Intense geodesic acousticlike modes driven by suprathermal ions in a tokamak plasma

R. Nazikian; G. Y. Fu; M. E. Austin; H. L. Berk; R. V. Budny; N. N. Gorelenkov; W. W. Heidbrink; C. T. Holcomb; G. J. Kramer; G. R. McKee; M. A. Makowski; W. M. Solomon; M. Shafer; E. J. Strait; M. A. Van Zeeland

doi:10.1103/PhysRevLett.101.185001

Intense geodesic acousticlike modes driven by suprathermal ions in a tokamak plasma

R. Nazikian, G. Y. Fu, M. E. Austin, H. L. Berk, R. V. Budny, N. N. Gorelenkov, W. W. Heidbrink, C. T. Holcomb, G. J. Kramer, G. R. McKee, M. A. Makowski, W. M. Solomon, M. Shafer, E. J. Strait, M. A. Van Zeeland

Research output: Contribution to journal › Article › peer-review

143 Scopus citations

Abstract

Intense axisymmetric oscillations driven by suprathermal ions injected in the direction counter to the toroidal plasma current are observed in the DIII-D tokamak. The modes appear at nearly half the ideal geodesic acoustic mode frequency, in plasmas with comparable electron and ion temperatures and elevated magnetic safety factor (qmin 2). Strong bursting and frequency chirping are observed, concomitant with large (10%-15%) drops in the neutron emission. Large electron density fluctuations (ne/ne1.5%) are observed with no detectable electron temperature fluctuations, confirming a dominant compressional contribution to the pressure perturbation as predicted by kinetic theory. The observed mode frequency is consistent with a recent theoretical prediction for the energetic-particle-driven geodesic acoustic mode.

Original language	English
Article number	185001
Journal	Physical Review Letters
Volume	101
Issue number	18
DOIs	https://doi.org/10.1103/PhysRevLett.101.185001
State	Published - Oct 30 2008
Externally published	Yes

Access to Document

10.1103/PhysRevLett.101.185001

Cite this

Nazikian, R., Fu, G. Y., Austin, M. E., Berk, H. L., Budny, R. V., Gorelenkov, N. N., Heidbrink, W. W., Holcomb, C. T., Kramer, G. J., McKee, G. R., Makowski, M. A., Solomon, W. M., Shafer, M., Strait, E. J., & Van Zeeland, M. A. (2008). Intense geodesic acousticlike modes driven by suprathermal ions in a tokamak plasma. Physical Review Letters, 101(18), Article 185001. https://doi.org/10.1103/PhysRevLett.101.185001

@article{b445c9e84e504af1b0a2ce9a83cab97d,

title = "Intense geodesic acousticlike modes driven by suprathermal ions in a tokamak plasma",

abstract = "Intense axisymmetric oscillations driven by suprathermal ions injected in the direction counter to the toroidal plasma current are observed in the DIII-D tokamak. The modes appear at nearly half the ideal geodesic acoustic mode frequency, in plasmas with comparable electron and ion temperatures and elevated magnetic safety factor (qmin 2). Strong bursting and frequency chirping are observed, concomitant with large (10%-15%) drops in the neutron emission. Large electron density fluctuations (ne/ne1.5%) are observed with no detectable electron temperature fluctuations, confirming a dominant compressional contribution to the pressure perturbation as predicted by kinetic theory. The observed mode frequency is consistent with a recent theoretical prediction for the energetic-particle-driven geodesic acoustic mode.",

author = "R. Nazikian and Fu, {G. Y.} and Austin, {M. E.} and Berk, {H. L.} and Budny, {R. V.} and Gorelenkov, {N. N.} and Heidbrink, {W. W.} and Holcomb, {C. T.} and Kramer, {G. J.} and McKee, {G. R.} and Makowski, {M. A.} and Solomon, {W. M.} and M. Shafer and Strait, {E. J.} and {Van Zeeland}, {M. A.}",

year = "2008",

month = oct,

day = "30",

doi = "10.1103/PhysRevLett.101.185001",

language = "English",

volume = "101",

journal = "Physical Review Letters",

issn = "0031-9007",

publisher = "American Physical Society",

number = "18",

}

Nazikian, R, Fu, GY, Austin, ME, Berk, HL, Budny, RV, Gorelenkov, NN, Heidbrink, WW, Holcomb, CT, Kramer, GJ, McKee, GR, Makowski, MA, Solomon, WM, Shafer, M, Strait, EJ & Van Zeeland, MA 2008, 'Intense geodesic acousticlike modes driven by suprathermal ions in a tokamak plasma', Physical Review Letters, vol. 101, no. 18, 185001. https://doi.org/10.1103/PhysRevLett.101.185001

TY - JOUR

T1 - Intense geodesic acousticlike modes driven by suprathermal ions in a tokamak plasma

AU - Nazikian, R.

AU - Fu, G. Y.

AU - Austin, M. E.

AU - Berk, H. L.

AU - Budny, R. V.

AU - Gorelenkov, N. N.

AU - Heidbrink, W. W.

AU - Holcomb, C. T.

AU - Kramer, G. J.

AU - McKee, G. R.

AU - Makowski, M. A.

AU - Solomon, W. M.

AU - Shafer, M.

AU - Strait, E. J.

AU - Van Zeeland, M. A.

PY - 2008/10/30

Y1 - 2008/10/30

N2 - Intense axisymmetric oscillations driven by suprathermal ions injected in the direction counter to the toroidal plasma current are observed in the DIII-D tokamak. The modes appear at nearly half the ideal geodesic acoustic mode frequency, in plasmas with comparable electron and ion temperatures and elevated magnetic safety factor (qmin 2). Strong bursting and frequency chirping are observed, concomitant with large (10%-15%) drops in the neutron emission. Large electron density fluctuations (ne/ne1.5%) are observed with no detectable electron temperature fluctuations, confirming a dominant compressional contribution to the pressure perturbation as predicted by kinetic theory. The observed mode frequency is consistent with a recent theoretical prediction for the energetic-particle-driven geodesic acoustic mode.

AB - Intense axisymmetric oscillations driven by suprathermal ions injected in the direction counter to the toroidal plasma current are observed in the DIII-D tokamak. The modes appear at nearly half the ideal geodesic acoustic mode frequency, in plasmas with comparable electron and ion temperatures and elevated magnetic safety factor (qmin 2). Strong bursting and frequency chirping are observed, concomitant with large (10%-15%) drops in the neutron emission. Large electron density fluctuations (ne/ne1.5%) are observed with no detectable electron temperature fluctuations, confirming a dominant compressional contribution to the pressure perturbation as predicted by kinetic theory. The observed mode frequency is consistent with a recent theoretical prediction for the energetic-particle-driven geodesic acoustic mode.

UR - http://www.scopus.com/inward/record.url?scp=55749113711&partnerID=8YFLogxK

U2 - 10.1103/PhysRevLett.101.185001

DO - 10.1103/PhysRevLett.101.185001

M3 - Article

AN - SCOPUS:55749113711

SN - 0031-9007

VL - 101

JO - Physical Review Letters

JF - Physical Review Letters

IS - 18

M1 - 185001

ER -

Intense geodesic acousticlike modes driven by suprathermal ions in a tokamak plasma

Abstract

Access to Document

Other files and links

Fingerprint

Cite this