| 摘要 |
The invention relates to measurement methods for time-of-flight mass spectrometers which operate with an ionization of analyte substances adsorbed at the surface of a sample support and an improvement in mass resolution through delayed ion acceleration (or "delayed extraction") in front of the sample support. It particularly relates to velocity focusing for good mass resolution simultaneously for wide ranges of masses within the spectrum. The invention consists of focusing the flight-times of the ions simultaneously for all masses in wide ranges of interest relative to their initial velocity, by allowing the acceleration in the first accelerating region to increase in time after being switched on. Thus a good resolution cannot only be set for one mass on the spectrum but for all masses in wide ranges simultaneously. In computer simulations, provided there is a correlation of space and velocity distribution, focusing of a least first order is obtained simultaneously for all ions.
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