An ion trap mass spectrometer including an ion trap analyzer, an ion packet injector, and an ion detector is disclosed, along with a method of mass spectrometry. The ion packet injector injects packets of ions into a field of the ion trap analyzer. The ion packets move along isochronous oscillations according to their mass-to-charge ration. The ion detector may be implemented as a novel image current detector, a novel time-of-flight detector, or a combination of the two. The novel image current detector may comprise segments along an X-axis or a Z-axis of the mass spectrometer. The novel time-of-flight detector may sample a portion of ions of the ion packet per each isochronous oscillation.