Far-infrared plasma reflectometry and instability detection

Abstract
A focused cyanide laser beam at 337 μ is used to study a steady‐state highly ionized plasma column operating at densities up to 1.5×1016 cm−3 in an axial magnetic field up to 10 kG. A reflectometer measures the energy reflected from the cutoff layer. A strong coherent m=1 instability in the plasma is detected by amplitude modulation of either an off‐axis transmitted beam or an on‐axis reflected beam. This technique allows electrodeless probing of the stability characteristics of a high‐energy‐density plasma.