An improved tandem mass spectrometer-ion-cyclotron-resonance spectrometer

An improved design for a tandem mass spectrometer-ion-cyclotron-resonance spectrometer (TICR) is presented. The TICR consists of an ion source, a 180° mass filter, and a separate reaction/detection region, consisting of an ICR cell. Since the ion formation and reaction regions are separate, determinations of kinetics and product distributions are greatly simplified.

The design presented includes two major changes from that of Smith and Futrell [4]: (1) a velocity filter at the entrance of the ICR cell, to remove translationally hot ions; and (2) the use of a second ICR cell as an ion source. This allows ICR double-resonance techniques to be used in the ion formation region.

Data on performance are presented, as well as examples of several novel experiments which are possible. The question of reactant-ion kinetic energy is discussed, and data are presented which indicate that the ions entering the ICR cell have kinetic energies of ∼ 0.5 eV (lab). Examples are presented illustrating the use of ICR double resonance to determine the effects of kinetic energy on reaction rate constants and product distributions.