Novel radio-frequency ion trap with spherical geometry

TL;DR

This paper introduces a spherical RF ion trap design that minimizes nonlinearity by eliminating the electric octupole moment, resulting in a trap with stability regions similar to ideal quadrupole traps and advantages for miniaturization.

Contribution

The paper presents a novel spherical RF ion trap design that reduces nonlinearity and mimics ideal quadrupole traps, with improved fabrication simplicity and increased trapping volume.

Findings

Optimized spherical ion trap suppresses electric octupole moment.

Stability regions match those of ideal quadrupole traps.

Design facilitates miniaturization and easier fabrication.

Abstract

Confinement of single ions in a novel radio-frequency (RF) quadrupole ion trap with spherical shape is investigated. An optimization of this spherical ion trap (SIT) is carried out in order to suppress its nonlinearity substantially by eliminating the electric octupole moment. Hence, a trapping potential and consequently an electric field very similar to the ideal quadrupole ion trap (QIT) are obtained. Afterwards, three stability regions for the optimized SIT are numerically computed. The regions coincide well with those reported in the literature for the ideal QIT. The reason is attributed to the zero electric octupole moment of our proposed trap. The SIT simple geometry and relative ease of fabrication along with its increased trapping volume compared to the conventional hyperbolic quadrupole ion trap, make it an appropriate choice for miniaturization.