Abstract
Limiter H-modes with centrally peaked density profiles have been obtained in TFTR using a highly conditioned graphite limiter. The transition to these centrally peaked H-modes takes place from the supershot to the H-mode rather than the usual L- to H-mode transition observed on other tokamaks. Bi-directional beam heating is required to induce the transition. Density peaking factors, n{sub e}(0)/{l angle}n{sub e}{r angle}, >2.3 are obtained and at the same time the H-mode characteristics are similar to those of limiter H-modes on other tokamaks and the global confinement, {tau}{sub E}, can be >2.5 times L-mode scaling. The TRANSP analysis shows that transport in these H-modes is similar to that of supershots within the inner 60 cm of the plasma, but the stored electron energy (calculated using measured values of T{sub e} and n{sub e}) is higher for the H-mode at the plasma edge. Microwave scattering near the edge shows broad spectra at k = 5.5 cm{sup {minus}1} which begin at the drop in D{sub {alpha}} radiation and are strongly shifted in the electron diamagnetic drift direction. At the same time beam emission spectroscopy shows a coherent mode near the boundary with m = 15--20 at 20--30 kHz which is propagating in
More>>
Bush, C;
[1]
Bretz, N L;
Fredrickson, E D;
McGuire, K M;
Nazikian, R;
Park, H K;
Schivell, J;
Taylor, G;
Bitter, B;
Budny, R;
Cohen, S A;
Kilpatrick, S J;
LeBlanc, B;
Manos, D M;
Meade, D;
Paul, S F;
Scott, S D;
Stratton, B C;
Synakowski, E J;
Towner, H H;
Weiland, R M;
Arunasalam, V;
Bateman, G;
Bell, M G;
Bell, R;
Boivin, R;
Cavallo, A;
Cheng, C Z;
Chu, T K;
Cowl,
- Oak Ridge National Lab., TN (USA)
Citation Formats
Bush, C, Bretz, N L, Fredrickson, E D, McGuire, K M, Nazikian, R, Park, H K, Schivell, J, Taylor, G, Bitter, B, Budny, R, Cohen, S A, Kilpatrick, S J, LeBlanc, B, Manos, D M, Meade, D, Paul, S F, Scott, S D, Stratton, B C, Synakowski, E J, Towner, H H, Weiland, R M, Arunasalam, V, Bateman, G, Bell, M G, Bell, R, Boivin, R, Cavallo, A, Cheng, C Z, Chu, T K, and Cowl,.
Limiter H-mode experiments on TFTR.
Austria: N. p.,
1990.
Web.
Bush, C, Bretz, N L, Fredrickson, E D, McGuire, K M, Nazikian, R, Park, H K, Schivell, J, Taylor, G, Bitter, B, Budny, R, Cohen, S A, Kilpatrick, S J, LeBlanc, B, Manos, D M, Meade, D, Paul, S F, Scott, S D, Stratton, B C, Synakowski, E J, Towner, H H, Weiland, R M, Arunasalam, V, Bateman, G, Bell, M G, Bell, R, Boivin, R, Cavallo, A, Cheng, C Z, Chu, T K, & Cowl,.
Limiter H-mode experiments on TFTR.
Austria.
Bush, C, Bretz, N L, Fredrickson, E D, McGuire, K M, Nazikian, R, Park, H K, Schivell, J, Taylor, G, Bitter, B, Budny, R, Cohen, S A, Kilpatrick, S J, LeBlanc, B, Manos, D M, Meade, D, Paul, S F, Scott, S D, Stratton, B C, Synakowski, E J, Towner, H H, Weiland, R M, Arunasalam, V, Bateman, G, Bell, M G, Bell, R, Boivin, R, Cavallo, A, Cheng, C Z, Chu, T K, and Cowl,.
1990.
"Limiter H-mode experiments on TFTR."
Austria.
@misc{etde_6358449,
title = {Limiter H-mode experiments on TFTR}
author = {Bush, C, Bretz, N L, Fredrickson, E D, McGuire, K M, Nazikian, R, Park, H K, Schivell, J, Taylor, G, Bitter, B, Budny, R, Cohen, S A, Kilpatrick, S J, LeBlanc, B, Manos, D M, Meade, D, Paul, S F, Scott, S D, Stratton, B C, Synakowski, E J, Towner, H H, Weiland, R M, Arunasalam, V, Bateman, G, Bell, M G, Bell, R, Boivin, R, Cavallo, A, Cheng, C Z, Chu, T K, and Cowl,}
abstractNote = {Limiter H-modes with centrally peaked density profiles have been obtained in TFTR using a highly conditioned graphite limiter. The transition to these centrally peaked H-modes takes place from the supershot to the H-mode rather than the usual L- to H-mode transition observed on other tokamaks. Bi-directional beam heating is required to induce the transition. Density peaking factors, n{sub e}(0)/{l angle}n{sub e}{r angle}, >2.3 are obtained and at the same time the H-mode characteristics are similar to those of limiter H-modes on other tokamaks and the global confinement, {tau}{sub E}, can be >2.5 times L-mode scaling. The TRANSP analysis shows that transport in these H-modes is similar to that of supershots within the inner 60 cm of the plasma, but the stored electron energy (calculated using measured values of T{sub e} and n{sub e}) is higher for the H-mode at the plasma edge. Microwave scattering near the edge shows broad spectra at k = 5.5 cm{sup {minus}1} which begin at the drop in D{sub {alpha}} radiation and are strongly shifted in the electron diamagnetic drift direction. At the same time beam emission spectroscopy shows a coherent mode near the boundary with m = 15--20 at 20--30 kHz which is propagating in the ion direction. During an ELM event these apparent rotations cease and Mirnov fluctuations in the 50--500 kHz increase in intensity.}
place = {Austria}
year = {1990}
month = {Dec}
}
title = {Limiter H-mode experiments on TFTR}
author = {Bush, C, Bretz, N L, Fredrickson, E D, McGuire, K M, Nazikian, R, Park, H K, Schivell, J, Taylor, G, Bitter, B, Budny, R, Cohen, S A, Kilpatrick, S J, LeBlanc, B, Manos, D M, Meade, D, Paul, S F, Scott, S D, Stratton, B C, Synakowski, E J, Towner, H H, Weiland, R M, Arunasalam, V, Bateman, G, Bell, M G, Bell, R, Boivin, R, Cavallo, A, Cheng, C Z, Chu, T K, and Cowl,}
abstractNote = {Limiter H-modes with centrally peaked density profiles have been obtained in TFTR using a highly conditioned graphite limiter. The transition to these centrally peaked H-modes takes place from the supershot to the H-mode rather than the usual L- to H-mode transition observed on other tokamaks. Bi-directional beam heating is required to induce the transition. Density peaking factors, n{sub e}(0)/{l angle}n{sub e}{r angle}, >2.3 are obtained and at the same time the H-mode characteristics are similar to those of limiter H-modes on other tokamaks and the global confinement, {tau}{sub E}, can be >2.5 times L-mode scaling. The TRANSP analysis shows that transport in these H-modes is similar to that of supershots within the inner 60 cm of the plasma, but the stored electron energy (calculated using measured values of T{sub e} and n{sub e}) is higher for the H-mode at the plasma edge. Microwave scattering near the edge shows broad spectra at k = 5.5 cm{sup {minus}1} which begin at the drop in D{sub {alpha}} radiation and are strongly shifted in the electron diamagnetic drift direction. At the same time beam emission spectroscopy shows a coherent mode near the boundary with m = 15--20 at 20--30 kHz which is propagating in the ion direction. During an ELM event these apparent rotations cease and Mirnov fluctuations in the 50--500 kHz increase in intensity.}
place = {Austria}
year = {1990}
month = {Dec}
}