skip to main content

SciTech ConnectSciTech Connect

Title: Nonlinear phenomena in RF wave propagation in magnetized plasma: A review

Nonlinear phenomena in RF wave propagation has been observed from the earliest days in basic laboratory experiments going back to the 1960s [1], followed by observations of parametric instability (PDI) phenomena in large scale RF heating experiments in magnetized fusion plasmas in the 1970s and beyond [2]. Although not discussed here, the importance of PDI phenomena has also been central to understanding anomalous absorption in laser-fusion experiments (ICF) [3]. In this review I shall discuss the fundamentals of nonlinear interactions among waves and particles, and in particular, their role in PDIs. This phenomenon is distinct from quasi-linear phenomena that are often invoked in calculating absorption of RF power in wave heating experiments in the core of magnetically confined plasmas [4]. Indeed, PDIs are most likely to occur in the edge of magnetized fusion plasmas where the electron temperature is modest and hence the oscillating quiver velocity of charged particles can be comparable to their thermal speeds. Specifically, I will review important aspects of PDI theory and give examples from past experiments in the ECH/EBW, lower hybrid (LHCD) and ICRF/IBW frequency regimes. Importantly, PDI is likely to play a fundamental role in determining the so-called “density limit” in lower hybrid experimentsmore » that has persisted over the decades and still central to understanding present day experiments [5-7].« less
Authors:
Publication Date:
OSTI Identifier:
22496178
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1689; Journal Issue: 1; Conference: 21. topical conference on radio frequency power in plasmas, Lake Arrowhead, CA (United States), 27-29 Apr 2015; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ABSORPTION; CHARGED PARTICLES; COMPARATIVE EVALUATIONS; ECR HEATING; ELECTRON TEMPERATURE; ICR HEATING; INTERACTIONS; ION CYCLOTRON-RESONANCE; LASER FUSION REACTORS; LOWER HYBRID CURRENT DRIVE; LOWER HYBRID HEATING; NONLINEAR PROBLEMS; PARAMETRIC INSTABILITIES; PLASMA; RADIOWAVE RADIATION; REVIEWS; VELOCITY; WAVE PROPAGATION