One- and two-pulse quadrupolar excitation schemes of the ion motion in a Penning trap investigated with FT-ICR detection

In a Penning ion trap the interconversion between the radial motional modes of stored particles can be accomplished by applying one- and two-pulse (Ramsey) azimuthal quadrupolar radio frequency fields. In this work the interaction of ions with the excitation fields has been probed by Fourier transform ion cyclotron resonance (FT-ICR) detection. A theoretical description of this interaction is derived by use of a quasi-classical coherent state and the interconversion of modes is interpreted in a quantum-mechanical context. The dipolar-detection FT-ICR signal at the modified cyclotron frequency has been studied as a function of the interaction parameters such as excitation frequency, amplitude and duration and is compared with the theoretical results.