The effect of parameter drift in the transport of magnetized plasma particles

Abstract

We investigate how time dependent modulations of drift wave amplitudes affect particle transport and chaos in a magnetized plasma. Using the Horton model, we apply a sawtooth ramp to a primary wave's amplitude and periodic rectangular kicks to secondary waves, simulating a driven system. Particle transport is quantified by the Mean Square Displacement (MSD) exponent, $\alpha$, and chaos by the Maximum Lyapunov Exponent (MLE). Our primary finding is a strong negative correlation between the system's average chaoticity and its transport efficiency. We show that rapid sawtooth ramping (short period $\tau$) produces highly efficient, superdiffusive transport ($\alpha > 1$). In contrast, slower ramping increases the system's chaos but suppresses transport, driving it towards normal diffusion ($\alpha \to 1$). This counter intuitive result demonstrates that heightened chaos destroys the coherent, streamer like structures necessary for superdiffusive flights. Our findings indicate that the coherence of the turbulent field, rather than its raw chaoticity, is the key determinant of transport efficiency, offering a new perspective on plasma control.