Marco Rosenbusch (RIKEN/Japan): The importance of atomic masses, and the tools for high-precision mass spectrometry

Physikalisches Kolloquium

One of the pillars for the study of exotic nuclides is the precise knowledge of the nuclear binding energy, which is directly (and model-independently) deduced from atomic-mass data. With the increasing challenge to determine the mass of isotopes, i.e. low production yields and short half-lives, the technology of mass spectrometry has to evolve continuously. Multi- reflection time-of-flight (MRTOF) mass spectrometry has grown from an initially rarely-used technology to the world’s most commonly-used method for measurements with a relative mass precision down to δm/m = 10−8. Besides CERN/Switzerland, and GSI/Germany, this technology has been developed at RIKEN/Japan for about two decades, in combination with gas-filled ion catchers for low-energy access of isotopes produced in-flight.

Recent achievements like high mass resolving power [1] followed by the installation of α/β-TOF detectors [2], and recent tricks like in-MRTOF ion selection have tremendously in- creased the selectivity of the systems, allowing for background-free identification of the rarest isotopes [3-5].

In this contribution, I will give a short overview about radioactive ion-beam facilities, the highlights of atomic mass spectrometry, and will further focus on MRTOF-MS developments and applications. An outlook will be given for future projects apart from nuclear research.