A new detection scheme for Fourier transform-ion cyclotron resonance spectrometry in Penning traps

Abstract

A new detection scheme for Fourier transform-ion cyclotron resonance (FT-ICR) studies is proposed and initial experimental results are presented. While in conventional FT-ICR, the difference of the transient signals from two opposite electrodes is recorded and Fourier transformed, it is also possible to use the sum of these signals. In this way resonances are observed at the harmonic of the reduced cyclotron frequency 2 ν+ as well as ν+−ν− and ν++ν−, the later being important for accurate mass measurements. The experiments were performed with a Penning trap in an electromagnet.

Dipolar and quadrupolar detection using an FT-ICR MS setup at the MPIK Heidelberg

“…6, in general. The (ν + + ν − ) signal also has an higher amplitude than the (ν + − ν − ) signal which may be called a radial parametric resonance frequency [28,30]. This signal appears due to the realization of quadrupolar detection by use of only one set of electrodes instead of the ideal configuration of the difference signal from two sets of opposite electrodes [26].…”

“…The full-width-at-half-maximum of the ν + and 2 ν + signals are identical. The signal at 2 ν + in the quadrupolar detection arises from the arrangement of two opposing detection electrodes which see the ion twice during one period of the cyclotron motion [27,28]. In contrast, one cyclotron period corresponds to one period of the image-charge transient function of the dipolar detection mode.…”

Advances in trapped ion cells for Fourier transform ion cyclotron resonance mass spectrometry

“…In each case, mass resolution at the higher harmonics increased independent of magnetic field strength or data acquisition time. A theoretical study of the excitation and detection scheme for multielectrode cells was presented by Schweikhard et al (163).…”

Model calculation of amplitudes for FT-ICR ion detection in a cylindrical Penning trap

“…All results discussed above refer to this case (single-electrode detection). Stronger signals are obtained by the use of two opposite detection electrodes, S 1 , S 3 or S 2 , S 4 , either subtracting (differential or dipole detection) or adding (sum or quadrupole detection) the corresponding signals [20][21][22][23].…”