AVS 56th International Symposium & Exhibition
    Vacuum Technology Monday Sessions
       Session VT-MoA

Paper VT-MoA4
A Novel Electrostatic Ion Trap Mass Spectrometer

Monday, November 9, 2009, 3:00 pm, Room C1

Session: Pressure, Partial Pressure, and Flow Measurement
Presenter: B.J. Hinch, Rutgers University
Authors: A.V. Ermakov, Rutgers University
B.J. Hinch, Rutgers University
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We have developed, built and tested a novel mass spectrometer which uses purely electrostatic fields for confinement of in-situ ionized residual gases within a linear trap. An anharmonic trapping potential well focuses the ion trajectories of all ion masses, and of a wide range of ion energies, such that their lifetimes are long enough to allow for systematic sequential ejection of the ion mass/charge ratios. Ions are generated within the ion trap by electron impact of residual gases. Mass selective ejection is achieved through a novel autoresonant pumping process. The mass spectrometer has an unlimited mass range, is capable of achieving high sensitivity at high and ultrahigh vacuum levels, and has demonstrated much faster scan rates than the widely used (larger size and) more complicated quadrupole or magnetic sector mass spectrometers. In addition, the new mass spectrometer is very compact (less than 2" long), and requires very low power (in the mW range, excluding ionizer) as it uses only static bias potentials and a very small RF voltage (in the 100mV range). The principles of autoresonant ejection of ions are presented, along with a detailed analysis of the design and operational parameters affecting mass spectral resolution, detection limit, and dynamic range.