Measurement and analysis ofZeffin EAST tokamak

This is the authors' abstract. We don't add key points for this paper.

Effective ion charge ( Z eff ) is an important parameter in fusion research and can be used to quantify impurity levels. Investigation into Z eff helps us to understand the impurity generation and transport mechanisms in order to find an effective way to control impurity levels. This key parameter Z eff is measured by the visible bremsstrahlung diagnostic in the EAST tokamak. In this report, Z eff and impurity behavior in siliconization and lithium coating experiments have been investigated. Comparisons of averaged Z eff and Z eff profiles have been made between L-mode and H-mode discharges. It is found that the dependence of Z eff on averaged electron density complies with the hyperbolic scaling. Finally, Z eff behavior in auxiliary heating experiments is analyzed in detail. The relationship between Z eff and external power injected into plasma in lower hybrid wave and ion cyclotron resonance frequency heating has been summarized and analyzed.