Ultra Radio Pure Sodium Iodide Detectors for Dark Matter

The quest to understand dark matter is a major goal in modern particle physics and astrophysics. Important discoveries in this area through the DAMA group) have been made by means of detecting rare radiation events, but because of contrary findings, there is a need to confirm the results. This requires new radiation detectors NaI scintillators) that can better distinguish between the critical events and naturally occurring radiation within the detectors that may obscure results. This proposal is to develop NaI detectors with considerably lower background having less radioactive contamination). This will be accomplished by intensive purification of the NaI raw materials, followed by special processes for crystal growth and detector fabrication. A new NaI experiment with lower radioactivity background levels would have a higher sensitivity that could confirm or refute the DAMA result. Radiation Monitoring Devices, Inc. RMD), in collaboration with Princeton University, has already made significant progress in producing NaI scintillation crystals with reduced background of radioactive impurities. The critical points of the proposed research is to perform rigorous investigation of the purification and crystal growth of NaI, and to characterize the purity and scintillation properties of the crystals produced. Prototype dark matter detectors will be built with the necessary purity and components to provide suitable performance for the DAMA experiments to be replicated with even better sensitivity. The technology being proposed is to improve the quality of NaI radiation detectors, which are amongst the most heavily used in the fields of medicine, homeland security, dosimetry and many forms of basic research. Developing techniques to both measure and remove contaminations whether radiation emitting or not) can benefit the production of this important material and possibly others) since detector performance is impacted be the quality of raw chemical stock.