Patent attributes
A time-of-flight type mass spectrometer in which, at the time when ions are generated by irradiating a sample with a laser beam, an extraction electric field having a potential gradient that decreases gradually from a sample plate toward an extraction electrode is formed. Ions are roughly separated in accordance with the m/z in the extraction region due to the effect of this electric field, and ions with a large m/z remain near the sample. The voltages applied to the sample plate and an auxiliary electrode are increased after a delay time has passed so as to form an acceleration electric field having a potential gradient with a polygonal line pattern. Since this electric field is similar to an ideal potential gradient curve, it is possible to provide the ions with appropriate potential energy changes for each m/z, improving resolution by appropriately realizing energy convergence over a wide m/z range.
