Numerical study of segmented-electrode planar Orbitraps

- Planar geometries approximating the field of the Orbitrap have been presented.
- Boundary element method (BEM) simulations have been carried out.
- The potentials applied to the segmented electrodes have been optimized.

This study proposes a planar geometry mass analyzer which has fields and performance like that of a reference Orbitrap.The planar geometry taken up for investigation consists of two planar surfaces with concentric ring electrodes on each facing surface. Appropriate potentials are applied to the individual rings for effecting trapping of ions. The study used both single particle and multi-particle simulations. In the multi-particle simulations spatial and energetic distribution as well as space charge effects in the ion ensemble have been incorporated. The performance of this planar geometry has been compared to that of a reference Orbitrap by computing (1) the variation in potential along the principle directions, (2) ion trajectories and (3) induced image currents in the two geometries. The potentials applied to the ring electrodes were optimized to improve the electric field inside the planar geometry.

142This study proposes a planar geometry mass analyzer which has fields and performance similar to that of a reference Orbitrap. The performance of the planar geometry was compared to that of the reference Orbitrap by computing (1) the variation in potential along r and z directions, (2) ion trajectories and (3) induced image currents in the two traps. The potentials applied to the ring electrodes of the planar trap were optimized to minimize the influence of ion's initial position on the axial frequency of ion motion. The planar Orbitrap was seen to have fields and performance like that of the reference Orbitrap.