J. Brodsky
A5025667115- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Radiation Detection and Scintillator Technologies
- Particle Detector Development and Performance
- Particle physics theoretical and experimental studies
- Atomic and Subatomic Physics Research
- Astrophysics and Cosmic Phenomena
- Scientific Research and Discoveries
- Quantum, superfluid, helium dynamics
- Nuclear Physics and Applications
- Radioactive contamination and transfer
- CCD and CMOS Imaging Sensors
- Cosmology and Gravitation Theories
- Nuclear reactor physics and engineering
- Astronomy and Astrophysical Research
- Medical Imaging Techniques and Applications
- Atmospheric Ozone and Climate
- Fault Detection and Control Systems
- Photocathodes and Microchannel Plates
- Stellar, planetary, and galactic studies
- Luminescence Properties of Advanced Materials
- Structural Health Monitoring Techniques
- Advanced biosensing and bioanalysis techniques
- Advanced Thermodynamic Systems and Engines
- Radioactivity and Radon Measurements
Lawrence Livermore National Laboratory
2016-2025
Lawrence Livermore National Security
2023
University of Illinois Urbana-Champaign
2021
Princeton University
2013-2017
John Wiley & Sons (United States)
2016
Iowa City Public Library
2016
Seattle University
2016
Hudson Institute
2016
We report the first results of DarkSide-50, a direct search for dark matter operating in underground Laboratori Nazionali del Gran Sasso (LNGS) and searching rare nuclear recoils possibly induced by weakly interacting massive particles (WIMPs). The detector is Liquid Argon Time Projection Chamber with (46.4+-0.7) kg active mass, operated inside 30 t organic liquid scintillator neutron veto, which turn installed at center 1 kt water Cherenkov veto residual flux cosmic rays. here null...
The PROSPECT Collaboration presents their improved results with new limits on the oscillation of electron antineutrinos to light sterile neutrinos and energy spectrum measurements several short baselines.
This paper introduces the neutrinoless double-beta decay (the rarest nuclear weak process) and describes status of research for this transition, both from point view theoretical physics in terms present future experimental scenarios. Implications phenomenon on crucial aspects particle are briefly discussed. The calculations matrix elements case mass mechanisms reviewed, a range these quantities is proposed most appealing candidates. After introducing general concepts—such as choice best...
Liquid argon is a bright scintillator with potent particle identification properties, making it an attractive target for direct-detection dark matter searches. The DarkSide-50 search here reports the first WIMP results obtained using of low-radioactivity argon. detector, two-phase liquid time projection chamber, located at Laboratori Nazionali del Gran Sasso. underground shown to contain Ar-39 level reduced by factor (1.4 +- 0.2) x 10^3 relative atmospheric We report background-free null...
This Letter reports the first scientific results from observation of antineutrinos emitted by fission products $^{235}\mathrm{U}$ at High Flux Isotope Reactor. PROSPECT, Precision Reactor Oscillation and Spectrum Experiment, consists a segmented 4 ton $^{6}\mathrm{Li}$-doped liquid scintillator detector covering baseline range 7--9 m reactor operating under less than 1 water equivalent overburden. Data collected during 33 live days operation nominal power 85 MW yield detection $25\text{...
The next-generation Enriched Xenon Observatory (nEXO) is a proposed experiment to search for neutrinoless double beta ($0\nu\beta\beta$) decay in $^{136}$Xe with target half-life sensitivity of approximately $10^{28}$ years using $5\times10^3$ kg isotopically enriched liquid-xenon time projection chamber. This improvement two orders magnitude over current limits obtained by significant increase the mass, monolithic and homogeneous configuration active medium, multi-parameter measurements...
Abstract The nEXO neutrinoless double beta (0 νββ ) decay experiment is designed to use a time projection chamber and 5000 kg of isotopically enriched liquid xenon search for the in 136 Xe. Progress detector design, paired with higher fidelity its simulation an advanced data analysis, based on one used final results EXO-200, produce sensitivity prediction that exceeds half-life 10 28 years. Specifically, improvements have been made understanding production scintillation photons charge as...
The Precision Reactor Oscillation and Spectrum Experiment, PROSPECT, is designed to make a precise measurement of the antineutrino spectrum from highly-enriched uranium reactor probe eV-scale sterile neutrinos by searching for neutrino oscillations over meter-long distances. PROSPECT conceived as 2-phase experiment utilizing segmented $^6$Li-doped liquid scintillator detectors both efficient detection antineutrinos through inverse beta decay reaction excellent background discrimination....
Nuclear recoil events produced by neutron scatters form one of the most important classes background in WIMP direct detection experiments, as they may produce nuclear recoils that look exactly like interactions. In DarkSide-50, we both actively suppress and measure rate neutron-induced using our veto, composed a boron-loaded liquid scintillator detector within water Cherenkov detector. This paper is devoted to description veto system including structure, fundamentals event reconstruction...
This Letter reports the first measurement of $^{235}$U $\overline{\nu_{e}}$ energy spectrum by PROSPECT, Precision Reactor Oscillation and Spectrum experiment, operating 7.9m from 85MW$_{\mathrm{th}}$ highly-enriched uranium (HEU) High Flux Isotope Reactor. With a surface-based, segmented detector, PROSPECT has observed 31678$\pm$304 (stat.) $\overline{\nu_{e}}$-induced inverse beta decays (IBD), largest sample HEU fission to date, 99% which are attributed $^{235}$U. Despite broad agreement,...
The DarkSide staged program utilizes a two-phase time projection chamber (TPC) with liquid argon as the target material for scattering of dark matter particles. Efficient background reduction is achieved using low radioactivity underground well several experimental handles such pulse shape, ratio ionization over scintillation signal, 3D event reconstruction, and active neutron muon vetos. DarkSide-10 prototype detector has proven high light yield, which particularly important parameter it...
Future tonne-scale liquefied noble gas detectors depend on efficient light detection in the VUV range. In 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 5 tonne liquid xenon time projection chamber, will use SiPMs for detecting $178\,\text{nm}$ scintillation light, order achieve an energy resolution of $\sigma / Q_{\beta\beta} =...
This paper describes the design and performance of a 50 liter, two-segment $^{6}$Li-loaded liquid scintillator detector that was designed operated as prototype for PROSPECT (Precision Reactor Oscillation Spectrum) Experiment. The constructed according to specifications experiment. It features low-mass optical separators, an integrated source calibration system, materials are compatible with $^{6}$Li-doped developed by PROSPECT. We demonstrate high light collection 850$\pm$20 PE/MeV, energy...
Although the existence of dark matter is supported by many evidences, based on astrophysical measurements, its nature still completely unknown. One major candidate represented weakly interacting massive particles (WIMPs), which could in principle be detected through their collisions with ordinary nuclei a sensitive target, producing observable low-energy (<100 keV) nuclear recoils. The DarkSide program aims at WIPMs detection using liquid argon time projection chamber (LAr-TPC). In this...
Detection of light signals is crucial to a wide range particle detectors. In particular, efficient detection vacuum ultraviolet (VUV) will provide new opportunities for some novel detectors currently being developed, but technically challenging. this article, we characterized the performance Hamamatsu VUV4 silicon photomultipliers (SiPMs) detecting VUV argon scintillation without wavelength shifting. Using customized cryogenic amplifier design, operated two models SiPMs inside liquid and...
The Axion Dark Matter eXperiment (ADMX) has previously excluded Dine-Fischler-Srednicki-Zhitnisky (DFSZ) axions between 680–790 MHz under the assumption that dark matter is described by isothermal halo model. However, precise nature of velocity distribution still unknown, and alternative models have been proposed. We report results a nonvirialized axion search over mass range 2.81–3.31 μeV, corresponding to frequency 680–800 MHz. This analysis marks most sensitive for Doppler effects in...
This work reports the production and characterization of lithium-loaded liquid scintillator (LiLS) for Precision Reactor Oscillation Spectrum Experiment (PROSPECT) . Fifty-nine 90 liter batches LiLS (6Li mass fraction 0.082%±0.001%) were produced samples from all characterized by measuring their optical absorbance relative to air, light yield a pure reference, pulse shape discrimination capability. Fifty-seven passed quality assurance criteria used PROSPECT experiment.
A meter-long, 23-liter EJ-309 liquid scintillator detector has been constructed to study the light collection and pulse-shape discrimination performance of elongated cells for PROSPECT reactor antineutrino experiment. The magnitude uniformity neutron/gamma power in energy range inverse beta decay products have studied using gamma spontaneous fission calibration sources deployed along cell long axis. We also neutron-gamma abilities differing PMT reflector configurations. Key design features...
Understanding reflective properties of materials and photodetection efficiency (PDE) photodetectors is important for optimizing energy resolution sensitivity the next generation neutrinoless double beta decay, direct detection dark matter, neutrino oscillation experiments that will use noble liquid gases, such as nEXO, DARWIN, DarkSide-20k, DUNE . Little information currently available about reflectivity PDE in because measurements are difficult to conduct a cryogenic environment at short...