%0 Journal Article
%T Temperature and Lifetime Measurements in the SSX Wind Tunnel
%A Adam D. Light
%A Kaitlin D Gelber
%A Manjit Kaur
%A Michael R. Brown
%J -
%D 2018
%R https://doi.org/10.3390/plasma1020020
%X Abstract We describe ion and electron temperature measurements in the Swarthmore Spheromak Experiment (SSX) MHD wind tunnel with the goal of understanding limitations on the lifetime of our Taylor-state plasma. A simple model based on the equilibrium eigenvalue and Spitzer resistivity predicted the lifetime satisfactorily during the first phase of the plasma evolution. We measured an average T e along a chord by taking the ratio of the C I I I 97.7 nm to C I V 155 nm line intensities using a vacuum ultraviolet (VUV) monochromator. We also recorded local measurements of T e and n e using a double Langmuir probe in order to inform our interpretation of the VUV data. Our results indicated that the plasma decayed inductively during a large part of the evolution. Ion Doppler spectroscopy measurements suggested that ions cooled more slowly than would be expected from thermal equilibration with the electrons, which maintained a constant temperature throughout the lifetime of the plasma. View Full-Tex
%K taylor states
%K magnetized plasma
%K spectroscopy
%K plasma lifetime
%K equilibration rate
%K e-folding time
%U https://www.mdpi.com/2571-6182/1/2/20