Eur. Phys. J. D 58, 47-52 (2010)
https://doi.org/10.1140/epjd/e2010-00092-9

Accuracy studies with carbon clusters at the Penning trap mass spectrometer TRIGA-TRAP^*

¹ Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudinger Weg 7, 55128 Mainz, Germany
² Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
³ Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Philosophenweg 12, 69120 Heidelberg, Germany
⁴ GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt, Germany
⁵ Institut für Kernchemie, Johannes Gutenberg-Universität Mainz, Fritz-Strassmann-Weg 2, 55128 Mainz, Germany

Corresponding author: ketela@uni-mainz.de

Received: 24 December 2009
Revised: 20 February 2010
Published online: 6 April 2010

Abstract

Extensive cross-reference measurements of well-known frequency ratios using various sizes of carbon cluster ions ¹²C_n⁺ (10 ≤ n ≤ 23) were performed to determine the effects limiting the accuracy of mass measurements at the Penning-trap facility TRIGA-TRAP. Two major contributions to the uncertainty of a mass measurement have been identified. Fluctuations of the magnetic field cause an uncertainty in the frequency ratio due to the required calibration by a reference ion of u_f(ν_ref)/ν_ref = 6(2) × 10^-11/min × Δ t. A mass-dependent systematic shift of the frequency ratio of ϵ_m(r)/r = -2.2(2) × 10^-9 × (m-m_ref)/u has been found as well. Finally, the nuclide ¹⁹⁷Au was used as a cross-check since its mass is already known with an uncertainty of 0.6 keV.