The quasilinear mixing-length approach to efficient prediction of transport in fusion devices is improved to account for the ‘Dimits’ upshift between linear and nonlinear critical pressure gradients in zonal-flow-saturated turbulence regimes. This modification uses the frequency mismatch between modes interacting turbulently to track changes in saturation efficiency. Near criticality, energy is transferred exclusively to stable eigenmodes, rapidly increasing the efficacy of the nonlinearity. The modified quasilinear model is able to predict below-threshold turbulent ion-temperature-gradient-driven transport accurately and also yields significantly improved predictions for trapped-electron-mode transport.

改进了用于有效预测聚变装置中传输的准线性混合长度方法，以解决带状流饱和湍流状态中线性和非线性临界压力梯度之间的“Dimits”上移。这种修改使用湍流交互模式之间的频率失配来跟踪饱和效率的变化。接近临界状态时，能量仅转移到稳定的本征模式，从而迅速提高非线性的功效。修改后的准线性模型能够准确预测低于阈值的湍流离子温度梯度驱动的传输，并且还显着改进了对俘获电子模式传输的预测。