Abstract
Multi-reflection time-of-flight (MR-ToF) analyzers must control the transversal ion dispersion, orthogonal to the axis of reflection, conventionally via periodic refocusing, or more recently the shaped electrode structure adopted by the Astral analyzer. In principle, the complexity of the dispersion control on every oscillation may be avoided at a cost of a smaller number of oscillations, during which the dispersion doesn't exceed the limit of unrecoverable overlap. A method of dispersion control has been demonstrated experimentally and in simulation, whereby the ion beam is configured by a long focus trans-axial lens made of a pair of quasi-elliptical plates mounted above and below the ion beam, in order to optimize the spatial spread of the ions at a distant detector. The collimation concept was shown to effectively control beam expansion. For experimental confirmation, a prototype Astral ana-lyzer was modified, and resolving power above 70k demonstrated.
Supplementary materials
Title
A Multi-Reflection Time-of-Flight Analyzer with a Long Focus Lens Supplementary Information
Description
Additional details and photographs of the experimental apparatus, further simulations of the including the beam expansion lens, beam reversing and enhanced resolution zoom mode, further experimental results covering optimization of the beam expander operation and reversing deflector.
Actions