Trapping and excitation of ions in a double well potential

Abstract

In Fourier transform ion cyclotron resonance mass spectrometry, simultaneous storage of positive and negative ions is possible with double well potentials. Positive and negative ions are stored in different locations of the cell (nested trap). For experiments with ion/ion reactions, positive or negative ions have to share the same region of the cell. An approximation of the potential can be used to calculate how ions can be brought together. Field-induced chaotic ion motion leads to total mixing of positive and negative ions in a suitable acceleration field.

Ion traps in modern mass spectrometry

“…The electrical field and the ion motion in such ICR cells with double‐well potentials were studied in detail, including predictions of exact frequencies for ions moving in differing radial and axial regions. Conditions for reactions between positive and negative ions were analyzed . The observations are compatible with a later work showing that electron capture dissociation works best when the relative energy of electrons is sufficiently low in the reaction zone in an ICR cell with similar field geometry …”

Characterization of a new open cylindrical ICR cell for ion–ion collision studies

“…Extending ICR capability to trap both ion polarities simultaneously was achieved by use of nested cells in a static electric field [14][15][16][17]. However, previous geometries of nested ICR cells, which are operated under double well potential configuration, provided a main central stability region for one ion polarity inside the detection region and two terminal ion stability regions for the other polarity outside and near the detection region.…”

RF-driven ion–ion long-range interaction in a new open cylindrical ICR cell

“…Both static [4,5] and dynamic [6][7][8] electric fields were employed in double well potential configurations.…”