ECH Density Pumpout and Small Scale Turbulence in DIII-D

Core density pumpout has been observed on DIII-D during ECCD experiments with 3~MW of injected ECH power absorbed at $\rho <\,$0.3 and 4~MW of counter neutral beam injection. The central plasma density dropped by almost 30\% in 150~ms after ECH was turned on. FIR scattering data showed a strong increase of turbulence at $k_\theta\sim\,$7~cm$^{-1}$, approximately synchronous with this density pumpout. The fluctuation scale is intermediate between $\rho_e$ and $\rho_i$ ($k\rho_i\sim\,$4). Mode identification (ITG, TEM [1] or other modes) is pending detailed data analysis. These results will be presented and compared with previously published data from TFTR [2] where a correlation between similar scale of turbulence and local electron energy transport was observed.\par \vspace{0.5em} \noindent [1]~C.~Angioni, et al., Nucl.\ Fusion $\bf {44}$, 827 (2004).\par \noindent [2]~K.L.\ Wong, et al., Phys.\ Lett.\ A $\bf {236}$, 339 (1997) and $\bf {276}$, 281 (2000).