KIP-Veröffentlichungen

In the cryogenic storage ring CSR at the Max Planck Institute for Nuclear Physics in Heidelberg, reactions such as the dissociative recombination of molecular ions can be investigated under environmental conditions similar to those in interstellar molecular clouds. In order to understand their underlying reaction mechanisms, the 64 × 64 MMC pixel detector array MOCCA, which can measure the positions and kinetic energies of the incident molecule fragments, will be used in the future. MMCs are metallic magnetic calorimeters that convert an energy deposition into a magnetic flux change, which is finally converted into a voltage signal by a SQUID. MOCCA consists of 4094 individual pixels, with an active area of 4.48 cm × 4.48 cm. Its readout is achieved by an innovative multiplexing method: a single SQUID reads out two rows of 64 pixels, each with a unique combination of signal decay time and signal polarity. This approach requires a total of only 32 SQUID channels to read out the entire detector. In this thesis, it was shown that all channels of the first prototype with linear decay time encoding are functional. An energy resolution of down to ΔE = 139 eV was achieved with a single-pixel position resolution for fast decay times. To realise this for all decay times, a simulation-based design was developed in this thesis, which includes an improved exponential decay time encoding.