Real-time protection of the ohmic heating coil force limits in DIII-D

Real Time Equilibrium Reconstruction for Control of the Discharge in the Diii–d Tokamak

Plasma Vertical Stabilization in the Presence of Coil Voltage Saturation in the DIII-D Tokamak∗

An anti-windup compensator is implemented for a given nominal plasma vertical controller guaranteeing global vertical stabilization of the plasma in the presence of actuactor saturation for all reference commands. The anti-windup synthesis problem is to find a nonlinear modification of the nominal linear controller that prevents vertical instability and undesirable oscillations but leaves the n...

The role of Ohmic heating in dc magnetron sputtering

Sustaining a plasma in a magnetron discharge requires energization of the plasma electrons. In this work, Ohmic heating of electrons outside the cathode sheath is demonstrated to be typically of the same order as sheath energization, and a simple physical explanation is given. We propose a generalized Thornton equation that includes both sheath energization and Ohmic heating of electrons. The s...

Observation of peak neoclassical toroidal viscous force in the DIII-D tokamak.

Observation of a theoretically predicted peak in the neoclassical toroidal viscosity (NTV) force as a function of toroidal plasma rotation rate Ω is reported. The NTV was generated by applying n=3 magnetic fields from internal coils to low Ω plasmas produced with nearly balanced neutral beam injection. Locally, the peak corresponds to a toroidal rotation rate Ω(0) where the radial electric fiel...

Diii – D Data Management

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