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Title: Effect of plasma shaping on performance in the National Spherical Torus Experiment

Abstract

The National Spherical Torus Experiment (NSTX) has explored the effects of shaping on plasma performance as determined by many diverse topics including the stability of global magnetohydrodynamic (MHD) modes (e.g., ideal external kinks and resistive wall modes), edge localized modes (ELMs), bootstrap current drive, divertor flux expansion, and heat transport. Improved shaping capability has been crucial to achieving βt ~ 40%. Precise plasma shape control has been achieved on NSTX using real-time equilibrium reconstruction. NSTX has simultaneously achieved elongation κ ~ 2.8 and triangularity delta ~ 0.8. Ideal MHD theory predicts increased stability at high values of shaping factor S equivalent to q95Ip/(aBt), which has been observed at large values of the S ~ 37[MA/(m • T)] on NSTX. The behavior of ELMs is observed to depend on plasma shape. A description of the ELM regimes attained as shape is varied will be presented. Increased shaping is predicted to increase the bootstrap fraction at fixed Ip. The achievement of strong shaping has enabled operation with 1 s pulses with Ip=1 MA, and for 1.6 s for Ip=700 kA. Analysis of the noninductive current fraction as well as empirical analysis of the achievable plasma pulse length as elongation is varied willmore » be presented. Data are presented showing a reduction in peak divertor heat load due to increasing in flux expansion.« less

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; « less
Publication Date:
Research Org.:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1081820
DOE Contract Number:  
DE-AC05-00OR22725; AC02-76CH03073
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 13; Journal Issue: 5; Journal ID: ISSN 1070-664X: PHPAEN
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English

Citation Formats

Gates, D. A., Maingi, R., Menard, J., Kaye, S., Sabbagh, S. A., Taylor, G., Wilson, J. R., 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., 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., Manickam, J., Maqueda, R., Marsala, R., Mastrovito, D., Mau, T. K., Medley, S. S., 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, W., 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, L., Ruskov, E., Ryan, P., 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., Tritz, K., Halle, A. von, Wade, M., White, R., Wilgen, J., Williams, M., Zhu, W., Zweben, S. J., Akers, R., Beiersdorfer, P., Betti, R., and Bigelow, T. Effect of plasma shaping on performance in the National Spherical Torus Experiment. United States: N. p., 2006. Web. doi:10.1063/1.2198174.
Gates, D. A., Maingi, R., Menard, J., Kaye, S., Sabbagh, S. A., Taylor, G., Wilson, J. R., 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., 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., Manickam, J., Maqueda, R., Marsala, R., Mastrovito, D., Mau, T. K., Medley, S. S., 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, W., 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, L., Ruskov, E., Ryan, P., 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., Tritz, K., Halle, A. von, Wade, M., White, R., Wilgen, J., Williams, M., Zhu, W., Zweben, S. J., Akers, R., Beiersdorfer, P., Betti, R., & Bigelow, T. Effect of plasma shaping on performance in the National Spherical Torus Experiment. United States. https://doi.org/10.1063/1.2198174
Gates, D. A., Maingi, R., Menard, J., Kaye, S., Sabbagh, S. A., Taylor, G., Wilson, J. R., 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., 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., Manickam, J., Maqueda, R., Marsala, R., Mastrovito, D., Mau, T. K., Medley, S. S., 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, W., 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, L., Ruskov, E., Ryan, P., 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., Tritz, K., Halle, A. von, Wade, M., White, R., Wilgen, J., Williams, M., Zhu, W., Zweben, S. J., Akers, R., Beiersdorfer, P., Betti, R., and Bigelow, T. 2006. "Effect of plasma shaping on performance in the National Spherical Torus Experiment". United States. https://doi.org/10.1063/1.2198174.
@article{osti_1081820,
title = {Effect of plasma shaping on performance in the National Spherical Torus Experiment},
author = {Gates, D. A. and Maingi, R. and Menard, J. and Kaye, S. and Sabbagh, S. A. and Taylor, G. and Wilson, J. R. 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 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 Manickam, J. and Maqueda, R. and Marsala, R. and Mastrovito, D. and Mau, T. K. and Medley, S. S. 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, W. 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, L. and Ruskov, E. and Ryan, P. 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 Tritz, K. and Halle, A. von and Wade, M. and White, R. and Wilgen, J. and Williams, M. and Zhu, W. and Zweben, S. J. and Akers, R. and Beiersdorfer, P. and Betti, R. and Bigelow, T.},
abstractNote = {The National Spherical Torus Experiment (NSTX) has explored the effects of shaping on plasma performance as determined by many diverse topics including the stability of global magnetohydrodynamic (MHD) modes (e.g., ideal external kinks and resistive wall modes), edge localized modes (ELMs), bootstrap current drive, divertor flux expansion, and heat transport. Improved shaping capability has been crucial to achieving βt ~ 40%. Precise plasma shape control has been achieved on NSTX using real-time equilibrium reconstruction. NSTX has simultaneously achieved elongation κ ~ 2.8 and triangularity delta ~ 0.8. Ideal MHD theory predicts increased stability at high values of shaping factor S equivalent to q95Ip/(aBt), which has been observed at large values of the S ~ 37[MA/(m • T)] on NSTX. The behavior of ELMs is observed to depend on plasma shape. A description of the ELM regimes attained as shape is varied will be presented. Increased shaping is predicted to increase the bootstrap fraction at fixed Ip. The achievement of strong shaping has enabled operation with 1 s pulses with Ip=1 MA, and for 1.6 s for Ip=700 kA. Analysis of the noninductive current fraction as well as empirical analysis of the achievable plasma pulse length as elongation is varied will be presented. Data are presented showing a reduction in peak divertor heat load due to increasing in flux expansion.},
doi = {10.1063/1.2198174},
url = {https://www.osti.gov/biblio/1081820}, journal = {Physics of Plasmas},
issn = {1070-664X: PHPAEN},
number = 5,
volume = 13,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}