Analytical theory of the period, amplitude and crash time of sawteeth in tokamaksFunded under: EAEC-FUSION 12C
A recently developed nonlinear dynamical model of turbulence is shown to result in scaling laws for the period, amplitude and crash time in terms of the sawtooth averaged quantities characteristic of the q < 1 core region to which it applies. These scaling relations involve plasma parameters such as the core plasma beta, confinement time, pressure length scale and shear parameter at the q = 1 radius. The analytic formulae are compared with numerical simulations for TEXT, TEXTOR and JET conditions and found to be in excellent agreement. The model is therefore able to predict the period, temperature amplitude and crash time given these core properties from experimental data. It also describes the temporal behaviour (during both ramp and crash) of the core-averaged temperature and turbulence level.
Bibliographic Reference: Report: EN (1995) 11 pp.
Availability: Available from the Librarian, UKAEA, Culham Laboratory, Abingdon, Oxon. OX14 3DB (GB)
Record Number: 199510805 / Last updated on: 1995-07-17
Original language: en
Available languages: en