First Observation of Alpha Particle Loss Induced by Kinetic Ballooning Modes in TFTR Deuterium-Tritium Experiments

Zuoyang Chang; R. V. Budny; L. Chen; D. Darrow; E. D. Fredrickson; A. Janos; D. Mansfield; E. Mazzucato; K. M. McGuire; R. Nazikian; G. Rewoldt; J. D. Strachan; W. M. Tang; G. Taylor; R. B. White; S. Zweben; TFTR Group

doi:10.1103/PhysRevLett.76.1071

First Observation of Alpha Particle Loss Induced by Kinetic Ballooning Modes in TFTR Deuterium-Tritium Experiments

Zuoyang Chang, R. V. Budny, L. Chen, D. Darrow, E. D. Fredrickson, A. Janos, D. Mansfield, E. Mazzucato, K. M. McGuire, R. Nazikian, G. Rewoldt, J. D. Strachan, W. M. Tang, G. Taylor, R. B. White, S. Zweben, and TFTR Group

Phys. Rev. Lett. 76, 1071 – Published 12 February 1996

Abstract

A correlation between the measured alpha particle loss and high frequency ( $\sim 100 - 200$ kHz) magnetohydrodynamic (MHD) modes has been observed in some high β ( $=$ plasma pressure/magnetic pressure) DT plasmas in TFTR. These modes are localized around the peak plasma pressure gradient and have ballooning characteristics. Particle simulation shows that the loss is due to wave-particle resonances. Linear instability analysis indicates that the plasma is unstable to the kinetic MHD ballooning modes driven by strong local pressure gradients.