Determination of equilibrium density distribution and temperature of a pure electron plasma confined in a Penning trap

Abstract

A fast scheme is proposed for determining the three-dimensional density distribution of a pure electron plasma under the thermal relaxation in a Penning trap on the basis of the observation of the axially integrated density distribution. The analysis that includes the contribution of the conducting wall reveals the appearance of a halo distribution surrounding the core distribution around the midplane. The core is confirmed to approach the Penning-type equilibrium distribution. Also proposed is a new scheme of the temperature determination of the electrons by analyzing a radial profile of the particles extracted with energy selection. This method is available on the basis of the self-consistent potential distribution associated with the equilibrium density distribution. The application of the two schemes of data analysis shows that the electron temperature decreases well below 0.1eV with a 1∕e folding time of ≈4× cyclotron-cooling time in the trap kept at room temperature.