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The Majorana Demonstrator will search for the neutrinoless double-beta (ββ0ν) decay of the isotope Ge with a mixed array of enriched and natural germanium detectors. The observation of this rare decay would indicate that the neutrino is its own antiparticle, demonstrate that lepton number is not conserved, and provide information on the absolute mass scale of the neutrino. The Demonstrator is being assembled at the 4850-foot level of the Sanford Underground Research Facility in Lead, South Dakota. The array will be situated in a low-background environment and surrounded by passive and active shielding. Here we describe the science goals of the Demonstrator and the details of its design.

CUORE-0 is a cryogenic detector that uses an array of tellurium dioxide bolometers to search for neutrinoless double-beta decay of 130 Te . We present the first data analysis with 7.1 kg · y of total TeO 2 exposure focusing on background measurements and energy resolution. The background rates in the neutrinoless double-beta decay region of interest (2.47 to 2.57 MeV ) and in the α background-dominated region (2.70 to 3.90 MeV ) have been measured to be 0.071 ± 0.011 and 0.019 ± 0.002 counts / ( keV · kg · y ) , respectively. The latter result represents a factor of 6 improvement from a predecessor experiment, Cuoricino. The results verify our understanding of the background sources in CUORE-0, which is the basis of extrapolations to the full CUORE detector. The obtained energy resolution (full width at half maximum) in the region of interest is 5.7 keV . Based on the measured background rate and energy resolution in the region of interest, CUORE-0 half-life sensitivity is expected to surpass the observed lower bound of Cuoricino with one year of live time.

Neutrinoless double-beta (0 ν β β ) decay is a hypothesized lepton-number-violating process that offers the only known means of asserting the possible Majorana nature of neutrino mass. The Cryogenic Underground Observatory for Rare Events (CUORE) is an upcoming experiment designed to search for 0 ν β β decay of 130Te using an array of 988 TeO2 crystal bolometers operated at 10 mK. The detector will contain 206 kg of 130Te and have an average energy resolution of 5 keV; the projected 0 ν β β decay half-life sensitivity after five years of livetime is 1.6 × 1026 y at 1 σ (9.5 × 1025 y at the 90% confidence level), which corresponds to an upper limit on the effective Majorana mass in the range 40–100 meV (50–130 meV). In this paper, we review the experimental techniques used in CUORE as well as its current status and anticipated physics reach.

Field-collected adults of three genera of turf-infesting scarabs, Japanese beetle (Popillia japonica Newman), June beetles (Phyllophaga spp.), and masked chafers (Cyclocephala spp.), were exposed to experimental and commercial granule formulations of the entomopathogenic fungus Metarhizium brunneum (Petch) strain F52 to determine their relative susceptibility. Experimental granules contained microsclerotia produced by liquid fermentation with the ability to produce fresh conidia when rehydrated and commercial granules were Met 52 granular bioinsecticide. All three groups of scarab adults showed a positive dosage response to the fungus when exposed in cups of potting mix treated with the granules. LC50 values for microsclerotia granules were 1.9 × 107, 7.1 × 106, and 3.2 × 106 conidia cup-1 for P. japonica, Phyllophaga spp., and Cyclocephala spp., respectively. LC50 values for Met 52 granules were 5.9 × 107, 5.1 × 107, and 7.6 × 106 conidia cup-1, respectively. The experimental granules containing microsclerotia show promise as a viable commercial control agent. They can be produced using lower cost fermentation methods and applied at lower dosages (97 g for 100 m2 as opposed to 489 g per 100 m2 for Met 52). If M. brunneum is applied to control the aforementioned white grubs, our data indicate the potential for the adult beetles to also be infected as they enter the soil to lay eggs.

The goal of the Majorana Demonstrator project is to search for 0νββ decay in 76Ge. Of all candidate isotopes for 0νββ, 76Ge has some of the most favorable characteristics. Germanium detectors are a well established technology, and in searches for 0νββ, the high purity germanium crystal acts simultaneously as source and detector. Furthermore, p-type germanium detectors provide excellent energy resolution and a specially designed point contact geometry allows for sensitive pulse shape discrimination. This paper will summarize the experiences the MAJORANA collaboration made with enriched germanium detectors manufactured by ORTEC®®. The process from production, to characterization and integration in MAJORANA mounting structure will be described. A summary of the performance of all enriched germanium detectors will be given.

A challenging aspect of the next generation detector for rare events searches (i.e. neutrinoless double beta decay and dark matter searches) is the reduction of the background in the region of interest that can mimic the expected signals. In the field of thermal detectors, which have a leading role in rare events searches thanks to their excellent energy resolution and to the wide choice of absorber materials, the background coming from surface contaminations is frequently dominant. A background surface rejection detector is a scintillation-based approach for tagging this type of background. We discuss the innovative application of this technique in non-scintillating thermal detectors. We will report on the performances of the prototype bolometric detector, realized to prove the feasibility of this new technique.

Neutrinoless double-beta (0νββ) decay is a hypothesized process where in some even-even nuclei it might be possible for two neutrons to simultaneously decay into two protons and two electrons without emitting neutrinos. This is possible only if neutrinos are Majorana particles, i.e. fermions that are their own antiparticles. Neutrinos being Majorana particles would explicitly violate lepton number conservation, and might play a role in the matter-antimatter asymmetry in the universe. The observation of neutrinoless double-beta decay would also provide complementary information related to neutrino masses. The Majorana Collaboration is constructing the MAJORANA DEMONSTRATOR, with a total of 40-kg Germanium detectors, to search for the 0νββ decay of 76Ge and to demonstrate a background rate at or below 3 counts/(ROI·t·y) in the 4 keV region of interest (ROI) around the 2039 keV Q-value for 76Ge 0νββ decay. In this paper, we discuss the physics of neutrinoless double beta decay and then focus on the MAJORANA DEMONSTRATOR, including its design and approach to achieve ultra-low backgrounds and the status of the experiment.

The CUORE (Cryogenic Underground Observatory for Rare Events) experiment will search for neutrinoless double beta decay in 130 Te. Observation of the process would unambiguously establish that neutrinos are Majorana particles as well as provide information about the absolute neutrino mass scale and mass hierarchy.The CUORE setup will consist of an array of 988 tellurium dioxide crystals (containing 206 kg of 130 Te in total), operated as bolometers at a temperature of ∼ 10 mK. The experiment is now under construction at the Gran Sasso National Laboratory in Italy. As a first step towards CUORE, a tower (CUORE-0) has been assembled and is taking data. Here a detailed description of the CUORE-0 tower and its performance is reported. The status of the CUORE experiment and its expected sensitivity will then be discussed.

Neutrinoless double beta decay ( 0 ν β β ) is one of the most sensitive probes for physics beyond the Standard Model, providing unique information on the nature of neutrinos. In this paper we review the status and outlook for bolometric 0 ν β β  decay searches. We summarize recent advances in background suppression demonstrated using bolometers with simultaneous readout of heat and light signals. We simulate several configurations of a future CUORE-like bolometer array which would utilize these improvements and present the sensitivity reach of a hypothetical next-generation bolometric 0 ν β β  experiment. We demonstrate that a bolometric experiment with the isotope mass of about 1 ton is capable of reaching the sensitivity to the effective Majorana neutrino mass ( | m e e | ) of order 10–20 meV, thus completely exploring the so-called inverted neutrino mass hierarchy region. We highlight the main challenges and identify priorities for an R&D program addressing them.

Neutrinoless double beta decay (0νββ) is one of the most sensitive probes for physics beyond the Standard Model, providing unique information on the nature of neutrinos. In this paper we review the status and outlook for bolometric 0νββ decay searches. We summarize recent advances in background suppression demonstrated using bolometers with simultaneous readout of heat and light signals. We simulate several configurations of a future CUORE-like bolometer array which would utilize these improvements and present the sensitivity reach of a hypothetical next-generation bolometric0νββ experiment. We demonstrate that a bolometric experiment with the isotope mass of about 1 ton is capable of reaching the sensitivity to the effective Majorana neutrino mass (|mee|) of order 10-20 meV, thus completely exploring the so-called inverted neutrino mass hierarchy region. In conclusion, we highlight the main challenges and identify priorities for an R&D program addressing them.