Overview of studies of turbulence, transport and flows in the Large Plasma Device
POSTER
Abstract
The Large Plasma Device (LAPD) at UCLA is a 17m long, 0.6m diameter linear magnetized plasma in which broadband edge turbulence driven by pressure and flow gradients is observed. Particle transport barriers are observed with bias-driven cross-field flows in LAPD.\footnote{J. E. Maggs, et al. Phys. Plasmas 14, 052507 (2007); T. A. Carter and J. E. Maggs, Phys. Plasmas 16, 012304 (2009)} New biasable limiters have been installed, allowing for a continuous variation in the edge flow and flow shear. Initial experiments using this new capability have shown confinement degradation at low flow/shear and improved confinement with both positive and negative azimuthal flow and flow shear. The 3D Braginskii fluid turbulence code BOUT (and now BOUT++) has been modified for and verified in cylindrical geometry for application to LAPD.\footnote{P. Popovich, et al. Phys. Plasmas 17, 102107 (2010)}. Nonlinear simulations yield good qualitative and semi-quantitative agreement with LAPD data\footnote{P. Popovich, et al., Phys. Plasmas 17, 122312 (2010)} Finally, a new fast-framing camera has been applied to imaging visible light fluctuations in LAPD as a turbulence diagnostic and initial results will be discussed.