Suppression of large edge-localized modes in high-confinement DIII-D plasmas with a stochastic magnetic boundary.
نویسندگان
چکیده
A stochastic magnetic boundary, produced by an applied edge resonant magnetic perturbation, is used to suppress most large edge-localized modes (ELMs) in high confinement (H-mode) plasmas. The resulting H mode displays rapid, small oscillations with a bursty character modulated by a coherent 130 Hz envelope. The H mode transport barrier and core confinement are unaffected by the stochastic boundary, despite a threefold drop in the toroidal rotation. These results demonstrate that stochastic boundaries are compatible with H modes and may be attractive for ELM control in next-step fusion tokamaks.
منابع مشابه
Resonant pedestal pressure reduction induced by a thermal transport enhancement due to stochastic magnetic boundary layers in high temperature plasmas.
Good alignment of the magnetic field line pitch angle with the mode structure of an external resonant magnetic perturbation (RMP) field is shown to induce modulation of the pedestal electron pressure p(e) in high confinement high rotation plasmas at the DIII-D tokamak with a shape similar to ITER, the next step tokamak experiment. This is caused by an edge safety factor q95 resonant enhancement...
متن کاملComparison of a low- to high-confinement transition theory with experimental data from DIII-D.
From our recent theory based on the generation of shear flow and field in finite beta plasmas, the criterion for bifurcation from low to high confinement mode yields a critical parameter proportional to T(e)/square root (L(n)), where T(e) is the electron temperature and L(n) is the density scale length. The predicted threshold shows very good agreement with edge measurements on discharges under...
متن کامل1 Edge dimensionless identity experiment on DIII - D and Alcator
Experiments were carried out to study the similarity of H-mode (High confinement mode) physics on the Alcator C-Mod [1] and DIII-D [2] tokamaks comparing plasmas with matched local edge dimensionless parameters (β, ρ∗, ν∗, q95) and shape (ε, κ, δ). It was observed that matching local values of the dimensionless parameters on top of the H-mode pedestals produces similar Te and ne profiles across...
متن کاملPedestal Structure Without And With 3D Fields
Achieving high pedestal pressures in H(high)-mode plasmas confined in tokamaks is critical for obtaining fusion burning plasmas in ITER. Recent characterizations of quasi-equilibrium plasma parameter profiles in low collisionality H-mode pedestals in the DIII-D tokamak are briefly summarized. Critical plasma transport properties (large radial electron heat flow, density pinch) that establish th...
متن کاملPotentials , E ́ B drifts , and ̄ uctuations in the DIII - D boundary
Reciprocating Langmuir probes are used to investigate the structure of electrostatic potentials, E ́ B drifts, and ̄uctuations in the edge (q < 1), scrape-o layer (SOL) and divertor of single null diverted discharges in the DIII-D tokamak. These measurements demonstrate that the X-point geometry suppresses potential ̄uctuations in the drift wave range of frequencies (20 kHz6 f6 300 kHz) as pred...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 92 23 شماره
صفحات -
تاریخ انتشار 2004