TIME-OF-FLIGHT MASS SPECTROMETER Russian patent published in 1997 - IPC

FIELD: mass spectrometry. SUBSTANCE: time-of-flight mass spectrometer has an ion source, detector, electrostatic axial- symmetric analyzer consisting of lateral electrodes made in the form of two coaxial cylinders, with sector cutouts for inlet and outlet of ions made in their upper and lower parts, power source, diaphragm with a port and conducting strips, to which the preset distribution of potential is applied. The diaphragm is made in the form of a plate of insulator, has a port, whose center is located in the center of the diaphragm; the port axial dimension equals the axial dimension of the detector inlet port, and the radial dimension is determined from relation: S=(2-4)10^-2r_o. The strips on the diaphragm plate are applied in parallel with the axis of symmetry of the analyzer for equalization of the field in the location of the diaphragm. Duration of the ion pack in the detector plane is determined by the second-order chromatic aberration, and the resolving power of the mass spectrometer increases due to cutting-out by the diaphragm, and the relative sensitivity of the mass spectrometer gets enhanced due to exclusion of the background of scattered ions. EFFECT: enhanced resolving power and relative sensitivity. 3 cl, 3 dwg