Triplet scattering lengths for rubidium and their role in Bose-Einstein condensation.

The triplet scattering lengths of 85Rb and 87Rb are evaluated as a function of C6 using a potential whose short-range form is fitted to an ab initio result. This is combined with a previous analysis of photoassociation measurements, which allows the determination of bounds on C6 and the scattering amplitudes to give sharper bounds for these quantities. Questions are raised about the use of scattering length as the sole atomic parameter in the description of Bose-Einstein condensates.

Stimulated Multiphoton Bremsstrahlung in Electron-Ion Collisions.

A review is presented of the basic classical mechanism whereby an electron can absorb energy from an electromagnetic field while undergoing a collision with an atom or ion. The process is also described for a quantum mechanical collision and the absorption or emission of photons. The appropriate formulations are described for weak and strong applied fields.