Measurement of Low Energy Nuclear Recoil Events with the phonon-mediated Voltage-Assisted Hybrid Detector for Rare Event Searches

Abstract: The phonon-mediated hybrid detector is made out of a monolithic silicon crystal characterized by two interconnected regions linked through a narrow neck. Operating solely on phonon signal measurements, the hybrid design facilitates the differentiation between electron recoil and nuclear recoil events, effectively discerning two types of interaction down to low energy levels. With a newly implemented software triggering technique (SWT), low-energy nuclear recoil events of approximately $500~eV_{ee}$ have been measured. In addition to this, an electron recoil background reduction of up to $95\%$ has been successfully demonstrated.