The present invention discloses an
ion source for a
rare gas isotope mass spectrometer, comprising a
cathode assembly and an
electron receiving stage
assembly, an
ionization box, a repeller, an extraction focusing lens group, and an
ion source fixing seat. The
cathode assembly and the
electron receiving stage assembly are respectively fixed at the upper and lower ends of the
ionization box, the repeller is fixed at the rear end of the
ionization box, the extraction focusing lens group is at the front end of the ionization box, the extraction focusing lens group is connected to the ionization box via a connecting porcelain column to achieve fixation and insulation, the extraction focusing lens group is composed of a pull-out
electrode, a z focusing
electrode, a grounding
electrode, a y focusing electrode, and an exit slit arranged in sequence, the extraction focusing lens group realizes extraction and focusing of sample ions in the ionization box, the other end of the connecting porcelain column is connected to the
ion source fixing seat, the center of the
ion source fixing seat has an exit slit, the structure is simple, the number of pole pieces is small, the internal volume is small, and the sensitivity is greatly improved. The repeller and extraction focusing
system has high ion extraction efficiency and good focusing effect.