oom temperature. When the atoms are cooled to near the photon recoil temperature, thermal atomic collisions can be neglected. A true Mott transition (or order-disorder transition) is expected.

The ultra-cold plasma is expected to be "strongly coupled", meaning that the average "nearest-neighbor" Coulomb energy is orders of magnitude larger than the mean thermal energy of particles in the plasma. If the electron temperature is thermalized to the ion temperature (and if the ion temperature is not too different from the neutral atom temperature), then the electron system is quantum-mechanically degenerate. The average deBroglie wavelength of the electrons is the same size as the distance between electrons. We plan to create and characterize this plasma.

We use calcium to create this plasma because the energy level scheme in Ca is favorable for laser cooling and trapping. Also, the resonance transitions in both Ca and Ca+ are accessible to CW diode laser technology, so that when plasma is created, the density and temperature of the ion system in the plasma can be probed using relatively inexpensive laser systems. The study of Rydberg systems at low temperatures is in its infancy, with the first papers appearing in 1998.

Our group achieved laser cooling of calcium atoms for the first time on April 30, 2001. We are developing and improving the lasers that will be used to excite the atoms and image the plasma. Once we have produced the plasma, several experiments are planned to study it. The first will be an attempt to trap the plasma optically.

Skills and Experience Required

None listed.

Contact Details

If you have questions or are interested in pursuing this research project, contact Scott D. Bergeson for more information.