The Selena Neutrino Experiment

Abstract Imaging sensors made from an ionization target layer of amorphous selenium (aSe) coupled to a silicon complementary metal-oxide-semiconductor (CMOS) active pixel array for charge readout are promising technology neutrino physics. The high spatial resolution in solid-state provides unparalleled rejection backgrounds natural radioactivity the search neutrinoless ββ decay and solar spectroscopy with 82 Se. We present results on response aSe measured photoabsorption 122 keV γ rays single-pixel device. report progress fabrication testing first prototype imaging based Topmetal II − pixelated CMOS chip. explore scientific reach large detector proposed our experimental understanding sensor performance.