Search for Alpha-Driven BAE Modes in TFTR
Author: W.W. Heidbrink,S. Batha, R. Bell, Z. Chang, D. Darrow, J. Fang, E. Fredrickson, R.A. James, F. Levinton, R. Nazikian, S. Paul, E. Ruskov, S. Sabbagh, E.J. Strait, E. Synakowski, G. Taylor, A. Turnbull, K.-L. Wong, and S. Zweben
A search for alpha-driven beta-induced Alfvén eigenmodes (BAE modes) was conducted in low current (1.0-1.6 MA) TFTR super- shots. Stable high-beta deuterium-tritium (DT) discharges were obtained with p = 2:4 and central alpha beta of 0.1%. Instabilities between 75- 200 kHz were observed by magnetic probes in many DT discharges, but the activity was also present in deuterium-deuterium (DD) comparison dis- charges, indicating that these modes are not destabilized (principally) by the alpha-particle population. Losses of fusion products are also similar in the two sets of discharges.