Measurement of the4He-D2 mass difference

Gerz, Ch.; Wilsdorf, D.; Werth, G.

doi:10.1007/bf01437665

Cited by 24 publications

(4 citation statements)

References 8 publications

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“…If the sum of the magnetron and cyclotron radii (after subsequent excitation of the cyclotron motion) exceeds the trap dimensions, the ion signal disappears, indicating that the prior magnetron excitation was resonant. This scheme is very similar to those in which the ion number is monitored by axial ejection of the ions through small holes in the trapping plates, followed by ion counting with multichannel plate detectors [37]. Equation 35 also shows that it is advisable not to include the ion magnetron frequency in the range of (29b) (30b) which leads to the differential equation and its solution J Am Soc Mass Spectrom 1993, 4,433-452 sin(wt) may be constructed as the sum of two counterrotating circularly polarized electric fields, E E Eo sine wt) = ---2. exp(r wt) + ---2. expt -iwt) (39) 2 2…”

Section: Magnetron Motion (Quadrupolar Trapping Potential)mentioning

confidence: 99%

Excitation modes for fourier transform-ion cyclotron resonance mass spectrometry

Schweikhard

Marshall

1993

J. Am. Soc. Mass Spectrom.

103

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Various geometric configurations for the excitation of coherent ion motion in Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR/MS) are analyzed (in some cases for the first time) with unified notation. The instantaneous power absorption, F v, in which v is ion velocity and F the force produced by the applied excitation electric field (harmonic, single frequency, on-resonance, in-phase), is time averaged and then set equal to the time rate of change of ion total (cyclotron + magnetron + trapping) energy, to yield a differential equation that is readily solved for the (time-dependent) amplitude of each of the various ion motions. The standard FT-ICR excitation (namely, radial dipolar) is reviewed. The effects of quadrature and radial quadrupolar excitation on ion radial (cyclotron and magnetron) motions are also reviewed. Frictional damping is shown to decrease the ion cyclotron orbital radius and trapping amplitude but increase the magnetron radius. Feedback excitation (i.e., excitation at the simultaneously detected ion cyclotron orbital frequency of the same ion packet) is introduced and analyzed as a means for exciting ions whose cyclotron frequency changes during excitation (as for relativistically shifted low-mass ions). In contrast to conventional radial dipolar excitation, axial dipolar excitation of the trapping motion leads to a mass-dependent ion motional amplitude. Parametric (i.e., axial quadrupolar) excitation is shown to produce an exponential increase in the ion motional amplitudes (hyperbolic sine and hyperbolic cosine amplitude for cyclotron and magnetron radii, respectively). More detailed consideration of parametric excitation leads to an optimal ion initial radial position in parametric-mode FT-ICRjMS.

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Section: Magnetron Motion (Quadrupolar Trapping Potential)mentioning

confidence: 99%

Excitation modes for fourier transform-ion cyclotron resonance mass spectrometry

Schweikhard

Marshall

1993

J. Am. Soc. Mass Spectrom.

103

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“…Using the above-described ways to minimize uncertainties we have completed determinations of two mass ratios: n~(D~)/m(~He) and m(3He)/m(H2). The experiments are described in Refs [9]…”

Section: Resultsmentioning

confidence: 99%

Mass determination of light ions in a Penning trap by time-of-flight detection of ion resonances

et al. 1992

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We describe an experimental setup to determine the cyclotron frequencies of ions confined in a Penning trap by resonant excitation of the ions eigenfrequencies and a time-of-flight detection of the resonances. Systematic shifts from trap- and B-field imperfections are discussed and methods to minimize those effects in our experiment are presented. Results on the mass ratio for 4He/D2 and 3He/H2 demonstrate the experimentally obtained precision in the ppb range, which might be further improved by modification of our apparatus.

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“…Remarkable accuracies have been demonstrated in measurements of the electron and positron g-factors [l] and various mass ratios involving the electron, positron, proton and the antiproton [2]. Other examples of extreme accuracies are provided by determinations of mass ratios of ions [3]. Penning traps have, during the last years, also found new applications in X-ray spectroscopy [4], atom-ion collisions [SI, condensation physics [SI, cluster physics [7], photodetachment studies [8] and measurements of the neutron lifetime [9].…”

Section: Introduction Penning Ion Traps Have Been Used In Several Exp...mentioning

confidence: 99%

The Stockholm–Mainz ion trap project

Bergström¹,

Borgenstrand²,

Carlberg³

et al. 1993

Phys. Scr.

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A new ion trap facility is described which is dedicated to studies of highly charged ions in a Penning trap. Such a trap will be connected to sources of highly charged ions, in particular the electron beam ion source CRYSIS, at the Manne Siegbahn Institute for Physics. The use of highly charged ions in a Penning trap increases the cyclotron frequency with a factor proportional to the charge which leads to a higher resolution. Also, the possibility to vary the charge state makes it possible to search for and identify different systematic effects. Thus, a substantial increase in accuracy can be expected. In addition, the combination of high charge state ions and a Penning trap allows new applications where one can take advantage of the controlled measuring situation, long observation time and high resolution detection. The initial priority will be given to high precision mass measurements of heavy stable ions. At a future stage, plans are to extend the use to other applications, such as charge exchange processes between neutrals and stored charged ions, electron impact ionization and exposure of clusters and molecules to highly charged ions as well as lifetime determinations of molecules and clusters.

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Measurement of the4He-D2 mass difference

Cited by 24 publications

References 8 publications

Excitation modes for fourier transform-ion cyclotron resonance mass spectrometry

Excitation modes for fourier transform-ion cyclotron resonance mass spectrometry

Mass determination of light ions in a Penning trap by time-of-flight detection of ion resonances

The Stockholm–Mainz ion trap project

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