Investigation of cosmic-ray muon induced processes by the MIREDO facility

•The results of the first measurements by the MIREDO facility are presented.•Muon induced radiation production in CaO powder was measured.•In CaO, low-energy continuous radiation and 511 keV gamma ray were produced.•Two neutron-induced lines in Ge have been found.

The MIREDO (Muon Induced Rare Event Dynamic Observatory) spectrometer system is primarily developed for the study of cosmic muon induced processes in different materials. Exploration of such interactions can be important for ultra-low background experiments. The system is based on the 100% relative efficiency ultra-low-background HPGe spectrometer. With the addition of two plastic scintillators and a fast-slow coincidence circuit, the coincidence events between the plastic detectors and the HPGe spectrometer have been investigated. First results derived for a CaO powder sample, placed in a Marinelli beaker, are presented and discussed.