Fast reciprocating probe system used to study edge turbulence on TEXT

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Abstract
We have combined several techniques in a new and unique way that allows us to measure edge profiles (ne, Te, and φp), their gradients, fluctuations (ñe and φ̃f), and fluctuation‐induced heat and particle transport on a single discharge of the TEXT tokamak. To do this we utilize a fast reciprocating probe drive, a four pin Langmuir probe array, and suitable data analysis techniques. With this method, many of the quantities of interest to turbulence studies can be obtained on one discharge. Scaling studies of fluctuations versus free‐energy drives (gradients) are easily carried out and data from such a scan are presented. This method also allows a study of changes to the profiles, fluctuations, and transport caused by perturbations to the plasma (ECH, pellets, etc.) during a single discharge.