Characterize Cs+/Xe clustering dynamics and transport-relevant properties

Determine the pressure-dependent clustering dynamics of Cs+ ions in xenon gas, including the formation and relative fractions of [CsXe]+ clusters, and quantify how this clustering modifies the reduced mobility and momentum-transfer cross-sections needed to accurately model ion transport on four-phased radio-frequency carpets at 100–600 mbar using SIMION or equivalent trajectory simulations.

Background

Accurate prediction of ion transport on phased radio-frequency carpets in xenon requires reliable input for ion–gas collision dynamics, specifically momentum-transfer cross-sections and mobilities. In dense xenon, monocations such as Cs+ can form weakly bound clusters (e.g., [CsXe]+), altering transport parameters relative to low-pressure values.

In this paper, the authors compare measured transport efficiencies of Cs+ at 200–600 mbar to SIMION simulations under several cross-section models. They note that, unlike Ba+/Xe where clustering has been studied, the degree and impact of Cs+/Xe clustering at these pressures is not well established, limiting quantitative agreement between data and simulation.

Resolving the unknown clustering behavior and its effects on mobility and cross-sections is necessary to achieve quantitatively predictive models of RF-carpet ion transport in dense xenon relevant to barium tagging applications.