Events at Physics |
Events During the Week of April 27th through May 4th, 2008
Monday, April 28th, 2008
- Plasma Physics (Physics/ECE/NE 922) Seminar
- Toward the Ultimate Goal of Radwaste-Free Fusion: Recycling and Clearance, Avoiding Geological Disposal
- Time: 12:05 pm
- Place: 2241 Chamberlin Hall
- Speaker: Laila A. El-Guebaly, UW-Madison, Fusion Technology Institute
- Chaos & Complex Systems Seminar
- Title to be announced
- Time: 12:05 pm
- Place: 4274 Chamberlin Hall
- Speaker: John Moreau, Geology and Geophysics
- Astronomy Colloquium
- Title to be announced
- Time: 3:45 pm
- Place: 6515 Sterling Hall (coffee at 3:30 pm)
- Speaker: Michelle J. Creech-Eakman, New Mexico Tech - Department of Physics, Socorro
- Medical Physics Seminar
- A Comparison of Computational Methods to Calculate Effective Connectivity from fMRI Time Series Data
- Time: 4:00 pm
- Place: 1345 Health Science Learning Center (refreshments will be served)
- Speaker: Suzanne Witt, Research Assistant, student of Dr. M. Elizabeth Meyerand, Department of Medical Physics, UW-School of Medicine and Public Health
- High Energy Seminar
- Neutrino-less double-beta decay, WIMPs, and Xenon: Will the Quest Converge?
- Time: 4:00 pm - 5:00 am
- Place: 4274 Chamberlin (coffee & cookies at 3:30 pm)
- Speaker: David Nygren, LBNL and Stockholm University
Tuesday, April 29th, 2008
- Astronomy Colloquium
- Magdalena Ridge Observatory Interferometer - A Fully Optimized Aperature Synthesis Array
- Time: 3:45 pm
- Place: 6515 Sterling Hall
- Speaker: Michelle J. Creech-Eakman, New Mexico Tech - Department of Physics, Socorro
- Abstract: I will present a brief overview of the Magdalena Ridge Observatory Interferometer (MROI), being built at an altitude of 10,500 feet just outside of Socorro, NM. The planned architecture of the system will include 10 1.4-m class alt-alt telescopes, the most modern detectors operating over the 0.6-2.4 micron range, with relocatable telescopes capable of resolving sources with sizes in the range of 30-0.3 milliarcseconds. I will present a brief description of the technique of optical interferometry and then demonstrate some of the science which has been done already with optical interferometers. I will introduce our key science mission for the MROI and demonstrate how the design for this array will provide unprecedented, model independent images for a wide variety of stellar and some extragalactic sources. The MROI is being built in collaboration by two principle institutions: New Mexico Tech and the University of Cambridge. We are following an aggressive schedule and anticipate first light on the first baseline in late 2009.<br>
Wednesday, April 30th, 2008
- No events scheduled
Thursday, May 1st, 2008
- R. G. Herb Condensed Matter Seminar
- Magnetic 1/f noise from the semiconductor/oxide interface and spin-dependent scattering in silicon transistors
- Time: 10:00 am
- Place: 5310 Chamberlin
- Speaker: Rogerio de Sousa, University of Victoria
- Abstract: In the first part of the talk I will discuss a mechanism of magnetic noise based on spin-flips of paramagnetic dangling-bonds at the semiconductor/oxide interface. The spin-flips are caused by the cross-relaxation of dangling-bond spins with the tunnelling-two-level-systems of the amorphous interface, leading to magnetic 1/f noise even at zero magnetic field. I will compare and fit this model to a recent electron spin resonance experiment in nuclear-spin free silicon, and show that the same amount of interface noise detected by spin resonance may explain the intrinsic flux noise of the best superconducting quantum interference devices (SQUIDs).
In the second part I will describe a theory of spin-dependent scattering in the two-dimensional electron gas of silicon transistors. The scattering of conduction electrons off neutral donor impurities depends sensitively on the relative orientation of their spin states, and the six-fold degeneracy of the silicon conduction band leads to a strongly oscillatory coupling of conduction electrons to donors placed at varying depths in the transistor channel. This coupling can be gate controlled, enabling optimization for single donor spin readout and spatially resolved characterization of the conduction electron spin polarization that does not rely on weak spin-orbit coupling effects or interface scattering. - Host: Friesen
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Effective Field Theory of Light Nuclei
- Time: 4:00 pm
- Place: 4274 Chamberlin Hall
- Speaker: Bira van Kolck, University of Arizona
- Abstract: Nucleons in light nuclei have binding momenta smaller than the pion mass. In this energy regime, strong interactions can be described by effective field theories (EFTs) where all nuclear interactions are of contact type. I will discuss some of the features of these EFTs such as unusual renormalization leading to limit cycles, universal behavior in three-body systems, and a surprising amount of fine-tuning.
- Physics Department Colloquium
- Winner of the Distinguished Alumni Award 2008
- Exoplanet Detection and Characterization: Status and Prospects
- Time: 5:00 pm
- Place: 2241 Chamberlin Hall (coffee at 4:30 pm)
- Speaker: Wesley A. Traub, Jet Propulsion Lab
- Abstract: Nearly 300 exoplanets have been discovered in the past 13 years. We know the approximate mass and orbit of each of these, and for a few we have additional information about radius, composition, and temperature. However for most exoplanets we do not know these properties, nor do we know how they were formed, or whether any may have evolved like the Earth. The discovery of these unexpected exoplanets has ignited a whole new field of inquiry in astrophysics as well as physics and planetary science. One of the attractions is the prospect of finding an Earth-like planet, and searching for signs of life. Another attraction is the sheer joy of discovering and understanding a whole new part of our universe. In this talk I will outline the current measurement techniques and discoveries to date, but focus on future measurement techniques and what we may learn from them.
Friday, May 2nd, 2008
- Physics Department Colloquium
- H.T. Richard Lecture
- Neutrino Oscillations: Recent Triumphs and Future Challenges
- Time: 4:00 pm
- Place: 2241 Chamberlin Hall (coffee at 3:30 pm)
- Speaker: Bob McKeown, Caltech
- Abstract: Recent studies of neutrino oscillations have established the existence of finite neutrino masses and mixing between generations of neutrinos. The combined results from studies of atmospheric neutrinos, solar neutrinos, reactor antineutrinos and neutrinos produced at accelerators paint an intriguing picture that clearly requires modification of the standard model of particle physics. These results also provide clear motivation for future neutrino oscillation experiments as well as searches for direct neutrino mass and nuclear double-beta decay. I will summarize the status of experimental and theoretical work in this field and discuss the future opportunities that have emerged in light of recent discoveries.
- Host: Heeger