  The primary goal of the novel photosensor technology called ABALONETM (U.S.
Pat. 9,064,678) has been to enable the next-generation of astroparticle physics
experiments to open new windows on the universe with large-area detectors of
unprecedented performance, radio-purity, robustness, and integration
flexibility. This foundational technology provides the means for modern,
scalable and cost-effective production. The wide range of possible
application-specific detector configurations can also make a difference in
homeland security and medical imaging. Thus far, we have reduced to practice
two such detector configurations: (i) the composite sandwich Panel assembly
that hosts matrices of closely packed ABALONE units (U.S. Pat. 10,823,861),
and, quite differently, the Tandem Detector Modules that host two back-to-back
oriented ABALONE photosensors. This article for the first time presents the
latter configuration, specifically designed to provide $2\times2\pi$ angular
acceptance for neutrino astronomy and other large-area radiation detectors.
