Parametric Mode Operation of a Hyperbolic Penning Trap for Fourier Transform Mass Spectrometry

The first known use of a parametrically excited hyperbolic Penning trap (cell) In Fourier transform mass spectrometry is described in this paper. The use of this trap builds upon the cylindrical cell of Lee, Wanczek, and Hartmann in which symmetry was used to solve a problem, namely, that of magnetron sidebands in the mass spectrum. Some of the symmetries of the hyperbolic Penning trap are reviewed enroute to developing a mass calibration law, which is fundamentally different than the cubic trap mass calibration law. The calibration law is tested at a magnetic field of 1.2 T by using 1,1,1,2-tetrachloroethane major fragment ions and a new pulse excitation method. The results of a comparison with a similar experiment for the cubic trap show a reduced sensitivity to space charge effects. Other advantages and some disadvantages of the hyperbolic Penning trap that are discussed are high order harmonic-free spectra, low ion cloud distortion, Image charge displacement sensitivity to magnetron radius, and pulse excitation induced z-mode ejection.