Technique for ion analysis in hyperboloidal mass spectrometer of tthree-dimensional trap type

The invention is refered to mass spectrometry and can be used for designing hyperboloidal mass spectrometers with high resolution and sensitivity. The purpose of the invention is to develope a technique for analyzing fission ions with their extraction from analyzer operation volume before the beginning of sorting and thus to suppress their peaks in mass spectrum. The purpose is achieved by additional separation of accumulated ions according to initial velocities before the beginning of sorting, leaving ions with preeminently thermal velocities in analyzed operation volume