PPPL-3694 is available in <a href="PPPL-3694.pdf">pdf</a> format (348 KB).

<p>
<b>Effect of Trapped Energetic Ions on MHD Activity in Spherical Tori</b>
</p>

<p>
<b>Authors:</b> Ya.I. Kolesnichenko, V.V. Lutsenko, V.S.Marchenko, and R.B. White 
</p>

<p>
<b>Date of PPPL Report:</b>  May 2002
</p>

<p>
<b>Submitted to:</b> Physics Letters A</p>


<p>

It is shown that the increase of beta (the ratio of plasma pressure to the magnetic field pressure) may change the character of the influence of trapped energetic ions on MHD stability in spherical tori. Namely, the energetic ions, which stabilize MHD modes (such as the ideal-kink mode, collisionless tearing mode, and semi-collisional tearing mode) at low beta, have a destabilizing influence at high beta unless the radial distribution of the energetic ions is very peaked.




</p>