Engineering topics

Drobizhev, A

Publications and source records attributed to Drobizhev, A.

16 records

DOE OSTI2020

Characterization of cubic Li$_{2}$$^{100}$MoO$_4$ crystals for the CUPID experiment

The CUPID Collaboration is designing a tonne-scale, background-free detector to search for double beta decay with sufficient sensitivity to fully explore the parameter space corresponding to the inverted neutrino mass hierarchy scenario. One of the CUPID demonstrators, CUPID-Mo, has proved the potential of enriched Li$_{2}$$^{100}$MoO$_4$ crystals as suitable detectors for neutrinoless double beta decay search. In this work, we characterised cubic crystals that, compared to the cylindrical crystals used by CUPID-Mo, are more appealing for the construction of tightly packed arrays. We measured an average energy resolution of (6.7$\pm$0.6) keV FWHM in the region of interest, approaching the CUPID target of 5 keV FWHM. We assessed the identification of $\alpha$ particles with and without a reflecting foil that enhances the scintillation light collection efficiency, proving that the baseline design of CUPID already ensures a complete suppression of this $\alpha$-induced background contribution. We also used the collected data to validate a Monte Carlo simulation modelling the light collection efficiency, which will enable further optimisations of the detector.

100Mo↗

DOE OSTI2019

Recent results of the Majorana Demonstrator experiment

The Majorana Demonstrator is searching for neutrinoless double-beta decay in 76Ge with two modular arrays of natural and 76Ge-enriched germanium detectors. It is located at the 4850' level of Sanford Underground Research Facility in Lead, South Dakota, USA, and its total mass of germanium detectors is 44.1 kg, of which 29.7 kg is enriched. The analysis of the first 26 kg-yr of data provides an unprecedented energy resolution of 0.13% in the region of interest at 2039 keV and a background level of 15.4 ±2.0 counts/(FWHM t yr). It establishes the lower limit of the half-life of neutrinoless double beta decay as 2.7 1025 yr in 76Ge at 90% CL. This analysis will be summarized here with an emphasis on the energy determination.

López-Castaño, JM↗

DOE OSTI2019

Results from the CUORE experiment

Neutrinoless double beta decay (0νββ) is a rare, second-order nuclear transition that occurs only if neutrinos are massive Majorana particles or through new physics beyond Standard Model. This process explicitly violates the lepton number (L) by two units and, therefore, the observation of 0νββ would demonstrate that L is not a symmetry of nature. Combined with flavour mixing and cosmological measurements, it can provide unique contraints on neutrino mass scale and establish whether neutrinos are Dirac or Majorana particles. The Cryogenic Underground Observatory for Rare Events (CUORE) is an experiment located at the LNGS searching for 0νββ decay of 130 Te. CUORE exploits the bolometric technique to reach high resolution around the Q-value (2527.5 keV). It consists of an array of 988 natural TeO 2 cubic crystals grouped into 19 towers. With a total active mass of 742 kg (~206 kg of 130 Te), CUORE is operated at very low temperature with a new 3 He/ 4 He refrigerator. Data taking started at the beginning of 2017. After a brief introduction on the detector and the way data analysis is performed, I describe CUORE first results for the search of the 0νββ decay that were published in March 2018.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2019

Results from the CUORE experiment

The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for neutrinoless double beta decay that has been able to reach the 1-ton scale. In this talk we present the neutrinoless doube beta decay results of CUORE from examining a total TeO 2 exposure of 86.3 kg yr, characterized by an effective energy resolution of 7.7 keV FWHM and a background in the region of interest of 0.014 counts/(keV kg yr). In this physics run, CUORE placed a lower limit on the decay half-life of 130 Te > 1.3 × 10 25 yr (90% C.L.). We then discuss the additional improvements in the detector performance achieved in 2018 and the latest update on the evaluation of the background budget.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2019

Results from the CUORE experiment

The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for neutrinoless double beta (0νββ) decay that has been able to reach the 1-ton scale. The detector consists of an array of 988 TeO2 crystals arranged in a cylindrical compact structure of 19 towers. The construction of the experiment and, in particular, the installation of all towers in the cryostat was completed in 2016 and data taking started in 2017. In this conference we present the 0νββ decay results of CUORE from examining a total TeO2 exposure of 86.3 kg yr, characterized by an effective energy resolution of 7.7 keV FWHM and a background in the region of interest of 0.014 counts/(keV kg yr). Based on these data, CUORE places a lower limit on the 0νββ decay half-life of (90% C.L.). We then discuss the latest updates in the analysis of background and in the evaluation of the half-life of 2νββ decay of 130Te.

Chiesa, D↗

DOE OSTI2018

Update on the recent progress of the CUORE experiment

CUORE is a 741 kg array of 988 TeO$_2$ bolometeric crystals designed to search for the neutrinoless double beta decay of $^{130}$Te and other rare processes. CUORE has been taking data since summer 2017, and as of summer 2018 collected a total of 86.3 kg$\cdot$yr of TeO$_2$ exposure. Based on this exposure, we were able to set a limit on the $0\nu\beta\beta$ half-life of $^{130}$Te of $T^{0\nu}_{1/2}>1.5\times10^{25}$ yr at 90% C.L. At this conference, we showed the decomposition of the CUORE background and were able to extract a $^{130}$Te $2\nu\beta\beta$ half-life of $T_{1/2}^{2\nu}=[7.9\pm0.1 \mathrm{(stat.)}\pm0.2 \mathrm{(syst.)}]\times10^{20}$ yr. This is the most precise measurement of this half-life and is consistent with previous measurements.

Adams, DQ↗

DOE OSTI2018

The CUORE and CUORE-0 experiments at LNGS

The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for neutrinoless double beta decay that has been able to reach the 1-ton scale. The detector consists of an array of 988 TeO2 crystals arranged in a cylindrical compact structure of 19 towers. The construction of the experiment and, in particular, the installation of all towers in the cryostat was completed in August 2016 and commissioning started in fall 2016. The experiment has completed the pre-operation phase and is currently in data taking. We present here the achievements of CUORE during the commissioning phase and the limit on the 130Te half-life for the neutrinoless double beta decay that has been released after the first 3 weeks of collected data. Physics results from CUORE-0 will also be updated.

Alduino, C↗

DOE OSTI2018

Study of Rare Nuclear Processes with CUORE

TeO 2 bolometers have been used for many years to search for neutrinoless double beta decay in 130-Te. CUORE, a tonne-scale TeO 2 detector array, recently published the most sensitive limit on the half-life, $T_{1/2}^{0\nu} > 1.5 \times 10^{25}\,$yr, which corresponds to an upper bound of $140-400$ meV on the effective Majorana mass of the neutrino. While it makes CUORE a world-leading experiment looking for neutrinoless double beta decay, it is not the only study that CUORE will contribute to in the field of nuclear and particle physics. As already done over the years with many small-scale experiments, CUORE will investigate both rare decays (such as the two-neutrino double beta decay of 130 Te and the hypothesized electron capture in 123 Te), and rare processes (e.g., dark matter and axion interactions). This paper describes some of the achievements of past experiments that used TeO 2 bolometers, and perspectives for CUORE.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2018

Controlling T c of Iridium films using interfacial proximity effects

High precision calorimetry using superconducting transition edge sensors requires the use of superconducting films with a suitable T c , depending on the application. To advance high-precision macrocalorimetry, we require low-T c films that are easy to fabricate. A simple and effective way to suppress T c of superconducting Iridium through the proximity effect is demonstrated by using Ir/Pt bilayers as well as Au/Ir/Au trilayers. While Ir/Au films fabricated by applying heat to the substrate during Ir deposition have been used in the past for superconducting sensors, we present results of T c suppression on Iridium by deposition at room temperature in Au/Ir/Au trilayers and Ir/Pt bilayers in the range of $\sim$20-100~mK. Measurements of the relative impedance between the Ir/Pt bilayers and Au/Ir/Au trilayers fabricated show factor of $\sim$10 higher values in the Ir/Pt case. These new films could play a key role in the development of scalable superconducting transition edge sensors that require low-T c films to minimize heat capacity and maximize energy resolution, while keeping high-yield fabrication methods.

Hennings-Yeomans, R↗

DOE OSTI2018

The CUORE bolometric detector for neutrinoless double beta decay searches

The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment reaching the 1-ton scale. The detector consists of an array of 988 TeO2 crystals arranged in 19 towers. The construction of the experiment and the installation of the detector was completed in August 2016. In this paper, the technical challenges of the construction, the design choices and measured performance of the electronic instrumentation are presented.

Cassina, L↗

DOE OSTI2018

Results from the CUORE experiment

The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment operated at about 10 mK reaching the ton-scale. CUORE main goal is the search for neutrinoless double beta decay in 130Te, while it is suitable also for other kinds of rare event searches, such as dark matter and axions. The detector is situated at Laboratori Nazionali del Gran Sasso (LNGS), Italy, and consists in an array of 988 TeO2 crystals, being both the detector and the source of the decay. Since the beginning of 2017, CUORE operations had both phases for physics data taking and campaigns of detector optimization to obtain the maximum from its potential. Here we briefly discuss one of the procedures for the optimization of the detector regarding noise reduction and report the achievements of CUORE concerning energy resolution and background in the region of interest after the first few months of data taking. Finally we conclude by examining the results from our first neutrinoless double beta decay analysis published at the beginning of 2018, which with a total TeO2 exposure of 86.3 kg·y allowed to place a lower limit on the decay half-life of T1/20ν(130Te) > 1.3 ×1025 yr (90% C.L.) .

Marini, L↗

DOE OSTI2017

The CUORE and CUORE-0 experiments at LNGS

The Cryogenic Underground Observatory for Rare Events (CUORE) is a 1-ton scale bolometric experiment devoted to the search of the neutrinoless double-beta decay (0νββ) in 130Te. The CUORE detector consists of an array of 988 TeO2 crystals operated at 10 mK. CUORE-0 is the CUORE demonstrator: it has been built to test the performance of the upcoming CUORE experiment and represents the largest 130Te bolometric setup ever operated. CUORE-0 has been running at Laboratori Nazionali del Gran Sasso (Italy) from 2013 to 2015. The final CUORE-0 analysis on 0νββ and the corresponding detector performance are presented. The present status of the CUORE experiment, now in its final construction and commissioning phase, are discussed. The results from assembly of the detector and the commissioning of the cryostat are reported.

D'Addabbo, A↗

DOE OSTI2017

Results from CUORE and CUORE-0

The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for neutrinoless double beta decay that has been able to reach the 1-ton scale. The detector consists of an array of 988 TeO2 crystals arranged in a cylindrical compact structure of 19 towers. The construction of the experiment and the installation of all towers in the cryostat was completed in August 2016: the experiment is now in data taking phase. In this talk, beyond updating the physics results from CUORE-0, we will discuss the achievements and technical challenges of the CUORE construction phase, with particular emphasis on the background reduction strategy, the performance of the detector during pre-operation and the projected first results from the full detector run.

Moggi, N↗

DOE OSTI2017

Status and prospects for CUORE

CUORE is a cryogenic detector consisting of 988 TeO 2 crystals, 750 g each, and will be operated at a temperature of ~10 mK, to search for neutrinoless double beta decay (0νββ) of 130 Te. The detector, in the final stages of construction at the Laboratori Nazionali del Gran Sasso (Italy), will start its operations in 2016. CUORE-0, its pilot experiment, has proven the feasibility of CUORE, demonstrating that the target background of 0.01 counts/keV/kg/y and the energy resolution of 5 keV are within reach. CUORE-0 also made the most precise measurement of the 2νββ decay. The expected sensitivity of CUORE to the 0νββ 130 Te half-life is 9 •10 25 y, for 5 years of data taking. Here, we report the most recent results of CUORE-0, their implications for CUORE, and the current status of the CUORE experiment.

Canonica, L↗

DOE OSTI2017

Lowering the CUORE energy threshold

The Cryogenic Underground Observatory for Rare Events (CUORE) is a ton-scale double beta decay experiment based on TeO2 cryogenic bolometers and is currently in the last construction stage at the Gran Sasso National Laboratory (LNGS). Its primary goal is to observe neutrino-less double beta decay of 130Te, however thanks to the ultra-low background and large projected exposure it could also be suitable for other rare event searches, as the detection of solar axions, neutrinos from type II supernovae or direct detection of dark matter. The sensitivity for these searches will depend on the performance achieved at the low energy threshold. For this reason a trigger algorithm based on continuous data filtering has been developed which will allow lowering the threshold down to the few keV region. The new trigger has been tested in CUORE-0, a single-tower CUORE prototype consisting of 52 TeO2 bolometers and recently concluded, and here we present the results in terms of trigger efficiency, data selection and low-energy calibration.

Copello, S↗

DOE OSTI2017

CUORE and CUORE-0 experiments

Neutrino oscillation experiments proved that neutrinos have mass and this enhanced the interest in neutrinoless double-beta decay (0vββ). The observation of this very rare hypothetical decay would prove the leptonic number violation and would give us indications about neutrinos mass hierarchy and absolute mass scale. CUORE (Cryogenic Underground Observatory for Rare Events) is an array of 988 crystals of TeO 2 , for a total sensitive mass of 741 kg. Its goal is the observation of 0vββ of 130 Te. The crystals, placed into the a dilution cryostat, are operated as bolometers at a temperature close to 10 mK. CUORE commissioning phase has been concluded recently in Gran Sasso National Laboratory, Italy, and data taking is expected to start in spring 2017. If target background rate is reached (0.01counts/day/keV/kg), the sensibility of CUORE will be, in five years of data taking, T 1/2 10 26 years (1σ CL). In order to test the quality of materials and optimize the construction procedures, the collaboration realized CUORE-0, that took data from spring of 2013 to summer 2015. Here, after a brief description of CUORE, I report its commissioning status and CUORE-0 results.

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