Precision Mass Measurements at the MLL in Garching: MLLTRAP
MLLTRAP is a cylindrical double Penning trap system that has been installed and commissioned at the Maier-Leibnitz-Laboratory (MLL) in Garching. This trap system has been designed to isobarically purify low-energy ion beams and perform highly accurate nuclear mass measurements. Among the goals of MLLTRAP are high-precision atomic mass spectrometry and developments for in-trap nuclear decay spectroscopy experiments within the MATS collaboration at FAIR/GSI. Therefore, several techniques will be employed to decelerate, cool, and purify the ions of interest prior to their measurement. For this purpose, a gas-filled stopping cell (MLL-IonCatcher) was developed at MLL for Penning trap mass spectrometers such as SHIPTRAP (at GSI/Darmstadt) and MLLTRAP. For a precise mass determination, the cyclotron frequencies of ions oscillating in the trap are determined. Since the achievable relative mass uncertainties are inversely proportional to the ionic charge states, the charge breeding of ions towards higher charge states is foreseen in future.
View of the MLLTRAP setup at the Maier-Leibnitz Accelerator Lab in Garching. Front: separator magnets, back: gas-cell setup, rear: Penning trap magnet