Dead layer determination for the new implantation detector of the LUNDIUM decay station

Abstract: The Nuclear Structure Group in Lund, focuses on nuclear spectroscopy of decays of rare isotopes. A new decay station, called LUNDIUM, is currently being built, which will involve silicon and germanium detectors for the study of these nuclei. This thesis focuses on the characterization of one of the new silicon detectors, the implantation one. More specifically, the dead layer is determined over the entire surface of the detector. The silicon detector is ion-implanted and silicon dioxide passivated, forming the dead layer, which is unable to record the energies of the particles passing through. Superheavy elements decay by alpha decay, and the energy registered on the detectors from the alpha particles depends on the amount of material that they have to pass through. By knowing the thickness of the dead layer, the full energy of the particles can be reconstructed. During superheavy experiments, the compound nucleus is implanted in the implantation detector. The dead layer plays a significant role in correcting the energy emission of the particles that escape the implantation detector and are stopped in one of the box detectors. For the dead layer thickness determination, data with two alpha sources Gd-148 and Cm-244, as well as an electron source Ba-133 were taken and analyzed. The dead layer was found to be in the order of 0.6 μm.