Role of self-generated and externally applied radial electric fields in the development of ITG driven modes
The delta f particle-in-cell (PIC) method provides an approach to solving the nonlinear gyrokinetic equations governing the ion-temperature-gradient-driven (ITG) instabilities commonly held responsible for core plasma transport. The method is, however, rather demanding with respect to current typically available computational resources. The global TORB code includes the parallel velocity nonlinearity allowing for an intrinsic energy conservation check, which has been well satisfied (approximately 20% deep into the nonlinear stage) using optimised phase space sampling. A surface average adiabatic electron response is used. The characteristics of the nonlinear state are described in detail. These results are compared with those obtained while excluding the parallel nonlinearity. The effect of externally applied electric field on linear ITG growth rates has been examined in some depth. Their role in determining the 'saturated' nonlinear state is addressed, with a view to shedding some light on the observed shearing-rate criterion.
Bibliographic Reference: A paper presented at the Joint Varenna-Lausanne International Workshop on "Theory of Fusion Plasmas", Varenna, Italy, August 27-30 2002, and published in EPFL Internal report 737/02, October 2002, pp.1-12.
Availability: Available free of charge from: École Polytechnique Fédérale de Lausanne (EPFL), Ecublens, CH-1015 Lausanne Fax +41-21-6934747 Available online on the workshop website: http://varenna-lausanne.epfl.ch/
Record Number: 200215539 / Last updated on: 2002-11-20
Original language: en
Available languages: en