Simulation of transition dynamics to high confinement in fusion plasmas

TL;DR

This paper uses a first-principles fluid model to simulate the L-H transition in fusion plasmas, accurately reproducing experimental observations and scaling laws, aiding the development of predictive models for fusion reactors.

Contribution

It introduces a first-principles four-field fluid model that successfully simulates the L-H transition dynamics and reproduces experimental scaling laws.

Findings

Numerical results match EAST measurements.

The model reproduces the slow transition with dithering phase.

Ion power threshold increases with particle density.

Abstract

The transition dynamics from the low (L) to the high (H) confinement mode in magnetically confined plasmas is investigated using a first-principles four-field fluid model. Numerical results are in close agreement with measurements from the Experimental Advanced Superconducting Tokamak - EAST. Particularly, the slow transition with an intermediate dithering phase is well reproduced by the numerical solutions. Additionally, the model reproduces the experimentally determined L-H transition power threshold scaling that the ion power threshold increases with increasing particle density. The results hold promise for developing predictive models of the transition, essential for understanding and optimizing future fusion power reactors.