The electron detector for the Quantum Invisible Particle Sensor (QuIPS) experiment

We present the design and first demonstration of the electron detector for the Quantum Invisible Particle Sensor (QuIPS) experiment, a novel architecture aimed at searching for heavy sterile neutrinos in the keV-MeV mass range. QuIPS features a nanometer-scale, optically levitated sensor embedded with unstable radioisotopes, surrounded by pixelated silicon detectors. By measuring the momentum of the outgoing electron from each decay with the silicon detector, together with the recoil momentum of the levitated sphere measured by the optomechanical sensor, the experiment enables full event-by-event reconstruction of the total momentum carried by the invisible decay products.

The electron detector uses two CMOS pixel sensors to determine the emission direction and a plastic scintillator to measure the energy, yielding an electron momentum resolution comparable to that of the recoil measurement. This talk will present the proof-of-concept demonstration of the electron detector, including its design, subsystem characterization, full-system performance, and integration with the optomechanical sensor.