Search for scalar interaction with the WITCH experiment - status and outlook

The WITCH experiment examines the nuclear beta decay of ions stored in a penning trap using a retardation spectrometer. With this experiment we measure the recoil spectrum, from which one can derive the beta neutrino angular correlation a. This allows us to search for a scalar interaction contribution in the weak interaction. The goal is to measure a with a precision of Δa<0.5%. In 2008 and 2009 various enhancements of the experimental setup have been carried out. Therefore many components of the system were modified and upgraded. In support of this, we performed tracking simulations and field calculations, that were also used for a further analysis of the measurement from 2006. This talk reviews the current status of the simulations as well as the experiment and gives an outlook for this year.