Speaker
Description
The Quantum Invisible Particle Search (QuIPS) experiment aims to detect sterile neutrinos in the keV-to-few-MeV mass range through weak nuclear decays. Our innovative detector system combines a nanometer-scale silica sphere in an optomechanical laser trap with active-pixel and scintillating detectors to achieve full kinematic reconstruction of beta decays. Nanospheres loaded with radioisotopes are optically trapped in ultra-high vacuum, enabling detection of the recoil momentum imparted by emitted decay products. Two parallel planes of compact CMOS sensors, backed by a plastic scintillator, provide vertexing and beta-momentum reconstruction. By measuring both the momentum imparted to the sphere and that of the emitted beta particle, we can reconstruct the neutrino momentum and thus probe for massive neutrinos. The beta‑momentum detectors are designed with a small‑form‑factor for operation in ultra‑high vacuum (10$^{-8}$ mbar) and deliver high momentum resolution. The QuIPS group at Yale is now loading nanospheres with $^{18}$F for the first recoil measurements across a range of beta energies. In this presentation I will discuss the calibration of the beta‑momentum detectors, the expected results from the $^{18}$F measurements, and the potential of QuIPS to explore the sterile‑neutrino parameter space.