Events at Physics |
Events During the Week of April 17th through April 24th, 2011
Monday, April 18th, 2011
- Plasma Physics (Physics/ECE/NE 922) Seminar
- How the Tail Wags the Dog: Understanding the Physics of the H-Mode Pedestal and ELMs in Tokamaks
- Time: 12:05 pm
- Place: 2241 Chamberlin Hall
- Speaker: Phil Snyder, General Atomics
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Microcalorimeter Arrays for High-Resolution X-ray Spectroscopy
- Time: 1:30 pm
- Place: 5310
- Speaker: Catherine Bailey, NASA Goddard Space Flight Center
- Abstract: High-resolution x-ray spectroscopy is a powerful tool for studying the evolving universe. Current x-ray missions have high-resolution grating spectrometers; however, non-dispersive spectrometers with improved spectral resolution around 6 keV will enable imaging spectroscopy of extended sources, such as supernova remnants and galaxy clusters. Arrays of microcalorimeters with superconducting transition-edge sensors (TESs) are capable of filling this need.
TES microcalorimeters measure the temperature change that occurs when individual photons are absorbed. In laboratory demonstrations, our TES devices achieve energy resolutions of ~2 eV at 6 keV. The X-ray Microcalorimeter Spectrometer (XMS) is a proposed instrument that will utilize these TES devices in a kilopixel-scale array that would go onboard the International X-ray Observatory (IXO). This instrument will be able to provide superior high-throughput, non-dispersive spectroscopy with high resolution and imaging capabilities in the 0.1 - 10 keV energy range.
In this talk I will introduce science drivers for the XMS instrument. I will then describe the XMS detector technology and the transition from individual pixels to large-scale arrays. I will conclude by showing state-of-the-art results as well as preliminary laboratory tests of a concept for the XMS anti-coincidence detector, which will be used to reject background events generated by cosmic rays. - Host: Reina Maruyama
Tuesday, April 19th, 2011
- Chaos & Complex Systems Seminar
- "Response of Pollen in Devils Lake WI to the Younger Dryas Event
- Time: 12:00 pm
- Place: 4274 Chamberlin Hall
- Speaker: Lou Maher and Clarence Clay, UW-Madison Dept of Geoscience
- High Energy Seminar
- China Jinping underground lab and the PANDAX dark matter experiment
- Time: 3:00 pm
- Place: 4274 Chamberlin Hall
- Speaker: Xiang Liu
- Abstract: China Jinping underground laboratory is located in Sichuan China. It
is built in the middle of a transporting tunnel of a hydropower plant.
With an overburden of more than 7000 m.w.e., it is among the deepest
underground laboratory in the world. Two dark matter experiments are planed at the underground lab, one is the CDEX (China Darkmatter EXperiment) utilizing point-contact HPGe detectors, another is the PANDAX (Particle AND Astroparticle Xenon observatory) using two-phase Xenon technique. I will give a review of the Jinping underground lab and the PANDAX experiment. - Host: Karsten Heeger
Wednesday, April 20th, 2011
- Department Meeting
- Time: 12:15 pm
- Place: 5310 Chamberlin Hall
Thursday, April 21st, 2011
- R. G. Herb Condensed Matter Seminar
- Interactions and superconductivivity in the polaronic Fermi liquid SrTiO<sub>3</sub>
- Time: 10:00 am
- Place: 5310 Chamberlin
- Speaker: Dirk van der Marel, University of Geneva
- Abstract: SrTiO3 is a semiconductor which, when doped with a low density of electrons, becomes superconducting with a dome-shaped doping dependence of the superconducting transition temperature. I will present optical, transport and specific heat data, and discuss a unified approach to the transport properties and superconductivity, showing that superconductivity emerges out of a liquid of interacting polarons. This interaction is rather weak, disfavouring the picture of uncondensed bipolarons above Tc.
- Host: Maxim Vavilov & Andrey Chubukov
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Recent Results From The VERITAS TeV Gamma-Ray Observatory
- Time: 4:00 pm
- Place: 4274 Chamberlin Hall
- Speaker: Andrew Smith, Argonne National Laboratory
- Host: Stefan Westerhoff
Friday, April 22nd, 2011
- Theory/Phenomenology Seminar
- News from ν's: Interpretations of Recent Neutrino Anomalies
- Time: 2:30 pm - 3:35 pm
- Place: 5280 Chamberlin Hall
- Speaker: Joachim Kopp, Fermilab
- Host: Maike Trenkel
- Physics Department Colloquium
- Next Steps in Nuclear Weapons Control
- Time: 4:00 pm
- Place: 2241 Chamberlin Hall (coffee at 3:30 pm)
- Speaker: Jay Davis, The Hertz Foundation
- Abstract: The climate for nuclear arms reductions has changed positively in recent years with the statements of the "Gang of Four" (Kissinger, Schultz, Perry and Nunn) that there is a credible path to zero, the ratification of the NEW START Treaty, the successful review conference for the Non-Proliferation Treaty, and the resubmission for ratification of the CTBT. Jay Davis, who served as an UNSCOM inspector in Iraq after the first Gulf War and as the head of all US inspection processes as first Director of the Defense Threat Reduction Agency, recently lead an APS/POPA study on the technology needs for future arms control treaties. However, in addition to technology, many other issues matter as the number of nuclear weapons is decreased. Among these are changes to theories of deterrence and the nuclear umbrella over non-nuclear states, the lesser granularity of military platforms that support the weapons, increased credibility of missile defensive systems, and the coupling of conventional and nuclear weapons, among others. Davis will walk the audience through a progressive set of weapons reductions that illustrate these points. Comparison to either Zeno's Paradox or Dante's Circles is discouraged. The talk does however end with an interesting technical proposal for evaluation.
- Host: Balantekin