Electron kinetics inferred from observations of microwave bursts during edge localized modes in the mega-amp spherical tokamak

TY - JOUR

T1 - Electron kinetics inferred from observations of microwave bursts during edge localized modes in the mega-amp spherical tokamak

AU - Freethy, S. J.

AU - McClements, K. G.

AU - Chapman, S. C.

AU - Dendy, R. O.

AU - Lai, W. N.

AU - Pamela, S. J. P.

AU - Shevchenko, V. F.

AU - Vann, R. D. L.

PY - 2015/3/27

Y1 - 2015/3/27

N2 - Recent measurements of microwave and x-ray emission during edge localized mode (ELM) activity in tokamak plasmas provide a fresh perspective on ELM physics. It is evident that electron kinetics, which are not incorporated in standard (fluid) models for the instability that drives ELMs, play a key role in the new observations. These effects should be included in future models for ELMs and the ELM cycle. The observed radiative effects paradoxically imply acceleration of electrons parallel to the magnetic field combined with rapid acquisition of perpendicular momentum. It is shown that this paradox can be resolved by the action of the anomalous Doppler instability which enables fast collective radiative relaxation, in the perpendicular direction, of electrons accelerated in the parallel direction by inductive electric fields generated by the initial ELM instability.

AB - Recent measurements of microwave and x-ray emission during edge localized mode (ELM) activity in tokamak plasmas provide a fresh perspective on ELM physics. It is evident that electron kinetics, which are not incorporated in standard (fluid) models for the instability that drives ELMs, play a key role in the new observations. These effects should be included in future models for ELMs and the ELM cycle. The observed radiative effects paradoxically imply acceleration of electrons parallel to the magnetic field combined with rapid acquisition of perpendicular momentum. It is shown that this paradox can be resolved by the action of the anomalous Doppler instability which enables fast collective radiative relaxation, in the perpendicular direction, of electrons accelerated in the parallel direction by inductive electric fields generated by the initial ELM instability.

UR - http://www.scopus.com/inward/record.url?scp=84925845646&partnerID=8YFLogxK

U2 - 10.1103/PhysRevLett.114.125004

DO - 10.1103/PhysRevLett.114.125004

M3 - Article

AN - SCOPUS:84925845646

SN - 0031-9007

VL - 114

JO - Physical Review Letters

JF - Physical Review Letters

IS - 12

M1 - 125004

ER -