I-mode for ITER?

ORAL

Abstract

I-mode is a recently explored confinement regime that features a temperature pedestal and H-mode energy confinement, yet with L-mode particle confinement and no density pedestal nor large ELMs. Experiments on Alcator C-Mod and ASDEX-Upgrade show this leads to a stationary collisionless pedestal that inherently does not require ELMs for core impurity and particle control, possibly making I-mode an attractive operating regime for ITER where ELM heat pulses are expected to surpass material limits. We speculate as to how I-mode could be obtained, maintained and exploited for the ITER burning plasma physics mission. Issues examined include I-mode topology and power threshold requirements, pedestal formation, density control, avoiding H-mode, and the response of I-mode to alpha self-heating. Key uncertainties requiring further investigation are identified.

*Supported by the US DOE Cooperative Agreement DE-FC02-99ER54512.

Authors

  • D.G. Whyte

    • MIT PSFC
  • E. Marmar

    • MIT PSFC
  • A. Hubbard

    • MIT PSFC
  • J. Hughes

    • MIT PSFC
  • A. Dominguez

    • MIT PSFC
  • M. Greenwald

    • MIT PSFC