Development of State-Space Model-Based Kalman Filter for n>=1 Resistive Wall Mode (RWM)

Y. In, J.S. Kim, J. Kim, D.A. Humphreys, G.L. Jackson, R.D. Johnson, R.J. La Haye, E.J. Strait, M.L. Walker, A.M. Garofalo, H. Reimerdes, M. Okabayashi, E. Schuster

Division of Plasma Physics (DPP) Annual Meeting of the American Physical Society (APS)

Orlando, Florida, November 12-16, 2007

Abstract

While significant progress has been made for n =1 RWM identification and control, it is now predicted that n > 1 RWMs could appear even after the n =1 RWM is suppressed. Algorithm development, as well as diagnostic capability enhancement, is being done in order to identify the n = 2 or 3 RWMs in the presence of a stabilized n =1 RWM for DIII-D. Specifically, taking advantage of the successful development of the Kalman filter to discriminate ELM noise from an n =1 RWM [1], a more advanced Kalman filter is being developed to detect both n=1 and n > 1 RWMs. Noise characterization and modeling is deemed critical to determine the optimized Kalman gain. This multi-mode state-space model will also serve as a basis to design a model-based RWM feedback controller.

[1] Y. In et al., Phys. Plasmas 13, 062512 (2006).