Abstract Details

Helimak as a testbed for novel divertors

Author: Michael C Pekker
Submitted: 2006-01-02 14:01:32

Co-authors: M. Kotschenreuther, P. Valanju, J. C. Wiley, K. Gentle, D. Miracle

Contact Info:
Institute for Fusion Studies
1 University Station
Austin, TX   78712
USA

Abstract Text:
Given the great difficulty in extrapolating standard divertors to reactor
relevant conditions, a plasma testbed is needed for novel divertors. The
novel divertors are based on 1) extreme flux expansion to reduce heat fluxes
and 2) the use of liquid metals as divertor surfaces. High surface heat
fluxes appear possible in the helimak using Ohmic plasma heating.

Appropriate magnetic geometries can be created on helimak to test
the concept by the addition of PF coils at the bottom of helimak. The extreme
flux expansion concept requires testing to verify that cross field transport
eliminates hot spots from surface irregularities. Bolometric and other
diagnostics are discussed.

Recent results from CDX-U (D. Majeski et. al) show that liquid
metal convection can improve heat flux capacity, and a liquid lithium
divertor has been proposed for NSTX. Here, we propose electromagnetically
induced convection concepts, which appear to scale well to high magnetic
fields. These concepts can be tested on helimak, either separately or in
conjunction with concept 1) above.

We have modeled blob transport on tokamak and validated our code
results with helimac data (see poster by Wiley et. al.). We will use
this code to simulate these configurations

Characterization: A5

Comments:
Group with posters by Valanju, Wiley, Pekker

The University of Texas at Austin

Innovative Confinement Concepts Workshop
February 13-16, 2006
Austin, Texas

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