A high-resolution CMOS imaging detector for the search of neutrinoless double β decay in ⁸²Se

We introduce high-resolution solid-state imaging detectors for the search of neutrinoless double β decay. Based on the present literature, imaging devices from amorphous ⁸²Se evaporated on a complementary metal-oxide-semiconductor (CMOS) active pixel array could have the energy and spatial resolution to produce two-dimensional images of ionizing tracks of utmost quality, effectively akin to an electronic bubble chamber in the double β decay energy regime. Still to be experimentally demonstrated, a detector consisting of a large array of these devices could have very low backgrounds, possibly reaching 1 × 10^-7/(kgy) in the neutrinoless decay region of interest (ROI), as it may be required for the full exploration of the neutrinoless double β decay parameter space in the most unfavorable condition of a strongly quenched nucleon axial coupling constant.