Ion density fluctuations are resolved in space, time, and parallel velocity using laser-induced fluorescence and a two-point correlation technique. These measurements reveal two parallel wavelengths of distinct correlation lengths, one of which is explained by fluid theory. The other wavelength (referred to as the kinetic component) is ion velocity dependent. The effect of collisions on the fluctuation spectrum is reported. Ion velocity-dependent measurements of the fluctuation-induced transport rate are also presented.
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