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Title: High poloidal beta equilibria in TFTR limited by a natural inboard poloidal field null

Abstract

Recent operation of the Tokamak Fusion Test Reactor TFTR, has produced plasma equilibria with values of {Lambda} {triple bond} {beta}{sub p eq} + l{sub i}/2 as large as 7, {epsilon}{beta}{sub p dia} {triple bond} 2{mu}{sub 0}{epsilon}/{much lt}B{sub p}{much gt}{sup 2} as large as 1.6, and Troyon normalized diamagnetic beta, {beta}{sub N dia} {triple bond} 10{sup 8}<{beta}{sub t}{perpendicular}>aB{sub 0}/I{sub p} as large as 4.7. When {epsilon}{beta}{sub p dia} {approx gt} 1.25, a separatrix entered the vacuum chamber, producing a naturally diverted discharge which was sustained for many energy confinement times, {tau}{sub E}. The largest values of {epsilon}{beta}{sub p} and plasma stored energy were obtained when the plasma current was ramped down prior to neutral beam injection. The measured peak ion and electron temperatures were as large as 24 keV and 8.5 keV, respectively. Plasma stored energy in excess of 2.5 MJ and {tau}{sub E} greater than 130 msec were obtained. Confinement times of greater than 3 times that expected from L-mode predictions have been achieved. The fusion power gain. Q{sub DD}, reached a values of 1.3 {times} 10{sup {minus}3} in a discharge with I{sub p} = 1 MA and {epsilon}{beta}{sub p dia} = 0.85. A large, sustained negative loop voltage duringmore » the steady state portion of the discharge indicates that a substantial non-inductive component of I{sub p} exists in these plasmas. Transport code analysis indicates that the bootstrap current constitutes up to 65% of I{sup p}. Magnetohydrodynamic (MHD) ballooning stability analysis shows that while these plasmas are near, or at the {beta}{sub p} limit, the pressure gradient in the plasma core is in the first region of stability to high-n modes. 24 refs., 10 figs.« less

Authors:
; ; ;  [1]; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »; ; ; ; ; ; « less
  1. Columbia Univ., New York, NY (United States). Dept. of Applied Physics
Publication Date:
Research Org.:
Princeton Univ., NJ (United States). Plasma Physics Lab.
Sponsoring Org.:
USDOE; USDOE, Washington, DC (United States)
OSTI Identifier:
5440464
Report Number(s):
PPPL-2775
ON: DE91016214
DOE Contract Number:  
AC02-76CH03073
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; TFTR TOKAMAK; HIGH-BETA PLASMA; PLASMA CONFINEMENT; BALLOONING INSTABILITY; CONFINEMENT TIME; MHD EQUILIBRIUM; NEUTRAL ATOM BEAM INJECTION; NEUTRONS; NON-INDUCTIVE CURRENT DRIVE; PRESSURE GRADIENTS; BARYONS; BEAM INJECTION; CONFINEMENT; ELEMENTARY PARTICLES; EQUILIBRIUM; FERMIONS; HADRONS; INSTABILITY; NUCLEONS; PLASMA; PLASMA INSTABILITY; PLASMA MACROINSTABILITIES; THERMONUCLEAR REACTORS; TOKAMAK TYPE REACTORS; 700101* - Fusion Energy- Plasma Research- Confinement, Heating, & Production

Citation Formats

Sabbagh, S A, Gross, R A, Mauel, M E, Navratil, G A, Bell, M G, Bell, R, Bitter, M, Bretz, N L, Budny, R V, Bush, C E, Chance, M S, Efthimion, P C, Fredrickson, E D, Hatcher, R, Hawryluk, R J, Hirshman, S P, Janos, A C, Jardin, S C, Jassby, D L, Manickam, J, McCune, D C, McGuire, K M, Medley, S S, Mueller, D, Nagayama, Y, and Ow,. High poloidal beta equilibria in TFTR limited by a natural inboard poloidal field null. United States: N. p., 1991. Web. doi:10.2172/5440464.
Sabbagh, S A, Gross, R A, Mauel, M E, Navratil, G A, Bell, M G, Bell, R, Bitter, M, Bretz, N L, Budny, R V, Bush, C E, Chance, M S, Efthimion, P C, Fredrickson, E D, Hatcher, R, Hawryluk, R J, Hirshman, S P, Janos, A C, Jardin, S C, Jassby, D L, Manickam, J, McCune, D C, McGuire, K M, Medley, S S, Mueller, D, Nagayama, Y, & Ow,. High poloidal beta equilibria in TFTR limited by a natural inboard poloidal field null. United States. https://doi.org/10.2172/5440464
Sabbagh, S A, Gross, R A, Mauel, M E, Navratil, G A, Bell, M G, Bell, R, Bitter, M, Bretz, N L, Budny, R V, Bush, C E, Chance, M S, Efthimion, P C, Fredrickson, E D, Hatcher, R, Hawryluk, R J, Hirshman, S P, Janos, A C, Jardin, S C, Jassby, D L, Manickam, J, McCune, D C, McGuire, K M, Medley, S S, Mueller, D, Nagayama, Y, and Ow,. 1991. "High poloidal beta equilibria in TFTR limited by a natural inboard poloidal field null". United States. https://doi.org/10.2172/5440464. https://www.osti.gov/servlets/purl/5440464.
@article{osti_5440464,
title = {High poloidal beta equilibria in TFTR limited by a natural inboard poloidal field null},
author = {Sabbagh, S A and Gross, R A and Mauel, M E and Navratil, G A and Bell, M G and Bell, R and Bitter, M and Bretz, N L and Budny, R V and Bush, C E and Chance, M S and Efthimion, P C and Fredrickson, E D and Hatcher, R and Hawryluk, R J and Hirshman, S P and Janos, A C and Jardin, S C and Jassby, D L and Manickam, J and McCune, D C and McGuire, K M and Medley, S S and Mueller, D and Nagayama, Y and Ow,},
abstractNote = {Recent operation of the Tokamak Fusion Test Reactor TFTR, has produced plasma equilibria with values of {Lambda} {triple bond} {beta}{sub p eq} + l{sub i}/2 as large as 7, {epsilon}{beta}{sub p dia} {triple bond} 2{mu}{sub 0}{epsilon}/{much lt}B{sub p}{much gt}{sup 2} as large as 1.6, and Troyon normalized diamagnetic beta, {beta}{sub N dia} {triple bond} 10{sup 8}<{beta}{sub t}{perpendicular}>aB{sub 0}/I{sub p} as large as 4.7. When {epsilon}{beta}{sub p dia} {approx gt} 1.25, a separatrix entered the vacuum chamber, producing a naturally diverted discharge which was sustained for many energy confinement times, {tau}{sub E}. The largest values of {epsilon}{beta}{sub p} and plasma stored energy were obtained when the plasma current was ramped down prior to neutral beam injection. The measured peak ion and electron temperatures were as large as 24 keV and 8.5 keV, respectively. Plasma stored energy in excess of 2.5 MJ and {tau}{sub E} greater than 130 msec were obtained. Confinement times of greater than 3 times that expected from L-mode predictions have been achieved. The fusion power gain. Q{sub DD}, reached a values of 1.3 {times} 10{sup {minus}3} in a discharge with I{sub p} = 1 MA and {epsilon}{beta}{sub p dia} = 0.85. A large, sustained negative loop voltage during the steady state portion of the discharge indicates that a substantial non-inductive component of I{sub p} exists in these plasmas. Transport code analysis indicates that the bootstrap current constitutes up to 65% of I{sup p}. Magnetohydrodynamic (MHD) ballooning stability analysis shows that while these plasmas are near, or at the {beta}{sub p} limit, the pressure gradient in the plasma core is in the first region of stability to high-n modes. 24 refs., 10 figs.},
doi = {10.2172/5440464},
url = {https://www.osti.gov/biblio/5440464}, journal = {},
number = ,
volume = ,
place = {United States},
year = {1991},
month = {7}
}