A measurement of the 2 neutrino double beta decay rate of Te-130 in the CUORICINO experiment [report]

Laura K. Kogler
2011 unpublished
CUORICINO was a cryogenic bolometer experiment designed to search for neutrinoless double beta decay and other rare processes, including double beta decay with two neutrinos (2νββ). The experiment was located at Laboratori Nazionali del Gran Sasso and ran for a period of about 5 years, from 2003 to 2008. The detector consisted of an array of 62 TeO 2 crystals arranged in a tower and operated at a temperature of ∼10 mK. Events depositing energy in the detectors, such as radioactive decays or
more » ... nging particles, produced thermal pulses in the crystals which were read out using sensitive thermistors. The experiment included 4 enriched crystals, 2 enriched with 130 Te and 2 with 128 Te, in order to aid in the measurement of the 2νββ rate. The enriched crystals contained a total of ∼350 g 130 Te. The 128-enriched (130-depleted) crystals were used as background monitors, so that the shared backgrounds could be subtracted from the energy spectrum of the 130enriched crystals. Residual backgrounds in the subtracted spectrum were fit using spectra generated by Monte-Carlo simulations of natural radioactive contaminants located in and on the crystals. The 2νββ half-life was measured to be T 2ν 1/2 = [9.81 ± 0.96(stat) ± 0.49(syst)] × 10 20 y. i To my family I would like to express my sincere gratitude to the following individuals, who contributed substantially to the completion of this work: To my advisor, Stuart Freedman, for supporting me through my graduate career, for giving me the freedom to pursue my own investigations, and for all the bits of wisdom slyly couched in deadpan anecdotes. To my committee members Yury Kolomensky and Rick Norman for their invaluable expertise and guidance on data analysis and nuclear physics, and for their careful reading and feedback on this document. To Maura Pavan for sharing her extensive knowledge about the intricacies, subtleties and quirks of CUORICINO data analysis, gained from years of experience on CUORICINO and its predecessor experiments. To the current and former LBNL post-docs and staff, Elena
doi:10.2172/1052174 fatcat:ydie47vljfex5l3kzqnjf75p3e