Pulsed ion cyclotron resonance mass spectrometer for studying ion-molecule reactions

A pulsed ion cyclotron resonance mass spectrometer utilizes the cyclotron resonance principle for mass analysis of ions trapped at low pressures by electric and magnetic fields. Both mass analysis and ion trapping are accomplished in a one-region device called a trapped ion analyzer cell. A pulsing sequence is described which allows for generation of ions by electron impact, reaction with added gases, and mass analysis of the products of ion-molecule reactions. Methods are described for measuring rate constants and equilibrium constants for ion-molecule reactions. The high ion trapping efficiency and open geometry of the analyzer cell make it well suited for studying the interaction of laser radiation with gaseous ions and may also be useful for high-accuracy isotope ration mass spectrometry.