A Device to Measure Low Levels of Radioactive Contaminants in Ultra-Clean Materials

75611-The search for rare events such as double beta decay and dark matter require large masses of detectors and support materials, which must be virtually free from radioactive contamination. Currently, no detector is available that has the sensitivity to readily detect the low levels of radioactivity contained in these materials. This project will use a large number of thin sheets of plastic scintillator as radiation detectors. By placing samples of material between and around the detectors, the very significant and detrimental attenuation of alpha, beta, and gamma radiation that occurs in large samples can be mitigated. In order to reduce the inherent background radiation to a tolerable level, the detector will be operated deeply underground, be shielded with radio-pure lead or copper, and utilize anti-cosmic active shielding. Phase I will design and build a prototype device, operate the device in a location deep underground, and evaluate the results. Commercial Applications and Other Benefits as described by the awardee: In addition to its application for scientific research, a radiation detector with this level of sensitivity could be used for screening lead and other materials used in the microchip industry ¿ information stored in computer memories can be altered by an alpha particle that originates in proximate material and strikes a sensitive area.