GRIDLESS, FOCUSING ION EXTRACTION DEVICE FOR A TIME-OF-FLIGHT MASS SPECTROMETER

摘要

A miniature time-of-flight mass spectrometer (TOF-MS) is provided having (1) a gridless, focusing ionization extraction device allowing for the use of very high extraction energies in a maintenance-free design, (2) a miniature flexible circuit-board reflector using rolled flexible circuit-board material, and (3) a low-noise, center-hole microchannel plate detector assembly that significantly reduces the noise (or "ringing") inherent in the coaxial design. A method is also provided for increasing the collection efficiency of laser-desorbed ions in the TOF-MS. The method includes the steps of providing within the TOF-MS an ionization extraction device having an unobstructed central chamber having a first region and a second region; creating an ion acceleration/extraction field within the first region; accelerating ions within the first region; de-accelerating the ions in the second region; and drifting the ions in a drift region to cause ion dispersion.