Patent ID: 6452168
Filing Date: 2002-09-17
Classification: H01J

Abstract:
A continuous beam Fourier transform mass spectrometer comprising:a. a confinement structure having a cavity, a first opening and a second opening; b. means for applying an RF voltage to the structure to form a trapping field in the cavity; c. means for supplying a continuous beam of ions through the first opening to the cavity to form a sample of ions with a range of masses, wherein the sample ions are trapped in the trapping field and each ion is characterized by a mass-to-charge dependent frequency of motion; d. means for continuously applying an excitation signal having a frequency spectrum and an amplitude to the trapped sample ions, wherein the frequency spectrum of the excitation signal includes characteristic frequencies corresponding to at least one of the mass-to-charge dependent frequencies of motion of the sample ions, and the amplitude of the excitation signal is sufficiently high to cause resonant motions of the ions with at least one of the characteristic frequencies of the excitation signal; and e. means for detecting signals responsive to the resonant motions of the ions, wherein the second opening allows at least some of the sample ions to exit the cavity.