Storage of bio-molecular ions in the electrostatic storage ring

Singly or multiply charged bio-molecular ions produced with an electrospray ion source are stored in an electrostatic storage ring after being bunched and mass-analyzed. The measured 1/e-lifetimes of stored ions are from 12–20 s. These lifetimes are long enough to cool vibrationally excited molecular ions, and their intensities are tolerable for practical use, like atomic-collision experiments.