부산대학교 도서관

Calorimetric decay energy spectroscopy of electron-capture-decaying isotopes is a promising method to achieve the sensitivity required for electron neutrino mass measurement. The very low total nuclear decay energy $$(Q_\mathrm{EC}$$ $$<$$ 3 keV) and short half-life (4570 years) of $$^{163}$$ Ho make it attractive for high-precision electron-capture spectroscopy (ECS) near the kinematic endpoint, where the neutrino momentum goes to zero. In the ECS approach, an electron-capture-decaying isotope is embedded inside a microcalorimeter designed to capture and measure the energy of all the decay radiation except that of the escaping neutrino. We have developed a complete process for proton irradiation-based isotope production, isolation, and purification of $$^{163}$$ Ho. We have developed transition-edge sensors for this measurement and methods for incorporating $$^{163}$$ Ho into high-resolution microcalorimeters, and have measured the electron-capture spectrum of $$^{163}$$ Ho. We present our work in these areas and discuss the measured spectrum and its comparison to current theory. [ABSTRACT FROM AUTHOR]