Abstract
Parametric decay instabilities (PDIs) are nonlinear processes by which energy from a strong pump wave may be directed into other waves at other frequencies, in particular natural modes of the medium, provided that energy and momentum are conserved. The particle-in-cell (PIC) code EPOCH is used to simulate PDIs in a magnetically confined fusion plasma converting a 105 GHz microwave X-mode pump wave into electrostatic daughter waves at the upper hybrid (UH) layer. Modes associated with the PDIs as well as a linearly converted electron Bernstein wave (EBW) are identified in f- and k-space. The PDI daughter modes are found to agree with experimental observations from ASDEX Upgrade as well as with analytical predictions, showing a nonlinear increase in power above a predicted threshold.
Original language | English |
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Article number | 025010 |
Journal | Plasma Physics and Controlled Fusion |
Volume | 62 |
Issue number | 2 |
Number of pages | 13 |
ISSN | 0741-3335 |
DOIs | |
Publication status | Published - 2020 |
Keywords
- Parametric decay instabilities
- Particle in cell
- Upper hybrid layer
- Electron Bernstein waves