Magnetic geometry and physics of advanced divertors: The X-divertor and the snowflake

Journal Article · Tue Oct 15 04:00:00 EDT 2013 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4824735· OSTI ID:22218532

Kotschenreuther, Mike; Valanju, Prashant; Covele, Brent; Mahajan, Swadesh ^[1]

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1. Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712 (United States)

Advanced divertors are magnetic geometries where a second X-point is added in the divertor region to address the serious challenges of burning plasma power exhaust. Invoking physical arguments, numerical work, and detailed model magnetic field analysis, we investigate the magnetic field structure of advanced divertors in the physically relevant region for power exhaust—the scrape-off layer. A primary result of our analysis is the emergence of a physical “metric,” the Divertor Index DI, which quantifies the flux expansion increase as one goes from the main X-point to the strike point. It clearly separates three geometries with distinct consequences for divertor physics—the Standard Divertor (DI = 1), and two advanced geometries—the X-Divertor (XD, DI > 1) and the Snowflake (DI < 1). The XD, therefore, cannot be classified as one variant of the Snowflake. By this measure, recent National Spherical Torus Experiment and DIIID experiments are X-Divertors, not Snowflakes.

• OSTI ID: 22218532
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 10 Vol. 20; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
DIVERTORS
INDEXES
MAGNETIC FIELDS
PLASMA
PLASMA CONFINEMENT
PLASMA EXPANSION
PLASMA SCRAPE-OFF LAYER
SPHERICAL CONFIGURATION
THERMONUCLEAR REACTORS