Some aspects of space-charge effect calculation in high-resolution mass spectrometry

A variational 3D approach to the problem of simulating stationary distributions of ions in the radiofrequency low-vacuum ion traps with regard to Coulomb interaction and collisions of ions with buffer gas molecules is proposed. The software developed in the course of this work is employed to study the structure of stationary ion ensembles in the radiofrequency ion traps of various types. The effect of high frequency and constant voltages, space-charge density, and buffer gas temperature on the formation of stationary distributions in the radiofrequency ion traps and their limiting capacitance is investigated. It is shown that the use of electrodes with a constant voltage in the presence of high enough ion density allows pre-filtering of ions directly in a high-frequency trap-accumulator. (C) 2016 Elsevier B.V. All rights reserved.