Methods for the correction of second-order aberrations in laser time-of-flight analyzers with axial-symmetric fields

摘要

A rigorous way is described to increase the resolution of laser time-of-flight (TOF) mass spectrometers with an axially symmetric electrostatic analyzer by more than one order of magnitude. The inventive method consists in the introduction of a reflector into the ion optics of the mass spectrometer, which generates a second-order temporal aberration with an opposite polarity with respect to the aberration occurring in the free plasma drift space because of the compensation of time aberrations by energy of the second order, optimization of the ion-optical scheme of a laser time-of-flight mass spectrometer, and taking into account the partial compensation of the third-order aberrations, the resolution of the mass spectrometer is increased to (1-2) x 10(4). Theoretical calculations justifying the proposed method are presented.