# Spontaneous spin-up induced by turbulence-driven topological transition of orbits in a tokamak plasma

## TL;DR

This paper presents a kinetic theory explaining spontaneous plasma spin-up in tokamaks, linking turbulence-driven orbit topology changes to intrinsic core rotation, with predictions aligning with experimental scaling laws.

## Contribution

It introduces a novel kinetic model connecting turbulence-induced topological transitions of particle orbits to spontaneous plasma rotation in tokamaks.

## Key findings

- The theory predicts intrinsic core flow speeds of about 100 km/s for ITER.
- Predictions align with Rice-scaling of intrinsic plasma flow.
- The model emphasizes the role of turbulence-driven orbit topology changes.

## Abstract

Spontaneous spin-up are widely observed in tokamak plasmas, which is crucially important for plasma confinement. A kinetic theory is proposed to show that a toroidal rotation of core plasma is induced by the topological transition of orbits driven by turbulent diffusion in a collisionless tokamak plasma. The theoretical prediction agrees well with the well-known Rice-scaling of intrinsic core plasma flow. This new theory predicts an intrinsic core parallel flow of $\sim 100km/s$ for the International Thermonuclear Experimental Reactor.