Observation of non-local effects in ion transport channel in J-TEXT plasmas

TL;DR

This paper reports the observation of non-local effects in ion transport in J-TEXT plasmas, showing rapid ion temperature changes and reduced density fluctuations during cold pulse experiments, revealing new insights into plasma transport phenomena.

Contribution

It presents the first experimental evidence of non-local ion transport effects in J-TEXT plasmas, highlighting similarities with electron transport and identifying a cutoff density for these effects.

Findings

Ion temperature in the core rises promptly after cold pulse injection.

High-frequency density fluctuations are significantly reduced during non-local transport.

A cutoff density for ion non-local effects is identified.

Abstract

In cold pulse experiments in J-TEXT, the ion transport shows similar non-local response as the electron transport channel. Very fast ion temperatures decreases are observed in the edge, while the ion temperature in core promptly begin to rise after the injection of cold pulse. Moreover, the cutoff density is also found for the ion non-local effect. The experimental observed density fluctuation in a high frequency ranging from 500 kHz to 2 MHz is obviously reduced in the whole plasma region during non-local transport (NLT) phase.