Ultracold neutral plasmas

Killian, TC, Chen YC, Gupta P, Laha S, Martinez YN, Mickelson PG, Nagel SB, Saenz AD, Simien CE.  2005.  Ultracold neutral plasmas, May. Plasma Physics and Controlled Fusion. 47:A297-A306.


Ultracold neutral plasmas are formed by photo-ionizing laser-cooled atoms near the ionization threshold. Through the application of atomic physics techniques and diagnostics, these experiments stretch the boundaries of traditional neutral plasma physics. The electron temperature in these plasmas ranges from 1 to 1000 K and the ion temperature is around 1 K. The density can approach 10(11) 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. Optical absorption images of a strontium plasma, using the Sr+ S-2(1/2) -> P-2(1/2) transition at 422 mn, 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 microsecond after photo-ionization.


Times Cited: 2 Si 5a 12th International Congress on Plasma Physics (ICPP2004) Oct 25-29, 2004 Nice, FRANCE Int Advisory Comm