Design and simulation of a wire quadrupole ion trap for ion trapping and cooling

Abstract

Serving as the core device of an ion trapping system, radiofrequency ion traps are widely employed in chemical reaction dynamics, atomic and molecular physics, precise measurement, and ion spectroscopy. They can store, enrich, and cool ions down to very low temperatures in combination with a cryogenic cooler, thus greatly facilitating the following experiments, such as, high-resolution spectroscopy. In this work, we describe in detail the structural design of a radiofrequency wire quadrupole trap (w4PT) that utilizes six wire electrodes to act as one cylindrical electrode of the conventional quadrupole ion trap to simulate the hyperboloids. We simulated the electric fields and ion motion trajectories within the trap to investigate the performance of the designed w4PT, and showed that it is capable of reaching a tight confinement of ions in a small volume. We also conducted the heat transfer simulations based on the designed supporting platform for the trap, and the chosen materials for the electrodes, trap cavity, and printed circuit boards for installing the electrodes. The simulated temperature distributions showed that the current trap could cool ions to a low temperature below 5 K using a helium cryogenic cooler. This work shall be helpful for the development of ion trap technology to be employed in high-precision spectroscopy.