Toward a more accurate Q value measurement of tritium: status of THe-Trap

The goal of the THe-Trap experiment is to measure the tritium/helium-3 mass ratio in order to deduce the Q value of the tritium β-decay. A relative uncertainty of 10 parts per trillion in the mass ratio would allow determining the Q value with a precision of 30 meV. This value is of relevance for the Karlsruhe Tritium Neutrino (KATRIN) collaboration, which is building a spectrometer to measure the mass of the electron antineutrino. In this contribution, we present the progress made in the past 2 years. We can, e.g., store, manipulate and detect single ions. To demonstrate the current accuracy, we measured the carbon-12 to oxygen-16 mass ratio with a relative uncertainty of 120 parts per trillion in early 2013. The improvements, current status and future perspectives will be presented.