  We report on a study of the structure of edge turbulence in NSTX H-mode
discharges with applied n=1 and n=3 non-axisymmetric magnetic perturbations.
The edge turbulence is diagnosed in NSTX using the gas puff imaging (GPI)
system to understand how these 3D fields affect edge transport. The presented
database study uses a selection of discharges that have a change in the RWM
coil current during the GPI gas puff. We compare the turbulence before and
after this change in the applied non-axisymmetric fields, and compares the
turbulence between the two states. Our findings show that these 3D fields do
not have a strong, statistically significant impact on the average poloidal
size, autocorrelation time, or relative fluctuation levels of the turbulence.
In addition, we find that the displacement of the radial location of the GPI
signal peak intensity is correlated with the shift in the perturbed separatrix
location as predicted by the 3D vacuum magnetic field code MAFOT. We find that
in general the non-axisymmetric fields from the RWM coils locally displace the
edge flux surface as expected even when the self-consistent plasma response is
not included, and that the model reproduces the localized shift observed by
GPI.
