Abstract
In the Engineering Test Facility (ETF), the plasma pulse duration is expected to be hundreds of seconds, which is comparable to the resistive time scale that governs the resistive diffusion of the equilibrium. The resistive evolution of the safety factorq profile may, for MHD stability reasons, limit the duration of the plasma burn in a tokamak reactor. It may be possible to control this evolution and extend the plasma burn time through proper profile tailoring. We study the evolution of theq profile on the resistive time scale numerically using a one- and-one-half-dimensional (1 1/2-D) single fluid transport code. Two high beta (βT ∼ 7–16%) cases are considered: (a) a beam-driven hydrogen plasma with no nuclear alpha heating for which the beam energy is used as a device to control the temperature profile, and (b) an ignited D-T plasma in which the neutral injection has been turned off. For the beam-driven plasma, it is shown that low beam energy heating profiles lead to resistive steady states having broad temperature profiles and flatq profiles, while high beam energy heating profiles lead to resistive steady states having peaked temperature profiles and deepq profiles. The centralized nuclear heating in an ignited D-T plasma causes the evolution of theq profile for this case to behave much like that in the high energy, beam-driven case: namely, theq values near the plasma center decrease on the resistive time scale until a deep, resistive, steady-stateq profile is reached.
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References
J. A. Holmes, Y-K. M. Peng, and S. J. Lynch,J. Comput. Phys. 36:35 (1980).
J. D. Callen and R. A. Dory,Phys. Fluids 15:1523 (1972).
F. L. Hinton and R. D. Hazeltine,Rev. Mod. Phys. 48:239 (1976).
R. D. Hazeltine, F. L. Hinton, and M. N. Rosenbluth,Phys. Fluids 16:1645 (1973).
S. P. Hirshman and S. C. Jardin,Phys. Fluids 22:731 (1979).
N. A. Uckan, T. Uckan, and J. R. Moore, Calculation of magnetic field ripple effects in circular and noncircular tokamaks, Oak Ridge National Laboratory Report ORNL/TM-5603 (1976). N. A. Uckan, K. T. Tsang, and J. D. Callen, Effects of the poloidal variation of the magnetic field ripple on enhanced heat transport in tokamaks, Oak Ridge National Laboratory Report ORNL/TM-5438 (1976).
L. A. Berry et al., inProc. 6th Int. Atomic Energy Agency Conf. Plasma Phys. Controlled Nucl. Fusion Res. (1977), Vol. 1, p. 49.
M. Murakami et al., inProc. 7th Int. Atomic Energy Agency Conf. Plasma Phys. Controlled Nucl. Fusion Res. (1978), Vol. 1, p. 269.
E. Eubank et al., inProc. 7th Int. Atomic Energy Agency Conf. Plasma Phys. Controlled Nucl. Fusion Res. (1978), Vol. 1, p. 11.
W. A. Fowler, G. R. Caughlan, and B. A. Zimmerman,Annu. Rev. Astron. Astrophys. 13:69 (1975).
G. G. Lister, D. E. Post, and R. Goldston, Computer simulation of neutral beam injection into tokamaks using Monte Carlo techniques, inProc. 3rd Symp. Plasma Heating in Toroidal Devices, Varenna (1976), p. 303.
L. M. Hively, J. A. Rome, and G. H. Miley,Bull. Am. Phys. Soc. 24:941 (1979).
L. A. Charlton, D. B. Nelson, and R. A. Dory,Phys. Rev. Lett. 45:24 (1980).
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Research sponsored by the Office of Fusion Energy, U.S. Department of Energy, under contract W-7405-eng-26 with the Union Carbide Corporation.
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Holmes, J.A., Peng, Y.K.M. & Rothe, K.E. Equilibrium evolution on the resistive time scale in a tokamak reactor. J Fusion Energ 2, 123–130 (1982). https://doi.org/10.1007/BF01054579
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DOI: https://doi.org/10.1007/BF01054579