Towards the development of a polymer-based assembly for cryogenic detectors for neutrino-less double beta decay

Cryogenic single-particle detectors are devices, operated close to absolute zero, widely used in current and future generation detectors for the search for rare particle physics processes, for example neutrino-less double beta decay. Traditionally, these detectors are assembled in copper structures inside dilution refrigerators. The use of copper, however, is expected to become a limiting factor on the path towards the background reduction needed for future generation projects. Its high density and large Z make it an effective target where gamma-rays produced by radioactive contaminants can lose part of their energy undetected, and subsequently be measured as sensitivity-spoiling spurious signals in the region of interest of the energy spectrum. We present here a new method of building assemblies for kg-scale cryogenic single particle detectors based on low Z, low density additive manufacturing-compatible polymers that can in the future be doped with scintillating compounds thus making them an active component of the experimental setup. Additive manufacturing overcomes the limitations, imposed by traditional techniques, in the design of the structures. The assembly geometry can therefore be driven by the combined needs for reduction of mass and optimization of light production and collection. The experimental setup and the performance of the detectors in terms of energy resolution and temperature stability are described.