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19 results on '"H. S. Mclean"'

1. Focussing Protons from a Kilojoule Laser for Intense Beam Heating using Proximal Target Structures

Author

C. McGuffey, J. Kim, M. S. Wei, P. M. Nilson, S. N. Chen, J. Fuchs, P. Fitzsimmons, M. E. Foord, D. Mariscal, H. S. McLean, P. K. Patel, R. B. Stephens, and F. N. Beg

Subjects
Medicine, Science
Abstract

Abstract Proton beams driven by chirped pulse amplified lasers have multi-picosecond duration and can isochorically and volumetrically heat material samples, potentially providing an approach for creating samples of warm dense matter with conditions not present on Earth. Envisioned on a larger scale, they could heat fusion fuel to achieve ignition. We have shown in an experiment that a kilojoule-class, multi-picosecond short pulse laser is particularly effective for heating materials. The proton beam can be focussed via target design to achieve exceptionally high flux, important for the applications mentioned. The laser irradiated spherically curved diamond-like-carbon targets with intensity 4 × 1018 W/cm 2, producing proton beams with 3 MeV slope temperature. A Cu witness foil was positioned behind the curved target, and the gap between was either empty or spanned with a structure. With a structured target, the total emission of Cu Kα fluorescence was increased 18 fold and the emission profile was consistent with a tightly focussed beam. Transverse proton radiography probed the target with ps order temporal and 10 μm spatial resolution, revealing the fast-acting focussing electric field. Complementary particle-in-cell simulations show how the structures funnel protons to the tight focus. The beam of protons and neutralizing electrons induce the bright Kα emission observed and heat the Cu to 100 eV.

Published
2020
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3. Probing local electron temperature and density inside a sheared flow stabilized Z-pinch using portable optical Thomson scattering

Author

J. T. Banasek, C. Goyon, S. C. Bott-Suzuki, G. F. Swadling, M. Quinley, B. Levitt, B. A. Nelson, U. Shumlak, and H. S. McLean

Subjects
Instrumentation
Abstract

We report the first optical Thomson scattering measurements inside a high electron temperature (≳1 keV) and moderate electron density (mid 1016 cm−3) plasma. This diagnostic has been built to provide critical plasma parameters, such as electron temperature and density, for Advanced Research Projects Agency-Energy-supported fusion-energy concepts. It uses an 8 J laser at 532 nm in 1.5 ns to measure the high frequency feature of the Thomson scattering profile at 17 locations along the probe axis. It is able to measure electron density from 5 × 1017 cm−3 to several 1019 cm−3 and electron temperatures from tens of eV to several keV. Here, we describe the design, deployment, and analysis on the sheared flow stabilized Z-pinch machine at Zap Energy named FuZE. The probe beam is aimed at an axial distance of 20 cm from the central electrode and is timed within the temporal envelope of neutron emission. The high temperature and moderate density plasmas generated on FuZE lie in an unconventional regime for Thomson scattering as they are between tokamaks and laser-produced plasmas. We described the analysis considerations in this regime, show that the electron density was below 5 × 1016 cm−3 at all times during these measurements, and present a sample shot where the inferred electron temperature varied from 167 ± 16 eV to 700 ± 85 eV over 1.6 cm.

Published
2023
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4. Transport of an intense proton beam from a cone-structured target through plastic foam with unique proton source modeling

Author

K. Bhutwala, C. McGuffey, W. Theobald, O. Deppert, J. Kim, P. M. Nilson, M. S. Wei, Y. Ping, M. E. Foord, H. S. McLean, P. K. Patel, A. Higginson, M. Roth, and F. N. Beg

Abstract

Laser-accelerated proton beams are applicable to several research areas within high-energy density science, including warm dense matter generation, proton radiography, and inertial confinement fusion, which all involve transport of the beam through matter. We report on experimental measurements of intense proton beam transport through plastic foam blocks. The intense proton beam was accelerated by the 10ps, 700J OMEGA EP laser irradiating a curved foil target, and focused by an attached hollow cone. The protons then entered the foam block of density 0.38g/cm^{3} and thickness 0.55 or 1.00mm. At the rear of the foam block, a Cu layer revealed the cross section of the intense beam via proton- and hot electron-induced Cu-K_{α} emission. Images of x-ray emission show a bright spot on the rear Cu film indicative of a forward-directed beam without major breakup. 2D fluid-PIC simulations of the transport were conducted using a unique multi-injection source model incorporating energy-dependent beam divergence. Along with postprocessed calculations of the Cu-K_{α} emission profile, simulations showed that protons retain their ballistic transport through the foam and are able to heat the foam up to several keV in temperature. The total experimental emission profile for the 1.0mm foam agrees qualitatively with the simulated profile, suggesting that the protons indeed retain their beamlike qualities.

Published
2021

5. Investigation of laser pulse length and pre-plasma scale length impact on hot electron generation on OMEGA-EP

Author

J Peebles, M S Wei, A V Arefiev, C McGuffey, R B Stephens, W Theobald, D Haberberger, L C Jarrott, A Link, H Chen, H S McLean, A Sorokovikova, S Krasheninnikov, and F N Beg

Subjects
plasma physics, high intensity, electron beams, pre-plasma, bremsstrahlung spectrometer, high energy particles, Science, Physics, QC1-999
Abstract

A series of experiments studying pre-plasma’s effect on electron generation and transport due to a high intensity laser were conducted on the OMEGA-EP laser facility. A controlled pre-plasma was produced in front of an aluminum foil target prior to the arrival of the high intensity short pulse beam. Energetic electron spectra were characterized with magnetic and bremsstrahlung spectrometers. Pre-plasma and pulse length were shown to have a large impact on the temperature of lower energy, ponderomotive scaling electrons. Super-ponderomotive electrons, seen in prior pre-plasma experiments with shorter pulses, were observed without any initial pre-plasma in our experiment. 2D particle-in-cell and radiation-hydrodynamic simulations shed light on and validate these experimental results.

Published
2017
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6. Impact of extended preplasma on energy coupling in kilojoule energy relativistic laser interaction with cone wire targets relevant to fast ignition

Author

T Yabuuchi, R Mishra, C McGuffey, B Qiao, M S Wei, H Sawada, Y Sentoku, T Ma, D P Higginson, K U Akli, D Batani, H Chen, L A Gizzi, M H Key, A J Mackinnon, H S McLean, P A Norreys, P K Patel, R B Stephens, Y Ping, W Theobald, C Stoeckl, and F N Beg

Subjects
Science, Physics, QC1-999
Abstract

Cone-guided fast ignition laser fusion depends critically on details of the interaction of an intense laser pulse with the inside tip of a cone. Generation of relativistic electrons in the laser plasma interaction (LPI) with a gold cone and their subsequent transport into a copper wire have been studied using a kJ-class intense laser pulse, OMEGA EP (850 J, 10 ps). We observed that the laser-pulse-energy-normalized copper K α signal from the Cu wire attached to the Au cone is significantly reduced (by a factor of 5) as compared to that from identical targets using the Titan laser (150 J, 0.7 ps) with 60 × less energy in the prepulse. We conclude that the decreased coupling is due to increased prepulse energy rather than 10 ps pulse duration, for which this effect has not been previously explored. The collisional particle-in-cell code PICLS demonstrates that the preformed plasma has a significant impact on generation of electrons and their transport. In particular, a longer scale length preplasma significantly reduces the energy coupling from the intense laser to the wire due to the larger offset distance between the relativistic critical density surface and the cone tip as well as a wider divergence of source electrons. We also observed that laser-driven plasma ionization increase in the LPI region can potentially alter the electron density profile during the laser interaction, forcing the electron source to be moved farther away from the cone tip which contributes to the reduction of energy coupling.

Published
2013
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7. DIII-D research towards establishing the scientific basis for future fusion reactors

Author

L. Abadie, T. W. Abrams, J. Ahn, T. Akiyama, P. Aleynikov, J. Allcock, E. O. Allen, S. Allen, J. P. Anderson, A. Ashourvan, M. E. Austin, J. Bak, K. K. Barada, N. Barbour, L. Bardoczi, J. Barr, J. L. Barton, E. M. Bass, D. Battaglia, L. R. Baylor, J. Beckers, E. A. Belli, J. W. Berkery, N. Bertelli, J. M. Bialek, J. A. Boedo, R. L. Boivin, P. T. Bonoli, A. Bortolon, M. D. Boyer, R. E. Brambila, B. Bray, D. P. Brennan, A. R. Briesemeister, S. A. Bringuier, M. W. Brookman, D. L. Brower, B. R. Brown, W. D. Brown, D. Buchenauer, M. G. Burke, K. H. Burrell, J. Butt, R. J. Buttery, I. Bykov, J. M. Candy, J. M. Canik, N. M. Cao, L. Carbajal Gomez, L. C. Carlson, T. N. Carlstrom, T. A. Carter, W. Cary, L. Casali, M. Cengher, V. S. Chan, B. Chen, J. Chen, M. Chen, R. Chen, Xi Chen, W. Choi, C. Chrobak, C. Chrystal, R. M. Churchill, M. Cianciosa, C. F. Clauser, M. Clement, J. Coburn, C. S. Collins, A. W. Cooper, B. M. Covele, J. W. Crippen, N. A. Crocker, B. J. Crowley, A. Dal Molin, E. M. Davis, J. S. deGrassie, C. A. del-Castillo-Negrete, L. F. Delgado-Aparicio, A. Diallo, S. J. Diem, R. Ding, S. Ding, W. Ding, J. L. Doane, D. C. Donovan, J. Drake, D. Du, H. Du, X. Du, V. Duarte, J. D. Duran, N. W. Eidietis, D. Elder, D. Eldon, W. Elwasif, T. E. Ely, K. M. Eng, K. Engelhorn, D. Ennis, K. Erickson, D. R. Ernst, T. E. Evans, M. E. Fenstermacher, N. M. Ferraro, J. R. Ferron, D. F. Finkenthal, P. A. Fisher, B. Fishler, S. M. Flanagan, J. A. Fooks, L. Frassinetti, H. G. Frerichs, Y. Fu, T. Fulop, Q. Gao, F. Garcia, A. M. Garofalo, A. Gattuso, L. Giacomelli, E. M. Giraldez, C. Giroud, F. Glass, P. Gohil, X. Gong, Y. A. Gorelov, R. S. Granetz, D. L. Green, C. M. Greenfield, B. A. Grierson, R. J. Groebner, W. H. Grosnickle, M. Groth, H. J. Grunloh, H. Y. Guo, W. Guo, J. Guterl, R. C. Hager, S. Hahn, F. D. Halpern, H. Han, M. J. Hansink, J. M. Hanson, J. Harris, S. R. Haskey, D. R. Hatch, W. W. Heidbrink, J. Herfindal, D. N. Hill, M. D. Hill, E. T. Hinson, C. T. Holcomb, C. G. Holland, L. D. Holland, E. M. Hollmann, A. M. Holm, R. Hong, M. Hoppe, S. Houshmandyar, J. Howard, N. T. Howard, Q. Hu, W. Hu, H. Huang, J. Huang, Y. Huang, G. A. Hughes, J. Hughes, D. A. Humphreys, A. W. Hyatt, K. Ida, V. Igochine, Y. In, S. Inoue, A. Isayama, R. C. Isler, V. A. Izzo, M. R. Jackson, A. E. Jarvinen, Y. Jeon, H. Ji, X. Jian, R. Jimenez, C. A. Johnson, I. Joseph, D. N. Kaczala, D. H. Kaplan, J. Kates-Harbeck, A. G. Kellman, D. H. Kellman, C. E. Kessel, K. Khumthong, C. C. Kim, H. Kim, J. Kim, K. Kim, S. H. Kim, W. Kimura, J. R. King, A. Kirk, K. Kleijwegt, M. Knolker, A. Kohn, E. Kolemen, M. Kostuk, G. J. Kramer, P. Kress, D. M. Kriete, R. J. La Haye, F. M. Laggner, H. Lan, M. J. Lanctot, R. Lantsov, L. L. Lao, C. J. Lasnier, C. Lau, K. Law, D. Lawrence, J. Le, R. L. Lee, M. Lehnen, R. Leon, A. W. Leonard, M. Lesher, J. A. Leuer, G. Li, K. Li, K. T. Liao, Z. Lin, C. Liu, F. Liu, Y. Liu, Z. Liu, S. Loch, N. C. Logan, J. M. Lohr, J. Lore, T. C. Luce, N. C. Luhmann, R. Lunsford, C. Luo, Z. Luo, L. Lupin-Jimenez, A. Lvovskiy, B. C. Lyons, X. Ma, R. Maingi, M. A. Makowski, P. Mantica, M. Manuel, M. W. Margo, A. Marinoni, E. Marmar, W. C. Martin, R. L. Masline, G. K. Matsunaga, D. M. Mauzey, P. S. Mauzey, J. T. Mcclenaghan, G. R. Mckee, A. G. Mclean, H. S. Mclean, E. Meier, S. J. Meitner, J. E. Menard, O. Meneghini, G. Merlo, W. H. Meyer, D. C. Miller, W. J. Miller, C. P. Moeller, K. J. Montes, M. A. Morales, S. Mordijck, A. Moser, R. A. Moyer, S. A. Muller, S. Munaretto, M. Murakami, C. J. Murphy, C. M. Muscatello, C. E. Myers, A. Nagy, G. A. Navratil, R. M. Nazikian, A. L. Neff, T. F. Neiser, A. Nelson, P. Nguyen, R. Nguyen, J. H. Nichols, M. Nocente, R. E. Nygren, R. C. O'Neill, T. Odstrcil, S. Ohdachi, M. Okabayashi, E. Olofsson, M. Ono, D. M. Orlov, T. H. Osborne, N. A. Pablant, D. C. Pace, R. R. Paguio, A. Pajares Martinez, C. Pan, A. Pankin, J. M. Park, J. Park, Y. Park, C. T. Parker, S. E. Parker, P. B. Parks, C. J. Pawley, C. A. Paz-Soldan, W. A. Peebles, B. G. Penaflor, T. W. Petrie, C. C. Petty, Y. Peysson, A. Y. Pigarov, D. A. Piglowski, R. I. Pinsker, P. Piovesan, N. Piper, R. A. Pitts, J. D. Pizzo, M. L. Podesta, F. M. Poli, D. Ponce, M. Porkolab, G. D. Porter, R. Prater, J. Qian, O. Ra, T. Rafiq, R. Raman, C. Rand, G. C. Randall, J. M. Rauch, C. Rea, M. L. Reinke, J. Ren, Q. Ren, Y. Ren, T. L. Rhodes, J. Rice, T. D. Rognlien, J. C. Rost, W. L. Rowan, D. L. Rudakov, A. Salmi, B. S. Sammuli, C. M. Samuell, A. M. Sandorfi, C. Sang, O. J. Sauter, D. P. Schissel, L. Schmitz, O. Schmitz, E. J. Schuster, J. T. Scoville, A. Seltzman, I. Sfiligoi, M. Shafer, H. Shen, T. Shi, D. Shiraki, H. Si, D. R. Smith, S. P. Smith, J. A. Snipes, P. B. Snyder, E. R. Solano, W. M. Solomon, A. C. Sontag, V. A. Soukhanovskii, D. A. Spong, W. M. Stacey, G. M. Staebler, L. Stagner, B. Stahl, P. C. Stangeby, T. J. Stoltzfus-Dueck, D. P. Stotler, E. J. Strait, D. Su, L. E. Sugiyama, A. A. Sulyman, Y. Sun, C. Sung, W. A. Suttrop, Y. Suzuki, A. Svyatkovskiy, R. M. Sweeney, S. Taimourzadeh, M. Takechi, T. Tala, H. Tan, S. Tang, X. Tang, D. Taussig, G. Taylor, N. Z. Taylor, T. S. Taylor, A. Teklu, D. M. Thomas, M. B. Thomas, K. E. Thome, A. R. Thorman, R. A. Tinguely, B. J. Tobias, J. F. Tooker, H. Torreblanca, A. Torrezan De Sousa, G. L. Trevisan, D. Truong, F. Turco, A. D. Turnbull, E. A. Unterberg, P. Vaezi, P. J. Vail, M. A. Van Zeeland, M. Velasco Enriquez, M. C. Venkatesh, B. S. Victor, F. Volpe, M. R. Wade, M. L. Walker, J. R. Wall, G. M. Wallace, R. E. Waltz, G. Wang, H. Wang, Y. Wang, Z. Wang, F. Wang, S. H. Ward, J. G. Watkins, M. Watkins, W. P. Wehner, M. Weiland, D. B. Weisberg, A. S. Welander, A. E. White, R. B. White, D. Whyte, T. A. Wijkamp, R. Wilcox, T. Wilks, H. R. Wilson, A. Wingen, E. Wolfe, M. Wu, W. Wu, S. J. Wukitch, T. Xia, N. Xiang, B. Xiao, R. Xie, G. Xu, H. Xu, X. Xu, Z. Yan, Q. Yang, X. Yang, M. Yoshida, G. Yu, J. H. Yu, M. Yu, S. A. Zamperini, L. Zeng, B. Zhao, D. Zhao, H. Zhao, Y. Zhao, Y. Zhu, B. Zywicki, Abadie, L, Abrams, T, Ahn, J, Akiyama, T, Aleynikov, P, Allcock, J, Allen, E, Allen, S, Anderson, J, Ashourvan, A, Austin, M, Bak, J, Barada, K, Barbour, N, Bardoczi, L, Barr, J, Barton, J, Bass, E, Battaglia, D, Baylor, L, Beckers, J, Belli, E, Berkery, J, Bertelli, N, Bialek, J, Boedo, J, Boivin, R, Bonoli, P, Bortolon, A, Boyer, M, Brambila, R, Bray, B, Brennan, D, Briesemeister, A, Bringuier, S, Brookman, M, Brower, D, Brown, B, Brown, W, Buchenauer, D, Burke, M, Burrell, K, Butt, J, Buttery, R, Bykov, I, Candy, J, Canik, J, Cao, N, Carbajal Gomez, L, Carlson, L, Carlstrom, T, Carter, T, Cary, W, Casali, L, Cengher, M, Chan, V, Chen, B, Chen, J, Chen, M, Chen, R, Chen, X, Choi, W, Chrobak, C, Chrystal, C, Churchill, R, Cianciosa, M, Clauser, C, Clement, M, Coburn, J, Collins, C, Cooper, A, Covele, B, Crippen, J, Crocker, N, Crowley, B, Dal Molin, A, Davis, E, Degrassie, J, del-Castillo-Negrete, C, Delgado-Aparicio, L, Diallo, A, Diem, S, Ding, R, Ding, S, Ding, W, Doane, J, Donovan, D, Drake, J, Du, D, Du, H, Du, X, Duarte, V, Duran, J, Eidietis, N, Elder, D, Eldon, D, Elwasif, W, Ely, T, Eng, K, Engelhorn, K, Ennis, D, Erickson, K, Ernst, D, Evans, T, Fenstermacher, M, Ferraro, N, Ferron, J, Finkenthal, D, Fisher, P, Fishler, B, Flanagan, S, Fooks, J, Frassinetti, L, Frerichs, H, Fu, Y, Fulop, T, Gao, Q, Garcia, F, Garofalo, A, Gattuso, A, Giacomelli, L, Giraldez, E, Giroud, C, Glass, F, Gohil, P, Gong, X, Gorelov, Y, Granetz, R, Green, D, Greenfield, C, Grierson, B, Groebner, R, Grosnickle, W, Groth, M, Grunloh, H, Guo, H, Guo, W, Guterl, J, Hager, R, Hahn, S, Halpern, F, Han, H, Hansink, M, Hanson, J, Harris, J, Haskey, S, Hatch, D, Heidbrink, W, Herfindal, J, Hill, D, Hill, M, Hinson, E, Holcomb, C, Holland, C, Holland, L, Hollmann, E, Holm, A, Hong, R, Hoppe, M, Houshmandyar, S, Howard, J, Howard, N, Hu, Q, Hu, W, Huang, H, Huang, J, Huang, Y, Hughes, G, Hughes, J, Humphreys, D, Hyatt, A, Ida, K, Igochine, V, In, Y, Inoue, S, Isayama, A, Isler, R, Izzo, V, Jackson, M, Jarvinen, A, Jeon, Y, Ji, H, Jian, X, Jimenez, R, Johnson, C, Joseph, I, Kaczala, D, Kaplan, D, Kates-Harbeck, J, Kellman, A, Kellman, D, Kessel, C, Khumthong, K, Kim, C, Kim, H, Kim, J, Kim, K, Kim, S, Kimura, W, King, J, Kirk, A, Kleijwegt, K, Knolker, M, Kohn, A, Kolemen, E, Kostuk, M, Kramer, G, Kress, P, Kriete, D, La Haye, R, Laggner, F, Lan, H, Lanctot, M, Lantsov, R, Lao, L, Lasnier, C, Lau, C, Law, K, Lawrence, D, Le, J, Lee, R, Lehnen, M, Leon, R, Leonard, A, Lesher, M, Leuer, J, Li, G, Li, K, Liao, K, Lin, Z, Liu, C, Liu, F, Liu, Y, Liu, Z, Loch, S, Logan, N, Lohr, J, Lore, J, Luce, T, Luhmann, N, Lunsford, R, Luo, C, Luo, Z, Lupin-Jimenez, L, Lvovskiy, A, Lyons, B, Ma, X, Maingi, R, Makowski, M, Mantica, P, Manuel, M, Margo, M, Marinoni, A, Marmar, E, Martin, W, Masline, R, Matsunaga, G, Mauzey, D, Mauzey, P, Mcclenaghan, J, Mckee, G, Mclean, A, Mclean, H, Meier, E, Meitner, S, Menard, J, Meneghini, O, Merlo, G, Meyer, W, Miller, D, Miller, W, Moeller, C, Montes, K, Morales, M, Mordijck, S, Moser, A, Moyer, R, Muller, S, Munaretto, S, Murakami, M, Murphy, C, Muscatello, C, Myers, C, Nagy, A, Navratil, G, Nazikian, R, Neff, A, Neiser, T, Nelson, A, Nguyen, P, Nguyen, R, Nichols, J, Nocente, M, Nygren, R, O'Neill, R, Odstrcil, T, Ohdachi, S, Okabayashi, M, Olofsson, E, Ono, M, Orlov, D, Osborne, T, Pablant, N, Pace, D, Paguio, R, Pajares Martinez, A, Pan, C, Pankin, A, Park, J, Park, Y, Parker, C, Parker, S, Parks, P, Pawley, C, Paz-Soldan, C, Peebles, W, Penaflor, B, Petrie, T, Petty, C, Peysson, Y, Pigarov, A, Piglowski, D, Pinsker, R, Piovesan, P, Piper, N, Pitts, R, Pizzo, J, Podesta, M, Poli, F, Ponce, D, Porkolab, M, Porter, G, Prater, R, Qian, J, Ra, O, Rafiq, T, Raman, R, Rand, C, Randall, G, Rauch, J, Rea, C, Reinke, M, Ren, J, Ren, Q, Ren, Y, Rhodes, T, Rice, J, Rognlien, T, Rost, J, Rowan, W, Rudakov, D, Salmi, A, Sammuli, B, Samuell, C, Sandorfi, A, Sang, C, Sauter, O, Schissel, D, Schmitz, L, Schmitz, O, Schuster, E, Scoville, J, Seltzman, A, Sfiligoi, I, Shafer, M, Shen, H, Shi, T, Shiraki, D, Si, H, Smith, D, Smith, S, Snipes, J, Snyder, P, Solano, E, Solomon, W, Sontag, A, Soukhanovskii, V, Spong, D, Stacey, W, Staebler, G, Stagner, L, Stahl, B, Stangeby, P, Stoltzfus-Dueck, T, Stotler, D, Strait, E, Su, D, Sugiyama, L, Sulyman, A, Sun, Y, Sung, C, Suttrop, W, Suzuki, Y, Svyatkovskiy, A, Sweeney, R, Taimourzadeh, S, Takechi, M, Tala, T, Tan, H, Tang, S, Tang, X, Taussig, D, Taylor, G, Taylor, N, Taylor, T, Teklu, A, Thomas, D, Thomas, M, Thome, K, Thorman, A, Tinguely, R, Tobias, B, Tooker, J, Torreblanca, H, Torrezan De Sousa, A, Trevisan, G, Truong, D, Turco, F, Turnbull, A, Unterberg, E, Vaezi, P, Vail, P, Van Zeeland, M, Velasco Enriquez, M, Venkatesh, M, Victor, B, Volpe, F, Wade, M, Walker, M, Wall, J, Wallace, G, Waltz, R, Wang, G, Wang, H, Wang, Y, Wang, Z, Wang, F, Ward, S, Watkins, J, Watkins, M, Wehner, W, Weiland, M, Weisberg, D, Welander, A, White, A, White, R, Whyte, D, Wijkamp, T, Wilcox, R, Wilks, T, Wilson, H, Wingen, A, Wolfe, E, Wu, M, Wu, W, Wukitch, S, Xia, T, Xiang, N, Xiao, B, Xie, R, Xu, G, Xu, H, Xu, X, Yan, Z, Yang, Q, Yang, X, Yoshida, M, Yu, G, Yu, J, Yu, M, Zamperini, S, Zeng, L, Zhao, B, Zhao, D, Zhao, H, Zhao, Y, Zhu, Y, and Zywicki, B

Subjects
Physics, Nuclear and High Energy Physics, fusion, model, Tokamak, DIII-D, Divertor, Mechanics, Plasma, Fusion power, Dissipation, Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas, law.invention, Pedestal, Heat flux, law, Physics::Plasma Physics, 0103 physical sciences, 010306 general physics, tokamak, plasma, energy
Abstract

DIII-D research is addressing critical challenges in preparation for ITER and the next generation of fusion devices through focusing on plasma physics fundamentals that underpin key fusion goals, understanding the interaction of disparate core and boundary plasma physics, and developing integrated scenarios for achieving high performance fusion regimes. Fundamental investigations into fusion energy science find that anomalous dissipation of runaway electrons (RE) that arise following a disruption is likely due to interactions with RE-driven kinetic instabilities, some of which have been directly observed, opening a new avenue for RE energy dissipation using naturally excited waves. Dimensionless parameter scaling of intrinsic rotation and gyrokinetic simulations give a predicted ITER rotation profile with significant turbulence stabilization. Coherence imaging spectroscopy confirms near sonic flow throughout the divertor towards the target, which may account for the convection-dominated parallel heat flux. Core-boundary integration studies show that the small angle slot divertor achieves detachment at lower density and extends plasma cooling across the divertor target plate, which is essential for controlling heat flux and erosion. The Super H-mode regime has been extended to high plasma current (2.0 MA) and density to achieve very high pedestal pressures (~30 kPa) and stored energy (3.2 MJ) with H 98y2 ≈ 1.6–2.4. In scenario work, the ITER baseline Q = 10 scenario with zero injected torque is found to have a fusion gain metric independent of current between q 95 = 2.8–3.7, and a lower limit of pedestal rotation for RMP ELM suppression has been found. In the wide pedestal QH-mode regime that exhibits improved performance and no ELMs, the start-up counter torque has been eliminated so that the entire discharge uses ≈0 injected torque and the operating space is more ITER-relevant. Finally, the high- (⩽3.8) hybrid scenario has been extended to the high-density levels necessary for radiating divertor operation, achieving ~40% divertor heat flux reduction using either argon or neon with P tot up to 15 MW.

Published
2019
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8. DIII-D research towards establishing the scientific basis for future fusion reactors

Author

Abadie, L, Abrams, T, Ahn, J, Akiyama, T, Aleynikov, P, Allcock, J, Allen, E, Allen, S, Anderson, J, Ashourvan, A, Austin, M, Bak, J, Barada, K, Barbour, N, Bardoczi, L, Barr, J, Barton, J, Bass, E, Battaglia, D, Baylor, L, Beckers, J, Belli, E, Berkery, J, Bertelli, N, Bialek, J, Boedo, J, Boivin, R, Bonoli, P, Bortolon, A, Boyer, M, Brambila, R, Bray, B, Brennan, D, Briesemeister, A, Bringuier, S, Brookman, M, Brower, D, Brown, B, Brown, W, Buchenauer, D, Burke, M, Burrell, K, Butt, J, Buttery, R, Bykov, I, Candy, J, Canik, J, Cao, N, Carbajal Gomez, L, Carlson, L, Carlstrom, T, Carter, T, Cary, W, Casali, L, Cengher, M, Chan, V, Chen, B, Chen, J, Chen, M, Chen, R, Chen, X, Choi, W, Chrobak, C, Chrystal, C, Churchill, R, Cianciosa, M, Clauser, C, Clement, M, Coburn, J, Collins, C, Cooper, A, Covele, B, Crippen, J, Crocker, N, Crowley, B, Dal Molin, A, Davis, E, Degrassie, J, del-Castillo-Negrete, C, Delgado-Aparicio, L, Diallo, A, Diem, S, Ding, R, Ding, S, Ding, W, Doane, J, Donovan, D, Drake, J, Du, D, Du, H, Du, X, Duarte, V, Duran, J, Eidietis, N, Elder, D, Eldon, D, Elwasif, W, Ely, T, Eng, K, Engelhorn, K, Ennis, D, Erickson, K, Ernst, D, Evans, T, Fenstermacher, M, Ferraro, N, Ferron, J, Finkenthal, D, Fisher, P, Fishler, B, Flanagan, S, Fooks, J, Frassinetti, L, Frerichs, H, Fu, Y, Fulop, T, Gao, Q, Garcia, F, Garofalo, A, Gattuso, A, Giacomelli, L, Giraldez, E, Giroud, C, Glass, F, Gohil, P, Gong, X, Gorelov, Y, Granetz, R, Green, D, Greenfield, C, Grierson, B, Groebner, R, Grosnickle, W, Groth, M, Grunloh, H, Guo, H, Guo, W, Guterl, J, Hager, R, Hahn, S, Halpern, F, Han, H, Hansink, M, Hanson, J, Harris, J, Haskey, S, Hatch, D, Heidbrink, W, Herfindal, J, Hill, D, Hill, M, Hinson, E, Holcomb, C, Holland, C, Holland, L, Hollmann, E, Holm, A, Hong, R, Hoppe, M, Houshmandyar, S, Howard, J, Howard, N, Hu, Q, Hu, W, Huang, H, Huang, J, Huang, Y, Hughes, G, Hughes, J, Humphreys, D, Hyatt, A, Ida, K, Igochine, V, In, Y, Inoue, S, Isayama, A, Isler, R, Izzo, V, Jackson, M, Jarvinen, A, Jeon, Y, Ji, H, Jian, X, Jimenez, R, Johnson, C, Joseph, I, Kaczala, D, Kaplan, D, Kates-Harbeck, J, Kellman, A, Kellman, D, Kessel, C, Khumthong, K, Kim, C, Kim, H, Kim, J, Kim, K, Kim, S, Kimura, W, King, J, Kirk, A, Kleijwegt, K, Knolker, M, Kohn, A, Kolemen, E, Kostuk, M, Kramer, G, Kress, P, Kriete, D, La Haye, R, Laggner, F, Lan, H, Lanctot, M, Lantsov, R, Lao, L, Lasnier, C, Lau, C, Law, K, Lawrence, D, Le, J, Lee, R, Lehnen, M, Leon, R, Leonard, A, Lesher, M, Leuer, J, Li, G, Li, K, Liao, K, Lin, Z, Liu, C, Liu, F, Liu, Y, Liu, Z, Loch, S, Logan, N, Lohr, J, Lore, J, Luce, T, Luhmann, N, Lunsford, R, Luo, C, Luo, Z, Lupin-Jimenez, L, Lvovskiy, A, Lyons, B, Ma, X, Maingi, R, Makowski, M, Mantica, P, Manuel, M, Margo, M, Marinoni, A, Marmar, E, Martin, W, Masline, R, Matsunaga, G, Mauzey, D, Mauzey, P, Mcclenaghan, J, Mckee, G, Mclean, A, Mclean, H, Meier, E, Meitner, S, Menard, J, Meneghini, O, Merlo, G, Meyer, W, Miller, D, Miller, W, Moeller, C, Montes, K, Morales, M, Mordijck, S, Moser, A, Moyer, R, Muller, S, Munaretto, S, Murakami, M, Murphy, C, Muscatello, C, Myers, C, Nagy, A, Navratil, G, Nazikian, R, Neff, A, Neiser, T, Nelson, A, Nguyen, P, Nguyen, R, Nichols, J, Nocente, M, Nygren, R, O'Neill, R, Odstrcil, T, Ohdachi, S, Okabayashi, M, Olofsson, E, Ono, M, Orlov, D, Osborne, T, Pablant, N, Pace, D, Paguio, R, Pajares Martinez, A, Pan, C, Pankin, A, Park, J, Park, Y, Parker, C, Parker, S, Parks, P, Pawley, C, Paz-Soldan, C, Peebles, W, Penaflor, B, Petrie, T, Petty, C, Peysson, Y, Pigarov, A, Piglowski, D, Pinsker, R, Piovesan, P, Piper, N, Pitts, R, Pizzo, J, Podesta, M, Poli, F, Ponce, D, Porkolab, M, Porter, G, Prater, R, Qian, J, Ra, O, Rafiq, T, Raman, R, Rand, C, Randall, G, Rauch, J, Rea, C, Reinke, M, Ren, J, Ren, Q, Ren, Y, Rhodes, T, Rice, J, Rognlien, T, Rost, J, Rowan, W, Rudakov, D, Salmi, A, Sammuli, B, Samuell, C, Sandorfi, A, Sang, C, Sauter, O, Schissel, D, Schmitz, L, Schmitz, O, Schuster, E, Scoville, J, Seltzman, A, Sfiligoi, I, Shafer, M, Shen, H, Shi, T, Shiraki, D, Si, H, Smith, D, Smith, S, Snipes, J, Snyder, P, Solano, E, Solomon, W, Sontag, A, Soukhanovskii, V, Spong, D, Stacey, W, Staebler, G, Stagner, L, Stahl, B, Stangeby, P, Stoltzfus-Dueck, T, Stotler, D, Strait, E, Su, D, Sugiyama, L, Sulyman, A, Sun, Y, Sung, C, Suttrop, W, Suzuki, Y, Svyatkovskiy, A, Sweeney, R, Taimourzadeh, S, Takechi, M, Tala, T, Tan, H, Tang, S, Tang, X, Taussig, D, Taylor, G, Taylor, N, Taylor, T, Teklu, A, Thomas, D, Thomas, M, Thome, K, Thorman, A, Tinguely, R, Tobias, B, Tooker, J, Torreblanca, H, Torrezan De Sousa, A, Trevisan, G, Truong, D, Turco, F, Turnbull, A, Unterberg, E, Vaezi, P, Vail, P, Van Zeeland, M, Velasco Enriquez, M, Venkatesh, M, Victor, B, Volpe, F, Wade, M, Walker, M, Wall, J, Wallace, G, Waltz, R, Wang, G, Wang, H, Wang, Y, Wang, Z, Wang, F, Ward, S, Watkins, J, Watkins, M, Wehner, W, Weiland, M, Weisberg, D, Welander, A, White, A, White, R, Whyte, D, Wijkamp, T, Wilcox, R, Wilks, T, Wilson, H, Wingen, A, Wolfe, E, Wu, M, Wu, W, Wukitch, S, Xia, T, Xiang, N, Xiao, B, Xie, R, Xu, G, Xu, H, Xu, X, Yan, Z, Yang, Q, Yang, X, Yoshida, M, Yu, G, Yu, J, Yu, M, Zamperini, S, Zeng, L, Zhao, B, Zhao, D, Zhao, H, Zhao, Y, Zhu, Y, Zywicki, B, L. Abadie, T. W. Abrams, J. Ahn, T. Akiyama, P. Aleynikov, J. Allcock, E. O. Allen, S. Allen, J. P. Anderson, A. Ashourvan, M. E. Austin, J. Bak, K. K. Barada, N. Barbour, L. Bardoczi, J. Barr, J. L. Barton, E. M. Bass, D. Battaglia, L. R. Baylor, J. Beckers, E. A. Belli, J. W. Berkery, N. Bertelli, J. M. Bialek, J. A. Boedo, R. L. Boivin, P. T. Bonoli, A. Bortolon, M. D. Boyer, R. E. Brambila, B. Bray, D. P. Brennan, A. R. Briesemeister, S. A. Bringuier, M. W. Brookman, D. L. Brower, B. R. Brown, W. D. Brown, D. Buchenauer, M. G. Burke, K. H. Burrell, J. Butt, R. J. Buttery, I. Bykov, J. M. Candy, J. M. Canik, N. M. Cao, L. Carbajal Gomez, L. C. Carlson, T. N. Carlstrom, T. A. Carter, W. Cary, L. Casali, M. Cengher, V. S. Chan, B. Chen, J. Chen, M. Chen, R. Chen, Xi Chen, W. Choi, C. Chrobak, C. Chrystal, R. M. Churchill, M. Cianciosa, C. F. Clauser, M. Clement, J. Coburn, C. S. Collins, A. W. Cooper, B. M. Covele, J. W. Crippen, N. A. Crocker, B. J. Crowley, A. Dal Molin, E. M. Davis, J. S. deGrassie, C. A. del-Castillo-Negrete, L. F. Delgado-Aparicio, A. Diallo, S. J. Diem, R. Ding, S. Ding, W. Ding, J. L. Doane, D. C. Donovan, J. Drake, D. Du, H. Du, X. Du, V. Duarte, J. D. Duran, N. W. Eidietis, D. Elder, D. Eldon, W. Elwasif, T. E. Ely, K. M. Eng, K. Engelhorn, D. Ennis, K. Erickson, D. R. Ernst, T. E. Evans, M. E. Fenstermacher, N. M. Ferraro, J. R. Ferron, D. F. Finkenthal, P. A. Fisher, B. Fishler, S. M. Flanagan, J. A. Fooks, L. Frassinetti, H. G. Frerichs, Y. Fu, T. Fulop, Q. Gao, F. Garcia, A. M. Garofalo, A. Gattuso, L. Giacomelli, E. M. Giraldez, C. Giroud, F. Glass, P. Gohil, X. Gong, Y. A. Gorelov, R. S. Granetz, D. L. Green, C. M. Greenfield, B. A. Grierson, R. J. Groebner, W. H. Grosnickle, M. Groth, H. J. Grunloh, H. Y. Guo, W. Guo, J. Guterl, R. C. Hager, S. Hahn, F. D. Halpern, H. Han, M. J. Hansink, J. M. Hanson, J. Harris, S. R. Haskey, D. R. Hatch, W. W. Heidbrink, J. Herfindal, D. N. Hill, M. D. Hill, E. T. Hinson, C. T. Holcomb, C. G. Holland, L. D. Holland, E. M. Hollmann, A. M. Holm, R. Hong, M. Hoppe, S. Houshmandyar, J. Howard, N. T. Howard, Q. Hu, W. Hu, H. Huang, J. Huang, Y. Huang, G. A. Hughes, J. Hughes, D. A. Humphreys, A. W. Hyatt, K. Ida, V. Igochine, Y. In, S. Inoue, A. Isayama, R. C. Isler, V. A. Izzo, M. R. Jackson, A. E. Jarvinen, Y. Jeon, H. Ji, X. Jian, R. Jimenez, C. A. Johnson, I. Joseph, D. N. Kaczala, D. H. Kaplan, J. Kates-Harbeck, A. G. Kellman, D. H. Kellman, C. E. Kessel, K. Khumthong, C. C. Kim, H. Kim, J. Kim, K. Kim, S. H. Kim, W. Kimura, J. R. King, A. Kirk, K. Kleijwegt, M. Knolker, A. Kohn, E. Kolemen, M. Kostuk, G. J. Kramer, P. Kress, D. M. Kriete, R. J. La Haye, F. M. Laggner, H. Lan, M. J. Lanctot, R. Lantsov, L. L. Lao, C. J. Lasnier, C. Lau, K. Law, D. Lawrence, J. Le, R. L. Lee, M. Lehnen, R. Leon, A. W. Leonard, M. Lesher, J. A. Leuer, G. Li, K. Li, K. T. Liao, Z. Lin, C. Liu, F. Liu, Y. Liu, Z. Liu, S. Loch, N. C. Logan, J. M. Lohr, J. Lore, T. C. Luce, N. C. Luhmann, R. Lunsford, C. Luo, Z. Luo, L. Lupin-Jimenez, A. Lvovskiy, B. C. Lyons, X. Ma, R. Maingi, M. A. Makowski, P. Mantica, M. Manuel, M. W. Margo, A. Marinoni, E. Marmar, W. C. Martin, R. L. Masline, G. K. Matsunaga, D. M. Mauzey, P. S. Mauzey, J. T. Mcclenaghan, G. R. Mckee, A. G. Mclean, H. S. Mclean, E. Meier, S. J. Meitner, J. E. Menard, O. Meneghini, G. Merlo, W. H. Meyer, D. C. Miller, W. J. Miller, C. P. Moeller, K. J. Montes, M. A. Morales, S. Mordijck, A. Moser, R. A. Moyer, S. A. Muller, S. Munaretto, M. Murakami, C. J. Murphy, C. M. Muscatello, C. E. Myers, A. Nagy, G. A. Navratil, R. M. Nazikian, A. L. Neff, T. F. Neiser, A. Nelson, P. Nguyen, R. Nguyen, J. H. Nichols, M. Nocente, R. E. Nygren, R. C. O'Neill, T. Odstrcil, S. Ohdachi, M. Okabayashi, E. Olofsson, M. Ono, D. M. Orlov, T. H. Osborne, N. A. Pablant, D. C. Pace, R. R. Paguio, A. Pajares Martinez, C. Pan, A. Pankin, J. M. Park, J. Park, Y. Park, C. T. Parker, S. E. Parker, P. B. Parks, C. J. Pawley, C. A. Paz-Soldan, W. A. Peebles, B. G. Penaflor, T. W. Petrie, C. C. Petty, Y. Peysson, A. Y. Pigarov, D. A. Piglowski, R. I. Pinsker, P. Piovesan, N. Piper, R. A. Pitts, J. D. Pizzo, M. L. Podesta, F. M. Poli, D. Ponce, M. Porkolab, G. D. Porter, R. Prater, J. Qian, O. Ra, T. Rafiq, R. Raman, C. Rand, G. C. Randall, J. M. Rauch, C. Rea, M. L. Reinke, J. Ren, Q. Ren, Y. Ren, T. L. Rhodes, J. Rice, T. D. Rognlien, J. C. Rost, W. L. Rowan, D. L. Rudakov, A. Salmi, B. S. Sammuli, C. M. Samuell, A. M. Sandorfi, C. Sang, O. J. Sauter, D. P. Schissel, L. Schmitz, O. Schmitz, E. J. Schuster, J. T. Scoville, A. Seltzman, I. Sfiligoi, M. Shafer, H. Shen, T. Shi, D. Shiraki, H. Si, D. R. Smith, S. P. Smith, J. A. Snipes, P. B. Snyder, E. R. Solano, W. M. Solomon, A. C. Sontag, V. A. Soukhanovskii, D. A. Spong, W. M. Stacey, G. M. Staebler, L. Stagner, B. Stahl, P. C. Stangeby, T. J. Stoltzfus-Dueck, D. P. Stotler, E. J. Strait, D. Su, L. E. Sugiyama, A. A. Sulyman, Y. Sun, C. Sung, W. A. Suttrop, Y. Suzuki, A. Svyatkovskiy, R. M. Sweeney, S. Taimourzadeh, M. Takechi, T. Tala, H. Tan, S. Tang, X. Tang, D. Taussig, G. Taylor, N. Z. Taylor, T. S. Taylor, A. Teklu, D. M. Thomas, M. B. Thomas, K. E. Thome, A. R. Thorman, R. A. Tinguely, B. J. Tobias, J. F. Tooker, H. Torreblanca, A. Torrezan De Sousa, G. L. Trevisan, D. Truong, F. Turco, A. D. Turnbull, E. A. Unterberg, P. Vaezi, P. J. Vail, M. A. Van Zeeland, M. Velasco Enriquez, M. C. Venkatesh, B. S. Victor, F. Volpe, M. R. Wade, M. L. Walker, J. R. Wall, G. M. Wallace, R. E. Waltz, G. Wang, H. Wang, Y. Wang, Z. Wang, F. Wang, S. H. Ward, J. G. Watkins, M. Watkins, W. P. Wehner, M. Weiland, D. B. Weisberg, A. S. Welander, A. E. White, R. B. White, D. Whyte, T. A. Wijkamp, R. Wilcox, T. Wilks, H. R. Wilson, A. Wingen, E. Wolfe, M. Wu, W. Wu, S. J. Wukitch, T. Xia, N. Xiang, B. Xiao, R. Xie, G. Xu, H. Xu, X. Xu, Z. Yan, Q. Yang, X. Yang, M. Yoshida, G. Yu, J. H. Yu, M. Yu, S. A. Zamperini, L. Zeng, B. Zhao, D. Zhao, H. Zhao, Y. Zhao, Y. Zhu, B. Zywicki, Abadie, L, Abrams, T, Ahn, J, Akiyama, T, Aleynikov, P, Allcock, J, Allen, E, Allen, S, Anderson, J, Ashourvan, A, Austin, M, Bak, J, Barada, K, Barbour, N, Bardoczi, L, Barr, J, Barton, J, Bass, E, Battaglia, D, Baylor, L, Beckers, J, Belli, E, Berkery, J, Bertelli, N, Bialek, J, Boedo, J, Boivin, R, Bonoli, P, Bortolon, A, Boyer, M, Brambila, R, Bray, B, Brennan, D, Briesemeister, A, Bringuier, S, Brookman, M, Brower, D, Brown, B, Brown, W, Buchenauer, D, Burke, M, Burrell, K, Butt, J, Buttery, R, Bykov, I, Candy, J, Canik, J, Cao, N, Carbajal Gomez, L, Carlson, L, Carlstrom, T, Carter, T, Cary, W, Casali, L, Cengher, M, Chan, V, Chen, B, Chen, J, Chen, M, Chen, R, Chen, X, Choi, W, Chrobak, C, Chrystal, C, Churchill, R, Cianciosa, M, Clauser, C, Clement, M, Coburn, J, Collins, C, Cooper, A, Covele, B, Crippen, J, Crocker, N, Crowley, B, Dal Molin, A, Davis, E, Degrassie, J, del-Castillo-Negrete, C, Delgado-Aparicio, L, Diallo, A, Diem, S, Ding, R, Ding, S, Ding, W, Doane, J, Donovan, D, Drake, J, Du, D, Du, H, Du, X, Duarte, V, Duran, J, Eidietis, N, Elder, D, Eldon, D, Elwasif, W, Ely, T, Eng, K, Engelhorn, K, Ennis, D, Erickson, K, Ernst, D, Evans, T, Fenstermacher, M, Ferraro, N, Ferron, J, Finkenthal, D, Fisher, P, Fishler, B, Flanagan, S, Fooks, J, Frassinetti, L, Frerichs, H, Fu, Y, Fulop, T, Gao, Q, Garcia, F, Garofalo, A, Gattuso, A, Giacomelli, L, Giraldez, E, Giroud, C, Glass, F, Gohil, P, Gong, X, Gorelov, Y, Granetz, R, Green, D, Greenfield, C, Grierson, B, Groebner, R, Grosnickle, W, Groth, M, Grunloh, H, Guo, H, Guo, W, Guterl, J, Hager, R, Hahn, S, Halpern, F, Han, H, Hansink, M, Hanson, J, Harris, J, Haskey, S, Hatch, D, Heidbrink, W, Herfindal, J, Hill, D, Hill, M, Hinson, E, Holcomb, C, Holland, C, Holland, L, Hollmann, E, Holm, A, Hong, R, Hoppe, M, Houshmandyar, S, Howard, J, Howard, N, Hu, Q, Hu, W, Huang, H, Huang, J, Huang, Y, Hughes, G, Hughes, J, Humphreys, D, Hyatt, A, Ida, K, Igochine, V, In, Y, Inoue, S, Isayama, A, Isler, R, Izzo, V, Jackson, M, Jarvinen, A, Jeon, Y, Ji, H, Jian, X, Jimenez, R, Johnson, C, Joseph, I, Kaczala, D, Kaplan, D, Kates-Harbeck, J, Kellman, A, Kellman, D, Kessel, C, Khumthong, K, Kim, C, Kim, H, Kim, J, Kim, K, Kim, S, Kimura, W, King, J, Kirk, A, Kleijwegt, K, Knolker, M, Kohn, A, Kolemen, E, Kostuk, M, Kramer, G, Kress, P, Kriete, D, La Haye, R, Laggner, F, Lan, H, Lanctot, M, Lantsov, R, Lao, L, Lasnier, C, Lau, C, Law, K, Lawrence, D, Le, J, Lee, R, Lehnen, M, Leon, R, Leonard, A, Lesher, M, Leuer, J, Li, G, Li, K, Liao, K, Lin, Z, Liu, C, Liu, F, Liu, Y, Liu, Z, Loch, S, Logan, N, Lohr, J, Lore, J, Luce, T, Luhmann, N, Lunsford, R, Luo, C, Luo, Z, Lupin-Jimenez, L, Lvovskiy, A, Lyons, B, Ma, X, Maingi, R, Makowski, M, Mantica, P, Manuel, M, Margo, M, Marinoni, A, Marmar, E, Martin, W, Masline, R, Matsunaga, G, Mauzey, D, Mauzey, P, Mcclenaghan, J, Mckee, G, Mclean, A, Mclean, H, Meier, E, Meitner, S, Menard, J, Meneghini, O, Merlo, G, Meyer, W, Miller, D, Miller, W, Moeller, C, Montes, K, Morales, M, Mordijck, S, Moser, A, Moyer, R, Muller, S, Munaretto, S, Murakami, M, Murphy, C, Muscatello, C, Myers, C, Nagy, A, Navratil, G, Nazikian, R, Neff, A, Neiser, T, Nelson, A, Nguyen, P, Nguyen, R, Nichols, J, Nocente, M, Nygren, R, O'Neill, R, Odstrcil, T, Ohdachi, S, Okabayashi, M, Olofsson, E, Ono, M, Orlov, D, Osborne, T, Pablant, N, Pace, D, Paguio, R, Pajares Martinez, A, Pan, C, Pankin, A, Park, J, Park, Y, Parker, C, Parker, S, Parks, P, Pawley, C, Paz-Soldan, C, Peebles, W, Penaflor, B, Petrie, T, Petty, C, Peysson, Y, Pigarov, A, Piglowski, D, Pinsker, R, Piovesan, P, Piper, N, Pitts, R, Pizzo, J, Podesta, M, Poli, F, Ponce, D, Porkolab, M, Porter, G, Prater, R, Qian, J, Ra, O, Rafiq, T, Raman, R, Rand, C, Randall, G, Rauch, J, Rea, C, Reinke, M, Ren, J, Ren, Q, Ren, Y, Rhodes, T, Rice, J, Rognlien, T, Rost, J, Rowan, W, Rudakov, D, Salmi, A, Sammuli, B, Samuell, C, Sandorfi, A, Sang, C, Sauter, O, Schissel, D, Schmitz, L, Schmitz, O, Schuster, E, Scoville, J, Seltzman, A, Sfiligoi, I, Shafer, M, Shen, H, Shi, T, Shiraki, D, Si, H, Smith, D, Smith, S, Snipes, J, Snyder, P, Solano, E, Solomon, W, Sontag, A, Soukhanovskii, V, Spong, D, Stacey, W, Staebler, G, Stagner, L, Stahl, B, Stangeby, P, Stoltzfus-Dueck, T, Stotler, D, Strait, E, Su, D, Sugiyama, L, Sulyman, A, Sun, Y, Sung, C, Suttrop, W, Suzuki, Y, Svyatkovskiy, A, Sweeney, R, Taimourzadeh, S, Takechi, M, Tala, T, Tan, H, Tang, S, Tang, X, Taussig, D, Taylor, G, Taylor, N, Taylor, T, Teklu, A, Thomas, D, Thomas, M, Thome, K, Thorman, A, Tinguely, R, Tobias, B, Tooker, J, Torreblanca, H, Torrezan De Sousa, A, Trevisan, G, Truong, D, Turco, F, Turnbull, A, Unterberg, E, Vaezi, P, Vail, P, Van Zeeland, M, Velasco Enriquez, M, Venkatesh, M, Victor, B, Volpe, F, Wade, M, Walker, M, Wall, J, Wallace, G, Waltz, R, Wang, G, Wang, H, Wang, Y, Wang, Z, Wang, F, Ward, S, Watkins, J, Watkins, M, Wehner, W, Weiland, M, Weisberg, D, Welander, A, White, A, White, R, Whyte, D, Wijkamp, T, Wilcox, R, Wilks, T, Wilson, H, Wingen, A, Wolfe, E, Wu, M, Wu, W, Wukitch, S, Xia, T, Xiang, N, Xiao, B, Xie, R, Xu, G, Xu, H, Xu, X, Yan, Z, Yang, Q, Yang, X, Yoshida, M, Yu, G, Yu, J, Yu, M, Zamperini, S, Zeng, L, Zhao, B, Zhao, D, Zhao, H, Zhao, Y, Zhu, Y, Zywicki, B, L. Abadie, T. W. Abrams, J. Ahn, T. Akiyama, P. Aleynikov, J. Allcock, E. O. Allen, S. Allen, J. P. Anderson, A. Ashourvan, M. E. Austin, J. Bak, K. K. Barada, N. Barbour, L. Bardoczi, J. Barr, J. L. Barton, E. M. Bass, D. Battaglia, L. R. Baylor, J. Beckers, E. A. Belli, J. W. Berkery, N. Bertelli, J. M. Bialek, J. A. Boedo, R. L. Boivin, P. T. Bonoli, A. Bortolon, M. D. Boyer, R. E. Brambila, B. Bray, D. P. Brennan, A. R. Briesemeister, S. A. Bringuier, M. W. Brookman, D. L. Brower, B. R. Brown, W. D. Brown, D. Buchenauer, M. G. Burke, K. H. Burrell, J. Butt, R. J. Buttery, I. Bykov, J. M. Candy, J. M. Canik, N. M. Cao, L. Carbajal Gomez, L. C. Carlson, T. N. Carlstrom, T. A. Carter, W. Cary, L. Casali, M. Cengher, V. S. Chan, B. Chen, J. Chen, M. Chen, R. Chen, Xi Chen, W. Choi, C. Chrobak, C. Chrystal, R. M. Churchill, M. Cianciosa, C. F. Clauser, M. Clement, J. Coburn, C. S. Collins, A. W. Cooper, B. M. Covele, J. W. Crippen, N. A. Crocker, B. J. Crowley, A. Dal Molin, E. M. Davis, J. S. deGrassie, C. A. del-Castillo-Negrete, L. F. Delgado-Aparicio, A. Diallo, S. J. Diem, R. Ding, S. Ding, W. Ding, J. L. Doane, D. C. Donovan, J. Drake, D. Du, H. Du, X. Du, V. Duarte, J. D. Duran, N. W. Eidietis, D. Elder, D. Eldon, W. Elwasif, T. E. Ely, K. M. Eng, K. Engelhorn, D. Ennis, K. Erickson, D. R. Ernst, T. E. Evans, M. E. Fenstermacher, N. M. Ferraro, J. R. Ferron, D. F. Finkenthal, P. A. Fisher, B. Fishler, S. M. Flanagan, J. A. Fooks, L. Frassinetti, H. G. Frerichs, Y. Fu, T. Fulop, Q. Gao, F. Garcia, A. M. Garofalo, A. Gattuso, L. Giacomelli, E. M. Giraldez, C. Giroud, F. Glass, P. Gohil, X. Gong, Y. A. Gorelov, R. S. Granetz, D. L. Green, C. M. Greenfield, B. A. Grierson, R. J. Groebner, W. H. Grosnickle, M. Groth, H. J. Grunloh, H. Y. Guo, W. Guo, J. Guterl, R. C. Hager, S. Hahn, F. D. Halpern, H. Han, M. J. Hansink, J. M. Hanson, J. Harris, S. R. Haskey, D. R. Hatch, W. W. Heidbrink, J. Herfindal, D. N. Hill, M. D. Hill, E. T. Hinson, C. T. Holcomb, C. G. Holland, L. D. Holland, E. M. Hollmann, A. M. Holm, R. Hong, M. Hoppe, S. Houshmandyar, J. Howard, N. T. Howard, Q. Hu, W. Hu, H. Huang, J. Huang, Y. Huang, G. A. Hughes, J. Hughes, D. A. Humphreys, A. W. Hyatt, K. Ida, V. Igochine, Y. In, S. Inoue, A. Isayama, R. C. Isler, V. A. Izzo, M. R. Jackson, A. E. Jarvinen, Y. Jeon, H. Ji, X. Jian, R. Jimenez, C. A. Johnson, I. Joseph, D. N. Kaczala, D. H. Kaplan, J. Kates-Harbeck, A. G. Kellman, D. H. Kellman, C. E. Kessel, K. Khumthong, C. C. Kim, H. Kim, J. Kim, K. Kim, S. H. Kim, W. Kimura, J. R. King, A. Kirk, K. Kleijwegt, M. Knolker, A. Kohn, E. Kolemen, M. Kostuk, G. J. Kramer, P. Kress, D. M. Kriete, R. J. La Haye, F. M. Laggner, H. Lan, M. J. Lanctot, R. Lantsov, L. L. Lao, C. J. Lasnier, C. Lau, K. Law, D. Lawrence, J. Le, R. L. Lee, M. Lehnen, R. Leon, A. W. Leonard, M. Lesher, J. A. Leuer, G. Li, K. Li, K. T. Liao, Z. Lin, C. Liu, F. Liu, Y. Liu, Z. Liu, S. Loch, N. C. Logan, J. M. Lohr, J. Lore, T. C. Luce, N. C. Luhmann, R. Lunsford, C. Luo, Z. Luo, L. Lupin-Jimenez, A. Lvovskiy, B. C. Lyons, X. Ma, R. Maingi, M. A. Makowski, P. Mantica, M. Manuel, M. W. Margo, A. Marinoni, E. Marmar, W. C. Martin, R. L. Masline, G. K. Matsunaga, D. M. Mauzey, P. S. Mauzey, J. T. Mcclenaghan, G. R. Mckee, A. G. Mclean, H. S. Mclean, E. Meier, S. J. Meitner, J. E. Menard, O. Meneghini, G. Merlo, W. H. Meyer, D. C. Miller, W. J. Miller, C. P. Moeller, K. J. Montes, M. A. Morales, S. Mordijck, A. Moser, R. A. Moyer, S. A. Muller, S. Munaretto, M. Murakami, C. J. Murphy, C. M. Muscatello, C. E. Myers, A. Nagy, G. A. Navratil, R. M. Nazikian, A. L. Neff, T. F. Neiser, A. Nelson, P. Nguyen, R. Nguyen, J. H. Nichols, M. Nocente, R. E. Nygren, R. C. O'Neill, T. Odstrcil, S. Ohdachi, M. Okabayashi, E. Olofsson, M. Ono, D. M. Orlov, T. H. Osborne, N. A. Pablant, D. C. Pace, R. R. Paguio, A. Pajares Martinez, C. Pan, A. Pankin, J. M. Park, J. Park, Y. Park, C. T. Parker, S. E. Parker, P. B. Parks, C. J. Pawley, C. A. Paz-Soldan, W. A. Peebles, B. G. Penaflor, T. W. Petrie, C. C. Petty, Y. Peysson, A. Y. Pigarov, D. A. Piglowski, R. I. Pinsker, P. Piovesan, N. Piper, R. A. Pitts, J. D. Pizzo, M. L. Podesta, F. M. Poli, D. Ponce, M. Porkolab, G. D. Porter, R. Prater, J. Qian, O. Ra, T. Rafiq, R. Raman, C. Rand, G. C. Randall, J. M. Rauch, C. Rea, M. L. Reinke, J. Ren, Q. Ren, Y. Ren, T. L. Rhodes, J. Rice, T. D. Rognlien, J. C. Rost, W. L. Rowan, D. L. Rudakov, A. Salmi, B. S. Sammuli, C. M. Samuell, A. M. Sandorfi, C. Sang, O. J. Sauter, D. P. Schissel, L. Schmitz, O. Schmitz, E. J. Schuster, J. T. Scoville, A. Seltzman, I. Sfiligoi, M. Shafer, H. Shen, T. Shi, D. Shiraki, H. Si, D. R. Smith, S. P. Smith, J. A. Snipes, P. B. Snyder, E. R. Solano, W. M. Solomon, A. C. Sontag, V. A. Soukhanovskii, D. A. Spong, W. M. Stacey, G. M. Staebler, L. Stagner, B. Stahl, P. C. Stangeby, T. J. Stoltzfus-Dueck, D. P. Stotler, E. J. Strait, D. Su, L. E. Sugiyama, A. A. Sulyman, Y. Sun, C. Sung, W. A. Suttrop, Y. Suzuki, A. Svyatkovskiy, R. M. Sweeney, S. Taimourzadeh, M. Takechi, T. Tala, H. Tan, S. Tang, X. Tang, D. Taussig, G. Taylor, N. Z. Taylor, T. S. Taylor, A. Teklu, D. M. Thomas, M. B. Thomas, K. E. Thome, A. R. Thorman, R. A. Tinguely, B. J. Tobias, J. F. Tooker, H. Torreblanca, A. Torrezan De Sousa, G. L. Trevisan, D. Truong, F. Turco, A. D. Turnbull, E. A. Unterberg, P. Vaezi, P. J. Vail, M. A. Van Zeeland, M. Velasco Enriquez, M. C. Venkatesh, B. S. Victor, F. Volpe, M. R. Wade, M. L. Walker, J. R. Wall, G. M. Wallace, R. E. Waltz, G. Wang, H. Wang, Y. Wang, Z. Wang, F. Wang, S. H. Ward, J. G. Watkins, M. Watkins, W. P. Wehner, M. Weiland, D. B. Weisberg, A. S. Welander, A. E. White, R. B. White, D. Whyte, T. A. Wijkamp, R. Wilcox, T. Wilks, H. R. Wilson, A. Wingen, E. Wolfe, M. Wu, W. Wu, S. J. Wukitch, T. Xia, N. Xiang, B. Xiao, R. Xie, G. Xu, H. Xu, X. Xu, Z. Yan, Q. Yang, X. Yang, M. Yoshida, G. Yu, J. H. Yu, M. Yu, S. A. Zamperini, L. Zeng, B. Zhao, D. Zhao, H. Zhao, Y. Zhao, Y. Zhu, and B. Zywicki

Abstract

DIII-D research is addressing critical challenges in preparation for ITER and the next generation of fusion devices through focusing on plasma physics fundamentals that underpin key fusion goals, understanding the interaction of disparate core and boundary plasma physics, and developing integrated scenarios for achieving high performance fusion regimes. Fundamental investigations into fusion energy science find that anomalous dissipation of runaway electrons (RE) that arise following a disruption is likely due to interactions with RE-driven kinetic instabilities, some of which have been directly observed, opening a new avenue for RE energy dissipation using naturally excited waves. Dimensionless parameter scaling of intrinsic rotation and gyrokinetic simulations give a predicted ITER rotation profile with significant turbulence stabilization. Coherence imaging spectroscopy confirms near sonic flow throughout the divertor towards the target, which may account for the convection-dominated parallel heat flux. Core-boundary integration studies show that the small angle slot divertor achieves detachment at lower density and extends plasma cooling across the divertor target plate, which is essential for controlling heat flux and erosion. The Super H-mode regime has been extended to high plasma current (2.0 MA) and density to achieve very high pedestal pressures (∼30 kPa) and stored energy (3.2 MJ) with H 98y2 ≈ 1.6-2.4. In scenario work, the ITER baseline Q = 10 scenario with zero injected torque is found to have a fusion gain metric independent of current between q 95 = 2.8-3.7, and a lower limit of pedestal rotation for RMP ELM suppression has been found. In the wide pedestal QH-mode regime that exhibits improved performance and no ELMs, the start-up counter torque has been eliminated so that the entire discharge uses ≈0 injected torque and the operating space is more ITER-relevant. Finally, the high- (3.8) hybrid scenario has been extended to the high-density levels ne

Published
2019

9. Experiments and modeling of a helicon source

Author

P. A. Vitello, B. W. Stallard, H. S. McLean, J. A. Byers, R. H. Cohen, Albert R. Ellingboe, A. W. Molvik, E. B. Hooper, and T.D. Rognlien

Subjects
Physics, Mathematical model, Magnetic confinement fusion, Surfaces and Interfaces, Electron, Plasma, Condensed Matter Physics, Surfaces, Coatings and Films, symbols.namesake, Helicon, Physics::Plasma Physics, symbols, Langmuir probe, Plasma diagnostics, Atomic physics, Excitation
Abstract

We report on experimental results from the Lawrence Livermore National Laboratory Helicon Source plasma source and numerical models used to understand the observations. These include measurements of plasma density with Langmuir probes, and heating measurements with an electron energy analyzer to test transit‐time heating. The models describe helicon wave excitation, and electron heating. The wave fields are calculated using the ANTENA code including collisional and electron Landau heating. Numerical and analytic models are used to describe transit‐time heating of electrons and quantify the effect of collisions.

Published
1996
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10. Observation of pinching in the compact toroid injection experiment: Implications for a plasma opening switch

Author

R. W. Evans, R. D. Horton, H. S. McLean, David Hwang, S. D. Terry, and K. L. Baker

Subjects
Physics, Framing (visual arts), Physics and Astronomy (miscellaneous), business.industry, Compact toroid, Analytical chemistry, Plasma, Power factor, law.invention, Capacitor, Optics, Physics::Plasma Physics, law, Z-pinch, Electrical equipment, Electrode, business
Abstract

A compact toroid inductively stores the energy released by a capacitor bank as it is being accelerated. This energy can be stored for a period of more than ten microseconds and then transferred to a load on a much shorter time scale. This article presents framing camera images of the radial compression of plasma trailing behind a compact toroid as the compact toroid leaves its inner electrode. This compression illustrates the basic principles of a compact toroid plasma opening switch which could be used to drive fast z pinches.

Published
2001
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11. Spheromak Energy Transport Studies via Neutral Beam Injection

Author

H. S. McLean, J. Jayakumar, R. D. Wood, L D Pearlstein, and D. N. Hill

Subjects
Physics, Work (thermodynamics), Computer simulation, Spheromak, Nuclear engineering, Plasma, Auxiliary heating, Atomic physics, Beam (structure), Neutral beam injection, Energy transport
Abstract

Results from the SSPX spheromak experiment provide strong motivation to add neutral beam injection (NBI) heating. Such auxiliary heating would significantly advance the capability to study the physics of energy transport and pressure limits for the spheromak. This LDRD project develops the physics basis for using NBI to heat spheromak plasmas in SSPX. The work encompasses three activities: (1) numerical simulation to make quantitative predictions of the effect of adding beams to SSPX, (2) using the SSPX spheromak and theory/modeling to develop potential target plasmas suitable for future application of neutral beam heating, and (3) developing diagnostics to provide the measurements needed for transport calculations. These activities are reported in several publications.

Published
2008
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12. Time-resolved Temperature Measurements in SSPX

Author

J. M. Moller, R. D. Wood, D. N. Hill, A.R. Ludington, and H. S. McLean

Subjects
Physics, Spheromak, business.industry, Detector, Bremsstrahlung, Plasma, Electron, Temperature measurement, Photodiode, law.invention, Optics, law, Electron temperature, Atomic physics, business
Abstract

We seek to measure time-resolved electron temperatures in the SSPX plasma using soft X-rays from free-free Bremsstrahlung radiation. To increase sensitivity to changes in temperature over the range 100-300 eV, we use two photodiode detectors sensitive to different soft X-ray energies. The detectors, one with a Zr/C coating and the other with a Ti/Pd coating, view the plasma along a common line of sight tangential to the magnetic axis of the spheromak, where the electron temperature is a maximum. The comparison of the signals, over a similar volume of plasma, should be a stronger function of temperature than a single detector in the range of Te< 300 eV. The success of using photodiodes to detect changing temperatures along a chord will make the case for designing an array of the detectors, which could provide a time changing temperature profile over a larger portion of the plasma.

Published
2006
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13. LDRD Final Report for 01-ERD-100 FLIRT: A Magnetic Field Topology Diagnostic for Spheromaks and Other Self-Organized Magnetically Confined Plasmas

Author

H S McLean, H. Chen, and D D Ryutov

Subjects
Physics, Spheromak, Field (physics), Field line, Electron, Plasma, Topology, Sustained Spheromak Physics Experiment, Topology (chemistry), Magnetic field
Abstract

Tangled magnetic field lines are common in laboratory and space plasmas, but determining the geometrical structure of magnetic fields in the presence of plasma is a difficult and still unresolved problem. To address this open question we developed and tested a new technique for measuring the magnetic field-line topology in magnetically confined plasmas. Our field-line tracing diagnostic (FLIRT) uses a high-power, short-pulse laser to launch a burst of energetic ({approx}100 keV) electrons from a target passing through the plasma. These electrons then generally follow magnetic-field lines until they strike a solid surface, where a burst of x-rays is produced. The field-line connection length can be determined from the time delay between the laser pulse and the burst of x-rays. The topology of the field lines can be inferred by measuring the connection length as a function of initial target location inside the plasma. Measuring the spatial distribution of x-ray production provides further information on the field topology, including the effects of magnetic field fluctuations and stochasticity. The goals of this experiment were to test the appropriate x-ray detectors; measure the background x-ray emission in a spheromak plasma; measure the energetic electron production by a short-pulse, high-power laser; make preliminary measurementsmore » of the edge field line topology in the Sustained Spheromak Physics Experiment (SSPX), and perform analytic studies of electron production. These results are reported in detail in three publications listed. A brief summary is given.« less

Published
2003
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14. Final Report - Effect of Magnetic Configuration on Spheromak Performances, FY2000 - FY2001, Tracking No.00-SI-008

Author

H. S. McLean, B. W. Stallard, Simon Woodruff, E. B. Hooper, D. N. Hill, and R. D. Wood

Subjects
Physics, Toroid, Spheromak, Physics::Plasma Physics, Divertor, Nuclear engineering, Physics::Space Physics, Electron temperature, Plasma, Fusion power, Atomic physics, Sustained Spheromak Physics Experiment, Magnetic field
Abstract

This is the final report on LDRD SI-funded research to determine the Effect of Magnetic Field Configurations on Spheromak Performance for the years FY2000-FY2001, during which a new set of bias magnetic field coils was used to change the vacuum magnetic field configuration of the SSPX spheromak at LLNL. The USDOE Office of Fusion Energy Science funded the routine operation of the SSPX facility during FY00 and FY01. A photo of the SSPX facility as it appeared in mid-FY01, appears in this report. The main distinctive feature of the spheromak is that currents in the plasma itself produce the confining toroidal magnetic field, rather than a complex set of external coils. The Sustained Spheromak Physics Experiment (SSPX) device was designed and built study how well the spheromak can contain plasma energy while dynamo processes in the plasma maintain the confining magnetic fields. The spheromak potentially offers advantages over other fusion reactor concepts because it is compact, has no field coils linking the vacuum vessel, and can be operated in a steady state with voltage applied to external electrodes. It is predicted that the ability of the SSPX to contain the plasma thermal energy will increase with increasing plasma electron temperature;more » that is, the hotter it is, the better it will work. Our near-term goal for the SSPX facility is to determine which of several magnetic field configurations works best to produce hot, well-confined spheromak plasmas. We also want to verify the predicted inverse relation between plasma temperature and heat loss, and to use these results to design an even higher-temperature follow-on experiment that will push closer to fusion conditions. New features of the SSPX spheromak include a large-radius coaxial plasma injector to improve efficiency, a conformal flux conserver to minimize open field lines around the plasma, a divertor to aid in cold-particle exhaust, and the programmable-bias magnetic field coils to vary the magnetic geometry. The effect of operating SSPX with the bias magnetic-field coils is the subject of this LDRD research project.« less

Published
2002
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15. Ion Temperature Measurements in SSPX

Author

D. W. Auerbach, D N Hill, and H S McLean

Subjects
Physics, symbols.namesake, SIMPLE (dark matter experiment), Spectrometer, Heat exchanger, symbols, Ion temperature, Statistical model, Statistical physics, Doppler effect, Sustained Spheromak Physics Experiment, Ion, Computational physics
Abstract

The Ion Doppler Spectrometer instrument on the Sustained Spheromak Physics experiment is described, along with background about it's operation. Results are presented from recent experimental runs, and the data is compared to the results of simple statistical models of heat exchange in two species gasses.

Published
2001
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16. Beat wave launch of lower-hybrid wave for alpha particle diagnostic

Author

D. Q. Hwang, H. S. McLean, J. H. Rogers, R. D. Horton, and R. W. Evans

Subjects
Nuclear physics, Physics, symbols.namesake, Divertor, symbols, Langmuir probe, Beat (acoustics), Plasma diagnostics, Torus, Plasma, Lower hybrid oscillation, Computational physics, Magnetic field
Abstract

By use of nonlinear mixing of oppositely‐directed pump waves of frequency f0±δf≫fpe,fce, a beat wave of frequency f12=2δf and velocity v12=cδf/f0 may be launched deeply into the interior of a confined plasma. For launch perpendicular to magnetic field at a beat frequency in the lower‐hybrid range, fci≪f12≪fce, wave damping is proportional to the local derivative of the fast ion distribution function, ∂fα/dv‖v12, thus providing (in combination with a wave‐scattering diagnostic) a potential means for direct, noninvasive measurement of the local alpha‐particle distribution. Present experiments on the Davis Divertor Torus (DDT) are aimed at developing quantitative agreement between computed and actual Langmuir probe measurements of spatial and temporal beat‐wave distributions in a three‐dimensional plasma volume.

Published
1996
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17. Proton trajectories and electric fields in a laser-accelerated focused proton beam

Author

Teresa Bartal, H. S. McLean, Mingsheng Wei, M. H. Key, Leonard Jarrott, Kirk Flippo, Farhat Beg, Claudio Bellei, Richard B. Stephens, Mark Foord, and P. K. Patel

Subjects
Physics, Debye sheath, Proton, Field (physics), business.industry, Particle accelerator, Condensed Matter Physics, Laser, law.invention, symbols.namesake, Optics, law, Electric field, symbols, Physics::Accelerator Physics, Laser beam quality, Atomic physics, Nuclear Experiment, business, Beam (structure)
Abstract

The focusing properties of a laser generated proton beam have been investigated using hemispherical targets in both freestanding and enclosed cone-shaped geometries. The proton trajectories and focusing were strongly affected by the electric fields in the beam, bending the trajectories near the axis. In the cone targets, a sheath field effectively channels the proton beam through the open cone tip, substantially improving the beam focusing from ≈90 μm to ≈55 μm diameter for protons with energies >3 MeV. The proton generation and focusing were modeled using 2D hybrid particle-in-cell simulations, which compared well with the experimental results. Simulations predict further improvement in focusing with more uniform target illumination. These results are of significant interest to proton fast ignition and other high energy density physics applications.

Published
2012
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18. Tank-Mix Applications of Cyproconazole and Chlorothalonil for Control of Foliar and Soilborne Diseases of Peanut

Author

H. S. McLean, Alex S. Csinos, F. M. Shokes, Timothy B. Brenneman, and Albert K. Culbreath

Subjects
biology, Chlorothalonil, Plant Science, Rhizoctonia, biology.organism_classification, Arachis hypogaea, Fungicide, Rhizoctonia solani, chemistry.chemical_compound, Horticulture, chemistry, Botany, Leaf spot, Stem rot, Agronomy and Crop Science, Tifton
Abstract

Field tests were conducted during 1989-1991 at Tifton and Plains, Georgia, and Marianna, Florida, to evaluate the efficacy of full-season applications of tank-mix combinations of cyproconazole at rates of 0.062 kg a.i/ha and 0.093 kg a.i./ha with chlorothalonil at 0.63 kg a.i./ha for control of late leaf spot, caused by Cercosporidium personatum; southern stem rot, caused by Sclerotium rolfsii; and Rhizoctonia limb rot, caused by R. solani, of peanut (Arachis hypogaea) (.)

Published
1992
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19. Tungsten spectroscopy relevant to the diagnostics of ITER divertor plasmas.

Author

J Clementson, P Beiersdorfer, E W Magee, H S McLean, and R D Wood

Subjects
PLASMA diagnostics, FUSION reactors, ULTRAVIOLET radiation, TUNGSTEN ions, PHYSICS experiments, GLOW discharges, GRAZING incidence, PLASMA spectroscopy
Abstract

The possibility of using extreme ultraviolet emission from low charge states of tungsten ions to diagnose the divertor plasmas of the ITER tokamak has been investigated. Spectral modelling of Lu-like W3+ to Gd-like W10+ has been performed by using the Flexible Atomic Code, and spectroscopic measurements have been conducted at the Sustained Spheromak Physics Experiment (SSPX) in Livermore. To simulate ITER divertor plasmas, tungsten was introduced into the SSPX spheromak by prefilling it with tungsten hexacarbonyl prior to the usual hydrogen gas injection and initiation of the plasma discharge. The tungsten emission was studied using a grazing-incidence spectrometer. [ABSTRACT FROM AUTHOR]

Published
2010
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