DIII-D RESEARCH OPPORTUNITIES FORUM FOR THE 2013 EXPERIMENTAL CAMPAIGN Review | Direct submission with log-in | Request submission without log-in
Print this page

Print this page
Title	354: Control of Major Disruptions in DIII-D
Name:	Amiya Sen amiya@ee.columbia.edu	Affiliation:	Columbia University
Research Area:	Stability & Disruption Avoidance	Presentation time:	Not requested
Co-Author(s):	Robert Granitz, MIT; Rob Lahaye,DIII-D	ITPA Joint Experiment :	No
Description:	It is argued that major disruptions in ITER can be avoided by the feedback control of the causative MHD precursors. The sensors will be 2D-arrays of ECE detectors and the suppressors will be modulated ECH beams injected radially to produce non-thermal radial pressures to counter the radial dynamics of MHD modes. The appropriate amplitude and phase of this signal can stabilize the relevant MHD modes and prevent their evolution to a major disruption. For multimode MHD precursors, an optimal feedback scheme with a Kalman filter is discussed.	ITER IO Urgent Research Task :	No
Experimental Approach/Plan:	We propose a novel non-magnetic suppressor in the form of a radially injected and modulated (at MHD frequency in laboratory frame) ECH beam. In this case, there will be no current drive, but the transverse energy of electrons will nearly instantaneously increase with a resonance response. This implies a prompt local increase in electron non-thermal pressure, which at an appropriate phase can push the MHD mode radially inward. For hardware issues, the ECH beam will be used in pulsed mode (on or off), which will suffice.
Background:	The background is available in: "Feedback control of major disruptions in ITER" PHYSICS OF PLASMAS 18, 082502 (2011)
Resource Requirements:	Gating of ECH beams.
Diagnostic Requirements:	ECE imaging system based on shotky barrier diodes.
Analysis Requirements:	Image reconstruction and localization of the rough centroid of the relative MHD modes.
Other Requirements:	No