Events at Physics |
Events on Monday, November 24th, 2008
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- The Fermilab to Homestake Long Baseline Experiment
- Time: 2:00 pm
- Place: 4274 Chamberlin
- Speaker: Milind Diwan, BNL
- Abstract: I will describe the scientific and technical issues concerning building a very large detector at the new Homestake deep underground science and engineering laboratory and a new intense neutrino beam from Fermilab.
- Host: Albrecht Karle
- Physics Department Colloquium
- D.W. Kerst Lecture
- Studying Astrophysics in the Laboratory: How is Angular Momentum Rapidly Transported in Accretion Disks?
- Time: 4:00 pm
- Place: 2241 Chamberlin Hall (Coffee and cookies at 3.30 pm)
- Speaker: Hantao Ji, Center for Magnetic Self-Organization in Laboratory and Astrophysical Plasmas, Princeton Plasma Physics Laboratory, Princeton University
- Abstract: Rapid angular momentum transport in accretion disk plasmas has been a longstanding astrophysical puzzle. Since Keplerian flows are linearly stable in hydrodynamics, there exist only two viable mechanisms for the required turbulence: nonlinear hydrodynamic instability or linear magnetorotational instability (MRI). The latter is considered operating in hot disks ranging from quasars and X-ray binaries to cataclysmic variables. The former has been proposed mainly for cooler protoplanetary disk plasmas, whose Reynolds numbers are enormous. Despite their popularity, however, both candidate mechanisms have been rarely demonstrated and studied in the laboratory. In this talk, I will describe a novel laboratory experiment in a short Taylor-Couette flow geometry intended for such purposes. The experiments in water have shown, rather surprisingly, that quasi-Keplerian flows at Reynolds numbers as large as two millions are essentially laminar, effectively ruling out hydrodynamic turbulence as a candidate mechanism. The experiments in liquid gallium eutectic by imposing an axial magnetic field have shown the emergence of nonaxisymmetric modes identified as magnetocoriolis waves, one branch of which should become the MRI at higher speeds.
- Host: Forest
- High Energy Seminar
- Search for Anomalous Wtb Couplings in Single Top Quark Production
- Time: 4:00 pm - 4:00 pm
- Place: 4274 Chamberlin (Coffee and Cookies at 3:45 pm)
- Speaker: Liang Li, Search for Anomalous Wtb Couplings in Single Top Quark Production
- Host: Wesley Smith