Seminars
There are a number of plasma-related
seminars on the UCLA campus.
Space Physics seminars are held regularly throughout the quarter and are sponsored by the department of Earth, Planetary, and Space Sciences.
The Collaborative Center for Aerospace Sciences (CCAS), a joint venture of the Air Force Research Laboratory (Edwards AFB) and UCLA, sponsors seminars that are held throughout the year.
Plasma Seminars Fall 2020
Tuesday November 17, 2020 at 3:00pm, Nuno F. Loureiro, MIT, Boston MA, "New Insights into Plasma Turbulence." Contact Meg Murphy for Zoom meeting link and information.
Abstract: The current understanding of plasma turbulence in the MHD regime suggests that turbulent eddies become progressively more elongated structures in the plane perpendicular to the local mean magnetic field. Using recent results from reconnection theory, we argue that such eddies must inevitably fall prey to the tearing instability. As a result, there is a transition, in the inertial range, to a tearing (reconnection)-mediated turbulent cascade, where the spectral scaling k^{-11/5} is predicted. These results can be extended to collisionless plasmas; in the different regimes of interest that have been explored, the magnetic energy spectral scaling is invariably found to be in the range k^{-8/3} to k^{-3}, consistent with many observations.
SoCal Plasma Zoom Seminar: Tuesday November 3, 2020 at 9:00am, David Hughes (Leeds University UK), "Inertialess Dynamos in Rotating Convection." Contact Meg Murphy for Zoom meeting link and information. Co-sponsored by UC San Diego, UCI, UCLA.
Abstract: One of the great challenges in planetary magnetohydrodynamics is to understand how magnetic fields are regenerated (the dynamo process) in a convecting fluid that has little inertia or viscosity (more precisely, small Rossby number and small Ekman number). Here I shall consider dynamos driven by formally inertialess convection; this approach has the twin advantages of being in the relevant physical regime and also allowing a useful decomposition of the momentum equation. I shall show how two very distinct types of dynamo are possible (weak and strong field dynamos), how the crucial balance of forces differ in the two cases and what this might tell us about the Taylor constraint.