A High Dynamic Range Ion Detector for Multireflection Time-of-Flight Analyzers

Abstract

Reflectron-based time-of-flight analyzers rely on subnanosecond detector time response to achieve acceptable resolving power for low−mid-mass, multiple-ion peaks. With the adoption of multireflection analyzers, order of magnitude longer folded ion paths relax restrictions on detector response time, allowing implementation of new technologies that greatly improve dynamic range, detector lifetime, and ion detection efficiency. A detection system is presented, integrated into a multireflection analyzer, that combines 10 keV postacceleration and focal plane correction with a unique BxE focusing, optically coupled detector, preamplification, and dual-channel digitization. Calibration and peak-handling methods are also described. The instrument demonstrated >1 × 10 4 dynamic range in a single shot, > 100k resolving power, and a relative immunity to detector aging.