Turbulence at the edge of the plasma in a nuclear fusion reactor can cause loss of confinement of the plasma. In an effort to study the edge turbulence, the National Spherical Torus Experiment uses a gas puff imaging (GPI) diagnostic to capture images of the turbulence. A gas puff is injected into the torus and visible light emission from the gas cloud is captured by an ultra high-speed camera. Our goal is to detect and track coherent structures in the GPI images to improve our understanding of plasma edge turbulence. In this paper, we present results from various segmentation methods for the identification of the coherent structures. We consider three categories of methods - immersion-based, region-growing, and model-based - and empirically evaluate their performance on four sample sequences. Our preliminary results indicate that while some methods can be sensitive to the settings of parameters, others show promise in being able to detect the coherent structures.

Date Published: 24 September 2007
PDF: 12 pages
Proc. SPIE 6696, Applications of Digital Image Processing XXX, 66960D (24 September 2007);

Published in SPIE Proceedings Vol. 6696:
Applications of Digital Image Processing XXX
Andrew G. Tescher, Editor(s)