Events at Physics |
Events on Monday, February 15th, 2016
- R. G. Herb Condensed Matter Seminar
- The Emergent Collective Behavior of Bacteria Under Stress
- Time: 12:00 pm - 1:00 pm
- Place: 1003 Engineering Centers Building (Tong Auditorium)
- Speaker: Robert Austin, Princeton
- Abstract: Outside the ivied halls of the academy, Darwinian evolution and competition puts an enormous selection pressure on organisms. Although physicists tend to think of bacteria as being rather simple entities living rather solitary and brief lives, our experience has been that under high stress complex environments and at high concentrations they initiate complex, cryptic signaling and information exchange whose purposes we at this point can only guess at. I’ll present experiments showing the complexity of the signals that bacteria exchange under stress, and try to provide some sort of a model to understand the purposes of this emergent collective behavior.
- Host: Susan Coppersmith
- Plasma Physics (Physics/ECE/NE 922) Seminar
- Sustainment of a field reversed configuration with high power neutral beam injection
- Time: 12:00 pm - 1:00 pm
- Place: 1153 Mechanical Engineering
- Speaker: Dr. Richard Magee, Tri-Alpha
- Abstract: In the C-2 field reversed configuration (FRC) experiment, tangential neutral beam injection coupled with electrically-biased plasma guns, magnetic end plugs, and advanced surface conditioning led to dramatic reductions in turbulence driven losses and greatly improved plasma stability. Under such conditions, highly reproducible, macroscopically stable FRCs with a significant fast ion population and total plasma temperature of 1keV were achieved. In order to sustain the FRC, the C-2 device was recently upgraded with a new neutral beam injection (NBI) system, which increased the injected neutral power from 4 MW to 10+ MW, by far the largest ever used in a compact toroidal plasma experiment. The upgraded neutral beams produce a fast ion population that has a dramatic beneficial impact and allows the configuration to persist for time significantly longer (5+ ms) than all characteristic plasma decay times. The presentation with provide an overview of the C-2U device and recent experimental results, with a focus on the diagnosis of the fast ion population
and observations of benign fast ion driven collective effects. - Host: UW Madison