Coherent excitation/detection in pulsed ICR-MS

Abstract

Conventional excitation and detection schemes for pulsed ion-cyclotron resonance mass spectrometry (ICR-MS) utilize extremely broad bandwidth electronics in an effort to cover a wide mass range in a single experiment. However, in many cases such broad bandwidth coverage is unnecessary, and coherent pulsed excitation/super-heterodyne detection can be used. This approach has a number of benefits: (a) powder distributions of the excitation pulses are easily characterized; (b) low-noise, narrow band-pass detection electronics may be utilized; and (c) receiver immunity to non-coherent noise sources and instrumental artifacts can be greatly improved. A simple coherent excitation/detection system is described which has been developed for use in narrow mass-range experiments; applicability of such a system to wide mass-range problems is also discussed.