Search for: All records

Motivated by Cornell University's aspiration to use geothermal heat to replace fossil fuels to heat campus buildings, a 3-km deep geothermal exploratory well, the Cornell University Borehole Observatory (CUBO), was drilled on the Ithaca, NY campus in the summer of 2022. CUBO extends through largely low porosity and low permeability Paleozoic sedimentary rocks above low-grade metamorphic basement rocks. In order to assess the potential for and inform the design of an operational deep direct-use geothermal system within the US Northeast, the main objective of CUBO is to characterize the subsurface and potential fracture-dominated reservoir targets in both the sedimentary units and basement within a temperature range between 70 – 90 °C. Here we report results of our analysis which provide insight into the hydrologic, thermal, and mechanical conditions at depth and the associated physical rock fracture properties and characteristics. This integrative work incorporates regional well logs and geologic and geophysical data, as well as the CUBO-specific downhole logging and borehole image data collected during drilling operations, subsequent borehole temperature profiling and fluid sampling, downhole dual-packer mini-frac stress tests, and microstructural and physical property analysis of sidewall cores and cuttings. Altogether the knowledge from this information guides decisions regarding the design, depth, and orientation of subsequent injection and production wells at Cornell, as well as highlighting University, and highlights particular geologic targets and strategies for developing an effective and efficient enhanced geothermal reservoir. These comprehensive results, as well as lessons learned regarding the overall approach, can help de-risk decisions regarding the development of deep geothermal energy systems both at Cornell University and elsewhere. 

Abstract CUPID, the CUORE Upgrade with Particle Identification, is a next-generation experiment to search for neutrinoless double beta decay ($$0\mathrm {\nu \beta \beta }$$ $0\nu \beta \beta$) and other rare events using enriched Li$$_{2}$$ $_2^{}$$$^{100}$$ $_{}^{100}$MoO$$_{4}$$ $_4^{}$scintillating bolometers. It will be hosted by the CUORE cryostat located at the Laboratori Nazionali del Gran Sasso in Italy. The main physics goal of CUPID is to search for$$0\mathrm {\nu \beta \beta }$$ $0\nu \beta \beta$of$$^{100}$$ $_{}^{100}$Mo with a discovery sensitivity covering the full neutrino mass regime in the inverted ordering scenario, as well as the portion of the normal ordering regime with lightest neutrino mass larger than 10 meV. With a conservative background index of 10$$^{-4}$$ $_{}^{-4}$ cts$$/($$ $/($keV$$\cdot $$ $·$kg$$\cdot $$ $·$yr$$)$$ $)$, 240 kg isotope mass, 5 keV FWHM energy resolution at 3 MeV and 10 live-years of data taking, CUPID will have a 90% C.L. half-life exclusion sensitivity of$$1.8\cdot 10^{27}$$ $1.8·{10}^{27}$ yr, corresponding to an effective Majorana neutrino mass ($$m_{\beta \beta }$$ $m_{\beta \beta }$) sensitivity of 9–15 meV, and a$$3\sigma $$ $3\sigma$discovery sensitivity of$$1\cdot 10^{27}$$ $1·{10}^{27}$ yr, corresponding to an$$m_{\beta \beta }$$ $m_{\beta \beta }$range of 12–21 meV. 

The Cryogenic Underground Observatory for Rare Events (CUORE) is a detector array comprised by 988 $5\mathrm{cm}\times 5\mathrm{cm}\times 5\mathrm{cm}$ ${\mathrm{TeO}}_2$crystals held below 20 mK, primarily searching for neutrinoless double-beta decay in ${}^{130}\mathrm{Te}$. Unprecedented in size among cryogenic calorimetric experiments, CUORE provides a promising setting for the study of exotic throughgoing particles. Using the first tonne year of CUORE’s exposure, we perform a search for hypothesized (FCPs), which are well-motivated by various standard model extensions and would have suppressed interactions with matter. Across the searched range of charges $e/24-e/2$no excess of FCP candidate tracks is observed over background, setting leading limits on the underground FCP flux with charges $e/24-e/5$at 90% confidence level. Using the low background environment and segmented geometry of CUORE, we establish the sensitivity of tonne-scale subkelvin detectors to diverse signatures of new physics. Published by the American Physical Society2024