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Albert, J. B.

Publications and source records attributed to Albert, J. B..

15 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

First Measurement of Coherent Elastic Neutrino-Nucleus Scattering on Argon

We report the first measurement of coherent elastic neutrino-nucleus scattering (CEvNS) on argon using a liquid argon detector at the Oak Ridge National Laboratory Spallation Neutron Source. Two independent analyses prefer CEvNS over the background-only null hypothesis with greater than 3σ significance. The measured cross section, averaged over the incident neutrino flux, is (2.2±0.7)×10 –39 cm 2 —consistent with the standard model prediction. In conclusion, the neutron-number dependence of this result, together with that from our previous measurement on CsI, confirms the existence of the CEvNS process and provides improved constraints on nonstandard neutrino interactions.

39 ≤ A ≤ 58↗
DOE OSTI2018

Neutron inelastic scattering measurements on Xe 136 at E n = 0.7 to 100 MeV

Experiments searching for neutrinoless double ${\beta}$ decay ($0{\nu}{\beta}{\beta}$) require precise energy calibration and extremely low backgrounds. One of the most popular isotopes for $0{\nu}{\beta}{\beta}$ experiments is $^{136}\mathrm{Xe}$. In support of these experiments, the neutron inelastic scattering properties of this isotope have been measured at the GErmanium Array for Neutron Induced Excitations (GEANIE) at the Los Alamos Neutron Science Center. Time-of-flight techniques are utilized with high-purity germanium detectors to search for inelastic scattering ${\gamma}$ rays for neutron energies between 0.7 and 100 MeV. Limits are set on production of yet-unobserved ${\gamma}$ rays in the energy range critical for $0{\nu}{\beta}{\beta}$ studies, and measurements are made of multiple ${\gamma}$-ray production cross sections. In particular, we have measured the production of the 1313 keV ${\gamma}$ ray, which comes from the transition of the first-excited to ground state of $^{136}\mathrm{Xe}$. This neutron-induced ${\gamma}$ line may be useful for a novel energy calibration technique.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2018

VUV-sensitive Silicon Photomultipliers for Xenon Scintillation Light Detection in nEXO

Future ton-scale liquefied noble gas detectors depend on efficient light detection in the vacuum ultraviolet (VUV) range. In the past years, silicon photomultipliers (SiPMs) have emerged as a valid alternative to standard photomultiplier tubes or large-area avalanche photodiodes. The next-generation double-beta decay experiment, nEXO, with a 5-ton liquid xenon time projection chamber will use SiPMs for detecting the 175-nm xenon scintillation light, in order to achieve an energy resolution of σ/Q ββ =1 %. This paper presents recent measurements of the VUV-HD generation SiPMs from Fondazione Bruno Kessler, Trento, Italy, in two complementary setups. It includes measurements of the photon-detection efficiency (PDE) with gaseous xenon scintillation light in a vacuum setup and dark measurements in a dry nitrogen gas setup. Here, we report improved PDE at 175 nm compared to previous generation devices that would meet the criteria of nEXO. Furthermore, we present the projected nEXO detector light collection and energy resolution that could be achieved by using these SiPMs.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2018

Study of silicon photomultiplier performance in external electric fields

In this paper, we report on the performance of silicon photomultiplier (SiPM) light sensors operating in electric field strength up to 30 kV/cm and at a temperature of 149 K, relative to their performance in the absence of an external electric field. The SiPM devices used in this study show stable gain, photon detection efficiency, and rates of correlated pulses, when exposed to external fields, within the estimated uncertainties. No visible damage to the surface of the devices was caused by the exposure.

Noble liquid detectors (scintillation, ionization,↗
DOE OSTI2018

Deep neural networks for energy and position reconstruction in EXO-200

Here, we apply deep neural networks (DNN) to data from the EXO-200 experiment. In the studied cases, the DNN is able to reconstruct the relevant parameters—total energy and position—directly from raw digitized waveforms, with minimal exceptions. For the first time, the developed algorithms are evaluated on real detector calibration data. The accuracy of reconstruction either reaches or exceeds what was achieved by the conventional approaches developed by EXO-200 over the course of the experiment. Most existing DNN approaches to event reconstruction and classification in particle physics are trained on Monte Carlo simulated events. Such algorithms are inherently limited by the accuracy of the simulation. We describe a unique approach that, in an experiment such as EXO-200, allows to successfully perform certain reconstruction and analysis tasks by training the network on waveforms from experimental data, either reducing or eliminating the reliance on the Monte Carlo.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2018

Characterization of an Ionization Readout Tile for nEXO

Anewdesign for the anode of a time projection chamber, consisting of a charge-detecting "tile", is investigated for use in large scale liquid xenon detectors. The tile is produced by depositing 60 orthogonal metal charge-collecting strips, 3 mm wide, on a 10 cm 10 cm fused-silica wafer. These charge tiles may be employed by large detectors, such as the proposed tonne-scale nEXO experiment to search for neutrinoless double-beta decay. Modular by design, an array of tiles can cover a sizable area. The width of each strip is small compared to the size of the tile, so a Frisch grid is not required. A grid-less, tiled anode design is beneficial for an experiment such as nEXO, where a wire tensioning support structure and Frisch grid might contribute radioactive backgrounds and would have to be designed to accommodate cycling to cryogenic temperatures. The segmented anode also reduces some degeneracies in signal reconstruction that arise in large-area crossed-wire time projection chambers. A prototype tile was tested in a cell containing liquid xenon. Very good agreement is achieved between the measured ionization spectrum of a 207Bi source and simulations that include the microphysics of recombination in xenon and a detailed modeling of the electrostatic field of the detector. An energy resolution E=5.5% is observed at 570 keV, comparable to the best intrinsic ionization-only resolution reported in literature for liquid xenon at 936 V/cm.

Jewell, M J.↗
DOE OSTI2017

Searches for double beta decay of Xe 134 with EXO-200

Searches for double beta decay of 134 Xe were performed with EXO-200, a single-phase liquid xenon detector designed to search for neutrinoless double beta decay of 136 Xe. Using an exposure of 29.6 kg ∙ yr , the lower limits of T$2νββ\atop{1/2}$ > 8.7 × 10 20 yr and T$0νββ\atop{1/2}$ > 1.1 × 10 23 yr at 90% confidence level were derived, with corresponding half-life sensitivities of 1.2 × 10 21 yr and 1.9 × 10 23 yr . In conclusion, these limits exceed those in the literature for 134 Xe , improving by factors of nearly 10 5 and 2 for the two antineutrino and neutrinoless modes, respectively.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Sensitivity and discovery potential of nEXO to neutrinoless double beta decay

The next-generation Enriched Xenon Observatory (nEXO) is a proposed experiment to search for neutrinoless double beta (0νββ) decay in 136 Xe with a target half-life sensitivity of approximately 10 28 years using 5 × 10 3 kg of isotopically enriched liquid-xenon in a time projection chamber. This improvement of two orders of magnitude in sensitivity over current limits is obtained by a significant increase of the 136 Xe mass, the monolithic and homogeneous configuration of the active medium, and the multi-parameter measurements of the interactions enabled by the time projection chamber. Furthermore, the detector concept and anticipated performance are presented based upon demonstrated realizable background rates.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Observation of coherent elastic neutrino-nucleus scattering

The coherent elastic scattering of neutrinos off nuclei has eluded detection for four decades, even though its predicted cross section is by far the largest of all low-energy neutrino couplings. This mode of interaction offers new opportunities to study neutrino properties and leads to a miniaturization of detector size, with potential technological applications. In this paper, we observed this process at a 6.7σ confidence level, using a low-background, 14.6-kilogram CsI[Na] scintillator exposed to the neutrino emissions from the Spallation Neutron Source at Oak Ridge National Laboratory. Characteristic signatures in energy and time, predicted by the standard model for this process, were observed in high signal-to-background conditions. Finally, improved constraints on nonstandard neutrino interactions with quarks are derived from this initial data set.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Trace radioactive impurities in final construction materials for EXO-200

Here, we report results from a systematic measurement campaign conducted to identify low radioactivity materials for the construction of the EXO-200 double beta decay experiment. Partial results from this campaign have already been reported in a 2008 paper by the EXO collaboration. Here we release the remaining data, collected since 2007, to the public. The data reported were obtained using a variety of analytic techniques. The measurement sensitivities are among the best in the field. We concluded the construction of the EXO-200 detector and Phase-I data was taken from 2011 to 2014. The detector’s extremely low background implicitly verifies the measurements and the analysis assumptions made during construction and reported in this paper.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2017

Measurement of the drift velocity and transverse diffusion of electrons in liquid xenon with the EXO-200 detector

The EXO-200 Collaboration is searching for neutrinoless double β decay using a liquid xenon (LXe) time projection chamber. This measurement relies on modeling the transport of charge deposits produced by interactions in the LXe to allow discrimination between signal and background events. In this paper, we present measurements of the transverse diffusion constant and drift velocity of electrons at drift fields between 20 V/cm and 615 V/cm using EXO-200 data. Finally, at the operating field of 380 V/cm EXO-200 measures a drift velocity of 1.705 +0.014 –0.010 mm/μs and a transverse diffusion coefficient of 55 ± 4 cm 2 /s.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2017

COHERENT Experiment: current status

The COHERENT Collaboration is realizing a long term neutrino physics research program. The main goals of the program are to detect and study elastic neutrino-nucleus scattering (CEνNS). This process is predicted by Standard Model but it has never been observed experimentally because of the very low energy of the recoil nucleus. COHERENT is using different detector technologies: CsI[Na] and NaI scintillator crystals, a single-phase liquid Ar and a Ge detectors. The placement of all the detector setups is in the basement of the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). The current status of the COHERENT experimental program is presented.

36 MATERIALS SCIENCE↗