Building upon the first edition of Nuclear Electronics (Wiley 2005), the author returns with a focus on the technology of cryogenic detectors. Those of the quantum mechanical nature at ultra-low temperatures provide the best resolution, accuracy, and speed as radiation measurement tools. Providing reliable, powerful, and ultimately high-resolution diagnostic test results, a new generation of quantum cryogenic devices has appeared which are essential for Big Science (Astrophysics, Cosmology). For example, they are already installed in several large ground telescopes and will constitute base technology in the high-resolution spectrometer camera onboard the next X-ray telescope built by the European Space Agency (ESA), Athena, to be launched in 2032. However, analysis has shown that quantum cryogenic detectors are not used solely as stand-alone instruments but are often paired with semiconductor large frame cameras which provide |