Method for mass-spectroscopic examination of a gas mixture and mass spectrometer intended for carrying out this method

摘要

For mass-spectroscopic examinations of gas mixtures a mass spectrometer is used which comprises a quistor in which ions of the gas mixture whose charge-to-mass ratio is located in a predetermined range are stored by generating an electromagnetic field. By varying the field parameters, the ions are forced successively to leave the ion trap. The intensity of the ion flow leaving the ion trap is measured as a function of the variation of the field parameters. For improving the resolution, one uses a quistor of the type where the distance-related ratio Q of the radii of the inscribed vertex circles of the electrodes comply with the condition Q Re being the radius of the cross-section of the vertex of the end electrodes (3,5); Rr being the radius of the cross-section of the vertex of the annular electrode (4); zo being the distance between the vertex of each end electrode (3,5) and the center of the quistor; and ro being the distance between the vertex of the annular electrode (4) and the center of the quistor.