Physics Department Colloquium

Abstract: Highlights from research done on the National Ignition Facility (NIF) laser through the Discovery Science program will be presented. Plasma nuclear reactions relevant to stellar nucleosynthesis and nuclear reactions in high energy astrophysical scenarios are being studied. [1] Equations of state (EOS) at very high pressures (0.1-100 TPa or 1-1000 Mbar) relevant to planetary cores, brown dwarf interiors, and white dwarf envelopes are being measured on NIF, and show that the level of ionization can significantly affect the compressibility of the sample.

Abstract: Recent experiments at SLAC demonstrated beam-driven plasma acceleration with accelerating gradients in excess of 150 GeV/m. That’s nearly 10,000 times the accelerating gradient produced by RF cavities in the SLAC linac! Plasma accelerators are a promising technology for future ultra-high energy colliders and were identified by the P5 Panel as a path toward 10 TeV collisions. In this talk, I’ll review the physics of nonlinear plasma wakefield acceleration. What makes the plasma bubble nearly-ideal for electron acceleration?

The Higgs boson was discovered in 2012 by the ATLAS and CMS experiments at the world’s most powerful particle collider, the Large Hadron Collider (LHC) in Geneva, Switzerland. This particle plays a unique role in fundamental physics. It gives all of the known elementary particles, including itself, their masses.

Abstract: This presentation describes space weather impacts and their economic and societal costs. Modern technological society is characterized by a complex set of interdependencies across its critical infrastructures. These are vulnerable to the effects of intense geomagnetic storms and solar disturbances. Strong currents flowing in the ionosphere can disrupt and damage Earth-based electric power grids and contribute to the accelerated corrosion of oil and gas pipelines.

Abstract: Words of Richard Feynman “What I cannot create, I do not understand” inspire r

Abstract: The guided transmission of optical waves is essential for modern applications in communication, information processing, and energy systems. Traditionally, light guiding in structures like optical fibers has been predominantly achieved through total internal reflection. In periodic structures, a range of other physical mechanisms can also facilitate optical wave transport.

 Perhaps "The quark model for an AMO audience'' would be a better title? Anyway, I will tell you a bit about the spectroscopy of strongly interacting particles, a bit about the quark model, a bit about how people calculate the masses of bound states of quarks and gluons, and a bit about some states that I think are particularly interesting.

Abstract: We are all physicists, and have at least some acquaintance with mathematics. And we all have a fear of nuclear war. There are currently nine nations with these dreadful weapons. Can you name them? This colloquium will criticize the current meaning of deterrence, and offer an alternative, with evidence.

Abstract: The Dark Energy Spectroscopic Instrument (DESI) collaboration is conducting a 5 year redshift survey of 40 million extra-galactic sources over 14,000 square degrees of the northern sky. One of its primary goals is to measure the cosmic expansion history with baryon acoustic oscillations (BAO). I will present the measurement of BAO in galaxy, quasar and Lyman-alpha forest tracers from the first year of observation.

Abstract: The ability to measure what students are learning (or not) is a crucial component of crafting effective learning environments. In particular, low-stakes, standardized diagnostic assessments can provide a valuable tool for tracking student learning over time and between instructional approaches to identify effective strategies that improve students' understanding of core physics content.