München 2019 – wissenschaftliches Programm
HK 22.2: Vortrag
Dienstag, 19. März 2019, 14:30–14:45, HS 16
β-decay Q-value measurements using the phase-imaging ion-cyclotron-resonance detection with ISOLTRAP at CERN — •Jonas Karthein for the ISOLTRAP collaboration — CERN, Geneva, Switzerland — MPI für Kernphysik, Heidelberg, Germany
ISOLTRAP, located at the radioactive ion beam facility ISOLDE at CERN, is a high-precision Penning-trap mass spectrometer for short-lived nuclides. This gives access to the study of nuclear-structure effects and provides precision β-decay Q-values to test nuclear models and fundamental interactions. Previously, the measurement principle has been the time-of-flight ion-cyclotron-resonance (ToF-ICR) technique, which limits accessible half-lives and relative uncertainties. With the new phase-imaging ion-cyclotron-resonance (PI-ICR) technique [S. Eliseev et al., Phys. Rev. Lett. 110 082501 (2013)], experiments can be performed with fewer ions and higher resolving power, providing access to new areas of the nuclear chart and to new physics.
This contribution will report on the status of PI-ICR mass spectrometry (MS) with ISOLTRAP, including results from first on-line measurements in both the high-resolution and high-precision regimes. In particular, the Q-value of the 131Cs→131Xe β-decay, previously considered as a candidate for the direct neutrino-mass determination, was measured with a precision δ m/m=1.4·10−9 and a mass resolving power m/Δ m >7·106 in only 100 ms measurement time allowing to preclude it as a possible candidate in the neutrino-mass search.