UConn Physics Colloquium
Ultracold Neutral Plasmas
Department of Physics & Astronomy
Rice University (Houston, TX)
Ultracold neutral plasmas , formed by photoionizing laser-cooled atoms near the ionization threshold, stretch the boundaries of traditional neutral plasma physics. The electron temperature in these plasmas is from 1-1000 K and the ion temperature is around 1 K. The density can be as high as 1010 cm-3. Fundamental interest stems from the possibility of creating strongly-coupled plasmas, but recombination, collective modes, and thermalization in these systems have also been studied. The ultracold plasma group at Rice University recently demonstrated optical absorption imaging of a strontium plasma  using the Sr+ 2S1/2 -- 2P1/2 transition at 422 nm. Images depict the density profile of the plasma, and probe kinetics on a 50 ns time-scale. The Doppler-broadened ion absorption spectrum measures the ion velocity distribution, which gives an accurate measure of the ion dynamics in the first few hundred nanoseconds after photoionization. I will provide a review of ultracold plasma research and then describe recent imaging results in greater detail. This work is supported by the Department of Energy, National Science Foundation, Alfred P. Sloan Foundation, Research Corporation, and David and Lucille Packard Foundation.
 T. C. Killian, S. Kulin, S. D. Bergeson, L. A. Orozco, C. Orzel, and S. L. Rolston, Phys. Rev. Lett. 83, 4776 (1999).
 C. E. Simien, Y.C. Chen, P. Gupta, S. Laha, Y. N. Martinez, P. G. Mickelson, S. B. Nagel, T. C. Killian, Phys. Rev. Lett. 92, 143001 (2004).
Friday, November 19, 2004
Gant Science Complex
(We will meet for refreshments prior to the talk at 3:30 p.m., in the Gant Science Complex, Physics Library, Room P-103.)