Open AccessNovel internal measurements of ion cyclotron frequency range fast-ion driven modes
Author(s) -
N. A. Crocker,
Shawn Tang,
K. E. Thome,
Jeff Lestz,
Е. В. Белова,
Amani Zalzali,
R. O. Dendy,
W. A. Peebles,
K. Barada,
Rongjie Hong,
T. L. Rhodes,
Guiding Wang,
L. Zeng,
Troy Carter,
Genevieve DeGrandchamp,
W. W. Heidbrink,
R. I. Pinsker
Publication year - 2022
Publication title -
nuclear fusion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.774
H-Index - 120
eISSN - 1741-4326
pISSN - 0029-5515
DOI - 10.1088/1741-4326/ac3d6a
Subject(s) - cyclotron , ion , physics , atomic physics , amplitude , harmonics , harmonic , optics , quantum mechanics , voltage
Novel internal measurements and analysis of ion cyclotron frequency range fast-ion driven modes in DIII-D are presented. Observations, including internal density fluctuation ( n ~ ) measurements obtained via Doppler backscattering, are presented for modes at low harmonics of the ion cyclotron frequency localized in the edge. The measurements indicate that these waves, identified as coherent ion cyclotron emission (ICE), have high wave number, k ⊥ ρ fast ≳ 1, consistent with the cyclotron harmonic wave branch of the magnetoacoustic cyclotron instability, or electrostatic instability mechanisms. Measurements show extended spatial structure (at least ∼1/6 the minor radius). These edge ICE modes undergo amplitude modulation correlated with edge localized modes (ELM) that is qualitatively consistent with expectations for ELM-induced fast-ion transport.