Studies of Flows, Turbulence and Transport in the Large Plasma Device

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Most of the visible (light-emitting) matter in the universe is composed of plasma (ionized gas), e.g. stars like our sun. Most of these plasmas are permeated by magnetic fields; the forces associated with these magnetic fields tend to confine plasmas. Although gravity is the dominant force in stars, evidence of magnetic confinement can be found in the arcades and coronal loops that are visible in ultraviolet and soft x-ray images of the surface of our sun. Magnetic confinement of plasmas is used in the laboratory, in particular in fusion energy research: magnetic fields in a tokamak confine hot plasma so that nuclear fusion can occur and be harnessed as a power source. In the lab or in space, magnetic confinement is not perfect: plasma (and associated heat) leak across the magnetic field, primarily due to turbulence that arises spontaneously in confined plasmas. Understanding this leakage, or transport, of plasma and heat across a confining magnetic field is important both for basic understanding of astrophysical plasmas such as stars as well as for enabling the efficient production of fusion energy. This project will investigate the role of flow in controlling transport due to turbulence, making use of a laboratory experiment at UCLA (the Large Plasma Device or LAPD). The intellectual merit of this project stems from the fundamental importance of turbulence, transport, and flows in a wide range of plasmas. A detailed study of the interplay between transport, turbulence and flows will have an impact on a wide range of subfields of plasma physics, including magnetic confinement fusion, and space and astrophysical plasma physics. The broader impacts of this project are realized through both the research and educational activities. A major focus of the proposal is the training of two graduate students, both working toward a PhD. The proposed work will leverage and extend an existing effort in collaboration with Lawrence Livermore National Laboratory to compare experimental measurements to predictions of massively-parallel computer simulations. This comparative effort will help build a predictive capability in turbulence and transport in magnetized plasmas. This is important in advancing our understanding of fundamental plasma processes in a variety of settings, but is especially critical to progress in magnetic fusion energy research.