Detailed comparison of plasma turbulence correlation length measurements using microwave reflectometry and a Langmuir probe array

Detailed comparisons of reflectometer and Langmuir probe measurements of turbulent radial correlation lengths in the Large Plasma Device (LAPD) at UCLA are presented. The LAPD is a magnetized linear plasma device where detailed measurements of electrostatic turbulence with probe arrays are possible. Furthermore, density profiles are well known and experiments have been conducted over a large number of repeatable discharges, resulting in low levels of measurement and statistical error. It has been found that homodyne reflectometer and probe correlation length measurements are in good agreement, to within 10-15%, over a wide range of density gradient scale lengths and relative fluctuation levels.