoyong Fu, Larry R. Grisham, J. A. Murphy, M. Caorlin, Choong-Seock Chang, Harold P. Furth, J. C. Hosea, J. L. Anderson, R. A. Hulse, David Johnson, D. L. Jassby, R. Rossmassler, K. M. Young, B.P. LeBlanc, Richard Majeski, G. Pearson, G. Coward, M. P. Petrov, I. Semenov, Darin Ernst, Jay Kesner, R. Pysher, Manfred Bitter, R. Marsala, B. McCormack, J. Swanson, M. Williams, H.H. Duong, H. H. Towner, E. Perry, M. Viola, J. Stencel, M. Osakabe, M. McCarthy, D. Long, S. D. Scott, K. L. Wong, J. Machuzak, M. Kalish, Hyeon K. Park, D.C. McCune, N. Fromm, Stewart Zweben, R. T. Walters, W. Tighe, J. R. Timberlake, Z. Chang, G. Schilling, K. M. McGuire, R. E. Bell, P. Alling, E. Ruskov, G. A. Wurden, Michael Loughlin, E. Fredd, Cris W. Barnes, Michael E. Mauel, R. Newman, M. Oldaker, E. J. Synakowski, C. E. Bush, M. Sasao, P. H. LaMarche, C. K. Phillips, R. Camp, H.W. Kugel, M. H. Redi, S. H. Batha, J. Ongena, M. Norris, D.K. Owens, G Rewoldt, R. Durst, Dale Meade, M. Murakami, Nikolai Gorelenkov, K. W. Hill, J. H. Rogers, Gregory R. Hanson, David A Rasmussen, K. Wright, M. C. Zarnstorff, B. Grek, S. Yoshikawa, Roscoe White, T. Senko, G. Labik, H. Takahashi, S. Raftopoulos, S. Ramakrishnan, C. Gentile, H. Evenson, A. L. Qualls, J. McChesney, J. Winston, R. Wester, A. T. Ramsey, M. Hughes, Gerald Navratil, Robert Budny, D. R. Mikkelsen, J. D. Strachan, R. Sissingh, B. C. Stratton, E.D. Fredrickson, William Dorland, T. Stevenson, G. Ascione, H. W. Herrmann, S.A. Sabbagh, R. J. Fonck, L. Dudek, George McKee, J. Collins, W. Blanchard, J. Schivell, R. Scillia, T. Fujita, J.A. Snipes, S. Cauffman, M. E. Thompson, G. Martin, J. Gioia, S. V. Mirnov, A. von Halle, J. DeLooper, D. Ashcroft, John B Wilgen, C. Vannoy, J. Stevens, J. Kamperschroer, C. Ancher, L. C. Johnson, D. Roberts, R. Daugert, W. Park, F. M. Levinton, Gregory W. Hammett, M. Tuszewski, Nathaniel J. Fisch, J. W. Anderson, S. Sesnic, N. T. Lam, William Tang, Chio-Zong Cheng, Glenn Bateman, R. J. Hawryluk, E. Mazzucato, C.H. Skinner, F. C. Jobes, H. Hsuan, Earl Marmar, Michael A. Beer, Masaaki Yamada, R. Fisher, Paul Woskov, J.L. Terry, T. O’Connor, J. Gilbert, E. Lawson, R. Persing, S. F. Paul, D. Loesser, W. W. Heidbrink, G. Barnes, N. L. Bretz, D. Voorhees, W. Stodiek, R. O. Dendy, M. Cropper, G. Renda, P. B. Parks, D. Mueller, Kenji Tobita, A. Martin, S. S. Medley, G. L. Schmidt, G. Taylor, A. L. Roquemore, James R. Wilson, S. von Goeler, J. Levine, H. Adler, S. Pitcher, H. Anderson, Raffi Nazikian, C. Brunkhorst, R. Wieland, J. Chrzanowski, M. Phillips, D.K. Mansfield, and H. Carnevale
- Subjects
Nuclear physics ,Physics ,Thermonuclear fusion ,Tokamak ,Lawson criterion ,law ,Nuclear fusion ,Magnetic confinement fusion ,Fusion power ,Condensed Matter Physics ,Tokamak Fusion Test Reactor ,Inertial confinement fusion ,law.invention - Abstract
After many years of fusion research, the conditions needed for a D–T fusion reactor have been approached on the Tokamak Fusion Test Reactor (TFTR) [Fusion Technol. 21, 1324 (1992)]. For the first time the unique phenomena present in a D–T plasma are now being studied in a laboratory plasma.The first magnetic fusion experiments to study plasmas using nearly equal concentrations of deuterium and tritium have been carried out on TFTR. At present the maximum fusion power of 10.7 MW, using 39.5 MW of neutral‐beam heating, in a supershot discharge and 6.7 MW in a high‐βp discharge following a current rampdown. The fusion power density in a core of the plasma is ≊2.8 MW m−3, exceeding that expected in the International Thermonuclear Experimental Reactor (ITER) [Plasma Physics and Controlled Nuclear Fusion Research (International Atomic Energy Agency, Vienna, 1991), Vol. 3, p. 239] at 1500 MW total fusion power. The energy confinement time, τE, is observed to increase in D–T, relative to D plasmas, by 20% and the ni(0) Ti(0) τE product by 55%. The improvement in thermal confinement is caused primarily by a decrease in ion heat conductivity in both supershot and limiter‐H‐mode discharges. Extensive lithium pellet injection increased the confinement time to 0.27 s and enabled higher current operation in both supershot and high‐βp discharges. Ion cyclotron range of frequencies (ICRF) heating of a D–T plasma, using the second harmonic of tritium, has been demonstrated. First measurements of the confined alpha particles have been performed and found to be in good agreement with TRANSP [Nucl. Fusion 34, 1247 (1994)] simulations. Initial measurements of the alpha ash profile have been compared with simulations using particle transport coefficients from He gas puffing experiments. The loss of alpha particles to a detector at the bottom of the vessel is well described by the first‐orbit loss mechanism. No loss due to alpha‐particle‐driven instabilities has yet been observed. D–T experiments on TFTR will continue to explore the assumptions of the ITER design and to examine some of the physics issues associated with an advanced tokamak reactor.
- Published
- 1995
12. Preparations for deuterium–tritium experiments on the Tokamak Fusion Test Reactor*
- Author
-
V. Mastrocola, D. Wong, B. C. Stratton, G. Martin, William Tang, D. Monticello, P. Snook, C.H. Skinner, Yu. I. Pavlov, H. Carnevale, Richard Majeski, H. Anderson, H. Hsuan, Earl Marmar, Dale Meade, J. H. Rogers, J. Kamperschroer, C. Ancher, V. Garzotto, M. Williams, C. E. Bush, Takeo Nishitani, I. Collazo, R. Ramakrishnan, R. Newman, J. DeLooper, D. Roberts, H. W. Hermann, G. Ascione, E. Fredd, H. H. Towner, Darin Ernst, W. Park, H. Bush, J. Chrzanowski, M. Oldaker, J. W. Anderson, D. Aschroft, K. L. Wong, M. Ulrickson, D.K. Owens, M.G. Bell, S. Raftopoulos, M. Leonard, J. Gioia, J. R. Timberlake, N. T. Lam, A. von Halle, A. Yeun, J. Levine, Leonid E. Zakharov, Jay Kesner, Chio-Zong Cheng, Larry R. Grisham, M. Murakami, D. Loesser, M. J. Laughlin, R. Rossmassler, Liu Chen, J. A. Murphy, T. Golian, G Rewoldt, R. Durst, G. Labik, A. Martin, R. Scillia, M. E. Thompson, S. D. Scott, R.J. Hawryluk, S. S. Medley, John B Wilgen, G. L. Schmidt, Cris W. Barnes, H. Adler, D. R. Mikkelsen, S. Pitcher, F. W. Perkins, R. Sissingh, A. L. Qualls, J. R. Wilson, G. Barnes, T. Stevenson, J. C. Hosea, Raffi Nazikian, C. Brunkhorst, J. Schivell, Glenn Bateman, T. Burgess, V. Arunasalam, D. S. Darrow, P. C. Efthimion, A. L. Roquemore, Michael A. Beer, Guoyong Fu, R. Wieland, R.J. Fonck, E.D. Fredrickson, Gregory W. Hammett, W. Blanchard, S. Kwon, J. Stevens, M. Marchlik, L. C. Johnson, R. Camp, T. Senko, Nikolai Gorelenkov, K. W. Hill, B.P. LeBlanc, D. W. Johnson, William Heidbrink, Hyeon K. Park, R. Daugert, J. Swanson, Masaaki Yamada, David A Rasmussen, M. Sasao, F. M. Levinton, E. Perry, Donald B. Batchelor, J. Stencel, D.C. McCune, D. Long, Manfred Bitter, E. Mazzucato, S. Yoshikawa, K. M. McGuire, S.A. Sabbagh, G. A. Wurden, Michael E. Mauel, L. Dudek, P. Alling, C. Gentile, M. H. Redi, G. Gettelfinger, J. D. Strachan, F. C. Jobes, Paul Woskov, R. C. Goldfinger, G. Renda, B. Grek, D. L. Jassby, J. Snipes, J.L. Terry, D. Mueller, M. Caorlin, C. Vannoy, T. O’Connor, J. Gilbert, G. Taylor, W. Stodiek, M. Cropper, E. Lawson, E. J. Synakowski, A. T. Ramsey, Gerald Navratil, J. L. Anderson, R. Persing, G. R. Hanson, S. F. Paul, R. A. Hulse, G. Pearson, G. Coward, M. P. Petrov, E. F. Jaeger, J. Faunce, M. McCarthy, S. H. Batha, K. Wright, K. M. Young, S.L. Milora, Stewart Zweben, S. Popovichev, S.P. Hirshman, H.W. Kugel, J. Ongena, M. C. Zarnstorff, P.T. Bonoli, A. Nagy, D. J. Hoffman, M. Norris, A. Janos, R. Marsala, M. Osakabe, J. Machuzak, G. Schilling, T. S. Biglow, Harold P. Furth, B. McCormack, H.H. Duong, Z. Chang, P. H. LaMarche, C. K. Phillips, Robert Budny, Steven Cowley, D. E. Mansfield, J. Collins, N. L. Bretz, L. A. Baylor, John Scharer, N. Fromm, and M. J. Gouge
- Subjects
Nuclear physics ,Tritium illumination ,Physics ,Lawson criterion ,Deuterium ,Water cooling ,Tritium ,Neutron radiation ,Fusion power ,Condensed Matter Physics ,Tokamak Fusion Test Reactor - Abstract
The final hardware modifications for tritium operation have been completed for the Tokamak Fusion Test Reactor (TFTR) [Fusion Technol. 21, 1324 (1992)]. These activities include preparation of the tritium gas handling system, installation of additional neutron shielding, conversion of the toroidal field coil cooling system from water to a FluorinertTM system, modification of the vacuum system to handle tritium, preparation, and testing of the neutral beam system for tritium operation and a final deuterium–deuterium (D–D) run to simulate expected deuterium–tritium (D–T) operation. Testing of the tritium system with low concentration tritium has successfully begun. Simulation of trace and high power D–T experiments using D–D have been performed. The physics objectives of D–T operation are production of ≊10 MW of fusion power, evaluation of confinement, and heating in deuterium–tritium plasmas, evaluation of α‐particle heating of electrons, and collective effects driven by alpha particles and testing of diag...
- Published
- 1994
13. Efficient coupling of thermal electron Bernstein waves to the ordinary electromagnetic mode on the National Spherical Torus Experiment
- Author
-
John B Wilgen, John Caughman, Josef Preinhaelter, B.P. LeBlanc, R. W. Harvey, P. C. Efthimion, G. Taylor, Mark D. Carter, and S.A. Sabbagh
- Subjects
Physics ,Coupling ,Physics::Plasma Physics ,Harmonics ,Harmonic ,Plasma ,Electron ,Fusion power ,Atomic physics ,Condensed Matter Physics ,Electromagnetic radiation ,Power (physics) ,Computational physics - Abstract
Efficient coupling of thermal electron Bernstein waves (EBW) to ordinary-mode (O-mode) electromagnetic radiation has been measured in plasmas heated by energetic neutral beams and high harmonic fast waves in the National Spherical Torus Experiment (NSTX) [M. Ono, S. Kaye, M. Peng et al., Proceedings of the 17th IAEA Fusion Energy Conference, edited by S. Spak (IAEA, Vienna, Austria, 1999), Vol. 3, p. 1135]. The EBW to electromagnetic mode coupling efficiency was measured to be 0.8±0.2, compared to a numerical EBW modeling prediction of 0.65. The observation of efficient EBW coupling to O mode, in relatively good agreement with numerical modeling, is a necessary prerequisite for implementing a proposed high power EBW current drive system on NSTX.
- Published
- 2005
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.