Heisenberg’s uncertainty principle in the PTOLEMY project: A theory update
Not Available
79 ASTRONOMY AND ASTROPHYSICS↗
Engineering topics
Orlandi, D.
Publications and source records attributed to Orlandi, D..
Implementation and optimization of the PTOLEMY transverse drift electromagnetic filter
The PTOLEMY transverse drift filter is a new concept to enable precision analysis of the energy spectrum of electrons near the tritium β-decay endpoint. Here, we detail the implementation and optimization methods for successful operation of the filter for electrons with a known pitch angle. We present the first demonstrator that produces the required magnetic field properties with an iron return-flux magnet. Two methods for the setting of filter electrode voltages are detailed. The challenges of low-energy electron transport in cases of low field are discussed, such as the growth of the cyclotron radius with decreasing magnetic field, which puts a ceiling on filter performance relative to fixed filter dimensions. Additionally, low pitch angle trajectories are dominated by motion parallel to the magnetic field lines and introduce non-adiabatic conditions and curvature drift. To minimize these effects and maximize electron acceptance into the filter, we present a three-potential-well design to simultaneously drain the parallel and transverse kinetic energies throughout the length of the filter. These optimizations are shown, in simulation, to achieve low-energy electron transport from a 1 T iron core (or 3 T superconducting) starting field with initial kinetic energy of 18.6 keV drained to < 10 eV (< 1 eV) in about 80 cm. This result for low field operation paves the way for the first demonstrator of the PTOLEMY spectrometer for measurement of electrons near the tritium endpoint to be constructed at the Gran Sasso National Laboratory (LNGS) in Italy.
47 OTHER INSTRUMENTATION↗
Measurement of 216Po half-life with the CUPID-0 experiment
Not Available
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Background identification in cryogenic calorimeters through $\alpha -\alpha$ delayed coincidences
Localization and modeling of radioactive contaminations is a challenge that ultra-low background experiments are constantly facing. These are fundamental steps both to extract scientific results and to further reduce the background of the detectors. Here we present an innovative technique based on the analysis of $\alpha -\alpha$ delayed coincidences in 232 Th and 238 U decay chains, developed to investigate the contaminations of the ZnSe crystals in the CUPID-0 experiment. This method allows to disentangle surface and bulk contaminations of the detectors relying on the different probability to tag delayed coincidences as function of the $\alpha$ decay position.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
The CUORE cryostat: An infrastructure for rare event searches at millikelvin temperatures
The CUORE experiment is the world's largest bolometric experiment. The detector consists of an array of 988 TeO 2 crystals, for a total mass of 742 kg. CUORE is presently taking data at the Laboratori Nazionali del Gran Sasso, Italy, searching for the neutrinoless double beta decay of 130 Te. A large custom cryogen-free cryostat allows reaching and maintaining a base temperature of ~10 mK, required for the optimal operation of the detector. This apparatus has been designed in order to achieve a low noise environment, with minimal contribution to the radioactive background for the experiment. In this paper, we present an overview of the CUORE cryostat, together with a description of all its sub-systems, focusing on the solutions identified to satisfy the stringent requirements. We briefly illustrate the various phases of the cryostat commissioning and highlight the relevant steps and milestones achieved each time. Finally, we describe the successful cooldown of CUORE.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
Monte Carlo simulation of the SABRE PoP background
SABRE (Sodium-iodide with Active Background REjection) is a direct dark matter search experiment based on an array of radio-pure NaI(Tl) crystals surrounded by a liquid scintillator veto. Twin SABRE experiments in the Northern and Southern Hemispheres will differentiate a dark matter signal from seasonal and local effects. The experiment is currently in a Proof-of-Principle (PoP) phase, whose goal is to demonstrate that the background rate is low enough to carry out an independent search for a dark matter signal, with sufficient sensitivity to confirm or refute the DAMA result during the following full-scale experimental phase. As such, the impact of background radiation from the detector materials and the experimental site needs to be carefully investigated, including both intrinsic and cosmogenically activated radioactivity. Based on the best knowledge of the most relevant sources of background, we have performed a detailed Monte Carlo study evaluating the expected background in the dark matter search spectral region. The simulation model described in this paper guides the design of the full-scale experiment and will be fundamental for the interpretation of the measured background and hence for the extraction of a possible dark matter signal.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
CUPID-0: the first array of enriched scintillating bolometers for 0$\nu \beta \beta$ decay investigations
The CUPID-0 detector hosted at the Laboratori Nazionali del Gran Sasso, Italy, is the first large array of enriched scintillating cryogenic detectors for the investigation of 82 Se neutrinoless double-beta decay (0$\nu \beta \beta$). CUPID0 aims at measuring a background index in the region of interest (RoI) for 0$\nu \beta \beta$ at the level of 10 -3 counts/(keV kg years), the lowest value ever measured using cryogenic detectors. CUPID-0 operates an array of Zn 82 Se scintillating bolometers coupled with bolometric light detectors, with a state of the art technology for background suppression and thorough protocols and procedures for the detector preparation and construction. In this paper, the different phases of the detector design and construction will be presented, from the material selection (for the absorber production) to the new and innovative detector structure. The successful construction of the detector lead to promising preliminary detector performance which is discussed here.
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
An innovative bolometric Cherenkov-light detector for a double beta decay search
Here, we present here an innovative cryogenic light detector capable to measure a few tens of eV signal thanks to the amplification assisted by the Neganov-Luke effect. The thermal signal boost in the presence of an electric field allows us to improve the signal-to-noise ratio reaching a baseline noise of around 20 eV. This device - coupled to an enriched 130TeO 2 bolometer (435 g) - registered 160 eV Cherenkov light signal induced by 2615 keV 208 Tl with a signal to noise ratio about 6:1. Since α particles emitted in decays of natural radionuclides do not produce the Cherenkov radiation, we were then able to achieve an efficient α/γ separation in the region of interest for neutrinoless double beta decay of 130 Te (Q-value is 2527 keV). Specifically, a rejection factor of 99.9% for α particles was obtained with a 98.3% acceptance of β/γ events. The achieved α rejection efficiency is required to reduce the dominant α background in the follow-up of the CUORE experiment (CUPID), a ton-scale bolometric search with particle identification.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
Enriched TeO2 bolometers with active particle discrimination: Towards the CUPID experiment
Not Available
36 MATERIALS SCIENCE↗
First array of enriched Zn$^{82}$Se bolometers to search for double beta decay
The R&D activity performed during the last years proved the potential of ZnSe scintillating bolometers to the search for neutrino-less double beta decay, motivating the realization of the first large-mass experiment based on this technology: CUPID-0. The isotopic enrichment in 82 Se, the Zn 82 Se crystals growth, as well as the light detectors production have been accomplished, and the experiment is now in construction at Laboratori Nazionali del Gran Sasso (Italy). In this paper we present the results obtained testing the first three Zn 82 Se crystals operated as scintillating bolometers, and we prove that their performance in terms of energy resolution, background rejection capability and intrinsic radio-purity complies with the requirements of CUPID-o.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
Status of the CUORE and results from the CUORE-0 neutrinoless double beta decay experiments
CUORE is a 741 kg array of TeO 2 bolometers for the search of neutrinoless double beta decay of 130 Te. The detector is being constructed at the Laboratori Nazionali del Gran Sasso, Italy, where it will start taking data in 2015. If the target background of 0.01 counts/(keV·kg·y) will be reached, in five years of data taking CUORE will have a 1σ half life sensitivity of 10 26 y. CUORE-0 is a smaller experiment constructed to test and demonstrate the performances expected for CUORE. The detector is a single tower of 52 CUORE-like bolometers that started taking data in spring 2013. The status and perspectives of CUORE will be discussed, and the first CUORE-0 data will be presented.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Search for Neutrinoless Double-Beta Decay of with CUORE-0
We report the results of a search for neutrinoless double-beta decay in a 9.8 kg yr exposure of 130 Te using a bolometric detector array, CUORE-0. The characteristic detector energy resolution and background level in the region of interest are 5.1 ± 0.3 keV FWHM and 0.058 ± 0.004 (stat.) ± 0:002 (syst.) counts/(keV kg yr), respectively. The median 90% C.L. lower-limit sensitivity of the experiment is 2.9 x 10 24 yr and surpasses the sensitivity of previous searches. We find no evidence for neutrinoless double-beta decay of 130 Te and place a Bayesian lower bound on the decay half-life, T 0$_1$ 1/2 > 2.7 x 10 24 yr at 90% C.L. Combining CUORE-0 data with the 19.75 kg yr exposure of 130 Te from the Cuoricino experiment we obtain T 0$_1$ 1/2 > 4.0 x 10 24 yr at 90% C.L. (Bayesian), the most stringent limit to date on this half-life. Using a range of nuclear matrix element estimates we interpret this as a limit on the effective Majorana neutrino mass, m ββ < 270 - 760 meV.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
CUORE-0 results and prospects for the CUORE experiment
With 741 kg of TeO{sub 2} crystals and an excellent energy resolution of 5 keV (0.2%) at the region of interest, the CUORE (Cryogenic Underground Observatory for Rare Events) experiment aims at searching for neutrinoless double beta decay of {sup 130}Te with unprecedented sensitivity. Expected to start data taking in 2015, CUORE is currently in an advanced construction phase at LNGS. CUORE projected neutrinoless double beta decay half-life sensitivity is 1.6 × 10{sup 26} y at 1σ (9.5 × 10{sup 25} y at the 90 % confidence level), in five years of live time, corresponding to an upper limit on the effective Majorana mass in the range 40–100 meV (50–130 meV). Further background rejection with auxiliary bolometric detectors could improve CUORE sensitivity and competitiveness of bolometric detectors towards a full analysis of the inverted neutrino mass hierarchy. CUORE-0 was built to test and demonstrate the performance of the upcoming CUORE experiment. It consists of a single CUORE tower (52 TeO{sub 2} bolometers of 750 g each, arranged in a 13 floor structure) constructed strictly following CUORE recipes both for materials and assembly procedures. An experiment its own, CUORE-0 is expected to reach a sensitivity to the ββ(0ν) half-life of {sup 130}Te around 3×10{sup 24} y in one year of live time. We present an update of the data, corresponding to an exposure of 18.1 kg y. An analysis of the background indicates that the CUORE performance goal is satisfied while the sensitivity goal is within reach.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
The CUORE and CUORE-0 experiments at Gran Sasso
The Cryogenic Underground Observatory for Rare Events (CUORE) is an experiment to search for neutrinoless double beta decay ($0\nu\beta\beta$) in $^{130}$Te and other rare processes. CUORE is a cryogenic detector composed of 988 TeO$_2$ bolometers for a total mass of about 741 kg. The detector is being constructed at the Laboratori Nazionali del Gran Sasso, Italy, where it will start taking data in 2015. If the target background of 0.01 counts/(keV$\cdot$kg$\cdot$y) will be reached, in five years of data taking CUORE will have an half life sensitivity around $1\times 10^{26}$ y at 90\% C.L. As a first step towards CUORE a smaller experiment CUORE-0, constructed to test and demonstrate the performances expected for CUORE, has been assembled and is running. The detector is a single tower of 52 CUORE-like bolometers that started taking data in spring 2013. The status and perspectives of CUORE will be discussed, and the first CUORE-0 data will be presented.
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
The CUORE and CUORE-0 experiments at Gran Sasso
The Cryogenic Underground Observatory for Rare Events (CUORE) is an experiment to search for neutrinoless double beta decay (0νββ) in 130 Te and other rare processes. CUORE is a cryogenic detector composed of 988 TeO 2 bolometers for a total mass of about 741 kg. The detector is being constructed at the Laboratori Nazionali del Gran Sasso, Italy, where it will start taking data in 2015. If the target background of 0.01 counts/(keV·kg·y) will be reached, in five years of data taking CUORE will have an half life sensitivity around 1 × 10 26 y at 90% C.L. As a first step towards CUORE a smaller experiment CUORE-0, constructed to test and demonstrate the performances expected for CUORE, has been assembled and is running. The detector is a single tower of 52 CUORE-like bolometers that started taking data in spring 2013. The status and perspectives of CUORE will be discussed, and the first CUORE-0 data will be presented.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
CUORE and beyond: Bolometric techniques to explore inverted neutrino mass hierarchy
The CUORE (Cryogenic Underground Observatory for Rare Events) experiment will search for neutrinoless double beta decay of 130 Te. With 741 kg of TeO 2 crystals and an excellent energy resolution of 5 keV (0.2%) at the region of interest, CUORE will be one of the most competitive neutrinoless double beta decay experiments on the horizon. With five years of live time, CUORE projected neutrinoless double beta decay half-life sensitivity is 1.6 × 10 26 y at 1σ (9.5 × 10 25 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). Further background rejection with auxiliary light detector can significantly improve the search sensitivity and competitiveness of bolometric detectors to fully explore the inverted neutrino mass hierarchy with 130 Te and possibly other double beta decay candidate nuclei.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
First data from CUORE-0
CUORE-0 is an experiment built to test and demonstrate the performance of the upcoming CUORE experiment. Composed of 52 TeO 2 bolometers of 750 g each, it is expected to reach a sensitivity to the 0νββ half-life of 130 Te around 3 · 10 24 y in one year of live time. We present the first data, corresponding to an exposure of 7.1 kg y. An analysis of the background indicates that the CUORE sensitivity goal is within reach, validating our techniques to reduce the α radioactivity of the detector.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
Neutrinoless double-beta decay search with CUORE and CUORE-0 experiments
The Cryogenic Underground Observatory for Rare Events (CUORE) is an upcoming experiment designed to search for the neutrinoless double-beta decays. Observation of the process would unambiguously establish that neutrinos are Majorana particles and provide information on their absolute mass scale hierarchy. CUORE is now under construction and will consist of an array of 988 TeO 2 crystal bolometers operated at 10 mK, but the first tower (CUORE-0) is already taking data. The experimental techniques used will be presented as well as the preliminary CUORE-0 results. The current status of the full-mass experiment and its expected sensitivity will then be discussed.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗