Using absorption imaging to study ion dynamics in an ultracold neutral plasma.

We report optical absorption imaging of ultracold neutral strontium plasmas. The ion absorption spectrum determined from the images is Doppler broadened and thus provides a quantitative measure of the ion kinetic energy. For the particular plasma conditions studied, ions heat rapidly as they equilibrate during the first 250 ns after plasma formation. Equilibration leaves ions on the border between the weakly coupled gaseous and strongly coupled liquid states. On a longer time scale of microseconds, pressure exerted by the trapped electron gas accelerates the ions radially.

[1]  W. Itano,et al.  Direct observations of the structural phases of crystallized ion plasmas , 1999 .

[2]  S. Stenholm,et al.  Laser cooling and trapping , 1988 .

[3]  Gallagher,et al.  Spontaneous evolution of rydberg atoms into an ultracold plasma , 2000, Physical review letters.

[4]  James D. Hanson,et al.  Simulated expansion of an ultra-cold, neutral plasma , 2003 .

[5]  A. Fontana,et al.  Production and detection of cold antihydrogen atoms , 2002, Nature.

[6]  S. G. Kuzmin,et al.  Numerical simulation of ultracold plasmas , 2002 .

[7]  M. Murillo,et al.  Using Fermi statistics to create strongly coupled ion plasmas in atom traps. , 2001, Physical review letters.

[8]  S. Rolston,et al.  Formation of Rydberg atoms in an expanding ultracold neutral plasma. , 2001, Physical review letters.

[9]  S. I. Yakovlenko,et al.  Moderation of recombination in an ultracold laser-produced plasma , 2000 .

[10]  S. Rolston,et al.  Creation of an Ultracold Neutral Plasma , 1999, physics/9908051.

[11]  S. Ichimaru.  Strongly coupled plasmas: high-density classical plasmas and degenerate electron liquids , 1982 .

[12]  Fedor Trintchouk,et al.  Visualization of plasma turbulence with laser-induced fluorescence (invited) , 2001 .

[13]  R. Farouki,et al.  Thermodynamics of strongly‐coupled Yukawa systems near the one‐component‐plasma limit. II. Molecular dynamics simulations , 1994 .

[14]  Murillo.  Critical wave vectors for transverse modes in strongly coupled dusty plasmas , 2000, Physical review letters.

[15]  Bergeson,et al.  Plasma oscillations and expansion of an ultracold neutral plasma , 2000, Physical review letters.

[16]  L A Collins,et al.  Evolution of ultracold neutral plasmas. , 2002, Physical review letters.

[17]  William L. Barr,et al.  Spectral Line Broadening by Plasmas , 1975, IEEE Transactions on Plasma Science.

[18]  T. M. O'Neil,et al.  Trapped nonneutral plasmas, liquids, and crystals (the thermal equilibrium states) , 1999 .

[19]  S. Rolston,et al.  Ultracold neutral plasmas: recent experiments and new prospects , 2003 .

[20]  E. A. Hessels,et al.  Background-free observation of cold antihydrogen with field-ionization analysis of its states. , 2002, Physical review letters.