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Title: Progress towards high performance plasmas in the National Spherical Torus Experiment (NSTX)

Abstract

The major objective of the National Spherical Torus Experiment (NSTX) is to understand basic toroidal confinement physics at low aspect ratio and high β T in order to advance the spherical torus (ST) concept. In order to do this, NSTX utilizes up to 7.5 MW of neutral beam injection, up to 6 MW of high harmonic fast waves (HHFWs), and it operates with plasma currents up to 1.5 MA and elongations of up to 2.6 at a toroidal field up to 0.45 T. New facility, and diagnostic and modeling capabilities developed over the past two years have enabled the NSTX research team to make significant progress towards establishing this physics basis for future ST devices. Improvements in plasma control have led to more routine operation at high elongation and high β T (up to ~40%) lasting for many energy confinement times. β T can be limited by either internal or external modes. The installation of an active error field (EF) correction coil pair has expanded the operating regime at low density and has allowed for initial resonant EF amplification experiments. The determination of the confinement and transport properties of NSTX plasmas has benefited greatly from the implementation of higher spatialmore » resolution kinetic diagnostics. The parametric variation of confinement is similar to that at conventional aspect ratio but with values enhanced relative to those determined from conventional aspect ratio scalings and with a β T dependence. The transport is highly dependent on details of both the flow and magnetic shear. Core turbulence was measured for the first time in an ST through correlation reflectometry. Non-inductive start-up has been explored using PF-only and transient co-axial helicity injection techniques, resulting in up to 140 kA of toroidal current generated by the latter technique. Calculated bootstrap and beam-driven currents have sustained up to 60% of the flat-top plasma current in NBI discharges. Studies of HHFW absorption have indicated parametric decay of the wave and associated edge thermal ion heating. Energetic particle modes, most notably toroidal Alfven eigenmodes and fishbone-like modes result in fast particle losses, and these instabilities may affect fast ion confinement on devices such as ITER. Finally, a variety of techniques has been developed for fueling and power and particle control.« less

Authors:
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Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
898499
DOE Contract Number:  
AC02-76CH03073; AC05-00OR22725; AC04-94AL85000; W-7405-ENG-36; W-7405-ENG-48; FG02-99ER54523; FG03-99ER54519; FG03-99ER51069; FG02-99ER54525; FG02-99ER54521; FG02- 91ER54109; FG02-99ER54524; FG03-02ER54684; FG02- 99ER54520; FG02-99ER54518
Resource Type:
Journal Article
Journal Name:
Nuclear Fusion
Additional Journal Information:
Journal Volume: 45; Journal Issue: 10; Related Information: FG03-99ER54527; FG02- 99ER54522; FG03-02ER54681; FG02-93ER54215; DEFG02-86ER53223; FG02-01ER54619; Journal ID: ISSN 0029-5515
Publisher:
IOP Science
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ASPECT RATIO; BEAM INJECTION; CONFINEMENT TIME; ELECTRIC CURRENTS; HELICITY; KINETICS; PARTICLE LOSSES; PERFORMANCE; SPATIAL RESOLUTION

Citation Formats

Kaye, S. M., Bell, M. G., Bell, R. E., Bernabei, S, Bialek, J., Biewer, T., Blanchard, W., Boedo, J., Bush, C., Carter, M. D., Choe, W., Crocker, N., Darrow, D. S., Davis, W., Delgado-Aparicio, L., Diem, S., Ferron, J., Field, A., Foley, J., Fredrickson, E. D., Gates, D. A., Gibney, T., Harvey, R., Hatcher, R. E., Heidbrink, W., Hill, K., Hosea, J. C., Jarboe, T. R., Johnson, D. W., Kaita, R., Kessel, C., Kubota, S., Kugel, H. W., Lawson, J., LeBlanc, B. P., Lee, K. C., Levinton, F., Maingi, R., Manickam, J., Maqueda, R., Marsala, R., Mastrovito, D., Mau, T. K., Medley, S. S., Menard, J., Meyer, H., Mikkelsen, D. R., Mueller, D., Munsat, T., Nelson, B. A., Neumeyer, C., Nishino, N., Ono, M., Park, H., Park, W., Paul, S., Peebles, T., Peng, M., Phillips, C., Pigarov, A., Pinsker, R., Ram, A., Ramakrishnan, S., Raman, R., Rasmussen, D., Redi, M., Rensink, M., Rewoldt, G, Robinson, J., Roney, P., Roquemore, A. L., Ruskov, E, Ryan, P., Sabbagh, S. A., Schneider, H., Skinner, C. H., Smith, D. R., Sontag, A., Soukhanovskii, V., Stevenson, T., Stotler, D., Stratton, B., Stutman, D., Swain, D., Synakowski, E., Takase, Y., Taylor, G., Tritz, K., Halle, A. von, Wade, M., White, R., Wilgen, J., Williams, M., Wilson, J. R., Zhu, W., Zweben, S. J., Akers, R., Beiersdorfer, P., Betti, R., Bigelow, T., Bitter, M., Bonoli, P., Bourdelle, C., Chang, C. S., Chrzanowski, J., Domier, C., Dudek, L., Efthimion, P. C., Finkenthal, M., Fredd, E., Fu, G. Y., Glasser, A., Goldston, R. J., Greenough, N. L., Grisham, L. R., Gorelenkov, N., Guazzotto, L., Hawryluk, R. J., Hogan, J., Houlberg, W., Humphreys, D., Jaeger, F., Kalish, M., Krasheninnikov, S., Lao, L. L., Lawrence, J., Leuer, J., Liu, D., Luhmann, N. C., Mazzucato, E., Oliaro, G., Pacella, D., Parsells, R., Schaffer, M., Semenov, I., Shaing, K. C., Shapiro, M. A., Shinohara, K., Sichta, P., Tang, X., Vero, R., Walker, D., and Wampler, W. Progress towards high performance plasmas in the National Spherical Torus Experiment (NSTX). United States: N. p., 2005. Web. doi:10.1088/0029-5515/45/10/S14.
Kaye, S. M., Bell, M. G., Bell, R. E., Bernabei, S, Bialek, J., Biewer, T., Blanchard, W., Boedo, J., Bush, C., Carter, M. D., Choe, W., Crocker, N., Darrow, D. S., Davis, W., Delgado-Aparicio, L., Diem, S., Ferron, J., Field, A., Foley, J., Fredrickson, E. D., Gates, D. A., Gibney, T., Harvey, R., Hatcher, R. E., Heidbrink, W., Hill, K., Hosea, J. C., Jarboe, T. R., Johnson, D. W., Kaita, R., Kessel, C., Kubota, S., Kugel, H. W., Lawson, J., LeBlanc, B. P., Lee, K. C., Levinton, F., Maingi, R., Manickam, J., Maqueda, R., Marsala, R., Mastrovito, D., Mau, T. K., Medley, S. S., Menard, J., Meyer, H., Mikkelsen, D. R., Mueller, D., Munsat, T., Nelson, B. A., Neumeyer, C., Nishino, N., Ono, M., Park, H., Park, W., Paul, S., Peebles, T., Peng, M., Phillips, C., Pigarov, A., Pinsker, R., Ram, A., Ramakrishnan, S., Raman, R., Rasmussen, D., Redi, M., Rensink, M., Rewoldt, G, Robinson, J., Roney, P., Roquemore, A. L., Ruskov, E, Ryan, P., Sabbagh, S. A., Schneider, H., Skinner, C. H., Smith, D. R., Sontag, A., Soukhanovskii, V., Stevenson, T., Stotler, D., Stratton, B., Stutman, D., Swain, D., Synakowski, E., Takase, Y., Taylor, G., Tritz, K., Halle, A. von, Wade, M., White, R., Wilgen, J., Williams, M., Wilson, J. R., Zhu, W., Zweben, S. J., Akers, R., Beiersdorfer, P., Betti, R., Bigelow, T., Bitter, M., Bonoli, P., Bourdelle, C., Chang, C. S., Chrzanowski, J., Domier, C., Dudek, L., Efthimion, P. C., Finkenthal, M., Fredd, E., Fu, G. Y., Glasser, A., Goldston, R. J., Greenough, N. L., Grisham, L. R., Gorelenkov, N., Guazzotto, L., Hawryluk, R. J., Hogan, J., Houlberg, W., Humphreys, D., Jaeger, F., Kalish, M., Krasheninnikov, S., Lao, L. L., Lawrence, J., Leuer, J., Liu, D., Luhmann, N. C., Mazzucato, E., Oliaro, G., Pacella, D., Parsells, R., Schaffer, M., Semenov, I., Shaing, K. C., Shapiro, M. A., Shinohara, K., Sichta, P., Tang, X., Vero, R., Walker, D., & Wampler, W. Progress towards high performance plasmas in the National Spherical Torus Experiment (NSTX). United States. doi:10.1088/0029-5515/45/10/S14.
Kaye, S. M., Bell, M. G., Bell, R. E., Bernabei, S, Bialek, J., Biewer, T., Blanchard, W., Boedo, J., Bush, C., Carter, M. D., Choe, W., Crocker, N., Darrow, D. S., Davis, W., Delgado-Aparicio, L., Diem, S., Ferron, J., Field, A., Foley, J., Fredrickson, E. D., Gates, D. A., Gibney, T., Harvey, R., Hatcher, R. E., Heidbrink, W., Hill, K., Hosea, J. C., Jarboe, T. R., Johnson, D. W., Kaita, R., Kessel, C., Kubota, S., Kugel, H. W., Lawson, J., LeBlanc, B. P., Lee, K. C., Levinton, F., Maingi, R., Manickam, J., Maqueda, R., Marsala, R., Mastrovito, D., Mau, T. K., Medley, S. S., Menard, J., Meyer, H., Mikkelsen, D. R., Mueller, D., Munsat, T., Nelson, B. A., Neumeyer, C., Nishino, N., Ono, M., Park, H., Park, W., Paul, S., Peebles, T., Peng, M., Phillips, C., Pigarov, A., Pinsker, R., Ram, A., Ramakrishnan, S., Raman, R., Rasmussen, D., Redi, M., Rensink, M., Rewoldt, G, Robinson, J., Roney, P., Roquemore, A. L., Ruskov, E, Ryan, P., Sabbagh, S. A., Schneider, H., Skinner, C. H., Smith, D. R., Sontag, A., Soukhanovskii, V., Stevenson, T., Stotler, D., Stratton, B., Stutman, D., Swain, D., Synakowski, E., Takase, Y., Taylor, G., Tritz, K., Halle, A. von, Wade, M., White, R., Wilgen, J., Williams, M., Wilson, J. R., Zhu, W., Zweben, S. J., Akers, R., Beiersdorfer, P., Betti, R., Bigelow, T., Bitter, M., Bonoli, P., Bourdelle, C., Chang, C. S., Chrzanowski, J., Domier, C., Dudek, L., Efthimion, P. C., Finkenthal, M., Fredd, E., Fu, G. Y., Glasser, A., Goldston, R. J., Greenough, N. L., Grisham, L. R., Gorelenkov, N., Guazzotto, L., Hawryluk, R. J., Hogan, J., Houlberg, W., Humphreys, D., Jaeger, F., Kalish, M., Krasheninnikov, S., Lao, L. L., Lawrence, J., Leuer, J., Liu, D., Luhmann, N. C., Mazzucato, E., Oliaro, G., Pacella, D., Parsells, R., Schaffer, M., Semenov, I., Shaing, K. C., Shapiro, M. A., Shinohara, K., Sichta, P., Tang, X., Vero, R., Walker, D., and Wampler, W. Sat . "Progress towards high performance plasmas in the National Spherical Torus Experiment (NSTX)". United States. doi:10.1088/0029-5515/45/10/S14. https://www.osti.gov/servlets/purl/898499.
@article{osti_898499,
title = {Progress towards high performance plasmas in the National Spherical Torus Experiment (NSTX)},
author = {Kaye, S. M. and Bell, M. G. and Bell, R. E. and Bernabei, S and Bialek, J. and Biewer, T. and Blanchard, W. and Boedo, J. and Bush, C. and Carter, M. D. and Choe, W. and Crocker, N. and Darrow, D. S. and Davis, W. and Delgado-Aparicio, L. and Diem, S. and Ferron, J. and Field, A. and Foley, J. and Fredrickson, E. D. and Gates, D. A. and Gibney, T. and Harvey, R. and Hatcher, R. E. and Heidbrink, W. and Hill, K. and Hosea, J. C. and Jarboe, T. R. and Johnson, D. W. and Kaita, R. and Kessel, C. and Kubota, S. and Kugel, H. W. and Lawson, J. and LeBlanc, B. P. and Lee, K. C. and Levinton, F. and Maingi, R. and Manickam, J. and Maqueda, R. and Marsala, R. and Mastrovito, D. and Mau, T. K. and Medley, S. S. and Menard, J. and Meyer, H. and Mikkelsen, D. R. and Mueller, D. and Munsat, T. and Nelson, B. A. and Neumeyer, C. and Nishino, N. and Ono, M. and Park, H. and Park, W. and Paul, S. and Peebles, T. and Peng, M. and Phillips, C. and Pigarov, A. and Pinsker, R. and Ram, A. and Ramakrishnan, S. and Raman, R. and Rasmussen, D. and Redi, M. and Rensink, M. and Rewoldt, G and Robinson, J. and Roney, P. and Roquemore, A. L. and Ruskov, E and Ryan, P. and Sabbagh, S. A. and Schneider, H. and Skinner, C. H. and Smith, D. R. and Sontag, A. and Soukhanovskii, V. and Stevenson, T. and Stotler, D. and Stratton, B. and Stutman, D. and Swain, D. and Synakowski, E. and Takase, Y. and Taylor, G. and Tritz, K. and Halle, A. von and Wade, M. and White, R. and Wilgen, J. and Williams, M. and Wilson, J. R. and Zhu, W. and Zweben, S. J. and Akers, R. and Beiersdorfer, P. and Betti, R. and Bigelow, T. and Bitter, M. and Bonoli, P. and Bourdelle, C. and Chang, C. S. and Chrzanowski, J. and Domier, C. and Dudek, L. and Efthimion, P. C. and Finkenthal, M. and Fredd, E. and Fu, G. Y. and Glasser, A. and Goldston, R. J. and Greenough, N. L. and Grisham, L. R. and Gorelenkov, N. and Guazzotto, L. and Hawryluk, R. J. and Hogan, J. and Houlberg, W. and Humphreys, D. and Jaeger, F. and Kalish, M. and Krasheninnikov, S. and Lao, L. L. and Lawrence, J. and Leuer, J. and Liu, D. and Luhmann, N. C. and Mazzucato, E. and Oliaro, G. and Pacella, D. and Parsells, R. and Schaffer, M. and Semenov, I. and Shaing, K. C. and Shapiro, M. A. and Shinohara, K. and Sichta, P. and Tang, X. and Vero, R. and Walker, D. and Wampler, W.},
abstractNote = {The major objective of the National Spherical Torus Experiment (NSTX) is to understand basic toroidal confinement physics at low aspect ratio and high βT in order to advance the spherical torus (ST) concept. In order to do this, NSTX utilizes up to 7.5 MW of neutral beam injection, up to 6 MW of high harmonic fast waves (HHFWs), and it operates with plasma currents up to 1.5 MA and elongations of up to 2.6 at a toroidal field up to 0.45 T. New facility, and diagnostic and modeling capabilities developed over the past two years have enabled the NSTX research team to make significant progress towards establishing this physics basis for future ST devices. Improvements in plasma control have led to more routine operation at high elongation and high βT (up to ~40%) lasting for many energy confinement times. βT can be limited by either internal or external modes. The installation of an active error field (EF) correction coil pair has expanded the operating regime at low density and has allowed for initial resonant EF amplification experiments. The determination of the confinement and transport properties of NSTX plasmas has benefited greatly from the implementation of higher spatial resolution kinetic diagnostics. The parametric variation of confinement is similar to that at conventional aspect ratio but with values enhanced relative to those determined from conventional aspect ratio scalings and with a βT dependence. The transport is highly dependent on details of both the flow and magnetic shear. Core turbulence was measured for the first time in an ST through correlation reflectometry. Non-inductive start-up has been explored using PF-only and transient co-axial helicity injection techniques, resulting in up to 140 kA of toroidal current generated by the latter technique. Calculated bootstrap and beam-driven currents have sustained up to 60% of the flat-top plasma current in NBI discharges. Studies of HHFW absorption have indicated parametric decay of the wave and associated edge thermal ion heating. Energetic particle modes, most notably toroidal Alfven eigenmodes and fishbone-like modes result in fast particle losses, and these instabilities may affect fast ion confinement on devices such as ITER. Finally, a variety of techniques has been developed for fueling and power and particle control.},
doi = {10.1088/0029-5515/45/10/S14},
journal = {Nuclear Fusion},
issn = {0029-5515},
number = 10,
volume = 45,
place = {United States},
year = {2005},
month = {10}
}