Transport prediction using gyrokinetic simulations with in situ quasilinear model

First-principles, nonlinear solutions of the gyrokinetic equation are computationally expensive, particularly in the high-gradient, strongly-shaped H-mode pedestal. For predictions of transport, quasilinear models have the ability produce results using linear solutions at a fraction of the cost. Typically, these quasilinear models are applied to linear gyrokinetic or gyrofluid simulations post-hoc. In this work, we present the results from an in situ quasilinear model incorporated into the gyrokinetic code GENE as a replacement for the nonlinear coupling term in initial value calculations. We envision two major applications: (1) global simulations where different instabilities may be active in different regions of the radial domain, and (2) scenarios where many unstable modes coexist, for example, some stellarator scenarios.