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Smarter waste strategies: Helping deliver on the promise of advanced nuclear
At COP28, held in Dubai in 2023, a clear consensus emerged: Nuclear energy must be a cornerstone of the global clean energy transition. With electricity demand projected to soar as we decarbonize not just power but also industry, transport, and heat, the case for new nuclear is compelling. More than 20 countries committed to tripling global nuclear capacity by 2050. In the United States alone, the Department of Energy forecasts that the country’s current nuclear capacity could more than triple, adding 200 GW of new nuclear to the existing 95 GW by mid-century.
P. A. Politzer
Fusion Science and Technology | Volume 48 | Number 2 | October 2005 | Pages 1170-1177
Technical Paper | DIII-D Tokamak - Radio-Frequency Heating and Current Drive | doi.org/10.13182/FST05-A1069
Articles are hosted by Taylor and Francis Online.
Noninductive current drive is an essential part of the implementation of the DIII-D Advanced Tokamak program. For an efficient steady-state tokamak reactor, the plasma must provide close to 100% bootstrap fraction (fbs). For noninductive operation of DIII-D, current drive by injection of energetic neutral beams [neutral beam current drive (NBCD)] is also important. DIII-D experiments have reached ~80% bootstrap current in stationary discharges without inductive current drive. The remaining current is ~20% NBCD. This is achieved at N [approximately equal to] p > 3, but at relatively high q95 (~10). In lower q95 Advanced Tokamak plasmas, fbs ~ 0.6 has been reached in essentially noninductive plasmas. The phenomenology of high p and N plasmas without current control is being studied. These plasmas display a relaxation oscillation involving repetitive formation and collapse of an internal transport barrier. The frequency and severity of these events increase with increasing , limiting the achievable average and causing modulation of the total current as well as the pressure. Modeling of both bootstrap and NBCD currents is based on neoclassical theory. Measurements of the total bootstrap and NBCD current agree with calculations. A recent experiment based on the evolution of the transient voltage profile after an L-H transition shows that the more recent bootstrap current models accurately describe the plasma behavior. The profiles and the parametric dependences of the local neutral beam-driven current density have not yet been compared with theory.
