Abstract: A reflectron capable of focusing an entire mass range of product ions at substantially the same focal point, comprising a plurality of lens plates, each having an opening therein, for generating a non-linear electric field in the reflectron. To generate the non-linear electric field, the voltage applied to each successive lens plate increases non-linearly with respect to its adjacent lens plate. The voltage of the first lens plate having the opening through which the ions first enter the reflectron is set to a low potential and the voltage being applied to each successive lens plate increases in a non-linear manner with the largest voltage being applied to the lens plate furthest from the first lens plate. This non-linear voltage application, to generate the non-linear electric field, can be achieved by coupling a potentiometer between each lens plate and adjusting each potentiometer accordingly.

Abstract: A tandem time-of-flight mass spectrometer comprises a grounded vacuum housing, two reflecting-type mass analyzers coupled via a collision chamber, and flight channels electrically floated with respect to the grounded vacuum housing. The first reflecting-type mass analyzer receives ionized molecules (ions). These ions pass through the flight channel of the first reflecting-type mass analyzer and are fragmented in the collision chamber. The fragmented ions pass through the flight channel of the second reflecting-type mass analyzer. Detectors disposed in the collision chamber and in the second reflecting-type mass analyzer detect the spectrum of the first reflecting-type mass analyzer and the spectra of the tandem time-of-flight mass analyzer, respectively.