Trapped particle precession in advanced tokamaksFunded under: FP3-FUSION 11C
Plasma equilibrium parameters affect the precessional drift velocities of trapped particles, which can significantly influence plasma stability (for example, collisionless trapped electron driftwaves and fishbones). The calculation outlined computes the bounce averaged drift velocities of trapped particles for toroidally symmetric plasmas of arbitrary aspect ratio with elliptical and triangular shaping of the poloidal plasma cross-section. The calculation is then applied to flux surfaces with the properties characteristic of JET and also of the START experiment, where it has been postulated that favourable trapped particle drift effects may be responsible for improved confinement. This calculation fails to confirm this idea, and suggests that the drive for instability from toroidal drifts at START is similar to that in JET.
Bibliographic Reference: Report: UKAEA FUS 281 EN (1995) 42 pp.
Availability: Available from the Librarian, UKAEA, Culham Laboratory, Abingdon, Oxon. OX14 3DB (GB)
Record Number: 199510237 / Last updated on: 1995-02-21
Original language: en
Available languages: en