PPPL-3800 is available in <a href="PPPL-3800.pdf">pdf</a> format (852 KB).

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<b>A New Interpretation of Alpha-particle-driven Instabilities in Deuterium-tritium Experiments on the Tokamak Fusion Test Reactor</b>
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<b>Authors:</b> R. Nazikian, G.J. Kramer, C.Z. Cheng, N.N. Gorelenkov, H.L. Berk, and S.E. Sharapov
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<b>Date of PPPL Report:</b> March 2003
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<b>Submitted to:</b> Physical Review Letters</p>


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The original description of alpha-particle-driven instabilities in the Tokamak Fusion Test Reactor (TFTR) in terms of Toroidal Alfv&#233;n Eigenmodes (TAEs) remained inconsistent with three fundamental characteristics of the observations: (i) the variation of the mode frequency with toroidal mode number, (ii) the chirping of the mode frequency for a given toroidal mode number, and (iii) the anti-ballooning density perturbation of the modes. It is now shown that these characteristics can be explained by observing that cylindrical-like modes can exist in the weak magnetic shear region of the plasma that then make a transition to TAEs as the central safety factor decreases in time.




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