15th Topical Conference on High Temperature Plasma Diagnostics, 19 a 22 de Abril de 2004, San Diego, USA

	A Real-Time DSP-Based System for MHD Mode Identification in ISTTOK
	B. Carvalho, H. Fernandes, J. Sousa e C.A.F. Varandas
	Resumo
	A new diagnostic for the magnetohydrodynamic (MHD) mode identification is being implemented in the Tokamak ISTTOK using the signals from the set of 12 equally spaced magnetic coils. These poloidal field sensors have been recently installed inside the vessel and were designed for plasma shape and position equilibrium determination. The data acquisition and processing system is based on a new locally-developed galvanic isolated, 8 channel fast PCI transient recorder module with a 2 MSamples/sec sample rate, 14 bit resolution and a total memory capacity of 256 MWords. This module includes a Digital Signal Processor (DSP) and Field Programmable Gate Array (FPGA) allowing real-time determination of MHD modes using advanced identification algorithms. The output of this system is available to be used in active feedback control schemes of unstable modes. Initial measurements and identification tests are presented.