Geodesic modes driven by untrapped resonances of NB energetic ions in tokamaks

Elfimov, A. G.; Galvão, R. O.; Gorelenkov, N. N.

doi:10.1063/1.5110175

Title: Geodesic modes driven by untrapped resonances of NB energetic ions in tokamaks

Journal Article · Thu Oct 17 00:00:00 EDT 2019 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.5110175· OSTI ID:1668416

^[1]; Galvão, R. O. ^[2];

^[3]

Univ. of Sao Paulo (Brazil)
National Inst. for Space Research, São José dos Campos (Brazil)
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

Geodesic modes are typically excited by a minor concentration of energetic ions, but unstable mode frequencies are substantially different from Geodesic Acoustic Modes (GAMs) and are named EGAM (Energetic particle GAM). The EGAM instability driven by Neutral Beam Injection (NBI) has been observed in DIII-D tokamak experiments. The problem of the geodesic mode instability is analytically studied using a full drift kinetic equation. To analyze the instability condition, an ionization NBI location is assumed to be on the high field side of tokamaks. Here, a minority NBI ion distribution is modeled by an energetic ion tail in the untrapped-passing region that remains between a magnetic axis and the trapped NBI boundary. The EGAM instability condition is defined by the parallel NBI ion velocity v | | ≈ ( 1.2 – 1.5 ) ω R 0 q 0 that has to be above the effective EGAM phase velocity. In this case, the EGAM frequency is ≈ 50 % below the standard stable GAM frequency, which is reduced by a small concentration of energetic NBI ions. Qualitative comparison of the developed geodesic mode theory with NBI heating experiments in the midregion of the tokamak plasma is discussed.

View Accepted Manuscript (DOE)

View Accepted Manuscript (Publisher)

Cite

Export

Save

Research Organization:: Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)

Sponsoring Organization:: USDOE; CNPq (National Council of Scientific and Technological Development

Grant/Contract Number:: AC02-09CH11466; 306757/2015-0; 307984/2016-8

OSTI ID:: 1668416

Alternate ID(s):: OSTI ID: 1570782

Report Number(s):: 2020_156; TRN: US2203698

Journal Information:: Physics of Plasmas, Vol. 26, Issue 10; ISSN 1070-664X

Publisher:: American Institute of Physics (AIP)Copyright Statement

Country of Publication:: United States

Language:: English

Citation Metrics:

Cited by: 2 works

Citation information provided by
Web of Science

References (16)

Plateau regime dynamics of the relaxation of poloidal rotation in tokamak plasmas Lebedev, V. B.; Yushmanov, P. N.; Diamond, P. H. Physics of Plasmas, Vol. 3, Issue 8 https://doi.org/10.1063/1.871638	journal	August 1996
Structure and scaling properties of the geodesic acoustic mode McKee, G. R.; Gupta, D. K.; Fonck, R. J. Plasma Physics and Controlled Fusion, Vol. 48, Issue 4 https://doi.org/10.1088/0741-3335/48/4/S09	journal	March 2006
Energetic-Particle-Induced Geodesic Acoustic Mode Fu, G. Y. Physical Review Letters, Vol. 101, Issue 18 https://doi.org/10.1103/PhysRevLett.101.185002	journal	October 2008
Beam anisotropy effect on Alfvén eigenmode stability in ITER-like plasmas Gorelenkov, N. N.; Berk, H. L.; Budny, R. V. Nuclear Fusion, Vol. 45, Issue 4 https://doi.org/10.1088/0029-5515/45/4/002	journal	March 2005
Heating of toroidal plasmas by neutral injection Stix, T. H. Plasma Physics, Vol. 14, Issue 4 https://doi.org/10.1088/0032-1028/14/4/002	journal	April 1972
Intense Geodesic Acousticlike Modes Driven by Suprathermal Ions in a Tokamak Plasma Nazikian, R.; Fu, G. Y.; Austin, M. E. Physical Review Letters, Vol. 101, Issue 18 https://doi.org/10.1103/PhysRevLett.101.185001	journal	October 2008
Geodesic acoustic mode spectroscopy Itoh, S-I; Itoh, K.; Sasaki, M. Plasma Physics and Controlled Fusion, Vol. 49, Issue 8 https://doi.org/10.1088/0741-3335/49/8/L01	journal	July 2007
Particle transport due to energetic-particle-driven geodesic acoustic modes Zarzoso, D.; del-Castillo-Negrete, D.; Escande, D. F. Nuclear Fusion, Vol. 58, Issue 10 https://doi.org/10.1088/1741-4326/aad785	journal	August 2018
Geodesic mode instability driven during ion cyclotron heating in tokamaks Elfimov, A. G. Physics of Plasmas, Vol. 25, Issue 6 https://doi.org/10.1063/1.5041745	journal	June 2018
Beam ion losses due to energetic particle geodesic acoustic modes Fisher, R. K.; Pace, D. C.; Kramer, G. J. Nuclear Fusion, Vol. 52, Issue 12 https://doi.org/10.1088/0029-5515/52/12/123015	journal	November 2012
The features of the global GAM in OH and ECRH plasmas in the T-10 tokamak Melnikov, A. V.; Eliseev, L. G.; Perfilov, S. V. Nuclear Fusion, Vol. 55, Issue 6 https://doi.org/10.1088/0029-5515/55/6/063001	journal	April 2015
Geodesic acoustic eigenmode for tokamak equilibrium with maximum of local GAM frequency Lakhin, V. P.; Sorokina, E. A. Physics Letters A, Vol. 378, Issue 5-6 https://doi.org/10.1016/j.physleta.2013.12.008	journal	January 2014
Nonlocal theory of energetic-particle-induced geodesic acoustic mode Qiu, Zhiyong; Zonca, Fulvio; Chen, Liu Plasma Physics and Controlled Fusion, Vol. 52, Issue 9 https://doi.org/10.1088/0741-3335/52/9/095003	journal	July 2010
Explanation of the JET n = 0 chirping mode Berk, H. L.; Boswell, C. J.; Borba, D. Nuclear Fusion, Vol. 46, Issue 10 https://doi.org/10.1088/0029-5515/46/10/S04	journal	September 2006
Geodesic mode spectrum modified by the energetic particles in tokamak plasmas Elfimov, A. G. Physics Letters A, Vol. 378, Issue 47 https://doi.org/10.1016/j.physleta.2014.10.015	journal	November 2014
Mean and Oscillating Plasma Flows and Turbulence Interactions across the $L − H$ Confinement Transition Conway, G. D.; Angioni, C.; Ryter, F. Physical Review Letters, Vol. 106, Issue 6 https://doi.org/10.1103/PhysRevLett.106.065001	journal	February 2011