A new ion cyclotron resonance cell for simultaneous trapping of positive and negative ions

In Fourier transform ion cyclotron resonance (ICR) spectrometry until now either positive or negative ions (including electrons) could be trapped, due to the trapping potential applied. In the present article, the theory of simultaneous trapping of positive and negative ions, and the experimental realization are presented. Trajectory calculations for the ions trapped with both charge polarities are described. The new ICR cell employs a new kind of trapping electrodes, constructed with layers of grids. The simultaneous storage is illustrated by experimentals with sulfur hexafluoride.