The Thomson Scattering System on the Lithium Tokamak eXperiment (LTX)
Authors: T. Strickler, R. Majeski, R. Kaita, B. LeBlanc
Abstract:
The Lithium Tokamak eXperiment (LTX) is a spherical tokamak with R0 = 0.4m, a = 0.26m, BTF ~ 3.4kG, IP ~ 400kA, and pulse length ~ 0.25s. The goal of LTX is to investigate tokamak plasmas that are almost entirely surrounded by a lithium-coated plasma-facing shell conformal to the last closed magnetic flux surface. Based on
previous experimental results and simulation, it is expected that the low-recycling liquid lithium surfaces will result in higher temperatures at the plasma edge, flatter overall temperature profiles, centrally-peaked density profiles, and an increased confinement time. To test these predictions, the electron temperature and density profiles in LTX will be measured by a multi-point Thomson scattering system (TVTS). Initially, TS measurements will be made at up to 12 simultaneous points between the plasma center and plasma edge. Later, high resolution edge measurements will be deployed to study the lithium edge physics in greater detail. Technical challenges to implementing the TS system included limited "line of sight" access to the plasma due to the plasma-facing shell and problems associated with the presence of liquid lithium.
__________________________________________________
Published in: Review of Scientific Instruments 79, 10E738 (2008)
© (2008) American Institute of Physics.
This article may be downloaded for personal use only.
Any other use requires prior permission of the author
and the American Institute of Physics.
Presented at: 17th Topical Conference on High Temperature Plasma Diagnostics, Albuquerque, NM (May 2008)
__________________________________________________
Download PPPL-4338 (pdf 367.45KB 11pp)
__________________________________________________