12月19日 General considerations about the LHCD modeling and Nonlinear Propagation of Lower Hybrid Waves in the SOL of a Tokamak

报告题目一：General considerations about the LHCD modeling

报告时间：2025年12月19日（星期五）09:15

报告地点：EAST控制大厅二楼

主持人：丁伯江

报告人：Alessandro Cardinali教授

Abstract

In this brief discussion will be reviewed the theory of coupling, propagation and absorption of LH (Lower Hybrid) wave oriented to the generation of plasma current (LHCD). The related modeling will be critically discussed and in particular the problem of filling the "spectral gap" and the limitations of the "ray tracing multipass" approach in the formulation of wave propagation will be addressed again.

Biography:

Alessandro Cardinali was research director at ENEA in Frascati Research Center in the Fusion Department for more than 40 years. He is currently a research associate at the National Research Council in the Institute for Complex Systems (CNR-ISC) and the National Institute of Astrophysics, as well as adjunct professor at the University of Rome “Sapienza” in the Electrical Engineering Department. Throughout his career he has dealt, among other things, with the propagation of electromagnetic waves in laboratory and astrophysical plasmas, plasma propulsion, statistical theory of plasmas, asymptotic theory for the solution of differential equations etc.

报告题目二：Nonlinear Propagation of Lower Hybrid Waves in the SOL of a Tokamak

报告时间：2025年12月19日（星期五）10:15

报告地点：EAST控制大厅二楼

主持人：丁伯江

报告人：Francesco Napoli教授

Abstract

Although Lower Hybrid (LH) waves play a central role in current drive and profile control in magnetically confined plasmas, their interaction with the Scrape-Off Layer (SOL) is one of the least understood aspects affecting the wave accessibility to high-density plasmas and the overall efficiency of LH Current Drive (LHCD). In this talk, we present a nonlinear modelling framework based on kinetic theory, spectral method, and a full-wave description of LH wave propagation in the SOL. We emphasize the impact of parametric decay instabilities (PDIs) on wave–plasma coupling and propagation, which can modify the launched spectrum before it reaches the core. We will also analyze some results from LHCD experiments conducted on the FTU tokamak at ENEA Frascati (Italy), where high-density LHCD operations have been successfully performed based on nonlinear model predictions. Finally, we will highlight how a more complete understanding of LH wave behavior in the turbulent SOL could improve the optimization of LHCD systems in current devices and inform the design of next-generation fusion reactors. 

Biography:

Dr. Francesco Napoli is a researcher in the Nuclear Department at ENEA Frascati (Italy) with a background in nonlinear wave–plasma interaction in magnetically confined fusion devices. He earned a master's degree with honors in Electronic Engineering and a PhD in Applied Electromagnetism from the University of Roma Tre, where he began researching nonlinear microwave power coupling to the plasma edge. Since 2018, he works as a researcher at the ENEA Frascati, conducting theoretical and experimental studies on the nonlinear propagation and absorption of lower hybrid waves in the scrape-off layer of the FTU tokamak, as well as contributing to related investigations on EAST. His work includes developing numerical models for LH wave nonlinear scattering and parametric decay instabilities, and studying helicon waves, electrodeless plasma propulsion systems, and RF system design. He has authored several publications in plasma wave physics and serves as a reviewer for international scientific journals.