Darren Garnier
Columbia University/MIT Plasma Science and Fusion Center
"First Flight of the Levitated Dipole Experiment"
In the past year, the first levitated experiments have been conducted in the Levitated Dipole Experiment (LDX). LDX, which consists of a 560 kg superconducting coil floating within a 5m diameter vacuum chamber, is designed to study fusion relevant plasmas confined in a dipole magnetic field. In previous plasma run campaigns, conducted with the dipole coil held by thin supports, stable high beta plasma operations were demonstrated where the plasma kinetic energy is contained in population of energetic particles. It was expected that levitated experiments would improve confinement by removing the primary loss of energy and particles along field lines. This in turn would lead to higher plasma density and broader radial profiles which should increase the stable operational space. In February 2007, the first flight of the floating dipole coil was achieved with 40 minutes of continuous levitation and three demonstration plasma shots. This first flight experiment demonstrated the operation of the digital feedback system that provides for stable levitation of the coil. Further flights were undertaken this, leading to the first plasma experiments with the launcher fully removed from the plasma. Initial results confirm many of the expected behaviors, where significant changes in the plasma profiles have been observed.
Prof. Thomas Pedersen, host
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