High-Resolution Mass Spectrometry: The Trap Design and Detection System of Pentatrap and New Q-Values for Neutrino Studies

Abstract

The novel Penning-trap mass spectrometer Pentatrap aims for mass-ratio measure- ments of highly-charged ions with a relative precision of a few parts in 10^12. As the key part, an innovative trap assembly was designed. It consists of five cylindrical traps allowing for simultaneous measurements of two ion species and for continuous moni- toring of the trapping conditions. This promises a substantial reduction of systematic errors. Moreover, in the course of this thesis a detection system was developed and characterized, which will enable fast and accurate measurements through its single-ion sensitivity and high signal-to-noise ratio. In neutrino physics, the detection of neutrinoless double-electron capture would un- ambiguously prove the Majorana nature of neutrinos. In search for a suitable nuclide for the observation of this process, precise information about the total decay energy (Q-value) is needed in order to find a transition with a resonant enhancement of the decay rate. The mass ratios of 152Sm/152Gd and 164Dy/164Er were measured to a relative uncertainty of ∼ 10^−9 at Shiptrap. This presents the first directly determined Q-values for the corresponding transitions.