Laser-Cooled Trapped-Ion NIST' Experiments at

Abstract. We describe some m t experiments that use a new Penning trap to trap and laser-cool more than 10 ' Be ' ions. In this work the Coulomb coupling parameter was estimated to be typically greater than 100 and in some cases greater than 300. Shell structure was dfilcult to observe in the ion fluorescence from these large clouds. An initial Bragg scattering experiment to obtain information on the ion correlations is described. We also briefly review our work on the electrostatic modes of a Penning trap plasma, including the use of the modes to diagnose the shape and density of a cryogenic electron plasma Some applications of laser-cooled plasmas in Penning traps, such as atomic clocks, are discussed. I