Proof of Principle for Enhanced Resolution Multi-Pass Methods for the Astral Analyzer

Multi-pass zoom-mode methods have been described to extend the flight path and resolving power of multi-reflection time-of-flight mass spectrometers, by deflecting exiting ions back into repeat passes through the analyzer. Such methods have been adapted to the Astral analyzer, with repeated passes through a prism deflector found to compensate resolution-destroying aberrations. Changes to resolution were simulated and experimentally characterized, with more than a doubling of resolving power observed with only a moderate loss of transmission. Further methods are also proposed to eliminate the mass spectrum uncertainty caused by overlapping of signals from ions that have undergone unknown numbers of passes.