HIGH FUSION PERFORMANCE IN SUPER H-MODE EXPERIMENTS ON ALCATOR C-MOD AND DIII-D

Snyder, P.B.; Hughes, J.W.; Osborne, T.H.; Paz-Soldan, C.; Solomon, W.M.; Knolker, M.; Eldon, D.; Evans, T.; Golfinopoulos, T.; Grierson, B.A.; Groebner, R.J.; Hubbard, A.E.; Kolemen, E.; LaBombard, B.; Laggner, F.M.; Meneghini, O.; Mordijck, S.; Petrie, T.; Scott, S.; Wang, H.Q.; Wilson, H.R.; Zhu, Y.B.

doi:10.1088/1741-4326/ab235b

Title: HIGH FUSION PERFORMANCE IN SUPER H-MODE EXPERIMENTS ON ALCATOR C-MOD AND DIII-D

Journal Article · Mon Jan 01 00:00:00 EST 2018 · Nuclear Fusion

DOI:https://doi.org/10.1088/1741-4326/ab235b· OSTI ID:1489822

Snyder, P.B. ^[1]; Hughes, J.W. ^[2]; Osborne, T.H. ^[1]; Paz-Soldan, C. ^[1]; Solomon, W.M. ^[1]; Knolker, M. ^[3]; Eldon, D. ^[1]; Evans, T. ^[1]; Golfinopoulos, T. ^[2]; Grierson, B.A. ^[3]; Groebner, R.J. ^[1]; Hubbard, A.E. ^[2]; Kolemen, E. ^[3]; LaBombard, B. ^[2]; Laggner, F.M. ^[3]; Meneghini, O. ^[1]; Mordijck, S. ^[4]; Petrie, T. ^[1]; Scott, S. ^[3]; Wang, H.Q. ^[1] more »

General Atomics, San Diego, CA (United States)
MIT Plasma Science and Fusion Center, Cambridge, MA (United States)
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
College of William and Mary, Williamsburg, VA (United States)
University of York (United Kingdom); Culham Center for Fusion Energy, Culham Science Centre, Abingdon, Oxon (United Kingdom)
Univ. of California, Irvine, CA (United States)

The “Super H-Mode” regime is predicted to enable pedestal height and fusion performance substantially higher than standard H-Mode operation. This regime exists due to a bifurcation of the pedestal pressure, as a function of density, that is predicted by the EPED model to occur in strongly shaped plasmas above a critical pedestal density. Experiments on Alcator C-Mod and DIII-D have achieved access to the Super H-Mode (and Near Super H) regime, and obtained very high pedestal pressure, including the highest achieved on a tokamak (p_ped ~80 kPa) in C-Mod experiments operating near the ITER magnetic field. DIII-D Super H experiments have demonstrated strong performance, including the highest stored energy in the present configuration of DIII-D (W ~ 2.2-3.2MJ), while utilizing only about half of the available heating power (P_heat ~ 7-12 MW). These DIII-D experiments have obtained the highest value of peak fusion gain, Q _{DT, equiv} ~ 0.5, achieved on a medium scale (R < 2m) tokamak. Sustained high performance operation (β_N ~ 2.9, H₉₈ ~ 1.6) has been achieved utilizing n = 3 magnetic perturbations for density and impurity control. Pedestal and global confinement have been maintained in the presence of deuterium and nitrogen gas puffing, which enables a more radiative divertor condition. Here, a pair of simple performance metrics is developed to assess and compare regimes. Super H-Mode access is predicted for ITER and expected, based on both theoretical prediction and observed normalized performance, to allow ITER to achieve its goals (Q = 10) at I _p < 15MA, and to potentially enable more compact, cost effective pilot plant and reactor designs.

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Research Organization:: General Atomics, San Diego, CA (United States)

Sponsoring Organization:: USDOE Office of Science (SC), Fusion Energy Sciences (FES)

Grant/Contract Number:: FG02-95ER54309; FC02-04ER54698; FC02-99ER54512; FC02-06ER54873; SC0014264; SC0017992

OSTI ID:: 1489822

Alternate ID(s):: OSTI ID: 1572159

Journal Information:: Nuclear Fusion, Vol. 59, Issue 8; ISSN 0029-5515

Publisher:: IOP ScienceCopyright Statement

Country of Publication:: United States

Language:: English

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Cited by: 33 works

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